Journal of Medical Virology 2:117-125 (1978)
*Antigen and Age in Acute and Chronic Type B Hepatitis Victor M. Villarejos, Kirsten Anderson Visona, and Carlos E. Eduarte A. Louisiana State University-International Center for Medical Research and Training, San Jod, Costa Rica. (V.M. Villarejos and K.A. Visonsl and Hospital Valverde Vega, San Ramon, Costa Rica (C.E. Eduarte A.)
The influence of e-antigen upon the course and outcome of acute type B hepatitis was studied in a series of 202 patients. Of these, 54 (27%) had e-Ag, detected in the serum at the same time as HBsAg during the.incubation period or at onset. In 39 patients (73%) the e-Ag disappeared within eight weeks after onset, regularly followed by clearance of HBsAg approximately four weeks later; anti-HB, was detected shortly thereafter in 3 4 cases. In 1 5 (28%) of e-Ag-positive and in 4 (3%) of e-Ag-negative patients, HBsAg persisted for one year or longer; chronic hepatitis developed in 13 of these cases, 1 2 of which were e-Ag-positive. Among e-Ag-positives HBsAg persisted only in those cases in which the e-Ag also persisted; all these were persons under 15 years of age. Transaminase and bilirubin values were equally high in e-Ag-positive and e-Ag-negative patients with resolving hepatitis, but were low from the start in those who later developed chronic liver conditions, irrespective of the presence or absence of e-Ag. It is concluded that in e-Ag-positive acute type B hepatitis patients the disappearance of this antigen from the serum is a good prognostic sign, whereas its persistence beyond eight weeks, especially in young children with low transaminase and bilirubin response, signa!s evolution towards chronicity. Key words: e-antigen, age, type B hepatitis, HB,AG persistence
INTRODUCTION
The e-antigen/antibody system, reported first by Magnius and Epsmark [1972], is found only in type B hepatitis. It has been suggested that e-antigen (e-Ag) is a component of the hepatitis B virus (HBV) and represents the DNA polymerase protein in the Dane particle [Nordenfelt and Kjellen, 19751. However, Neurath and Strick [1977] recently published evidence indicating that the e-system constitutes an IgG antibody/anti-antibody system and as such is a product of the host response to HBV infection. A separate line of evidence in our laboratory supports this concept [Visoni, GuttiQrez, and Villarejos,
19771. Received for publication September 14, 1977. Address reprint requests to V.M. Villarejos, LSU-ICMRT, Apdo 10155, San Josk, Costa Rica.
0146-6615/78/0202-Ol17$02.000 1978 Alan R. Liss, Inc
118
Villarejos, Visona, and Eduarte A .
Since its discovery, e-Ag has been linked to persistence of hepatitis B antigen (HB,Ag) and evolution of the disease towards chronicity [Nielsen, Juhl, and Dietrichson, 1974; Vogten et al, 19761 . It has also been recognized as an indicator of infectivity of the HBsAg carrier [Okada et al, 19761, while e-antibody (anti-e) seems to denote inocuousness of the carrier. The e-Ag has been found in varying proportions of patients during the acute stage of type B hepatitis; however, opinions about the prognostic significance of this finding are contradictory [Nielsen, Juhl, and Dietrichson, 1974; Norkrans, Magnius, and Iwarson, 1976; Thamer, Gmelin, and Kommerell, 19761. There is not much published information on the frequency of distribution of e-Ag by age and sex nor about the duration of e-antigenernia in correlation with clearance of HB,Ag from the serum, information which should be important. In the course of epidemiologic studies conducted since 1966 in San Rambn and Wlmares, two counties of Costa Rica where contact-transmitted B hepatitis occurs in endoemoepidemic fashion [Villarejos, Serra, and Hernindez, 19751, we have examined the outcome of a series of cases of acute hepatitis B in relation t o age and to the presence or absence of e-Ag in the serum. The results of this longitudinal investigation are presented here.
PATIENTS AND METHODS
€Iepatitis cases found through surveillance of the endemic area were brought to the Regional Hospital in San Ram6n and blood samples were obtained weekly during the period of hospitalization, then at biweekly, monthly, and trimonthly intervals, according to the evolution of the case. Their families were observed, with weekly or biweekly collections of blood from each member of the household during the presumed time of incubation of the disease, in order to study the intrafamilial spread of the infection. Serial serum samples from 202 patients with acute type B hepatitis seen between 1972 and 1975, which had been kept frozen, were examined for the presence of e-Ag and anti-e. Forty-two of these patients were secondary cases found during surveillance of the families, and from these, consecutive serum samples were available for at least four to six weeks prior to onset. The clinical diagnosis was supported by determinations of pyruvic and oxaloacetic transaminases (method of Reitman and Frankel) and bilirubin (method of Malloy and Evelyn), and detection of HBsAg by radioimmunoassay (Ausria 11, Abbott). Liver biopsies were performed in 19 cases in which the HBsAg antigenemia persisted more than one year. In addition, acute sera from 200 HBsAg-negative hepatitis patients, matched b y age with the HBsAg-positive cases, were also examined for the presence of e-Ag and anti-e. e-Ag and anti-e were assayed by rheophoresis (Aus-tect, Abbott) at 25°C with readings at 24 and 48 hours. Reference sera were kindly provided by Dr James W. Mosley, University of Southern California, Los Angeles. Positive findings were confirmed by neutralization and thermolability tests. Antibodies to HBsAg (anti-HB,) were assayed by passive hemagglutination (PHA) [Vyas and Shulman, 19701. For statistical analysis the chi-square test or the relative deviations for significance of differences of means were calculated.
