Kinetics of human immunodeficiency virus type 1 (HIV-1) DNA and RNA synthesis during primary HIV-1 infection

HIV-1 replication and viral burden in peripheral blood mononuclear cells (PBMC) have been reported to be high in primary infection but generally very low during the prolonged period of clinical latency. It is uncertain precisely when this transition occurs during the HIV-1 infection and what the relationship is between the changes in HIV-1 replication versus the clearance of infected cells in the overall control of viral replication. In the present study, the kinetics of viral burden (i.e., frequency of HIV-1-infected cells) and replication during primary and early-chronic infection were analyzed in PBMC of four acutely infected individuals. High frequencies of HIV-1-infected cells and high levels of virus replication were observed in PBMC after primary HIV-1 infection. Down-regulation of virus replication in PBMC was observed in all four patients coincident with the emergence of HIV-1-specific immune responses. Other parameters of virus replication, such as circulating plasma p24 antigen and plasma viremia showed similar kinetics. In contrast, a significant decline in viral burden in PBMC was observed in only one of four patients. These results indicate that the down-regulation in the levels of virus replication associated with the clinical transition from acute to chronic infection does not necessarily reflect a reduction in viral burden, thus suggesting the involvement of additional factors. Identification of these factors will be important in elucidating the host mechanisms involved in the early control of HIV-1 infection and disease.

Detection and localization of HIV RNA and TNF mRNA in rectal biopsies from patients with AIDS

The objective of this study was to compare the localization of cells containing human immunodeficiency virus (HIV) RNA and tumor necrosis factor (TNF)-alpha mRNA in rectal mucosa by RNA in-situ hybridization in a retrospective analysis of archived rectal biopsy specimens. RNA in-situ hybridization studies were performed in 27 HIV-seropositive individuals and seven controls, using antisense and sense 35S-labeled riboprobes. The detection and localization of positive cells were compared. HIV was RNA detected in 44% of biopsies, while TNF-alpha mRNA detected in 22%. TNF mRNA was found in biopsies from patients with and without opportunistic infections. All cells expressing TNF-alpha mRNA and most of the cells expressing HIV RNA were found in close proximity to the epithelial surface. The content of an HIV-associated protein, p24, in mucosal homogenates, determined by a quantitative ELISA technique was significantly higher in the subgroup of patients with positive in situ hybridization studies for TNF-alpha mRNA than in the subgroup with negative studies. The colocalization of TNF-alpha mRNA and HIV RNA immediately beneath the epithelium suggests a specific relationship between them, as well as a possible relationship to a luminal factor.

Molecular epidemiology of HIV-1 based on phylogenetic analysis of in vivo gag p7/p9 direct sequences

Viruses of different geographical origin are circulating in Finland. We wanted to test whether phylogenetic analysis of patient lymphocyte proviral quasispecies sequences could be used to group different strains into genetic lineages. The gag p7/p9 coding region was analyzed using solid-phase direct sequencing from 30 patients in Finland and Estonia. Proviral sequences were found to represent at least four, possibly even five, different, highly diverged major lineages. Different methods of phylogenetic analysis resulted in the same conclusion. Serial samples from the same patients, taken over a period of several years showed limited variation over time. Cases of potential patient-to-patient transmission or common source of infection were identified based on the sequence analysis. Compared to similar analyses of longer genome segments, the gag p7/p9 nucleic acid binding protein coding region produces analogous results in phylogenetic analysis. The method can be used as a rapid way of determining the genetic subtype of HIV-1 strains circulating in populations.

[Molecular characterization of human T-cell lymphotrophic virus type II]

Human T-cell leukemia (or lymphotrophic) virus type II (HTLV-II) was isolated from eight HTLV seropositive patients. Restriction endonuclease mapping of the proviruses demonstrated consistent differences among isolates, and two distinct physical map patterns were observed. These studies have provided evidence for existence of two related, but distinct molecular subtype of HTLV-II, which are designated HTLV-II a and HTLV-II b. Between the two subtypes, the gag region encoding the p19 protein of HTLV-II b isolates contained a 66bp deletion in addition to single nucleotide differences. Immunoblotting methods employing sera from infected patients with each subtype failed to demonstrate any antigenic differences when recombinant gag p19 protein of each subtype was used as antigen. However, similar assays using recombinant HTLV-I and HTLV-II p19 proteins were able to differentiate the two viruses. ELISA using the synthetic peptides corresponding the deleted region gave the negative results for HTLV-II b (0/6) in contrast to the high positivity for HTLV-II a (6/10), which would provide an initial screening method for differentiation of the HTLV-II subtypes.

[Pneumococcal vaccine recommended for HIV-infected individuals]

The Epidemic Section at the Oslo City Department of Health and Environment, is responsible for monitoring communicable diseases in Oslo. We have registered an increase in the number of severe cases of pneumococcal disease with bacteremia, sepsis and meningitis. Fifty-two cases of invasive pneumococcal disease occurred in Oslo in 1992. There are no available data on the HIV-status of these patients. Streptococcus pneumoniae is frequently found as part of the normal flora of the upper respiratory tract, and is an important pathogen for patients infected with HIV. We discuss indications for use of pneumococcal vaccine, and recommend earlier and more extensive use of this vaccine in HIV-infected persons in Norway.

