Primary HIV-1 infection: a review of clinical manifestations, immunologic and virologic changes

In the past few years, major advances have been made in the field of primary HIV-1 infection. Several studies have reevaluated the clinical syndrome. The emergence of new molecular laboratory techniques has permitted a detailed analysis of viral dynamics and subsequent immunologic changes. Measurements of subsets of T-lymphocytes have allowed greater insight into the early pathogenesis of HIV-1 disease. There is now evidence that HIV-1-specific cytotoxic T-lymphocytes occur early during primary HIV-1 infection and are probably the most important immune defense against HIV-1. However, HIV-1 immune escape mutants have been identified during primary infection, which may be one reason for the failure of the immune system to completely eradicate the virus. Cytokines have been shown to play a role in primary HIV-1 infection, and the therapy of primary infection has gained more interest due to the introduction of potent triple combinations, including protease inhibitors.     

Virologic, immunologic, and clinical benefits from early combined antiretroviral therapy in infants with perinatal HIV-1 infection

OBJECTIVE: To investigate the impact of early versus deferred combined antiretroviral treatment (ART) in asymptomatic or moderately symptomatic [Centers for Disease Control and Prevention (CDC) category N, A or B] infants with perinatal HIV-1 infection. METHODS: A multi-centre nationwide case-control study was conducted. Data from 30 infants treated with combined ART with three or more drugs before 6 months of age were compared with data from 103 infants starting ART with three or more drugs after 6 months of age. The median follow-up time was 4.1 years (range, 1.0-6.5 years). RESULTS: No difference was evident in the first available viral load and CD4 T-lymphocyte percentage between the two groups of children. Early-treated infants showed significantly lower viral loads than infants receiving deferred treatment at all the follow-up periods. A higher proportion of early-treated infants than infants receiving deferred treatment (73.3% versus 30.1%; P < 0.0001) reached an undetectable viral load. Higher CD4 T-lymphocyte percentages were found in early-treated infants at 13-24 (P < 0.0001), 25-36 (P < 0.0001), and 37-48 (P = 0.003) months of age. No early-treated infant versus 20 of 103 (19.4%) infants receiving deferred ART (P = 0.02) showed a CD4 T-lymphocyte percentage of less than 15% at one time point during follow-up. No CDC category A, B or C clinical event occurred in early-treated infants over the follow-up period while 44 of 103 (42.7%) infants receiving deferred treatment presented a decline in the CDC category. Kaplan-Meier analyses revealed significant differences in CDC category A (P = 0.0002), B (P = 0.0003), and C (P = 0.0018) event-free survivals. CONCLUSION: The data suggest virologic, immunologic, and clinical benefits from early administration of ART.     

Correlation between immunologic responses to a recombinant glycoprotein 120 vaccine and incidence of HIV-1 infection in a phase 3 HIV-1 preventive vaccine trial

BACKGROUND: An objective of the first efficacy trial of a candidate vaccine containing recombinant human immunodeficiency virus (HIV) type 1 envelope glycoprotein 120 (rgp120) antigens was to assess correlations between antibody responses to rgp120 and the incidence of HIV-1 infection. METHODS: Within the randomized trial (for vaccinees, n=3598; for placebo recipients, n=1805), binding and neutralizing antibody responses to rgp120 were quantitated. A case-cohort design was used to study correlations between antibody levels and HIV-1 incidence. RESULTS: Peak antibody levels were significantly inversely correlated with HIV-1 incidence. The relative risk (RR) of infection was 0.63 (95% confidence interval, 0.45-0.89) per log(10) higher neutralization titer against HIV-1(MN), and the RRs of infection for second-, third-, and fourth-quartile responses of antibody blocking of gp120 binding to soluble CD4 versus first-quartile responses (the lowest responses) were 0.35, 0.28, and 0.22, respectively. CONCLUSIONS: Despite inducing a complex, robust immune response, the vaccine was unable to reduce the incidence of HIV-1. Two interpretations of the correlative results are that the levels of antibodies (i) caused both an increased (low responders) and decreased (high responders) risk of HIV-1 acquisition or (ii) represented a correlate of susceptibility to HIV-1 but had no causal effect on susceptibility. Although the data cannot definitively discriminate between these 2 explanations, (ii) appears to be more likely.     

