PRIMO Cohort Research Articles

Despite being highly diverse, immunovirological status strongly correlates with clinical symptoms during primary HIV-1 infection: a cross-sectional study based on 674 patients enrolled in the ANRS CO 06 PRIMO cohort

To analyse immunovirological status during primary HIV-1 infection (PHI) according to contemporary clinical status and time since infection. Plasma HIV-RNA and peripheral blood mononuclear cell (PBMC) HIV-DNA levels and CD4 cell counts were determined at enrolment in the ANRS PRIMO cohort. Time since infection was estimated based on both the number of antibodies on western blot at enrolment (0-1, 2-4 or > or =5 specific antibodies) and the estimated interval between infection and enrolment based on clinical and epidemiological features. Patients were classified according to the presence or absence of clinical symptoms at enrolment. Between 1996 and 2006, 674 patients were enrolled an estimated median of 47 days after infection. Median marker values were as follows: HIV-RNA 5.10 log(10) copies/mL (range <1.70-8.33); HIV-DNA 3.30 log(10) copies/10(6) PBMCs (<1.84-4.93); and 506 CD4 cells/mm(3) (40-1542). Median HIV-RNA and PBMC HIV-DNA levels were significantly higher in patients with 0 or 1 specific antibody (n = 71) than in patients with 2-4 (n = 228) or > or =5 antibodies (n = 375). Symptomatic patients had significantly higher HIV-RNA and PBMC HIV-DNA levels and lower CD4 cell counts. However, 10% of symptomatic patients recruited shortly after infection had favourable immunovirological status. Plasma HIV-RNA, PBMC HIV-DNA and CD4 cell count values were highly diverse and correlated strongly with clinical status during PHI. Early diagnosis was not always associated with severe PHI. Combining PBMC HIV-DNA with HIV-RNA, CD4 cell count and clinical symptoms would have allowed identification of 179 patients (26.5%) at high risk of rapid disease progression who did not meet current guidelines for early treatment initiation.

Spontaneous Control of Viral Replication during Primary HIV Infection: When Is “HIV Controller” Status Established?

Eight patients in the ANRS PRIMO cohort experienced early spontaneous viral control. Viral control was established a median of 6.2 months after primary human immunodeficiency virus type 1 infection and lasted a median of 4.1 years. Seven of the patients initially had detectable viral replication. For 4 patients, viral control was lost during follow-up.

No evidence of a change in HIV-1 virulence since 1996 in France

We investigated temporal trends in the CD4 cell count and in plasma HIV RNA and total HIV DNA levels measured at the time of primary HIV infection, as proxies for HIV-1 virulence, taking changes in patient characteristics into account. We studied 903 patients enrolled during primary HIV infection in the French multicenter ANRS PRIMO cohort from 1996 to 2007. Associations between the year of primary HIV infection and the values of the three markers were tested with regression models. The year of primary HIV infection was first introduced as a restricted cubic splines function in a regression model in order to explore the shape of the associations, and then as a continuous/categorical variable. The following confounders were considered in multiple regression analysis: time since infection and age (introduced as restricted cubic spline functions), sex, place of birth (Africa vs. others), symptomatic primary HIV infection, smoking, and virus-related factors (subtype B vs. non-B, and drug resistance mutations). Multivariate analysis showed no temporal trends in the CD4 cell count (square-root) or in HIV-1 RNA and DNA levels (log10) measured at the time of primary HIV infection. We observed the well described associations between the prognostic markers and the time since infection, sex, symptomatic primary HIV infection, and smoking. The CD4 cell count and HIV RNA and DNA levels measured at the time of primary HIV-1 infection remained stable across 12 consecutive years (1996-2007) in the ANRS PRIMO cohort, suggesting no major change in virulence, after taking into account changes in patient characteristics.