Relation of phenotype evolution of HIV-1 to envelope V2 configuration

Biological variability of human immunodeficiency virus type-1 (HIV-1) is involved in the pathogenesis of acquired immunodeficiency syndrome (AIDS). Syncytium-inducing (SI) HIV-1 variants emerge in 50 percent of infected individuals during infection, preceding accelerated CD4+ T cell loss and rapid progression to AIDS. The V1 to V2 and V3 region of the viral envelope glycoprotein gp120 contained the major determinants of SI capacity. The configuration of a hypervariable locus in the V2 domain appeared to be predictive for non-SI to SI phenotype conversion. Early prediction of HIV-1 phenotype evolution may be useful for clinical monitoring and treatment of asymptomatic infection.

Nested polymerase chain reaction assay for the detection of B19 parvovirus DNA in human immunodeficiency virus patients

Persistent B19 parvovirus infection has been recognized in immunocompromised patients, often occurring with a low-titer viremia. In this study, nested polymerase chain reaction (PCR) for the detection of B19 parvovirus DNA was carried out on the sera of 49 human immunodeficiency virus (HIV)-1-seropositive patients, negative for the detection of B19 DNA at dot blot hybridization assay and with different values of serum anti-B19 IgM (27 patients proved positive and 22 negative). Of the 49 HIV-seropositive samples tested by nested PCR, seven were positive for the detection of B19 DNA. All seven belonged to the group of subjects seropositive for specific anti-B19 IgM. The study shows that, in the presence of specific B19 IgM, circulating virus may still be present but can be detected only by PCR. In that B19 infection can occur with low-titer viremia in immunocompromised patients, PCR may be the only method for virus detection.

Clinical aspects and microbiology of HIV-associated periodontal lesions

This study examines the clinical aspects of HIV-associated periodontal lesions and the prevalence of periodontal pathogens. Subgingival plaque samples were taken from 55 subjects in six study groups: 1) HIV-seropositive patients with gingivitis, 2) necrotizing gingivitis, 3) periodontitis or 4) with health periodontium, 5) patients with rapidly progressive periodontitis or 6) periodontally healthy in whom there was no evidence of HIV infection. Among HIV-positive patients there was a majority (66%) of intravenous drug users. We detected more Bacteroides intermedius, B. buccae and B. oralis in HIV-infected patients with periodontal lesions and in HIV-negative subjects with rapidly progressive periodontitis than in the other groups. High levels of Spirochetes were recovered in both HIV associated necrotizing gingivitis and periodontitis. The results indicate that there is a similarity in the microbiological profile of HIV-associated gingivitis, necrotizing gingivitis, periodontitis and rapidly progressive periodontitis of HIV-negative subjects although significant differences in the clinical aspects of the lesions and in the immune status of the host have been observed.

[Detection of HIV-1 proviral DNA and RNA in serum from HIV-1 sero-positive hemophiliacs by polymerase chain reaction]

We amplified HIV-1 proviral DNA and RNA in serum by DNA-PCR and RT-RCR in 20 HIV-1 seropositive hemophiliacs asymptomatic carrier (AC): 10, AIDS-related complex (ARC):8, AIDS:2). HIV-1 DNA sequences were identified in 44 (93.6%) of 47 specimens. 23 (92.0%) of 25 samples in AC, 13 (100%) of 13 in ARC, 8 (88.8%) of 9 in AIDS had detectable bands. RNA sequences were identified in 36 (85.7%) of 42 specimens. 17 (70.8%) of 24 specimens in AC, 13 (100%) of 13 in ARC, 5 (100%) of 5 in AIDS cases had detectable bands. RNA in serum was strongly positive in two asymptomatic patients with progression to AIDS who showed no changes of other markers. Patients with almost normal CD4 cell counts had trace amounts of proviral DNA and RNA in serum. RNA in serum is the parameter most predictive of progression to AIDS and is detectable earlier than other parameters. From the results of RT-PCR before and after seroconversion, the serum of one patient was shown to be positive at 5 months before seroconversion.

Lack of mother-to-infant transmission of hepatitis C virus in human immunodeficiency virus-seronegative women: a prospective study with hepatitis C virus RNA testing

The published risk of mother-to-infant transmission of hepatitis C virus varies according to the population studied and the tests used. In a prospective study we used the polymerase chain reaction to assess the risk of vertical transmission of hepatitis C virus in an unselected population of women uninfected by human immunodeficiency virus. Hepatitis C virus antibodies were sought with a second-generation enzyme-linked immunosorbent assay in 2,367 consecutive pregnant women. Forty-one were positive, and 17 consented to serological follow-up of their offspring (n = 18). A second-generation recombinant immunoblot assay, ALT determination and hepatitis C virus RNA testing were performed on maternal sera obtained during pregnancy and sera from the offspring at birth and thereafter. Five older brothers or sisters were also tested. Hepatitis C virus RNA sequences in serum were amplified with a modified nested polymerase chain reaction procedure with primers from the highly conserved 5' noncoding region of the hepatitis C virus genome. All the neonates were positive for hepatitis C virus antibodies, with enzyme-linked immunosorbent assay titers and recombinant immunoblot assay patterns similar to those of their mothers. After birth hepatitis C virus antibodies gradually disappeared within 6 mo. Hepatitis C virus RNA was consistently negative in the 18 children from birth to 24 mo (range = 3 to 24 mo) and in the 5 older children, regardless of the hepatitis C virus polymerase chain reaction status of the mothers (8 of whom were positive).(ABSTRACT TRUNCATED AT 250 WORDS)

Differential lobe lavage for diagnosis of acute Pneumocystis carinii pneumonia in patients receiving prophylactic aerosolized pentamidine therapy