The clinical prognosis of HIV-1 infection

Thirty-two follow-up studies of patients with HIV-1 infection, but without AIDS at baseline, were examined for information on the risk of developing AIDS or other conditions. Disease progression in asymptomatic groups was similar to that found in patients with persistent generalized lymphadenopathy (PGL) without other symptoms. Among these asymptomatic and PGL groups, the risk of developing AIDS reached 10% to 15% between 24 and 36 months of follow up. The risk of progression to AIDS continued to increase in the studies with longer follow-up periods, reaching 36% at 88 months. However, more than 40% of “high-risk” groups (characterized by the presence of constitutional symptoms, oral thrush, herpes zoster, and/or low T4 counts) developed AIDS after only 36 months of follow-up. Reliable information about progression to other states (e.g., AIDS-related complex) has not been consistently provided. Received from the Division of General Internal Medicine, Department of Medicine, Uniformed Services University of Health Sciences, Bethesda, Maryland, and Walter Reed Army Medical Center, Washington, DC. The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense.     

Puberty in perinatal HIV-1 infection: a multicentre longitudinal study of 212 children

OBJECTIVE: To define age at entry into Tanner stages in children with perinatal HIV-1 infection. DESIGN: Multicentre longitudinal study including 212 perinatally HIV-1-infected children (107 girls and 105 boys) followed-up during puberty (from 8 and 9 years onwards in girls and boys, respectively). Healthy children (843 girls and 821 boys) provided reference percentiles. P2 or B2 stages in girls and P2 or G2 stages in boys defined onset of puberty. METHODS: The cumulative probability [95% confidence limit (CI)] of entry into each stage at different ages was estimated by the Kaplan-Meier product-limit method; differences were evaluated by log rank test. Relationships were tested using the Spearman's rank correlation coefficient. RESULTS: Ages of girls [years (95%CI)] at P2 [12.9 (12.6-13.2)], P3 [13.4 (13.0-13.8)], P4 [14.6 (14.0-15.2)], B2 [12.7 (12.2-13.2)], B3 [13.3 (12.8-14.0)] and B4 [14.6 (14.0-15.2)] stages were > 97th percentile (> or = 21 month delay) of controls. Ages of boys [years (95%CI)] at P2 [12.6 (12.1-13.1)], P3 [13.9 (13.4-14.4)], P4 [14.9 (14.2-15.6)], G2 [12.1 (11.5-12.7)], G3 [13.6 (13.1-14.1)] and G4 [14.9 (14.1-15.7)] stages were at the 75-97th percentiles (< or = 15 month delay). Age at onset of puberty was not related to clinical and immunological condition, antiretroviral treatment, weigh for height and age at onset of severe disease or immune suppression. CONCLUSION: Perinatal HIV-1 infection interferes with sexual maturation. The mechanisms by which this occurs should be elucidated and intervention strategies designed. Intervention could save much psychological distress, since associated linear growth failure can exacerbate adolescents' feelings of being different and unwell.     

Human immunodeficiency virus type 1 (HIV-1) and Mycobacterium leprae co-infection: HIV-1 subtypes and clinical, immunologic, and histopathologic profiles in a Brazilian cohort

Co-infections with human immunodeficiency virus (HIV) and Mycobacterium leprae represent unique opportunities to investigate the interaction of both pathogens. We determined the immunologic, virologic, and histopathologic characteristics of 22 co-infected Brazilian patients (median age = 38 years, 81.8% males, 72.2% with paucibacillary leprosy, and 95.4% with acquired immunodeficiency syndrome). The HIV-1 subtypes B and BF predominated in envelope and gag heteroduplex mobility analysis. Borderline tuberculoid (BT), tuberculoid, lepromatous, and indeterminate morphology with CD3+, CD8+, and CD68+ cell distributions compatible with leprosy patients not infected with HIV were observed. Histologic evidence of nerve damage was observed in BT lesions. IgM antibody to M. leprae-specific phenolic glycolipid I was not detected. Two of six co-infected patients monitored during highly active antiretroviral therapy (HAART) developed a leprosy type 1 reaction after an increase in CD4+ cells, suggesting an immune restoration phenomenon. Clinical, immunologic, histopathologic, and virologic features among these HIV-leprosy co-infected patients indicate that each disease progressed as in single infection. However, HAART immune reconstitution may trigger potential adverse effects, such as leprosy acute inflammatory episodes.     

