EUROPEAN JOURNAL OF EPIDEMIOLOGY
Eur. J. Epidemiol. 0392-2990 July 1992,p. 580-584
Vol. 8, No. 4
D E V E L O P M E N T OF ANTIBODY TO HEPATITIS C VIRUS (HCV) IN ACUTE AND CHRONIC NON-A, NON-B POST-TRANSFUSION HEPATITIS G. PASTORE*, L. MONNO*, M. MILELLA*, T. SANTANTONIO*, M.G. RUMI**, M. COLOMBO**, A. GIANNELLI*, C. FICO*, G. DE STASIO***, A. LATTANZIO***, M. DE RUVO*** and E. SFORZA* *Istituto di Malattie Infettive- University o f B a r i - Piazza G. Cesare, 11 - 70124 B a r i - ltaO,. **Istituto di Medicina Interna - University o f Milan - Milan - Itaty. ***Ospedale "Di Venere" - Carbonara - Bari - Italy.
Key words: TAH - HCV - NANB hepatitis The antibody to hepatitis C virus (anti-HCV) was measured by an immunoassay in 507 serum samples from 94 patients with acute and chronic post-transfusion non-A, non-B hepatitis (NANB) and in 436 healthy blood donors. Anti-HCV was found in 70.8 of patients with acute hepatitis, in 78.2 with chronic hepatitis, and in 1.4 of healthy blood donors. In acute hepatitis, anti-HCV appeared in the serum from 4 to 34 weeks after transfusion and from 1 to 30 weeks after the onset of the overt disease. Three patients with resolving hepatitis (21%) and 2 who developed chronic hepatitis (10%) lost anti-HCV during a mean follow-up period of 28 months. Among the 36 patients with chronic hepatitis, 2 (6%) lost anti-HCV after 12 months and 8 years respectively. These data indicate that in recent years HCV has been the major etiologic agent of acute and chronic transfusion-associated hepatitis (TAH) in our geographical area. The late appearance of anti-HCV from the onset of clinical and biochemical signs of acute hepatitis in more than 70% of patients limits the diagnostic utility of this assay for an earlier serological diagnosis of acute NANB hepatitis. Additional studies are required to determine the diagnostic significance of this antibody in chronic NANB hepatitis.
INTRODUCTION
Non-A, non-B hepatitis (NANB) virus is a frequent cause of transfusion-associated hepatitis (TAH) worldwide (1, 7, 11, 18). In Italy the estimated annual incidence of TAH is 50,000. The clinical importance of this infection lies in its tendency to progress into chronic hepatitis and cirrhosis (9, 14, 15, 16). Moreover, several lines of evidence suggest that there is a link between TAH and an increased risk of hepatocellular carcinoma (5, 6). Molecular cloning of cDNA libraries from infected chimp plasma has led to the recognition of a 1 Corresponding author.
blood-borne virus agent (designated hepatitis C virus, HCV) which seems to be a major, if not the only, etiologic agent of parenterally-transmitted non-A, non-B hepatitis (12). With the development of a specific assay (13) for detecting serum antibodies to HCV (anti-HCV), HCV appears to be the major etiologic agent not only for parenterally-transmitted hepatitis, but also for the socalled community-acquired NANB hepatitis (8, 9, 13, 17). In order to study the role and the pattern of HCV infection in our geographical area, anti-HCV was measured by a sensitive enzyme immunoassay in 94 patients with acute and chronic TAH and 436 healthy blood donors.
580
Anti-HCV in non-A, non-B hepatitis
Vol. 8, 1992
Testing for anti-HCV was made under code in only one specimen from blood donors and in all 507 available serum samples from patients with acute and chronic hepatitis. Anti-HCV was assayed in ELISA in a three-stage test carded out in a microwell coated with recombinant hepatitis C virus (rHCV) antigen kindly provided by Ortho Diagnostic System. Statistical analysis was carded out using the Chisquare test.