The diagnostic yield of bronchoalveolar lavage (BAL) for Pneumocystis carinii pneumonia (PCP) in patients infected with human immunodeficiency virus has been reported to be 95 percent, but falls to 62 percent in patients receiving aerosolized pentamidine. Because aerosolized pentamidine appears to be preferentially deposited in the middle and lower lobes, we postulated that an upper lobe lavage would have a higher diagnostic yield than the standard middle/lower lobe lavage in patients receiving aerosolized pentamidine. Twenty-five patients receiving aerosolized pentamidine suspected of having acute PCP underwent separate BAL of an upper lobe and lower lobe as well as transbronchial biopsy. Fifteen of the 25 (60 percent) were diagnosed as having PCP. Of the 15, one had the samples inadvertently combined. In the remaining 14, BAL was positive for P carinii organisms in 12 lavages of the lower lobe and 14 of the upper lobe. Upper lobe lavage had statistically significantly more P carinii organisms by semiquantitative technique than the lower lobe. In patients receiving aerosolized pentamidine, who develop acute PCP, an upper lobe lavage may have a higher diagnostic yield than the standard middle/lower lobe lavage. In addition, the transbronchial biopsy specimen offered no treatable diagnosis that was not made by lavage alone in the 25 patients. This raises the question of the utility of transbronchial biopsies in these patients.

Sexual transmission of hepatitis C virus and HIV-1 infection in female intravenous drug users

We examined the relationship between the presence of antibody to HCV and sexually transmitted diseases in 151 female, intravenous drug users aged 17-43 years. Anti-HCV was present in 49 of 66 HIV-1-negative women (74.2%), and 63 of 85 HIV-1-positive women (74.1%). Anti-HCV seropositivity was significantly related to sexually transmitted infections (Ureaplasma urealyticum infections excluded) in HIV-1-seronegative women, but not in HIV-1-positive women. Also, in HIV-1-negative subjects. Trichomonas vaginalis infections (and infections with M. hominis) were significantly related to anti-HCV seropositivity, and a positive relation between the number of sexual partners and the presence of anti-HCV was demonstrated. In HIV-1-positive subjects a shared use of needles and syringes was more likely, and an increased parenteral exposure to HCV may decrease the relative contribution by sexual transmission. However, in HIV-1-negative subjects, sexual transmission of HCV appears to be both a possible and important means of transmission.

Standardized nested polymerase chain reaction-based assay for detection of human immunodeficiency virus type 1 DNA in whole blood lysates

The routine detection of human immunodeficiency virus type 1 (HIV-1) proviral DNA in clinical samples requires a standardized, simple, and sensitive test. To identify the HIV-1 proviral DNA in blood, we used a solid-phase assay based on the affinity capture and the gamma counting of the amplified product after a nested polymerase chain reaction (AMPLICIS test). In order to simplify the general process, whole-blood lysates rather than peripheral blood mononuclear cell lysates were used for the amplifications. The solid-phase capture and counting of the final amplified products allowed us to define precise interpretive criteria to determine the positivity level of the test. Three new primer sets located in the gag and pol structural genes and in the tat regulatory gene of HIV-1 were studied. The results obtained in 54 seropositive and 120 seronegative individuals demonstrated the ability of the AMPLICIS test to be used for HIV-1 provirus detection: 53 of 54 of the seropositive specimens were found to be positive with at least two primer sets. We also assessed the usefulness of this test for the estimation of the HIV-1 DNA load by the end point dilution method with serial dilutions of blood lysates from 26 HIV-1-seropositive patients.

Detection of polymerase chain reaction-amplified human immunodeficiency virus type 1 proviral DNA with a digoxigenin-labeled RNA probe and an enzyme-linked immunoassay

An enzyme-linked immunoassay (EIA) combined with a solution hybridization (SH) reaction was devised to detect human immunodeficiency virus type 1 (HIV-1) provirus amplified by the polymerase chain reaction (PCR). In this nonisotopic PCR assay, designated PCR-EIASH, a fragment of the HIV-1 gag gene from peripheral blood mononuclear cells (PBMCs) was first amplified with biotinylated primers. The biotinylated amplified DNA segment was reacted in solution with an internal RNA probe labeled with digoxigenin-11-UTP. Hybrids were captured in a microtiter plate coated with streptavidin. Specific bound hybrids were quantitated by the addition of an enzyme-labeled antibody against digoxigenin and a fluorogenic substrate. The hybridization, immunological, and amplification parameters of PCR-EIASH were optimized as follows: 12.5 pmol of each primer was used in the PCR; the reannealing reaction of amplified products with the RNA probe, which was used at 0.30 microgram/ml, was completed in 30 min at 70 degrees C in 2x SSC (1x SSC is 0.15 M NaCl plus 0.015 M sodium citrate). Five copies of HIV-1 DNA diluted in a lysate of 100,000 PBMCs from a seronegative control could be detected by PCR-EIASH with a signal of 41 +/- 3 fluorescent units above a background noise of 13 +/- 2 fluorescent units. A total of 91 PBMC lysates from 91 seropositive patients sampled once and 20 PBMC lysates from 10 seropositive patients sampled twice were tested in duplicate in the PCR-EIASH; 107 samples were positive in duplicate tests, 1 sample was indeterminate, and 3 samples were negative. Of the latter three samples, one became positive by diluting the cell lysate, suggesting the presence of an inhibitor of Taq polymerase. The three samples negative for HIV-1 by PCR-EIASH were also negative when amplified with SK145-SK39 and detected with 32P-labeled SK102.