e-Antigen and Age in Type B Hepatitis
119
RESULTS
e-Ag was not present in any of the 200 patients with acute HBsAg-negative hepatitis. At the onset of disease, the e-Ag was found in the sera of 54 (27%) of the 202 patients with acute type B hepatitis. In 15 (28%) of these and in 4 (3%)of 148 e-Agnegatives, HBsAg persisted over periods of one year or more. There was no difference between sexes in the proportion of cases having e-Ag or those developing persistent HBs antigenemia (Table I), either with or without e-Ag. However, the difference in the proportion of e-Ag-positive and e-Ag-negative patients in which the HBsAg persisted was highly significant (x' = 29; p < 0.0005). Fourteen of the 54 e-Ag-positive patients were secondary cases detected during the prepatent period; the e-Ag appeared in these cases at approximately the same time as the HBsAg, two to four weeks before onset of clinical disease. The other 40 patients were already positive for both e-Ag and HBsAG when first examined at onset. Cases which were e-Ag-negative before or at onset did not subsequently become positive, as confirmed by repeated examinations during the course of the disease. All but four sera containing e-Ag became negative when heated at 56°C for 30 minutes; the other four sera, which also produced strong precipitation bands, required three hours for inactivation of e-Ag. This thermolability test would mark the majority of the e-Ag found in our series as e2 according to Williams and Le Bouvier [1976]. However, this identification could nct be confirmed serologically because reference antisera for the el and e, reactants were not available. In 39 patients the e-Ag disappeared from the serum in two to eight weeks (average four weeks) after onset (Table 11). In three cases, the HB,Ag disappeared from the blood at the same time as the e-Ag; in all other cases it did so one to seven weeks later (average four weeks). Three e-Ag-negative patients were lost early during during observation, while still HBsAg-positive. The average duration of HBsAg after onset was 58 f 32 days in e-Agpositive and 38 f 20 days in e-Ag-negative cases; this was a significant difference (p
*Antigen and Age in Acute and Chronic Type B Hepatitis Victor M. Villarejos, Kirsten Anderson Visona, and Carlos E. Eduarte A. Louisiana State University-International Center for Medical Research and Training, San Jod, Costa Rica. (V.M. Villarejos and K.A. Visonsl and Hospital Valverde Vega, San Ramon, Costa Rica (C.E. Eduarte A.)
The influence of e-antigen upon the course and outcome of acute type B hepatitis was studied in a series of 202 patients. Of these, 54 (27%) had e-Ag, detected in the serum at the same time as HBsAg during the.incubation period or at onset. In 39 patients (73%) the e-Ag disappeared within eight weeks after onset, regularly followed by clearance of HBsAg approximately four weeks later; anti-HB, was detected shortly thereafter in 3 4 cases. In 1 5 (28%) of e-Ag-positive and in 4 (3%) of e-Ag-negative patients, HBsAg persisted for one year or longer; chronic hepatitis developed in 13 of these cases, 1 2 of which were e-Ag-positive. Among e-Ag-positives HBsAg persisted only in those cases in which the e-Ag also persisted; all these were persons under 15 years of age. Transaminase and bilirubin values were equally high in e-Ag-positive and e-Ag-negative patients with resolving hepatitis, but were low from the start in those who later developed chronic liver conditions, irrespective of the presence or absence of e-Ag. It is concluded that in e-Ag-positive acute type B hepatitis patients the disappearance of this antigen from the serum is a good prognostic sign, whereas its persistence beyond eight weeks, especially in young children with low transaminase and bilirubin response, signa!s evolution towards chronicity. Key words: e-antigen, age, type B hepatitis, HB,AG persistence
INTRODUCTION
The e-antigen/antibody system, reported first by Magnius and Epsmark [1972], is found only in type B hepatitis. It has been suggested that e-antigen (e-Ag) is a component of the hepatitis B virus (HBV) and represents the DNA polymerase protein in the Dane particle [Nordenfelt and Kjellen, 19751. However, Neurath and Strick [1977] recently published evidence indicating that the e-system constitutes an IgG antibody/anti-antibody system and as such is a product of the host response to HBV infection. A separate line of evidence in our laboratory supports this concept [Visoni, GuttiQrez, and Villarejos,
19771. Received for publication September 14, 1977. Address reprint requests to V.M. Villarejos, LSU-ICMRT, Apdo 10155, San Josk, Costa Rica.