MATERIALS AND METHODS
Stored sera from 48 patients with an episode of acute NANB hepatitis associated with a recent blood transfusion and from 46 patients who, on first observation, were identified as having chronic hepatitis and a previous history of blood transfusion were examined for the presence of anti-HCV. Furthermore, sera from 436 healthy non-paid blood donors were also investigated. Acute NANB hepatitis was diagnosed if the alanine aminotransferase (ALT) level exceeded at least 3-4 times the upper limit of the normal range (30 U/l) in the absence of any other non-viral and viral causes of liver damage, including serodiagnosis for acute infection by HAV, HBV, CMV and EBV. Over a period ranging from 9 to 18 months from the onset of the disease, 26 (54°/0) of the patients recovered with persistent ALT normalization; otherwise, 22 (460/0) showed persistent or fluctuating elevation of the ALT level for more than one year. Chronic hepatitis was confirmed by liver biopsy in 12 of these patients (chronic persistent hepatitis, CPH, in 9 and chronic active hepatitis, CAH, in 3). All 46 patients with chronic hepatitis on first observation had received one or more blood transfusions between 2 to 5 years earlier, 26 of these patients denied a previous history of acute clinical hepatitis. Liver biopsy obtained from 34 of them showed chronic lobular hepatitis (CLH) in 4, CPH in 20, and CAH or CAH with cirrhosis in 8 patients. In patients with acute hepatitis, serum samples were taken upon admission and weekly or biweekly for the first 3 months, monthly for the next 3 months and from 9 to 12 months thereafter. Patients with chronic hepatitis were placed on long-term follow-up during which they were seen at 36 month intervals depending on their clinical course.
RESULTS
Table 1 reports some of epidemiological and clinical features of the patients under investigation. No significant difference was observed between acute and chronic hepatitis patients in relation to age and number of blood units received, whereas there were twice as many females in the group of chronic hepatitis patients. All acute hepatitis patients were anti-HCV negative in the first serum sample taken on admission. Sequential sera reactive f o r anti-HCV were detected in 34 of the 48 acute hepatitis patients, with an overall seroconversion rate of 70.8 (Table 2). The detection of anti-HCV was more frequent (76.9%) in patients with short incubation hepatitis compared to patients with long incubation hepatitis (44.4%). Anti-HCV seroconversion (Table 3) developed from 1 to 4 weeks after the onset of hepatitis (first ALT elevation) in 9 cases (26.4%), from 4 to 12 weeks in 7 (20.5%), from 12 to 18 weeks in 11 (32.3%) and from 18 to 24 weeks in 5 cases (14.7o/0). Two patients (5.8O/o) seroconverted after 25 and 30 weeks respectively from the first ALT elevation. Anti-HCV was not detected within the first month after blood transfusion in any of the cases.
TABLE 1. - Epidemiological and clinical features of patients under investigation. Groups of patients
No. of subjects
Sex M/F
Age (years) (mean ___ SD)
Blood units transfused (mean ___ SD)
Hepatitis
48
25/ 23
51.2 ___ 12.3
- Resolved hepatitis
26 (54%)
5-----3
- Unresolved hepatitis
22 (460/0)
6-----2
Liver biopsy (No. patients)
Acute NANB
12
Chronic NANB
Hepatitis Healty blood donors
46
12/ 34
436
311/125
44.9 ± 15.5 34
± 581
5.6
• 34
Pastore G. et aL
Eur. J. Epidemiol.
TABLE 2 . - Development of anti-HCV in patients with acute and chronic TAH and in healthy blood donors. No. of anti-HCV positive subjects No %
Study groups A) Acute hepatitis
48
34
70.8
- Short incubation (< 90 days)
39
30
76.9
- Long incubation (> 90 days)
9
4
44.4
"p"
n.s.
- Resolved
26
14 (3)
53.8
- Unresolved
22
20 (2)
90.0
B) Chronic hepatitis
46
36 (2)
78.2
C) Healthy blood donors
Finally, anti-HCV was detected in 6 of the 436 volunteer blood donors (1.4%) and in 36 of the 46 patients with chronic NANB hepatitis diagnosed between 18 months and 9 years from the likely source of infection (blood transfusion). During a follow-up period ranging from 12 months to 8 years only 2 patients with CAH with cirrhosis lost anti-HCV. Among the 34 patients who persisted as anti-HCV positive, 4 had a permanent normalization of ALT.
436
6
DISCUSSION
p _< 0.01
1.4
0 patients who lost anti-HCV during follow-up.