Diagnosis of Pneumocystis carinii pneumonia in a population of HIV-positive drug users, with particular reference to sputum induction and fluorescent antibody techniques

Between June 1990 and May 1991, 200 sputum inductions were examined by a fluorescent antibody test (FAT) for Pneumocystis carinii (PC). A total of 164 specimens were negative, 36 were positive and a further 20 inductions were unsuccessful. All patients with a positive result, seven of whom had normal chest X-rays and blood gas analyses, were treated for Pneumocystis carinii pneumonia (PCP) with symptomatic response. Two additional patients were diagnosed as PCP during the study period. No patient with a negative or unsuccessful result developed clinical PCP during that admission, although six did develop 10 episodes of PCP (FAT positive for PC on induced sputum samples) within 3 months of a negative result. Sputum induction was well tolerated by patients and not associated with adverse events. Sensitivity of FAT for PC was 95% and specificity was 100%. These results may in part be because most of the patients were injection drug users (IDUs) who often suffer from chronic productive cough, and also because sputum induction in all cases was supervised by an experienced physiotherapist.

Patients infected with human immunodeficiency virus type 1 have low levels of virus in saliva even in the presence of periodontal disease

In two consecutive studies, 80 subjects human immunodeficiency virus (HIV)-1-seropositive (21 asymptomatic, 6 persistent generalized lymphadenopathy, 13 AIDS-related complex, and 40 AIDS) were examined for oral lesions. Paired serum and saliva specimens were tested for HIV isolation, DNA, and antigen. HIV antigen was detected in sera from 31 patients, but not in saliva. HIV was isolated from blood mononuclear cells of 83% and saliva supernatants of 21%. In the second study of 25 patients, HIV was detected in plasma of 56% (titers, 1/10 to > 1/1000) but not in diluted saliva supernatants, even in those with severe periodontal disease. HIV DNA was detected using polymerase chain reaction in 2 of 7 saliva cell pellets and 4 of 5 blood samples. Hence, infectious HIV and DNA was found at very low concentrations in 21% and 28% of HIV-seropositive patients, respectively, at all stages of HIV infection.

Anti-human immunodeficiency virus type 1 activity of an anti-CD4 immunoconjugate containing pokeweed antiviral protein

The ability of an alpha CD4-pokeweed antiviral protein (PAP) immunoconjugate to inhibit replication of human immunodeficiency virus type 1 (HIV-1) was evaluated in vitro with 22 clinical HIV-1 strains obtained from four seropositive asymptomatic individuals, three patients with AIDS-related complex, and four patients with AIDS. Fifteen isolates were from zidovudine-untreated individuals, whereas seven isolates were obtained after 24 to 104 weeks of therapy with zidovudine, alone or alternating with zalcitabine. Mean zidovudine 50% inhibitory concentrations (IC50s) were 126 nM (range, 1 to 607 nM) for isolates from zidovudine-untreated individuals and 2,498 nM (range, 14 to 6,497 nM) for strains from patients treated with antiretroviral agents. Mean alpha CD4-PAP IC50s were 48 x 10(-3) nM (range, 0.02 x 10(-3) to 212 x 10(-3) nM) for isolates from zidovudine-untreated individuals, and 16 x 10(-3) nM (range, 2 x 10(-3) to 28 x 10(-3) nM) for isolates from treated patients. Overall, higher concentrations of alpha CD4-PAP were necessary to inhibit HIV-1 strains from untreated individuals at more advanced stages of disease. Seventeen isolates were susceptible to zidovudine (mean IC50, 117 nM), and five were resistant to zidovudine (mean IC50, 3,724 nM). Mean alpha CD4-PAP IC50s were 43 x 10(-3) nM for zidovudine-susceptible isolates and 19 x 10(-3) nM for isolates resistant to zidovudine. All HIV-1 strains had IC50s greater than 0.5 nM for unconjugated PAP, the alpha CD19-PAP immunoconjugate, and monoclonal antibody alpha CD4. At concentrations as high as 5,000 nM, alphaCD4-PAP did not inhibit colony formation by normal bone marrow progenitor cells(BFU-E, CFU-GM , and CFU-GEMM) or myeloid cell lines (KG-1 and HL-60) and did not decrease cell viabilities of T-cell (Jurkat) or B-cell (FL-112 and Raji) precursor lines. Overall, alphaCD4-PAP demonstrated more potent anti-HIV-1 activity than zidovudine and inhibited replication of zidovudine-susceptible and zidovudine-resistant viruses at concentrations that were not toxic to lymphohematopoietic cell populations.

Detection of human immunodeficiency virus type 1 in semen: effects of disease stage and nucleoside therapy

The effects of clinical stage of infection and antiviral therapy on the detection of human immunodeficiency virus type 1 (HIV-1) nucleic acids in semen were investigated by the polymerase chain reaction. HIV-1 was detected in 45 (87%) of 52 semen specimens from 29 (81%) of 36 men. Seventeen (77%) of 22 stage II or III subjects and 12 (86%) of 14 stage IV subjects had positive specimens. The CD4+ lymphocyte count was not significantly different comparing subjects with positive and negative semen. Moreover, 6 (67%) of 9 untreated men had positive specimens compared with 23 (85%) of 27 men treated with zidovudine, 2',3'-dideoxyinosine, or both for a mean of 20 months. Thus, the detection of HIV-1 in semen was independent of both stage of infection and long-term treatment. In a semiquantitative analysis of 6 men followed for 8 weeks after the start of nucleoside therapy, a decrease in HIV-1 RNA in seminal plasma was demonstrated in 2.