High frequency of X4/DM-tropic viruses in PBMC samples from patients with primary HIV-1 subtype-B infection in 1996-2007: the French ANRS CO06 PRIMO Cohort Study

To estimate the frequency of viruses with X4 or dual-X4/DM tropism from peripheral blood mononuclear cells (PBMCs) of 390 human immunodeficiency virus type 1 (HIV-1) subtype-B patients diagnosed at the time of primary HIV-1 infection (PHI) between 1996 and 2007 and enrolled in the PRIMO Cohort. V3 loop sequences were amplified from HIV-1-DNA and analysed with a combination of five genotypic rules to predict tropism: (i) the '11/25 rule'; (ii) the net charge rule; (iii) the PSSM(X4/DM) algorithm; (iv) the PSSM(SI/NSI) algorithm; and (v) the SVM(Geno2pheno) algorithm. A high proportion (62/390, 15.9%) of patients harboured X4/DM-tropic viruses. This prevalence was stable over time: 18.1% before 2003 versus 14.8% since 2003. No difference according to HIV tropism was noted in HIV-RNA levels, CD4 cell count, time between infection and enrolment, and HIV infection risk factor. The frequency of X4/DM-tropic virus was similar among patients infected with a resistant virus (12/62, 19.4%) compared with patients harbouring wild-type strains (50/328, 15.2%). This large French epidemiological study evidenced a high proportion of patients (15.9%) harbouring X4/DM-tropic viruses in PBMCs at the time of PHI, suggesting the existence of a cellular X4/DM viral reservoir that could persist for lengthy period of time. Several reports identified that HIV-1 CXCR4 usage was more frequent among patients who developed AIDS and was a powerful predictor of the response to antiretrovirals. Further studies are needed to evaluate the impact of such strains on the outcome of HIV disease, when they are detected at the time of primary infection.

New and old complex recombinant HIV-1 strains among patients with primary infection in 1996–2006 in France: The French ANRS CO06 primo cohort study

BackgroundPrevalence of HIV-1 non-B subtypes has increased overtime in patients diagnosed at the time of primary infection (PHI) in France. Our objective was to characterize in detail non-B strains which could not be genetically classified into the known subtypes/Circulating Recombinant Forms (CRFs).MethodsAmong 744 patients enrolled in the ANRS PRIMO Cohort since 1996, 176 (23.7%) were infected with HIV-1 non-B strains. The subtype/CRF could not be identified in RT for 15 (2%). The V3-V5 env region was sequenced and 3 strains (04FR-KZS, 06FR-CRN, 04FR-AUK) were full-length sequenced. Phylogenetic and bootscan analyses were used to characterize the mosaic structures.ResultsAmong V3-V5 sequences, 6 were divergent A, 2 distantly related to E or D, 2 C, 1 B and 2 remained unclassified. 04FR-KZS, isolated in a Congolese woman infected in France, clustered with 2 previously described viruses from the Democratic Republic of Congo. They represent CRF27_cpx involving A/E/G/H/J/K/U subtypes. 06FR-CRN, isolated in a homosexual Caucasian patient, was a B/C/U recombinant involving a Brazilian C strain. 04FR-AUK, isolated in a Congolese patient infected in France, was a A/K/CRF09/U recombinant clustering from gag to vif with HIV-1 MAL. Others PHI were further observed in 2006–2007 with 1 KZS and 5 CRN-like viruses, suggesting their spread in France.ConclusionThis study illustrates the increasing HIV-1 diversity in France associating new (06FR-CRN) and old (CRF27_cpx and "MAL-like" 04FR-AUK) strains, which are rare in their region of origin but may have a possible founder effect in France. Our results strengthen the French guidelines recommending viro-epidemiological surveillance of HIV-1 diversity.

Response to HAART in French patients with resistant HIV-1 treated at primary infection: ANRS Resistance Network

The aim of the study was to analyse the response to highly active antiretroviral therapy (HAART) initiated at the time of primary HIV infection (PHI) in patients infected with a virus resistant to > or = 1 drug of their treatment compared with patients infected with a wild-type virus. We analysed data from 350 patients who were enrolled from 1996-2004 in the French ANRS PRIMO Cohort or in the ANRS Resistance Group and treated with HAART during PHI. During the study period, HAART was initiated before the result of the genotypic resistance test was available. We compared patients infected with a virus resistant to > or = 1 drug of their regimen (GR group, n = 46) with patients harbouring a wild-type virus (WT group, n = 304). Virological and immunological response to treatment according to drug-resistance profile was analysed 3 months and 6 months after HAART initiation. In GR and WT groups, HIV RNA level was < 400 copies/ml in 68% and 83% (P = 0.02) and < 50 copies/ml in 23% and 40% (P = 0.08) 3 months after HAART initiation. In multivariable logistic regression taking into account gender, age, boosted PI regimen, plasma HIV RNA and CD4+ T-cell count at HAART initiation, patients with virus resistant to > or = 1 drug of their regimen were significantly less likely to achieve undetectable viral load at month 3 (odds ratio 0.32, 95% confidence interval 0.15-0.72) than the others. This difference was sustained up to month 6. In this large cohort of HAART-treated PHI-patients, the presence of drug resistance mutations led to suboptimal response to early therapy.