The interval between transfusion and seroconversion ranged from 4 to 12 weeks in 10 patients (29.4°/0), 12-18 weeks in 11 (32.3%)i'18-24 weeks in 7 (20.5%)~and from 24 to 34 weeks in 6 patients (17.6%). Acute hepatitis ran a self-limite~ 'course with normalization o f ALT with'in 6 months inq4 of the 34 anti-HCV positive (41%) and in 12 of the 14 anti-HCV negative (86%) patients (p _< 0.001). In all but one patient monitoring of ALT was as long as 12 months (15 patients were followed up to 12 months). Furthermore, a significant difference (p < = 0.01) was observed in the prevalence of anti-HCV in patients with resolving hepatitis (53.8%) compared to patients who developed chronic hepatitis (90.9%). Among the 34 seroconverters, 3 patients with resolving hepatitis (21.4%) and 2 who developed chronic hepatitis lost anti-HCV during a follow-up period averaging 28 months.
The development of anti-HCV in 34 of the 48 subjects (70.8%) with well defined acute TAH and in 36 of-the 46 patients (78.2%) with chronic NANB hepatitis;and a previous history of blood transfusion suggest that HCV is the primary cause of blood-borne hepatitis in our geographical area. Our results are consistent with those obtained in other areas from patients with either TAH or community-acquired NANB hepatitis, indicating a worldwide diffusion of HCV (2, 10, 13, 17, 19). Analysis of sequential serum samples from acute hepatitis patients revealed that antibody to HCV nonstructural protein generally appears late in the serum: it was detected after a mean period of two months from the onset of clinical and biochemical signs of hepatic necrosis in more than 70% of the patients. Since the presence of circulating HCV-RNA assayed by cDNA/polymerase chain reaction (PCR) has been detected in the early phase of acute hepatitis in both humans and chimpanzees before the appearance of anti-HCV (20), this prolonged window period actually limits the diagnostic utility of antiHCV for an earlier serological diagnosis of acute NANB hepatitis. Furthermore, this diagnostic delay suggests that some blood donors capable of transmitting NANB hepatitis will not be detected by this assay. Therefore, the development of a test for the detection of an earlier antibody of IgM class or to more immunogenic new HCV epitopes should be suitable.
TABLE 3. - Interval for anti-HCV seroconversion from blood transfusion and from first ALT elevation in prospectivly-followed patients with acute TAH. Time from blood transf. (weeks)
Time from ALT elevation (weeks)
anti-HCV+ No %
anti-HCV+ No %
1-4
0
-
1-4
9
26.4
4-12
10
29.4
4-12
7
20.5
12-18
11
32.3
12-18
11
32.3
18-24
7
20.5
18-24
5
14.7
24-34
6
17.6
24-30
2
5.8
582
Vol. 8, 1992
Anti-HCV in non-A, non-B hepatitis
The lack of detection of anti-HCV in cases clinically diagnosed as acute T A H give rise to a number of questions. Since we cannot rule out the role of HCV as the causative agent of seronegative T A H (20), it is likely that the lack o f sensitivity of the available assay or lower antibody response account for these seronegative patients. On the other hand, the significantly different recovery rate observed in anti-HCV positive compared to seronegative subjects (41% vs 86°/0) supports the existence of different types of HCV, or of other parenteral NANB agents, with likely differences in pathogenic activity. During the long-term follow-up of our patients we documented that anti-HCV persisted in the serum for at least 48 months following acute infection in subjects who had full clinical and biochemical recovery as well as in patients with stable chronic hepatitis who showed spontaneous remission of the disease and normalization of ALT values. These data suggest that anti-HCV may persist in the serum even though its presence is not necessarily related to concomitant hepatocellular damage. On the other hand, the strong correlation between the presence of circulating antiHCV and the detection of HCV-RNA sequences both in liver and serum (20) indicates anti-HCV as an infectivity marker also in individuals with normal ALT levels. Finally, the reason why some patients with chronic NANB hepatitis and persistent disease activity lose this antibody remains to be investigated. Current studies are in progress for a better definition o f the diagnostic and clinical usefulness of the anti-HCV assay in the natural history of acute and chronic hepatitis C and for the safety of the world's blood supply in the prevention o f TAIl.
4. Bradley D.W. (1985): The agents of non-A, non-B viral hepatitis - J. Virol. Methods 10: 307-309. 5. Bruix J., Calvet X., Costa J. et al. (1989): Prevalence of antibodies to hepatitis C virus in Spanish patients with hepatocellular carcinoma and hepatic cirrhosis Lancet ii: 1004-1006. 6.
