427
Viral Phenotype and Immune Response in Primary Human Immunodeficiency Virus Type 1 Infection Marijke T. L. Roos, J oep M. A. Lange, Ruud E. Y. de Goede, Roel A. Coutinho, Peter T. A. Schellekens, Frank Miedema, and Matthijs Tersmette
Central Laboratory of the Netherlands Red Cross Blood Transfusion Service (Laboratory of Experimental and Clinical Immunology). Department of Internal Medicine and National AIDS Therapy Evaluation Centre (Academic Medical Centre), University ofAmsterdam; Department of Infectious Diseases, Municipal Health Service, Amsterdam. Netherlands
Primary human immunodeficiency virus type 1 (HIV-1) infection has a variable clinical course. In a minority of patients this phase of infection is subclinical, but in 50%-70% an acute clinical syndrome occurs 2-4 weeks after the moment of infection, which in general lasts 1-2 weeks [1]. Although in exceptional cases the patient may progress to AIDS very rapidly [2], most individuals subsequently enter a clinically asymptomatic phase and progression to AIDS occurs only after 1 to > 10 years [3]. Previously, we demonstrated an association between the clinical course of asymptomatic HIV-l-eseropositive individuals and the biologic phenotype of their viral isolates, Presence of syncytium-inducing (SI), T cell line tropic HIV-l variants correlated with rapid CD4+ T cell decline. In contrast, in seropositive individuals with stable CD4+ T cell numbers, only low-replicating non-syncytium-inducing (NSI) variants were observed [4, 5]. In longitudinal studies of seropositive asymptomatic individuals, we found that, whereas NSI variants are present throughout HIV-1 infection, SI variants generally emerge during the course of HIV-I infection [4, 6]. In the present study we analyzed virologic and immuno-
Received 19 August 1991; revised 28 October 1991. Financial support: Netherlands Foundation for Preventive Medicine and Ministry of Health (grants 28-1079. -1026) and Royal Netherlands Academy of Arts and Science (F.M. is a senior fellow). Reprints or correspondence: Dr. M. Tersmette, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service. P.O. Box 9406. 1006 AK Amsterdam. Netherlands. The Journal of Infectious Diseases 1992;165:427-32 © 1992 by The University of Chicago. All rights reserved. 0022-1899/92/6503-0003$01.00
logic events early after HIV-1 transmission. In particular we wanted to determine if and how the HIV-l biologic phenotype early after infection is related to the clinical and immunologic events during primary HIV-1 infection and thereafter.
Subjects and Methods Subjects. Virologic and immunologic events were studied in 19 persons. Subjects 1-6 presented clinically with symptoms of acute HIV-1 infection. Subject 7, a participant of the Amsterdam cohort study on the natural course of HIV-1 infection [7], seroconverted during the study period. Subject 8 was accidentally infected with a small amount of blood from an individual with end-stage HIV-I-related disease. The clinical features of subjects 1-3 and 6-8 have been reported [2, 8-10]. In addition to these individuals from whom frequent blood samples were obtained, at 3-month intervals virologic and immunologic data were obtained from 11 participants in the Amsterdam cohort study who were seronegative at entry and who seroconverted during follow-up. The source of infection was unknown for 16 subjects. The virus donor could be identified for the accidentally infected subject 8, for subject 2, a monogamous heterosexual individual with a confirmed seropositive Zairean partner as single-risk factor, and for 1 of the 11 cohort participants, subject 17, a monogamous homosexual man. For subject 17, the origin of the virus was confirmed by comparison of the third hypervariable envelope domain (V3) sequences of HIV-I RNA in his serum and that of his partner, revealing the same uncommon sequence variant [II] in both (Wolfs T, personal communication). Healthy heterosexual individuals, healthy HIV-seronegative homosexual men at high risk, and HIV-seronegative individuals with acute influenza, rubella, cytomegalovirus, or Epstein-Barr
Downloaded from http://jid.oxfordjournals.org/ at University of Exeter on July 15, 2015
Nineteen individuals were studied for virologic and immunologic events during primary human immunodeficiency virus type 1 (HIV-l) infection. In 16 individuals only non-syncytium-inducing (NSI) isolates were detected; syncytium-inducing (SI) isolates were obtained from 3. Studies of transmitter-recipient pairs indicated that both NSI variants and SI variants were transmitted and that SI variants may be suppressed in the recipient. CD4+T cells remained in the normal range in 15 of 16 individuals with NSI isolates but rapidly declined in all 3 individuals with SI variants, 1 of whom was treated with zidovudine. The most marked increase in CD8+ T cells and activated CD8+ T cells was observed in individuals with the most pronounced clinical signs of acute HIV-1 infection. Activated CD8+ T cells were only transiently elevated in individuals with SI variants, suggesting that an impaired cellular anti-HIV-1 immune response plays a role in the rapid progression to AIDS.