Yearly number of patients diagnosed with primary HIV-1 infection in France estimated by a capture–recapture approach

We used a two-source capture-recapture method to estimate the number of patients diagnosed at the time of primary HIV infection in France between 1999 and 2002. The sources were the French PRIMO cohort and the French Hospital Database on HIV. The estimated number of patients was 325 per year, which represents only 5% (approximately 6000 cases) of all new cases diagnosed each year and only 8% of all new infections (approximately 4000 cases).

Impact of highly active antiretroviral therapy on the maturation of anti‐HIV‐1 antibodies during primary HIV‐1 infection

To study the impact of highly active antiretroviral therapy (HAART) on isotype switching and avidity maturation of HIV-1-specific immunoglobulin G (IgG) in patients with primary HIV-1 infection (PHI). We studied the emergence and the evolution of anti-HIV IgG antibodies by quantitative immunoblotting to analyse IgG subclasses and IgG avidity. Serum samples were obtained from 16 PHI patients from the French PRIMO Cohort Study at various points in the first year of infection: eight patients received no treatment (group I), and eight patients received efficient HAART (group II) during the study period. Early initiation of HAART in PHI patients partially prevented an increase in anti-HIV-1 IgG levels. Within IgG subclasses, the amount of anti-HIV-1 IgG1 gradually increased with time in both groups, although levels remained lower in treated patients. The anti-p24 IgG2 level was always lower in group II. We observed a decrease in anti-p24 IgG3 over time in both groups. Treatment did not affect the maturation of HIV-1 IgG avidity, which increased in both groups until month 3 and then remained high until the end of the 12-month follow-up period. HAART in PHI partially prevents the emergence of HIV-1 IgG antibodies, but does not affect the quality of these antibodies, as reflected in their isotype and avidity.

CD4 Cell Count and HIV DNA Level Are Independent Predictors of Disease Progression after Primary HIV Type 1 Infection in Untreated Patients

Treatment initiation at the time of primary human immunodeficiency virus (HIV) type 1 (HIV-1) infection has become less frequent in recent years. In the French prospective PRIMO Cohort, in which patients are enrolled at the time of primary HIV-1 infection, 30% of the 552 patients recruited during 1996-2004 did not start receiving antiretroviral treatment during the first 3 months after diagnosis. We analyzed the patients' clinical and immunological outcomes and examined potential predictors of disease progression. Progression was defined as the occurrence of an acquired immunodeficiency syndrome (AIDS)-related clinical event or a CD4 cell count <350 cells/mm3. Fifty-six (34%) of the untreated patients experienced immunological progression during a median duration of follow-up of 24 months, and 1 of these patients had an AIDS-related event. The estimated risks of progression were 25%, 34%, and 42% at 1, 2, and 3 years after enrollment, respectively. Compared with patients who did not have progression, those with progression had significantly lower CD4 cell counts at diagnosis (455 vs. 738 cells/mm3), higher plasma HIV RNA levels (4.9 vs. 4.5 log10 copies/mL), and higher HIV DNA levels (3.3 vs. 3.0 log(10) copies/10(6) peripheral blood mononuclear cells [PBMCs]). All 3 parameters were significantly associated with progression in univariate analysis. In multivariate analysis, only the CD4 cell count and HIV DNA level were independently predictive of disease progression (relative hazard for CD4 cell count, 1.84 per decrease of 100 cells/mm3; relative hazard for HIV DNA level, 2.73 per increase of 1 log(10) copies/10(6) PBMCs). Both a low initial CD4 cell count and a high HIV DNA level are predictive of rapid progression of untreated primary HIV-1 infection. Affected patients may therefore benefit from close clinical and laboratory monitoring and/or early administration of treatment.