Colombo M., Choo Q.L., Del Ninno E., et aL (1989): Prevalence of antibodies to hepatitis C virus in Italian patients with hepatocellular carcinoma. Lancet ii: 1006-1008.
7. Dienstag J.L. and Alter H.J. (1986): Non-A, non-B hepatitis. Evolving epidemiologic and clinical perspective - Semin. Liver Dis. 6: 67-81. 8. Esteban H.I., Esteban R., Viladomiu L., et al. (1989): Hepatitis C virus antibodies among risk groups in Spain - Lancet ii: 294-295. 9. Fagan E.A. and Williams R. (1984): Non-A, non-B hepatitis - Semin. Liver Dis. 4: 314-335. 10. Hopf U., Moller B., Kuther D., et aL (1990): Long-term follow-up of post-transfusion and sporadic chronic hepatitis non-A, non-B and frequency of circulating antibodies to hepatitis C virus (HCV) - J. Hepatol. 10: 69-76. 11. Iwarson S.D. (1987): Non-A, non-B hepatitis: dead ends or new horizons - Br. Med. J. 295: 946-948. 12. Khoo Q-L., Kuo G., Weiner A.J., Overby L.R., Bradley D.W. and Houghton M. (1989): Isolation of a cDNA clone derived from a blood-born non-A, non-B viral hepatitis genome - Science 244: 359-362. 13. Kuo G., Choo K-L., Alter H.J., et aL (1989): An assay for circulating antibodies to a major etiologic virus non-A, non-B hepatitis - Science 244: 362-364.
Acknowledgements
This work was supported in part by a grant from Ministero Universit~tand Ricerca Scientifica and Tecnologica, Rome, Italy. REFERENCES
1. AlterH.J. (1988): Transfusion associated non-A, nonB hepatitis. The first decade. In: "Viral hepatitis and liver disease". Zuckerman Ed. A.R. Liss Inc. New York, pp 537-542. 2. Alter H.J., Purcell R.H., Shih J.W. et al. (1989): Detection of antibody to hepatitis C virus in prospectively followed recipients with acute and chronic non-A, non-B hepatitis - N. Engl. J. Med. 321: 1494-1500. 3. Bradley D.W., Maynard J.E. and Popper H. (1983): Post-transfusion non-A, non-B viral hepatitis physicochemical properties of two distinct agents - J. Infect. Dis. 148: 254-265. 583
14. Pastore G., Dentico P., Angarano G., Monno L., Tannoia N. and Schiraldi O. (1982): Non-A, non-B chronic hepatitis in thalassemic patients. In: "Viral hepatitis" Szmuness W., Alter. H.J., Maynard J. Eds. Franklin Institute Press - Philadelphia, pp 775-776. 15. Pastore G., Monno L., Santantonio T., Angarano G., Trotta F. and Schiraldi O. (1985): Monophasic and poliphasic pattern of alanine aminotransferase in acute nonA, nonB hepatitis. Clinical and prognostic implications - Hepatogastroenterol. 32: 155-158. 16. Rakela J. and Redeker A.G. (1979): Chronic liver disease after acute non-A, non-B viral hepatitis Gastroenterology 77: 1200-1202. 17. Saracco G., Kuo G., Brunetto M.G., et al. (1989): Hepatitis C virus. A major cause ofnonA, nonB posttransfusion hepatitis (PT-NANBH) in Italy - Ital. J. Gastroenterol. 21: 95.
Pastore G. et al.
Eur. J. Epidemiol.
18. Skidmore S.J., Jones T.E.G. and Boxall E.H. (1981): Non-A, non-B hepatitis in patients receiving blood products - J. Med. Virol. 6: 85-89.
20. Weiner A.J., Kuo G., Bradley D.W., et al. (1990): Detection of hepatitis C viral sequences in nonA, nonB hepatitis - Lancet 335: 1-3.
19. Vander Poel C.L., Reesink H.W., Leslie P.N., et al. (1989): Anti-hepatitis C antibodies and non-A, non-B post-transfusion hepatitis in Netherlands - Lancet ii: 297-298.
21. Yoshizawa H., Itoh Y. and Iwakiri S. (1981): Demonstration of two different types of non-A, nonB hepatitis by reinjection and cross-challenge studies in chimpanzees - Gastroenterology 81: 107-113.