Study of human immunodeficiency virus resistance to 2'-3'-dideoxyinosine and zidovudine in sequential isolates from pediatric patients on long-term therapy

Resistance to zidovudine (3'-azido-3'-deoxythymidine) and 2',3'-dideoxyinosine (ddI) has been reported for human immunodeficiency virus (HIV) isolates from adults, but little is known about these drugs in children. A new micrococulture assay was developed for evaluation of drug susceptibility using single-passage HIV isolates cocultured with peripheral blood mononuclear cells from healthy donors. HIV isolates from children treated with zidovudine or ddI were evaluated to define the emergence of resistance to these antiretroviral agents. Four patients were treated with ddI and 3 with zidovudine for > 15 months. There was a > or = 20-fold decrease in susceptibility to ddI for sequential isolates of HIV recovered from 4 patients treated with ddI for 22-31 months and a 4- to 10-fold decrease in susceptibility to zidovudine in 3 patients. HIV isolates from 3 patients treated with ddI or zidovudine alone showed a minor amount of cross-resistance to the other antiretroviral agent. Results indicate the importance of monitoring antiretroviral drug susceptibility of HIV isolates when assessing clinical deterioration in children treated for > 1 year.

Immunologic and viral markers in the circulation of anti-HIV negative heroin addicts

To assess the degree of immune system activation associated with addiction or hepatotropic viruses infection, we examined 60 HIV-negative heroin addicts for the presence of hepatitis B virus (HBV) infection markers, hepatitis C virus antibodies (anti-HCV), various auto-antibodies, and serum levels of soluble interleukin-2 receptors (sIL-2R). In addition, 28 anti-HCV positive patients comprising the disease control group, were also examined. Our results demonstrated a high prevalence of anti-HCV antibodies (61.7% and 90% with 1st and 2nd generation ELISA, respectively). Eighty-seven percent (87%) of the addicts positive for anti-HCV by the latter and 92.8% of the disease control patients, were also positive with 2nd generation recombinant immunoblot assay (RIBA-II). In 88.9% of anti-HCV positive addicts, antibody to C22-3 was the predominant (anti-C33c in 81.5%). Antibodies to C33c and C22-3 polypeptides were also more frequent in disease control group (92.8% and 85.7%, respectively). Anti-HCV antibodies were associated with increased transaminases (ALT or AST, P < 0.05), as well as with longer duration of addiction (P < 0.005). HBV infection markers (HBsAg, anti-HBc only and anti-HBs) were also present in the addicts (5%, 28.3% and 26.7%, respectively). Rheumatoid factors (RF) were detected in 36.7%, antinuclear antibodies (ANA) in 11.7%, antibodies (IgG and/or IgM) against cardiolipin (anti-CL) and double stranded DNA (anti-ds DNA) in 20% and 50%, respectively. RF, ANA, anti-CL and anti-dsDNA antibodies were also detected in the disease control group (32.1%, 89.3%, 28.5% and 28.5% respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Massive covert infection of helper T lymphocytes and macrophages by HIV during the incubation period of AIDS

Animal and human lentiviruses elude host defences by establishing covert infections and eventually cause disease through cumulative losses of cells that die with activation of viral gene expression. We used polymerase chain reaction in situ double-label methods to determine how many CD4+ lymphocytes are latently infected by human immunodeficiency virus (HIV) in patient lymph nodes and whether the pool of infected cells is large enough to account for immune depletion through continual activation of viral gene expression and attrition of cells responding to antigens. We discovered an extraordinarily large number of latently infected CD4+ lymphocytes and macrophages throughout the lymphoid system from early to late stages of infection, and confirmed the extracellular association of HIV with follicular dendritic cells. Follicular dendritic cells may transmit infection to cells as they migrate through lymphoid follicles. Latently infected lymphocytes and macrophages constitute an intracellular reservoir large enough ultimately to contribute to much of the immune depletion in AIDS, and represent a difficult problem that must be resolved in developing effective treatments and protective vaccine.

HIV infection is active and progressive in lymphoid tissue during the clinically latent stage of disease

Primary infection with the human immunodeficiency virus (HIV) is generally followed by a burst of viraemia with or without clinical symptoms. This in turn is followed by a prolonged period of clinical latency. During this period there is little, if any, detectable viraemia, the numbers of infected cells in the blood are very low, and it is extremely difficult to demonstrate virus expression in these cells. We have analysed viral burden and levels of virus replication simultaneously in the blood and lymphoid organs of the same individuals at various stages of HIV disease. Here we report that in early-stage disease there is a dichotomy between the levels of viral burden and virus replication in peripheral blood versus lymphoid organs. HIV disease is active in the lymphoid tissue throughout the period of clinical latency, even at times when minimal viral activity is demonstrated in blood.