0146-6615/78/0202-Ol17$02.000 1978 Alan R. Liss, Inc
118
Villarejos, Visona, and Eduarte A .
Since its discovery, e-Ag has been linked to persistence of hepatitis B antigen (HB,Ag) and evolution of the disease towards chronicity [Nielsen, Juhl, and Dietrichson, 1974; Vogten et al, 19761 . It has also been recognized as an indicator of infectivity of the HBsAg carrier [Okada et al, 19761, while e-antibody (anti-e) seems to denote inocuousness of the carrier. The e-Ag has been found in varying proportions of patients during the acute stage of type B hepatitis; however, opinions about the prognostic significance of this finding are contradictory [Nielsen, Juhl, and Dietrichson, 1974; Norkrans, Magnius, and Iwarson, 1976; Thamer, Gmelin, and Kommerell, 19761. There is not much published information on the frequency of distribution of e-Ag by age and sex nor about the duration of e-antigenernia in correlation with clearance of HB,Ag from the serum, information which should be important. In the course of epidemiologic studies conducted since 1966 in San Rambn and Wlmares, two counties of Costa Rica where contact-transmitted B hepatitis occurs in endoemoepidemic fashion [Villarejos, Serra, and Hernindez, 19751, we have examined the outcome of a series of cases of acute hepatitis B in relation t o age and to the presence or absence of e-Ag in the serum. The results of this longitudinal investigation are presented here.
PATIENTS AND METHODS
€Iepatitis cases found through surveillance of the endemic area were brought to the Regional Hospital in San Ram6n and blood samples were obtained weekly during the period of hospitalization, then at biweekly, monthly, and trimonthly intervals, according to the evolution of the case. Their families were observed, with weekly or biweekly collections of blood from each member of the household during the presumed time of incubation of the disease, in order to study the intrafamilial spread of the infection. Serial serum samples from 202 patients with acute type B hepatitis seen between 1972 and 1975, which had been kept frozen, were examined for the presence of e-Ag and anti-e. Forty-two of these patients were secondary cases found during surveillance of the families, and from these, consecutive serum samples were available for at least four to six weeks prior to onset. The clinical diagnosis was supported by determinations of pyruvic and oxaloacetic transaminases (method of Reitman and Frankel) and bilirubin (method of Malloy and Evelyn), and detection of HBsAg by radioimmunoassay (Ausria 11, Abbott). Liver biopsies were performed in 19 cases in which the HBsAg antigenemia persisted more than one year. In addition, acute sera from 200 HBsAg-negative hepatitis patients, matched b y age with the HBsAg-positive cases, were also examined for the presence of e-Ag and anti-e. e-Ag and anti-e were assayed by rheophoresis (Aus-tect, Abbott) at 25°C with readings at 24 and 48 hours. Reference sera were kindly provided by Dr James W. Mosley, University of Southern California, Los Angeles. Positive findings were confirmed by neutralization and thermolability tests. Antibodies to HBsAg (anti-HB,) were assayed by passive hemagglutination (PHA) [Vyas and Shulman, 19701. For statistical analysis the chi-square test or the relative deviations for significance of differences of means were calculated.
e-Antigen and Age in Type B Hepatitis
119
RESULTS
e-Ag was not present in any of the 200 patients with acute HBsAg-negative hepatitis. At the onset of disease, the e-Ag was found in the sera of 54 (27%) of the 202 patients with acute type B hepatitis. In 15 (28%) of these and in 4 (3%)of 148 e-Agnegatives, HBsAg persisted over periods of one year or more. There was no difference between sexes in the proportion of cases having e-Ag or those developing persistent HBs antigenemia (Table I), either with or without e-Ag. However, the difference in the proportion of e-Ag-positive and e-Ag-negative patients in which the HBsAg persisted was highly significant (x' = 29; p < 0.0005). Fourteen of the 54 e-Ag-positive patients were secondary cases detected during the prepatent period; the e-Ag appeared in these cases at approximately the same time as the HBsAg, two to four weeks before onset of clinical disease. The other 40 patients were already positive for both e-Ag and HBsAG when first examined at onset. Cases which were e-Ag-negative before or at onset did not subsequently become positive, as confirmed by repeated examinations during the course of the disease. All but four sera containing e-Ag became negative when heated at 56°C for 30 minutes; the other four sera, which also produced strong precipitation bands, required three hours for inactivation of e-Ag. This thermolability test would mark the majority of the e-Ag found in our series as e2 according to Williams and Le Bouvier [1976]. However, this identification could nct be confirmed serologically because reference antisera for the el and e, reactants were not available. In 39 patients the e-Ag disappeared from the serum in two to eight weeks (average four weeks) after onset (Table 11). In three cases, the HB,Ag disappeared from the blood at the same time as the e-Ag; in all other cases it did so one to seven weeks later (average four weeks). Three e-Ag-negative patients were lost early during during observation, while still HBsAg-positive. The average duration of HBsAg after onset was 58 f 32 days in e-Agpositive and 38 f 20 days in e-Ag-negative cases; this was a significant difference (p