ACTH and cortisol secretions in children with perinatal HIV-1 infection

Serum cortisol and adrenocorticotropic hormone (ACTH) values and CD4 cell count were evaluated in 25 perinatally HIV-1-infected children. The children were divided into three groups: group 1 included eight asymptomatic or paucisymptomatic children, group 2 nine moderately symptomatic children, and group 3 eight children with severe clinical manifestations. Group 1 children were without antiretroviral therapy; the remaining children received zidovudine (AZT) treatment. Only one group 3 patient had primary adrenal insufficiency. No significant differences in cortisol and ACTH secretion were found either between all HIV-1-infected and 126 age- and sex-matched normal children or among the three groups of patients. Mean CD4 cell count of each group declined in parallel to disease progression. No correlations were found between cortisol or ACTH values and CD4 cell count. Adrenal failure may be a late complication of HIV-1 infection and should be searched for in severely ill patients. Our data argue against the hypothesis of a cortisol-induced shift from T-helper-1 (Th1) to Th2 cytokine production profile as the pathogenetic mechanism of progression to AIDS.     

Primary HIV-1 infection in African children infected through breastfeeding

OBJECTIVES: To describe acute retroviral syndrome and associated primary viraemia in African children infected with HIV-1 through breastfeeding. DESIGN: Matched case-control study performed retrospectively within the ANRS 049 DITRAME project conducted in 1995-1998 in Abidjan, C?te d'Ivoire. METHODS: Cases were children infected by HIV-1 postnatally through breastfeeding. All were HIV-1 negative by DNA PCR at least 45 days of age, but positive on a subsequent sample. This period was considered as surrounding the estimated date of postnatal contamination. Signs/symptoms occurring within this period were recorded in cases and compared with those occurring during the same time period in uninfected breastfed children (controls). For cases, plasma specimens were tested for HIV-1 plasma RNA using the branched DNA assay. RESULTS: Of 22 infants infected postnatally (median age at first positive sample, 185 days; range, 87-373 days), 21 (95.5%) exhibited at least one clinical sign, compared with only 27 of the 44 (61.4%) uninfected children (P = 0.003). Three independent factors were associated with primary HIV-1 infection: mononucleosis-like syndrome [odds ratio (OR), 8.3; 95% confidence interval (CI), 1.4-47.8], dermatitis (OR, 6.0; CI, 1.1-31.9), and generalized lymphadenopathy (OR, 26.5; CI, 2.0-348.4). Among cases, initial median plasma HIV-1 RNA viral load was 5.92 log10 copies/ml; this declined to 4.96 log10 12 months after the first positive viral load. CONCLUSIONS: These results may be useful for the recognition of early paediatric cases of postnatal transmission in Africa and could enable targeting of those who should benefit from HIV RNA or DNA testing for primary HIV-1 infection and their subsequent care.     

HIV-1 Env蛋白与HIV-1感染

人免疫缺陷病毒Ⅰ型(HIV-1)是艾滋病的主要病原体,HIV-1 Env蛋白在病毒的感染、侵入和干扰机体免疫机能等方面发挥着重要作用,它可以干扰细胞正常的信号转导途径、导致合胞体的形成、引发细胞病变。HIV-1感染的细胞类型包括 CD_4~+辅助T细胞、单核巨噬细胞、树突状细胞、朗罕氏细胞、胎盘滋养层细胞、神经元细胞等。HIV-1感染引发的病理变化与免疫系统的变化密切相关,免疫系统的     

Role of molecular mimicry to HIV-1 peptides in HIV-1-related immunologic thrombocytopenia

Patients with early HIV-1 infection develop an autoimmune thrombocytopenia in which antibody is directed against an immunodominant epitope of the beta3 (glycoprotein IIIa [GPIIIa]) integrin, GPIIIa49-66. This antibody induces thrombocytopenia by a novel complement-independent mechanism in which platelets are fragmented by antibody-induced generation of H2O2 derived from the interaction of platelet nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and 12-lipoxygenase. To examine whether sharing of epitope between host and parasite may be responsible for this immunodominant epitope, we screened for antibody-reactive peptides capable of inhibiting platelet lysis and oxidation in vitro, using a filamentous phage display 7-mer peptide library. Fourteen of these phage-peptide clones were identified. Five shared close sequence similarity with GPIIIa49-66, as expected. Ten were molecular mimics with close sequence similarity to HIV-1 proteins nef, gag, env, and pol. Seven were synthesized as 10-mers from their known HIV-1 sequence and found to inhibit anti-GPIIIa49-66-induced platelet oxidation/fragmentation in vitro. Three rabbit antibodies raised against these peptides induced platelet oxidation/fragmentation in vitro and thrombocytopenia in vivo when passively transferred into mice. One of the peptides shared a known epitope region with HIV-1 protein nef and was derived from a variant region of the protein. These data provide strong support for molecular mimicry in HIV-1-immunologic thrombocytopenia within polymorphic regions of HIV-1 proteins. A known epitope of nef is particularly incriminated.     