428
Roos et al.
Results Clinical findings during primary infection. Virologic and immunologic studies were done of 19 recently infected individuals, 8 of whom (patients 1-8) could be studied in detail because frequent samples were obtained. Patients 1-7 presented clinically with symptoms of acute HIV-I infection (table I). Patient 8 was accidentally infected with a small amount of blood from a patient with end-stage HIV-l-related disease during a diagnostic procedure, 14 days after a partial jejunum resection. He received zidovudine within 45 min after exposure and did not develop clinical symptoms of acute HIV-I infection [10]. Patients 1-6 and 8 had no evidence of other recent infections, patient 7 early after seroconversion had serologic evidence of recent syphilis and hepatitis B. The other II individuals did not undergo physical examination at the early stage of infection. Retrospective evidence for symptoms compatible with acute HIV-l infection was obtained for 8 of these [17]. Virologic analysis. In patients 1-7 seroconversion occurred 11-27 days after the onset of symptoms. In patient 8, despite early treatment with zidovudine, seroconversion occurred 41 days after exposure to HIV-I-infected blood (table 2). Transient HIV-l antigenemia before seroconversion
Clinical findings in seven patients with acute human immunodeficiency virus type I.
Table 1.
Clinical finding Myalgia/arthralgia Oral thrush/ulcerations Fever Skin rash Headache Fever> I week Diarrhea Cough Weight loss Lymphadenopathy Sore throat Dysphagia Nosebleed
No. patients (n = 7) 6 6
5 5 4
3 3 3 3 3 2 I I
was detected in seven of eight patients (table 2). In patients 1-5 only NSI isolates were recovered. In patients 6 and 8 only SI isolates were detected. An SI isolate was obtained from patient 7 at seroconversion; at day 42 an NSI isolate was recovered and subsequently SI isolates reappeared, preceding progression to AIDS (table 2). In II seroconverting participants of the Amsterdam cohort from whom virus was obtained at seroconversion and on at least two dates after seroconversion, only NSI isolates were recovered (data not shown). For three of the individuals studied, the virus donor was identified (table 3). In two cases the viruses of donorrecipient pairs displayed similar phenotypes: The wife ofpatient 2 yielded an NSI isolate, and an SI isolate was recovered from the patient whose blood infected patient 8. A discordance of viral phenotype was observed in the third donor-recipient pair: An SI isolate was recovered from the steady homosexual partner of one of the cohort participants (subject 17) before and after the estimated time of transmission. For subject 17, however, isolates obtained at and after seroconversion were of the NSI phenotype. Immunologic analysis. At or directly preceding seroconversion, a transient CD4+ and CD8+ T lymphocytopenia was observed in six of the eight frequently sampled individuals, profound in patients 1,3,7, and 8 «0.3 X 109/1) and less dramatic in patients 4 and 6. After seroconversion, CD8+ T cell numbers recovered completely but CD4+ T cell numbers recovered only partly (table 2). In the 16 subjects with NSI isolates, except for patient 5, CD4+ T cell numbers remained stable and in the normal range until the end ofthe study (table 2; data not shown). No opportunistic infections were observed in this group; however, two individuals developed Kaposi's sarcoma with normal CD4+ T cell numbers (1.3 X 10 9/1 and 0.7 X 109/1, respectively) 25 and II months after seroconversion. In contrast, in all three individuals with SI isolates, CD4+ T cell numbers, after a temporary recovery to low-normal values,
Downloaded from http://jid.oxfordjournals.org/ at University of Exeter on July 15, 2015