Fusion of human B cell lines with HIV-1 envelope-expressing T cells is enhanced by antigen-specific Ig receptors. Possible mechanism for elimination of gp120-specific B cells in vivo

The possible contribution of Ag-specific Ig receptors on B cells to syncytium formation with HIV-1 envelope (env)-expressing cells was examined. A unique model system was designed that used anti-TNP/TNP interactions between a panel of TNP-specific human B cell lines and TNP-haptenated HIV-1 env-expressing T cells. The prototype B cell line 1:13 (CD4dull) produced few syncytia with vaccinia gp120/41-infected CD4- T cell effectors. However, TNP-haptenation of the HIV-1 env-expressing cells resulted in a five- to 10-fold increase in syncytium formation. The "enhanced" syncytia were blocked by OKT4A mAb, soluble CD4, anti-TNP serum, and TNP-BSA, suggesting a role for both CD4 and Ig receptors. In contrast, the number of syncytia formed between CD4+ CEM T cells and TNP-haptenated effectors was reduced by 30 to 40%, compared with the unhaptenated effectors, suggesting that a fraction of the TNP haptens bound close to the CD4 binding regions on the gp120 envelope, which was confirmed by other experiments. The possibility that B cells specific for the CD4 binding site on HIV-1 gp120 may be involved in syncytium formation with HIV-1 env-expressing cells was tested by screening a panel of five hybrid B cell lines from HIV-1-seropositive individuals. One of these lines produced anti-gp120 antibodies, which bound near the CD4 binding site, and also formed syncytia with HIV-1 env-expressing cells. This study suggests that, in addition to CD4 receptors, certain B cell Ig receptors that bind to gp120 may induce conformational changes leading to cell fusion and their elimination.

Transfusion-associated transmission of human T-lymphotropic virus types I and II: experience of a regional blood center

During a 22-month period, 78,000 blood donors were screened for human T-lymphotropic virus types I and II (HTLV-I/II) at Belle Bonfils Memorial Blood Center (Denver, Colorado). Positive donors and the living recipients of their previously donated blood components were evaluated for risk factors and symptoms related to HTLV-I infection, were screened by enzyme immunoassay, confirmed by Western blot for HTLV-I/II, and subsequently tested by polymerase chain reaction and peptide enzyme immunoassay to distinguish between HTLV-I and -II infection. Six seropositive blood donors (0.008%) were identified; four were typed as having HTLV-I infection and two as having HTLV-II. Of 18 living recipients of components from seropositive donors, none had risk factors for HTLV-I infection prior to transfusion and none had signs or symptoms of HTLV-I infection at follow-up. The mean time from transfusion to testing was 6.4 years. Seven recipients of HTLV-I-infected components were HTLV seropositive; all were typed as having HTLV-I. A possible case of posttransfusion HTLV-I-associated myelopathy was identified in one patient who died before complete evaluation. One possible case of transfusion-associated HTLV-II was identified. These data further support the continued screening of blood donors for HTLV-I/II.

Some characteristics of hospitalized HIV seropositive patients in Myanmar

Twenty-two hospitalized HIV seropositive patients were studied prospectively between July 1991 and January 1992. The majority of the patients were intravenous drug users (IVDUs). Their age ranged from 20 to 38 years with a male preponderance of 12 to 1. Anemia, lymphopenia and thrombocytopenia were observed in 100%, 36% and 41%, respectively. The common pathogens like malaria parasites, Mycobacterium tuberculosis, Entamoeba histolytica, Streptococcus and Salmonella were isolated/identified rather than opportunistic organisms.

Comparative study of the isolation of human immunodeficiency virus from the lung and peripheral blood of AIDS patients

HIV-1 proviral DNA was detected by the polymerase chain reaction (PCR) in leucocytes from the peripheral blood (PBL) and bronchoalveolar lavage (BAL) of 100% and 72%, respectively, of HIV-1 seropositive patients. Infective virus isolated by cocultivation was recovered from the PBL and BAL of 50% and 59% of individuals, respectively. Isolation of HIV-1 was more readily made from the lung of individuals undergoing Pneumocystis carinii pneumonia (PCP) than from patients with non-PCP lung infections. The concomitant infection of lung cells with cytomegalovirus did not affect the isolation rate of HIV-1 from the lung. HIV-1 was isolated from BAL of 23 out of 36 (64%) individuals receiving no antiviral chemotherapy and from 13 out of 24 (54%) patients who were receiving AZT.

Nonradioactive, colorimetric microplate hybridization assay for detecting amplified human immunodeficiency virus DNA

A nonradioactive, colorimetric microplate hybridization procedure was used to assay human immunodeficiency virus (HIV) DNA, amplified by the polymerase chain reaction (PCR). Under the PCR conditions used, four proviral copies per 150,000 cells were detected by amplifying a series of DNA mixtures that contained various copy numbers of HIV. Assays of PCR-amplified DNA from peripheral blood mononuclear cells of seronegative individuals yielded negative results (104 of 104), whereas samples from seropositive individuals yielded > 99% positive results (141 of 142). Similar results were obtained in a chemiluminescent assay with an acridinium ester-labeled probe and in a solution hybridization assay in which a 32P-labeled probe was used.

Human immunodeficiency virus type 1 nucleic acids detected before p24 antigenemia in a blood donor

A blood donation from a 46-year-old homosexual man was discarded because of elevated alanine aminotransferase levels. Thirteen days later, the patient presented with symptomatic primary human immunodeficiency virus type 1 (HIV-1) infection. Virologic investigations were performed retrospectively on blood samples (including the donated blood) obtained before the symptoms. The HIV-1 genome was present, either integrated in mononuclear cell DNA or circulating in plasma, 39 days before the appearance of p24 antigen and 65 days before the appearance of HIV-1 or HIV type 2 antibody. It is concluded that p24 antigenemia is present during only a fraction of the seronegative "window" period. This case illustrates the risk of infection associated with blood transfusion in spite of HIV-1 antibody testing and stresses the need to improve nontechnical exclusion procedures as well as non-antibody-based diagnostic tests.