HIV-1 resistant strains acquired at the time of primary infection massively fuel the cellular reservoir and persist for lengthy periods of time

Characterization of the early establishment of the viral reservoir in patients acquiring resistant strains at primary HIV-1 infection (PHI), and longitudinal analysis of resistance mutations in circulating virions and intracellular HIV strains. Drug-resistance was compared between HIV RNA and peripheral blood mononuclear cell (PBMC)-HIV DNA at the time of PHI in 44 patients enrolled in the Primo Cohort and harbouring plasma HIV-1 resistant to at least one antiretroviral drug. Longitudinal monitoring of viral load and resistance genotype was performed in plasma-HIV RNA and PBMC HIV DNA for at least 24 months in a subset of 10 patients. Phylogenetic analysis of HIV DNA protease gene clones was used to explore the diversity of quasi-species at baseline. Baseline resistance profile was identical in paired HIV RNA and PBMC HIV DNA for all 44 patients. All resistance-associated mutations persisted in plasma and PBMC over 2 years in the five untreated patients. Of the five patients started on empirical HAART, two achieved undetectable HIV RNA at month 6, with long-term persistence of archived drug-resistance mutations in PBMC HIV DNA. Virological failure was observed in the other three patients, resulting in the accumulation of additional drug-resistance mutations in HIV RNA and HIV DNA for two of them. Phylogenetic analysis of HIV DNA clones showed highly homogenous and exclusively resistant quasi-species in the cellular reservoir at baseline. HIV resistant strains acquired at the time of PHI massively fuel the cellular reservoir, and their prolonged persistence is supported by the early expansion of a dominant homogenous and resistant viral population. Results in treated patients showed that classical empirical triple-combination may be suboptimal.

Increase in at-risk sexual behaviour among HIV-1-infected patients followed in the French PRIMO cohort.

With the current increase in sexually transmitted infections in industrialized countries, we assessed the characteristics and plasma viral load of HIV-1-infected patients reporting sexual behaviour at risk for HIV transmission (SBR). The study population consisted of 223 patients with primary HIV-1 infection who were enrolled in the French PRIMO cohort between 1996 and 2001 and who had at least 3 months of follow-up. Patients were interviewed on condom use at each visit according to the partner (gender, steady versus casual nature, and HIV serostatus). SBR was defined as unprotected sex with partners of unknown or negative HIV serostatus. Sixty-one SBR were reported by 43 patients. SBR with casual partners increased from 5.1% in 1998 to 21.1% in 2001-2002, after a fall between 1997 and 1998. Reporting of SBR was more frequent among patients with casual partners, those with asymptomatic or briefly (< or = 15 days) symptomatic primary infection, and those who had developed clinical lipodystrophy or signs of anxiety/depression. Eighty-six per cent of patients reporting SBR had previously initiated highly active antiretroviral therapy (HAART); plasma viral load was above the detection limit (200/500 copies/ml) in 41% of visits reporting an SBR. Viral load was similar in patients reporting SBR and other patients, suggesting that the patient's knowledge of his/her response to HAART was not a major determinant of subsequent SBR. Our results confirm the recent increase in unsafe sex observed among HIV-infected individuals in industrialized countries. Levels of viral load of these individuals raise concern about the potential for re-emerging HIV epidemics.

Proviral HIV-1 DNA in subjects followed since primary HIV-1 infection who suppress plasma viral load after one year of highly active antiretroviral therapy.

An assessment of the impact of one year potent antiretroviral treatment initiated during primary HIV infection on the cell-associated viral burden. Proviral HIV-1 DNA was quantified in serial peripheral blood mononuclear cell (PBMC) samples from 19 patients enrolled in the French prospective PRIMO Cohort for whom plasma HIV RNA was suppressed to undetectable levels after one year of triple therapy; that is, plasma HIV-1 RNA was maintained below 200 copies/ml. Results were compared with those observed in 19 patients with chronic HIV-1 infection presenting the same degree of virus suppression after 12 months of treatment. At study entry, PRIMO subjects presented heterogeneous levels of proviral HIV-1 DNA: 2-3.92 log10 copies/10(6) PBMC and plasma HIV RNA: 2.3-6.5 log10 copies/ml. One year of effective highly active antiretroviral therapy (HAART) resulted in a median diminution of proviral DNA of -0.78 log10/10(6) PBMC in PRIMO subjects. The median decline in chronic-phase patients was -0.32 for those who were pre-treated and -0.52 for those previously naive of treatment. The decline in cell-associated HIV DNA observed throughout one year treatment indicated that HAART reduces the proviral HIV-DNA load more effectively when initiated during the primary rather than the chronic phase of HIV infection. These findings therefore tend to lend support to the early initiation of treatment. Nevertheless, heterogeneous baseline values observed for CD4 cell count, plasma HIV RNA and proviral HIV DNA in PRIMO subjects, raise the question of whether treatment should be delayed in some to spare early adverse effects of HAART.