virus infection were used as a control population for the immunologic parameters. Serology. Antibodies to HIV-I were determined by commercial assay (HIV 1/2 EIA; Abbott Laboratories, North Chicago) and confirmed by Western blot [12, 13]. HIV-I p24 antigen in serum was detected in a commercial antigen capture assay (Abbott Laboratories) (I2]. Viral isolation. HIV-I was recovered from cryopreserved peripheral blood mononuclear cells (PBMC) as described [14]. Briefly, PBMC of infected individuals were cocultivated with 2-day phytohemagglutinin-stimulated peripheral blood lymphocytes from a seronegative blood donor. This cocultivation procedure was repeated each week. Cultures were observed for syncytium formation 3 times a week as described [4, 14]. Twice weekly culture supernatants were tested for the presence of viral p24 [14, 15]. Virus was recovered from >95% of the PBMC samples. Immunologic studies. PBMC were isolated from heparinized venous blood by density-gradient centrifugation on ficoll-hypaque. Lymphocyte immunophenotyping for CD4 and CD8 cells was done by flow cytometry. Anti-CD38 and anti-HLA-DR monoclonal antibodies (Central Laboratory of the Netherlands Red Cross Blood Transfusion Service; Becton Dickinson Immunocytometry Systems, San Jose, CA) were used to define the activation state of CD8+ T cells [16]. Median values and ranges (10-90 percentiles) ofT cell subsets relevant to this study in the HI V-seronegative heterosexuals were: CD4+ cells, 0.89 X 109/1 (0.57-1.38); CD8+ cells, 0.52 X 109/1 (0.30-0.91); CD38+/ CD8+ cells, 6% (0-14) of total CD8+ T cells. In the HIV-seronegative homosexual control group the median values and ranges were: CD4+ cells, 0.7 X 109/1 (0.45-1. I); CD8+ cells, 0.9 X 109/1 (0.45-1.3); CD38+/CD8+ cells, 10% (3-27) of total CD8+ T cells.
JID 1992; 165 (March)
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430
JID 1992; 165 (March)
Roos et al.
Table 2. (Continued) Virologic parameters Patient (no. clinical symptoms"), days after seroconversion
HIV-I p24 antigen
8 (0) -38:1: -28 -25 -18 -II
HIV-I antibody
HIV-I phenotype 51+/-
CD4+ (X 10-9 )
CD8+ (X 10- 9 )
C038+/CD8+ (% of total CD8+ cells)
,
1.2 0.9 1.4 0.7 0.4 0.2 0.7 0.7 0.3 0.3 0.1
Viral Phenotype and Immune Response in Primary Human Immunodeficiency Virus Type 1 Infection Marijke T. L. Roos, J oep M. A. Lange, Ruud E. Y. de Goede, Roel A. Coutinho, Peter T. A. Schellekens, Frank Miedema, and Matthijs Tersmette
Central Laboratory of the Netherlands Red Cross Blood Transfusion Service (Laboratory of Experimental and Clinical Immunology). Department of Internal Medicine and National AIDS Therapy Evaluation Centre (Academic Medical Centre), University ofAmsterdam; Department of Infectious Diseases, Municipal Health Service, Amsterdam. Netherlands
Primary human immunodeficiency virus type 1 (HIV-1) infection has a variable clinical course. In a minority of patients this phase of infection is subclinical, but in 50%-70% an acute clinical syndrome occurs 2-4 weeks after the moment of infection, which in general lasts 1-2 weeks [1]. Although in exceptional cases the patient may progress to AIDS very rapidly [2], most individuals subsequently enter a clinically asymptomatic phase and progression to AIDS occurs only after 1 to > 10 years [3]. Previously, we demonstrated an association between the clinical course of asymptomatic HIV-l-eseropositive individuals and the biologic phenotype of their viral isolates, Presence of syncytium-inducing (SI), T cell line tropic HIV-l variants correlated with rapid CD4+ T cell decline. In contrast, in seropositive individuals with stable CD4+ T cell numbers, only low-replicating non-syncytium-inducing (NSI) variants were observed [4, 5]. In longitudinal studies of seropositive asymptomatic individuals, we found that, whereas NSI variants are present throughout HIV-1 infection, SI variants generally emerge during the course of HIV-I infection [4, 6]. In the present study we analyzed virologic and immuno-
Received 19 August 1991; revised 28 October 1991. Financial support: Netherlands Foundation for Preventive Medicine and Ministry of Health (grants 28-1079. -1026) and Royal Netherlands Academy of Arts and Science (F.M. is a senior fellow). Reprints or correspondence: Dr. M. Tersmette, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service. P.O. Box 9406. 1006 AK Amsterdam. Netherlands. The Journal of Infectious Diseases 1992;165:427-32 © 1992 by The University of Chicago. All rights reserved. 0022-1899/92/6503-0003$01.00
logic events early after HIV-1 transmission. In particular we wanted to determine if and how the HIV-l biologic phenotype early after infection is related to the clinical and immunologic events during primary HIV-1 infection and thereafter.