Development of a selective and sensitive polymerase chain reaction assay for the detection of Mycoplasma pirum

A new assay using the polymerase chain reaction to amplify a 173-nucleotide DNA fragment within the 16S ribosomal RNA gene of Mycoplasma pirum has been developed. The assay selectively amplified DNA from all strains of M. pirum tested with a high level of sensitivity, even in a context of human DNA. DNA from other mollicute species, including those closely related to M. pirum, from bacteria phylogenetically close to mollicutes (Clostridium innocuum, C. ramosum and Bacillus subtilis), from Escherichia coli and from human peripheral blood mononuclear cells, did not produce the amplified DNA product specific for M. pirum.

Human T-cell lymphotropic virus type I and II DNA amplification in seropositive and seronegative at-risk individuals

To determine the presence or the absence of human T-lymphotropic virus type I and/or II (HTLV-I/II) DNA in at-risk individuals who were persistently negative for specific serologic assays, polymerase chain reaction with two primer pairs in common and conserved regions of HTLV-I and -II genomes was used. Seronegative individuals at risk for HTLV-I/II infection (15 heterosexual partners of seropositive individuals, 17 breastfed children born to HTLV-I-infected mothers, 47 multiply transfused patients, 22 intravenous drug users) were studied (n = 101); 35 seropositive individuals and 25 seronegative low-risk individuals were used as positive and negative controls, respectively. No positive polymerase chain reaction was observed in the seronegative at-risk individuals or in the negative controls. Positive controls gave positive results with at least one primer pair in all cases except one. A latent HTLV-I/II infection with a persistently negative serologic test for HTLV-I/II seems unlikely.

Differential requirements for HIV-1 replication in naive and memory CD4 T cells from asymptomatic HIV-1 seropositive carriers and AIDS patients

One of the major routes for modulating HIV-1 expression by infected T cells is through the control of transcription initiation from the HIV-1 long terminal repeat (LTR), which is regulated either by its own viral gene products or by several cellular DNA-binding proteins induced during T cell activation. Previous work reported preferential HIV-1 infection and replication of memory CD4 T cells from infected individuals, which was explained either by a higher viral burden of this subset or by differences between naive and memory cells in the activation of the general transcription machinery involved in HIV-1 replication. In this work, we have studied HIV-1 replication by highly purified naive and memory CD4 T cells from asymptomatic seropositive carriers (ASC) and AIDS patients following different activation signals. Our results demonstrate that viral replication in memory cells from ASC was observed after mitogenic (phytohaemagglutinin (PHA) and/or phorbol myristate acetate (PMA)) recombinant tumour necrosis factor-alpha (rTNF-alpha) and CD3-mediated activation. In contrast, in naive subsets, early viral replication was almost exclusively observed upon CD3-mediated activation. AIDS patients are characterized by similar levels of viral replication in both subsets after PHA and soluble or immobilized anti-CD3 MoAb activation. However, naive subsets from AIDS patients still displayed differential requirements since they failed to replicate HIV-1 after treatment with PMA and rTNF-alpha. Taken together, these results provide evidence that HIV-1 replication in CD4+ T cells from infected individuals is a function of the differentiation stage of the cells, the disease stage of the patient and the activation signal employed.

Mycoplasma fermentans in individuals seropositive and seronegative for HIV-1

Mycoplasmas have been suggested as a co-factor to explain various puzzling features of infection by human immunodeficiency virus 1 (HIV-1). We sought Mycoplasma fermentans by means of a semi-nested polymerase chain reaction (PCR) in samples of peripheral-blood mononuclear cells (PBMC), throat swabs, and urine samples from 117 HIV-seropositive patients (of whom 114 were homosexual men). M fermentans was detected in 12 (10%) PBMC samples, 15 (23%) of 65 throat samples, and 4 (8%) of 55 urine samples from the seropositive subjects. The organism was detected in similar proportions among 73 HIV-seronegative patients recruited from a sexually transmitted diseases clinic (9%, 20%, and 6%, respectively); again, most of the men (40 of 50) in this group were homosexual. We found no association between infection by the mycoplasma and stage of disease, CD4 count, or HIV-1 load. These findings do not, however, eliminate the possibility that the mycoplasmal infection could affect the speed of disease progression.

Isolation of human immunodeficiency virus from peritoneal dialysate

Human immunodeficiency virus (HIV)-seropositive individuals represent a growing population of peritoneal dialysis (PD) patients. An important health care issue in these patients is the potential for their PD fluid to transmit virus. Some body fluids, such as urine, have been demonstrated to be negative for HIV and therefore presumably to be of low risk for virus transmission. To determine whether HIV could be recovered from PD fluid, we cultured the PD fluid from two asymptomatic HIV-seropositive patients and one patient with the acquired immunodeficiency syndrome (AIDS). HIV was isolated from both the PD fluid and the blood of two of the three patients tested, one being only HIV-seropositive and one with AIDS. These findings indicate that such fluid could potentially be a source of viral transmission and emphasize the need for conscientious application of universal precautions both in and out of the hospital.

Occupational blood exposure among health care workers: II. Exposure mechanisms and universal precautions

We investigated mechanisms of mucocutaneous exposure (MCE) and percutaneous exposure (PCE) to blood, and compliance with protective barriers among all former and presently employed medical staff at a Danish Department of Infectious Diseases. All subjects were asked to complete an anonymous questionnaire. 135 out of 168 (80%) subjects responded. 37 incidents of PCE and 15 MCE were described. More than 50% of PCE had occurred without obvious explanation during medical procedures, or were caused by unexpected patient movement, while only 1 PCE was caused by recapping. 35% of PCE occurred during drawing of venous blood samples. Compliance with usage of gloves was high (70-100%), depending on the procedure, and 72% of the subjects claimed to have sufficient knowledge of the risk of blood exposure and how to prevent it. Yet 11 (73%) out of 15 MCE might have been prevented by appropriate use of protective barriers. To further reduce the frequency of blood exposure, the development of safer instruments and unceasing education in safer technique and use of protective barriers are of major importance.