584
Eur. J. Epidemiol. 0392-2990 July 1992,p. 580-584
Vol. 8, No. 4
D E V E L O P M E N T OF ANTIBODY TO HEPATITIS C VIRUS (HCV) IN ACUTE AND CHRONIC NON-A, NON-B POST-TRANSFUSION HEPATITIS G. PASTORE*, L. MONNO*, M. MILELLA*, T. SANTANTONIO*, M.G. RUMI**, M. COLOMBO**, A. GIANNELLI*, C. FICO*, G. DE STASIO***, A. LATTANZIO***, M. DE RUVO*** and E. SFORZA* *Istituto di Malattie Infettive- University o f B a r i - Piazza G. Cesare, 11 - 70124 B a r i - ltaO,. **Istituto di Medicina Interna - University o f Milan - Milan - Itaty. ***Ospedale "Di Venere" - Carbonara - Bari - Italy.
Key words: TAH - HCV - NANB hepatitis The antibody to hepatitis C virus (anti-HCV) was measured by an immunoassay in 507 serum samples from 94 patients with acute and chronic post-transfusion non-A, non-B hepatitis (NANB) and in 436 healthy blood donors. Anti-HCV was found in 70.8 of patients with acute hepatitis, in 78.2 with chronic hepatitis, and in 1.4 of healthy blood donors. In acute hepatitis, anti-HCV appeared in the serum from 4 to 34 weeks after transfusion and from 1 to 30 weeks after the onset of the overt disease. Three patients with resolving hepatitis (21%) and 2 who developed chronic hepatitis (10%) lost anti-HCV during a mean follow-up period of 28 months. Among the 36 patients with chronic hepatitis, 2 (6%) lost anti-HCV after 12 months and 8 years respectively. These data indicate that in recent years HCV has been the major etiologic agent of acute and chronic transfusion-associated hepatitis (TAH) in our geographical area. The late appearance of anti-HCV from the onset of clinical and biochemical signs of acute hepatitis in more than 70% of patients limits the diagnostic utility of this assay for an earlier serological diagnosis of acute NANB hepatitis. Additional studies are required to determine the diagnostic significance of this antibody in chronic NANB hepatitis.
INTRODUCTION
Non-A, non-B hepatitis (NANB) virus is a frequent cause of transfusion-associated hepatitis (TAH) worldwide (1, 7, 11, 18). In Italy the estimated annual incidence of TAH is 50,000. The clinical importance of this infection lies in its tendency to progress into chronic hepatitis and cirrhosis (9, 14, 15, 16). Moreover, several lines of evidence suggest that there is a link between TAH and an increased risk of hepatocellular carcinoma (5, 6). Molecular cloning of cDNA libraries from infected chimp plasma has led to the recognition of a 1 Corresponding author.
blood-borne virus agent (designated hepatitis C virus, HCV) which seems to be a major, if not the only, etiologic agent of parenterally-transmitted non-A, non-B hepatitis (12). With the development of a specific assay (13) for detecting serum antibodies to HCV (anti-HCV), HCV appears to be the major etiologic agent not only for parenterally-transmitted hepatitis, but also for the socalled community-acquired NANB hepatitis (8, 9, 13, 17). In order to study the role and the pattern of HCV infection in our geographical area, anti-HCV was measured by a sensitive enzyme immunoassay in 94 patients with acute and chronic TAH and 436 healthy blood donors.
580
Anti-HCV in non-A, non-B hepatitis
Vol. 8, 1992
Testing for anti-HCV was made under code in only one specimen from blood donors and in all 507 available serum samples from patients with acute and chronic hepatitis. Anti-HCV was assayed in ELISA in a three-stage test carded out in a microwell coated with recombinant hepatitis C virus (rHCV) antigen kindly provided by Ortho Diagnostic System. Statistical analysis was carded out using the Chisquare test.