Subjects and Methods Subjects. Virologic and immunologic events were studied in 19 persons. Subjects 1-6 presented clinically with symptoms of acute HIV-1 infection. Subject 7, a participant of the Amsterdam cohort study on the natural course of HIV-1 infection [7], seroconverted during the study period. Subject 8 was accidentally infected with a small amount of blood from an individual with end-stage HIV-I-related disease. The clinical features of subjects 1-3 and 6-8 have been reported [2, 8-10]. In addition to these individuals from whom frequent blood samples were obtained, at 3-month intervals virologic and immunologic data were obtained from 11 participants in the Amsterdam cohort study who were seronegative at entry and who seroconverted during follow-up. The source of infection was unknown for 16 subjects. The virus donor could be identified for the accidentally infected subject 8, for subject 2, a monogamous heterosexual individual with a confirmed seropositive Zairean partner as single-risk factor, and for 1 of the 11 cohort participants, subject 17, a monogamous homosexual man. For subject 17, the origin of the virus was confirmed by comparison of the third hypervariable envelope domain (V3) sequences of HIV-I RNA in his serum and that of his partner, revealing the same uncommon sequence variant [II] in both (Wolfs T, personal communication). Healthy heterosexual individuals, healthy HIV-seronegative homosexual men at high risk, and HIV-seronegative individuals with acute influenza, rubella, cytomegalovirus, or Epstein-Barr
Downloaded from http://jid.oxfordjournals.org/ at University of Exeter on July 15, 2015
Nineteen individuals were studied for virologic and immunologic events during primary human immunodeficiency virus type 1 (HIV-l) infection. In 16 individuals only non-syncytium-inducing (NSI) isolates were detected; syncytium-inducing (SI) isolates were obtained from 3. Studies of transmitter-recipient pairs indicated that both NSI variants and SI variants were transmitted and that SI variants may be suppressed in the recipient. CD4+T cells remained in the normal range in 15 of 16 individuals with NSI isolates but rapidly declined in all 3 individuals with SI variants, 1 of whom was treated with zidovudine. The most marked increase in CD8+ T cells and activated CD8+ T cells was observed in individuals with the most pronounced clinical signs of acute HIV-1 infection. Activated CD8+ T cells were only transiently elevated in individuals with SI variants, suggesting that an impaired cellular anti-HIV-1 immune response plays a role in the rapid progression to AIDS.
428
Roos et al.
Results Clinical findings during primary infection. Virologic and immunologic studies were done of 19 recently infected individuals, 8 of whom (patients 1-8) could be studied in detail because frequent samples were obtained. Patients 1-7 presented clinically with symptoms of acute HIV-I infection (table I). Patient 8 was accidentally infected with a small amount of blood from a patient with end-stage HIV-l-related disease during a diagnostic procedure, 14 days after a partial jejunum resection. He received zidovudine within 45 min after exposure and did not develop clinical symptoms of acute HIV-I infection [10]. Patients 1-6 and 8 had no evidence of other recent infections, patient 7 early after seroconversion had serologic evidence of recent syphilis and hepatitis B. The other II individuals did not undergo physical examination at the early stage of infection. Retrospective evidence for symptoms compatible with acute HIV-l infection was obtained for 8 of these [17]. Virologic analysis. In patients 1-7 seroconversion occurred 11-27 days after the onset of symptoms. In patient 8, despite early treatment with zidovudine, seroconversion occurred 41 days after exposure to HIV-I-infected blood (table 2). Transient HIV-l antigenemia before seroconversion
Clinical findings in seven patients with acute human immunodeficiency virus type I.
Table 1.