Mixed cryoglobulinemia in HIV-1 infection: the role of HIV-1

BACKGROUND: Cryoglobulins are associated with chronic infections. OBJECTIVE: To investigate the prevalence of mixed cryoglobulinemia in patients with HIV-1 infection, the clinical spectrum of cryoglobulinemia in these patients, and the possible role of HIV-1 in cryoglobulin formation. DESIGN: Prospective cohort study. SETTING: Laiko Hospital, Athens, Greece. PATIENTS: 89 patients with HIV-1 infection. MEASUREMENTS: Serum and cryoglobulins were evaluated for antibodies to HIV and hepatitis C virus (HCV), HIV-1, and HCV viral load. RESULTS: Mixed cryoglobulins were detected in 24 patients with HIV-1 infection (27% [95% CI, 18% to 36%]). The HIV-1 viral load was higher in cryoglobulin-positive patients (median, 38.25 x 10(3) copies/mL [25th, 75th percentiles: 13.8 x 10(3) copies/mL, 78.55 x 10(3) copies/mL]) than in cryoglobulin-negative patients (median, 5.3 x 10(3) copies/mL [25th, 75th percentiles: 0.7 x 10(3) copies/mL, 27.2 x 10(3) copies/mL]) (P = 0.001). Antibodies to HIV were detected in all cryoprecipitates, and HIV-1 RNA sequences were identified in 22 of the 23 cryoprecipitates examined. Nine cryoglobulin-positive patients (38% [CI, 19% to 54%]) had clinical manifestations compatible with cryoglobulinemia. CONCLUSIONS: Mixed cryoglobulinemia is common in patients with HIV-1 infection.     

Interleukin-18: a proinflammatory cytokine in HIV-1 infection

Interleukin (IL)-18 is a proinflammatory cytokine that plays an important role in both innate and adaptive immune responses against viruses and intracellular pathogens. Increased levels of circulating IL-18 from HIV-1 infected patients have been reported especially in the advanced and late stages of the disease, whereas in the initial stage serum levels of IL-18 were not increased. In contrast, low production of Il-18 was observed in vitro from peripheral blood mononuclear cells (PBMC) of HIV-1 infected patients, and these results were also observed in macaques infected with simian immunodeficiency virus (SIV). In addition, decreased IL-18 production from PBMC was significantly correlated with low production of IL-2. Furthermore, serum levels of IL-18 significantly decreased after highly active antiretroviral therapy. During the early stage of HIV-1 infection there is a decreased production of gamma interferon (IFN), IL-12 and IL-2 as well as not activation of IL-18 production and this leads to inhibition of Th1 immune response, whereas in the advanced stage of the disease, strong activation of IL-18 production along with persistent decreased production of gamma IFN, IL-12 and IL-2 may promote a Th2 immune response, which leads to persistent viral replication. Several studies have shown increased levels of IL-18 in HIV-seronegative subjects with obesity, insulin resistance and type II diabetes. Metabolic disorders, fat redistribution and cardiovascular manifestations are becoming more frequent in HIV-1 infected patients treated with antiretroviral drugs. Consequently, involvement of IL-18 in these disorders has been postulated and demonstrated in patients with lipodistrophy, or with hypertriglyceridemia. Finally, higher serum levels of IL-18 may represent an useful marker in HIV-1 infected patients with metabolic disorders and fat redistribution, as well as a sensitive predictor of cardiovascular complications in treated patients.     

DEFB1 gene polymorphisms and increased risk of HIV-1 infection in Brazilian children

In our study we analysed three single nucleotide polymorphisms (SNPs) in the 5' untranslated region (UTR) of the DEFB1 gene, namely -52(G/A) -44(C/G) and -20(G/A), in three groups of northeastern Brazilian children in order to assess their role in HIV-1 infection. Our results allowed us to hypothesize that the SNPs located in the 5' UTR of the DEFB1 gene can be employed as a marker of risk for HIV-1 infection.