MATERIALS AND METHODS
Stored sera from 48 patients with an episode of acute NANB hepatitis associated with a recent blood transfusion and from 46 patients who, on first observation, were identified as having chronic hepatitis and a previous history of blood transfusion were examined for the presence of anti-HCV. Furthermore, sera from 436 healthy non-paid blood donors were also investigated. Acute NANB hepatitis was diagnosed if the alanine aminotransferase (ALT) level exceeded at least 3-4 times the upper limit of the normal range (30 U/l) in the absence of any other non-viral and viral causes of liver damage, including serodiagnosis for acute infection by HAV, HBV, CMV and EBV. Over a period ranging from 9 to 18 months from the onset of the disease, 26 (54°/0) of the patients recovered with persistent ALT normalization; otherwise, 22 (460/0) showed persistent or fluctuating elevation of the ALT level for more than one year. Chronic hepatitis was confirmed by liver biopsy in 12 of these patients (chronic persistent hepatitis, CPH, in 9 and chronic active hepatitis, CAH, in 3). All 46 patients with chronic hepatitis on first observation had received one or more blood transfusions between 2 to 5 years earlier, 26 of these patients denied a previous history of acute clinical hepatitis. Liver biopsy obtained from 34 of them showed chronic lobular hepatitis (CLH) in 4, CPH in 20, and CAH or CAH with cirrhosis in 8 patients. In patients with acute hepatitis, serum samples were taken upon admission and weekly or biweekly for the first 3 months, monthly for the next 3 months and from 9 to 12 months thereafter. Patients with chronic hepatitis were placed on long-term follow-up during which they were seen at 36 month intervals depending on their clinical course.
RESULTS
Table 1 reports some of epidemiological and clinical features of the patients under investigation. No significant difference was observed between acute and chronic hepatitis patients in relation to age and number of blood units received, whereas there were twice as many females in the group of chronic hepatitis patients. All acute hepatitis patients were anti-HCV negative in the first serum sample taken on admission. Sequential sera reactive f o r anti-HCV were detected in 34 of the 48 acute hepatitis patients, with an overall seroconversion rate of 70.8 (Table 2). The detection of anti-HCV was more frequent (76.9%) in patients with short incubation hepatitis compared to patients with long incubation hepatitis (44.4%). Anti-HCV seroconversion (Table 3) developed from 1 to 4 weeks after the onset of hepatitis (first ALT elevation) in 9 cases (26.4%), from 4 to 12 weeks in 7 (20.5%), from 12 to 18 weeks in 11 (32.3%) and from 18 to 24 weeks in 5 cases (14.7o/0). Two patients (5.8O/o) seroconverted after 25 and 30 weeks respectively from the first ALT elevation. Anti-HCV was not detected within the first month after blood transfusion in any of the cases.
TABLE 1. - Epidemiological and clinical features of patients under investigation. Groups of patients
No. of subjects
Sex M/F
Age (years) (mean ___ SD)
Blood units transfused (mean ___ SD)
Hepatitis
48
25/ 23
51.2 ___ 12.3
- Resolved hepatitis
26 (54%)
5-----3
- Unresolved hepatitis
22 (460/0)
6-----2
Liver biopsy (No. patients)
Acute NANB
12
Chronic NANB
Hepatitis Healty blood donors
46
12/ 34
436
311/125
44.9 ± 15.5 34
± 581
5.6
• 34
Pastore G. et aL
Eur. J. Epidemiol.
TABLE 2 . - Development of anti-HCV in patients with acute and chronic TAH and in healthy blood donors. No. of anti-HCV positive subjects No %
Study groups A) Acute hepatitis
48
34
70.8
- Short incubation (< 90 days)
39
30
76.9
- Long incubation (> 90 days)
9
4
44.4
"p"
n.s.
- Resolved
26
14 (3)
53.8
- Unresolved
22
20 (2)
90.0
B) Chronic hepatitis
46
36 (2)
78.2
C) Healthy blood donors
Finally, anti-HCV was detected in 6 of the 436 volunteer blood donors (1.4%) and in 36 of the 46 patients with chronic NANB hepatitis diagnosed between 18 months and 9 years from the likely source of infection (blood transfusion). During a follow-up period ranging from 12 months to 8 years only 2 patients with CAH with cirrhosis lost anti-HCV. Among the 34 patients who persisted as anti-HCV positive, 4 had a permanent normalization of ALT.
436
6
DISCUSSION
p _< 0.01
1.4
0 patients who lost anti-HCV during follow-up.