Clinical finding Myalgia/arthralgia Oral thrush/ulcerations Fever Skin rash Headache Fever> I week Diarrhea Cough Weight loss Lymphadenopathy Sore throat Dysphagia Nosebleed
No. patients (n = 7) 6 6
5 5 4
3 3 3 3 3 2 I I
was detected in seven of eight patients (table 2). In patients 1-5 only NSI isolates were recovered. In patients 6 and 8 only SI isolates were detected. An SI isolate was obtained from patient 7 at seroconversion; at day 42 an NSI isolate was recovered and subsequently SI isolates reappeared, preceding progression to AIDS (table 2). In II seroconverting participants of the Amsterdam cohort from whom virus was obtained at seroconversion and on at least two dates after seroconversion, only NSI isolates were recovered (data not shown). For three of the individuals studied, the virus donor was identified (table 3). In two cases the viruses of donorrecipient pairs displayed similar phenotypes: The wife ofpatient 2 yielded an NSI isolate, and an SI isolate was recovered from the patient whose blood infected patient 8. A discordance of viral phenotype was observed in the third donor-recipient pair: An SI isolate was recovered from the steady homosexual partner of one of the cohort participants (subject 17) before and after the estimated time of transmission. For subject 17, however, isolates obtained at and after seroconversion were of the NSI phenotype. Immunologic analysis. At or directly preceding seroconversion, a transient CD4+ and CD8+ T lymphocytopenia was observed in six of the eight frequently sampled individuals, profound in patients 1,3,7, and 8 «0.3 X 109/1) and less dramatic in patients 4 and 6. After seroconversion, CD8+ T cell numbers recovered completely but CD4+ T cell numbers recovered only partly (table 2). In the 16 subjects with NSI isolates, except for patient 5, CD4+ T cell numbers remained stable and in the normal range until the end ofthe study (table 2; data not shown). No opportunistic infections were observed in this group; however, two individuals developed Kaposi's sarcoma with normal CD4+ T cell numbers (1.3 X 10 9/1 and 0.7 X 109/1, respectively) 25 and II months after seroconversion. In contrast, in all three individuals with SI isolates, CD4+ T cell numbers, after a temporary recovery to low-normal values,
Downloaded from http://jid.oxfordjournals.org/ at University of Exeter on July 15, 2015
virus infection were used as a control population for the immunologic parameters. Serology. Antibodies to HIV-I were determined by commercial assay (HIV 1/2 EIA; Abbott Laboratories, North Chicago) and confirmed by Western blot [12, 13]. HIV-I p24 antigen in serum was detected in a commercial antigen capture assay (Abbott Laboratories) (I2]. Viral isolation. HIV-I was recovered from cryopreserved peripheral blood mononuclear cells (PBMC) as described [14]. Briefly, PBMC of infected individuals were cocultivated with 2-day phytohemagglutinin-stimulated peripheral blood lymphocytes from a seronegative blood donor. This cocultivation procedure was repeated each week. Cultures were observed for syncytium formation 3 times a week as described [4, 14]. Twice weekly culture supernatants were tested for the presence of viral p24 [14, 15]. Virus was recovered from >95% of the PBMC samples. Immunologic studies. PBMC were isolated from heparinized venous blood by density-gradient centrifugation on ficoll-hypaque. Lymphocyte immunophenotyping for CD4 and CD8 cells was done by flow cytometry. Anti-CD38 and anti-HLA-DR monoclonal antibodies (Central Laboratory of the Netherlands Red Cross Blood Transfusion Service; Becton Dickinson Immunocytometry Systems, San Jose, CA) were used to define the activation state of CD8+ T cells [16]. Median values and ranges (10-90 percentiles) ofT cell subsets relevant to this study in the HI V-seronegative heterosexuals were: CD4+ cells, 0.89 X 109/1 (0.57-1.38); CD8+ cells, 0.52 X 109/1 (0.30-0.91); CD38+/ CD8+ cells, 6% (0-14) of total CD8+ T cells. In the HIV-seronegative homosexual control group the median values and ranges were: CD4+ cells, 0.7 X 109/1 (0.45-1. I); CD8+ cells, 0.9 X 109/1 (0.45-1.3); CD38+/CD8+ cells, 10% (3-27) of total CD8+ T cells.
JID 1992; 165 (March)
Downloaded from http://jid.oxfordjournals.org/ at University of Exeter on July 15, 2015
430
JID 1992; 165 (March)
Roos et al.
Table 2. (Continued) Virologic parameters Patient (no. clinical symptoms"), days after seroconversion
HIV-I p24 antigen
8 (0) -38:1: -28 -25 -18 -II
HIV-I antibody
HIV-I phenotype 51+/-
CD4+ (X 10-9 )
CD8+ (X 10- 9 )
C038+/CD8+ (% of total CD8+ cells)
,
1.2 0.9 1.4 0.7 0.4 0.2 0.7 0.7 0.3 0.3 0.1