The interval between transfusion and seroconversion ranged from 4 to 12 weeks in 10 patients (29.4°/0), 12-18 weeks in 11 (32.3%)i'18-24 weeks in 7 (20.5%)~and from 24 to 34 weeks in 6 patients (17.6%). Acute hepatitis ran a self-limite~ 'course with normalization o f ALT with'in 6 months inq4 of the 34 anti-HCV positive (41%) and in 12 of the 14 anti-HCV negative (86%) patients (p _< 0.001). In all but one patient monitoring of ALT was as long as 12 months (15 patients were followed up to 12 months). Furthermore, a significant difference (p < = 0.01) was observed in the prevalence of anti-HCV in patients with resolving hepatitis (53.8%) compared to patients who developed chronic hepatitis (90.9%). Among the 34 seroconverters, 3 patients with resolving hepatitis (21.4%) and 2 who developed chronic hepatitis lost anti-HCV during a follow-up period averaging 28 months.
The development of anti-HCV in 34 of the 48 subjects (70.8%) with well defined acute TAH and in 36 of-the 46 patients (78.2%) with chronic NANB hepatitis;and a previous history of blood transfusion suggest that HCV is the primary cause of blood-borne hepatitis in our geographical area. Our results are consistent with those obtained in other areas from patients with either TAH or community-acquired NANB hepatitis, indicating a worldwide diffusion of HCV (2, 10, 13, 17, 19). Analysis of sequential serum samples from acute hepatitis patients revealed that antibody to HCV nonstructural protein generally appears late in the serum: it was detected after a mean period of two months from the onset of clinical and biochemical signs of hepatic necrosis in more than 70% of the patients. Since the presence of circulating HCV-RNA assayed by cDNA/polymerase chain reaction (PCR) has been detected in the early phase of acute hepatitis in both humans and chimpanzees before the appearance of anti-HCV (20), this prolonged window period actually limits the diagnostic utility of antiHCV for an earlier serological diagnosis of acute NANB hepatitis. Furthermore, this diagnostic delay suggests that some blood donors capable of transmitting NANB hepatitis will not be detected by this assay. Therefore, the development of a test for the detection of an earlier antibody of IgM class or to more immunogenic new HCV epitopes should be suitable.
TABLE 3. - Interval for anti-HCV seroconversion from blood transfusion and from first ALT elevation in prospectivly-followed patients with acute TAH. Time from blood transf. (weeks)
Time from ALT elevation (weeks)
anti-HCV+ No %
anti-HCV+ No %
1-4
0
-
1-4
9
26.4
4-12
10
29.4
4-12
7
20.5
12-18
11
32.3
12-18
11
32.3
18-24
7
20.5
18-24
5
14.7
24-34
6
17.6
24-30
2
5.8
582
Vol. 8, 1992
Anti-HCV in non-A, non-B hepatitis
The lack of detection of anti-HCV in cases clinically diagnosed as acute T A H give rise to a number of questions. Since we cannot rule out the role of HCV as the causative agent of seronegative T A H (20), it is likely that the lack o f sensitivity of the available assay or lower antibody response account for these seronegative patients. On the other hand, the significantly different recovery rate observed in anti-HCV positive compared to seronegative subjects (41% vs 86°/0) supports the existence of different types of HCV, or of other parenteral NANB agents, with likely differences in pathogenic activity. During the long-term follow-up of our patients we documented that anti-HCV persisted in the serum for at least 48 months following acute infection in subjects who had full clinical and biochemical recovery as well as in patients with stable chronic hepatitis who showed spontaneous remission of the disease and normalization of ALT values. These data suggest that anti-HCV may persist in the serum even though its presence is not necessarily related to concomitant hepatocellular damage. On the other hand, the strong correlation between the presence of circulating antiHCV and the detection of HCV-RNA sequences both in liver and serum (20) indicates anti-HCV as an infectivity marker also in individuals with normal ALT levels. Finally, the reason why some patients with chronic NANB hepatitis and persistent disease activity lose this antibody remains to be investigated. Current studies are in progress for a better definition o f the diagnostic and clinical usefulness of the anti-HCV assay in the natural history of acute and chronic hepatitis C and for the safety of the world's blood supply in the prevention o f TAIl.
4. Bradley D.W. (1985): The agents of non-A, non-B viral hepatitis - J. Virol. Methods 10: 307-309. 5. Bruix J., Calvet X., Costa J. et al. (1989): Prevalence of antibodies to hepatitis C virus in Spanish patients with hepatocellular carcinoma and hepatic cirrhosis Lancet ii: 1004-1006. 6.
Colombo M., Choo Q.L., Del Ninno E., et aL (1989): Prevalence of antibodies to hepatitis C virus in Italian patients with hepatocellular carcinoma. Lancet ii: 1006-1008.
7. Dienstag J.L. and Alter H.J. (1986): Non-A, non-B hepatitis. Evolving epidemiologic and clinical perspective - Semin. Liver Dis. 6: 67-81. 8. Esteban H.I., Esteban R., Viladomiu L., et al. (1989): Hepatitis C virus antibodies among risk groups in Spain - Lancet ii: 294-295. 9. Fagan E.A. and Williams R. (1984): Non-A, non-B hepatitis - Semin. Liver Dis. 4: 314-335. 10. Hopf U., Moller B., Kuther D., et aL (1990): Long-term follow-up of post-transfusion and sporadic chronic hepatitis non-A, non-B and frequency of circulating antibodies to hepatitis C virus (HCV) - J. Hepatol. 10: 69-76. 11. Iwarson S.D. (1987): Non-A, non-B hepatitis: dead ends or new horizons - Br. Med. J. 295: 946-948. 12. Khoo Q-L., Kuo G., Weiner A.J., Overby L.R., Bradley D.W. and Houghton M. (1989): Isolation of a cDNA clone derived from a blood-born non-A, non-B viral hepatitis genome - Science 244: 359-362. 13. Kuo G., Choo K-L., Alter H.J., et aL (1989): An assay for circulating antibodies to a major etiologic virus non-A, non-B hepatitis - Science 244: 362-364.
Acknowledgements
This work was supported in part by a grant from Ministero Universit~tand Ricerca Scientifica and Tecnologica, Rome, Italy. REFERENCES
1. AlterH.J. (1988): Transfusion associated non-A, nonB hepatitis. The first decade. In: "Viral hepatitis and liver disease". Zuckerman Ed. A.R. Liss Inc. New York, pp 537-542. 2. Alter H.J., Purcell R.H., Shih J.W. et al. (1989): Detection of antibody to hepatitis C virus in prospectively followed recipients with acute and chronic non-A, non-B hepatitis - N. Engl. J. Med. 321: 1494-1500. 3. Bradley D.W., Maynard J.E. and Popper H. (1983): Post-transfusion non-A, non-B viral hepatitis physicochemical properties of two distinct agents - J. Infect. Dis. 148: 254-265. 583
14. Pastore G., Dentico P., Angarano G., Monno L., Tannoia N. and Schiraldi O. (1982): Non-A, non-B chronic hepatitis in thalassemic patients. In: "Viral hepatitis" Szmuness W., Alter. H.J., Maynard J. Eds. Franklin Institute Press - Philadelphia, pp 775-776. 15. Pastore G., Monno L., Santantonio T., Angarano G., Trotta F. and Schiraldi O. (1985): Monophasic and poliphasic pattern of alanine aminotransferase in acute nonA, nonB hepatitis. Clinical and prognostic implications - Hepatogastroenterol. 32: 155-158. 16. Rakela J. and Redeker A.G. (1979): Chronic liver disease after acute non-A, non-B viral hepatitis Gastroenterology 77: 1200-1202. 17. Saracco G., Kuo G., Brunetto M.G., et al. (1989): Hepatitis C virus. A major cause ofnonA, nonB posttransfusion hepatitis (PT-NANBH) in Italy - Ital. J. Gastroenterol. 21: 95.
Pastore G. et al.
Eur. J. Epidemiol.
18. Skidmore S.J., Jones T.E.G. and Boxall E.H. (1981): Non-A, non-B hepatitis in patients receiving blood products - J. Med. Virol. 6: 85-89.
20. Weiner A.J., Kuo G., Bradley D.W., et al. (1990): Detection of hepatitis C viral sequences in nonA, nonB hepatitis - Lancet 335: 1-3.
19. Vander Poel C.L., Reesink H.W., Leslie P.N., et al. (1989): Anti-hepatitis C antibodies and non-A, non-B post-transfusion hepatitis in Netherlands - Lancet ii: 297-298.
21. Yoshizawa H., Itoh Y. and Iwakiri S. (1981): Demonstration of two different types of non-A, nonB hepatitis by reinjection and cross-challenge studies in chimpanzees - Gastroenterology 81: 107-113.
584