Quantitation of zidovudine-resistant human immunodeficiency virus type 1 in the blood of treated and untreated patients

A nonselective ex vivo assay was used to directly detect and quantify zidovudine (AZT)-resistant human immunodeficiency virus type 1 (HIV-1) in the blood of treated and untreated patients. In contrast to previous reports, drug-resistant virus was detected in peripheral blood mononuclear cells of a few of the patients who had never received AZT. The AZT resistance of HIV-1 isolates from one untreated individual was confirmed by further susceptibility studies in vitro and by the finding of a characteristic mutation (Lys-->Arg at codon 70) in the reverse transcriptase. In patients who were clinically stable while on AZT, HIV-1 titers in plasma and mononuclear cells were generally low but resistant viruses already predominated. In those individuals who were deteriorating despite AZT administration, high levels of viremia were observed, and the resistance phenotype was nearly universal. These findings serve to emphasize the magnitude of the AZT-resistance problem in patients on drug treatment.

Detection of human immunodeficiency virus type 1 (HIV-1) proviral DNA in breast milk and colostrum of seropositive mothers

There is increasing evidence of vertical transmission of HIV-1 to infants through breast feeding of milk from HIV-1 infected mothers. It has been postulated that transmission occurs mainly via ingestion of infected cells in breast milk and colostrum. In this study, detection of HIV-1 proviral DNA was used to prove that cells from colostrum and milk do contain HIV. DNA were extracted from these cells of colostrum and milk of 18 seropositive mothers and amplified by nested PCR for HIV-1 gag and pol and 44 per cent were positive mostly by two primers. All ten negative control samples from seronegative mothers were negative. This study demonstrated the infectivity of breast milk and colostrum. Nevertheless, recommendation against breast-feeding should be weighed against poor alternatives in low socioeconomic families.

Periodontal microflora of HIV positive subjects with gingivitis or adult periodontitis

The subgingival microflora of 39 HIV+ subjects with gingivitis or adult periodontitis was cultured quantitatively anaerobically for bacteria, spirochetes, and mycoplasma and aerobically for yeasts. Isolates were characterized by conventional biochemical tests, polyacrylamide gel electrophoresis of soluble proteins, cellular fatty acid profiles, immunofluorescence, and immunodiffusion. In general, the same types of bacteria were isolated from the subgingival crevice of HIV+ subjects as we previously had isolated from the subgingival crevice of non-HIV subjects. A statistically significant difference was found between the composition of the flora of HIV+ subjects with adult periodontitis (AP) and concurrent studies of a non-HIV+ AP population. Mycoplasma salivarium was significantly elevated in the HIV+ subjects examined. Yeasts were isolated from only 10% of the samples and from 13% of the HIV-positive subjects at 0.05 to 0.0002% of the total cultivable count when present.

Analysis of human immunodeficiency virus-infected tissues by amplification and in situ hybridization reveals latent and permissive infections at single-cell resolution

Latent and productive viral infections are at the extremes of the spectrum of virus-cell interactions that are thought to play a major role in the ability of such important human pathogens as human immunodeficiency virus (HIV) to elude host defenses and cause disease. The recent development of PCR-based methods to amplify target sequences in individual cells in routinely fixed tissues affords opportunities to directly examine the subtle and covert virus-cell relationships at the latent end of the spectrum that are inaccessible to analysis by conventional in situ hybridization techniques. We have now used PCR in situ with in situ hybridization to document latent and permissive HIV infection in routinely fixed and paraffin-embedded tissue. In one of the first specimens we examined, a tumor biopsy from an HIV-infected individual, we found many of the lymphocytes and lymphocytes infiltrating the tumor had HIV DNA that was detectable only by PCR in situ. The fraction of positive cells varied regionally, but there were foci where most of the cells contained HIV DNA. Most of these lymphocytes and macrophages are latently infected, as we could detect HIV RNA in fewer than one in a thousand of these cells. We also detected HIV RNA, surprisingly, in 6% of the tumor cells, where the number of copies of viral RNA per cell was equivalent to productively infected cell lines. The alternative states of HIV-gene expression and high local concentration of latently infected lymphocytes and monocytes revealed by these studies conceptually supports models of lentiviral pathogenesis that attribute persistence to the reservoir of latently infected cells and disease to the consequences of viral-gene expression in this population. The magnitude of infection of lymphocytes documented in this report is also consistent with the emerging view that HIV infection per se could contribute substantially to depletion of immune cells in AIDS.

[Non-radioisotopic reverse transcriptase assay using biotin-11-deoxyuridine-triphosphate and a primer-immobilized microtiter plate: application for detection and identification of isolated retroviruses from HIV-1-seropositive hemophiliac patients]

Non-radioisotopic reverse transcriptase assay (Non-RTA) was successfully applied for detection and identification of the retroviruses isolated from peripheral mononuclear cells from eight HIV-1-seropositive hemophiliac patients. Of 40 samples, 36 (90%) were consistent in detection between Non-RI and RI RTA. Four samples which showed RT activities slightly above the cutoff level of RI RTA were not detected by Non-RI RTA. Non-specific RT-inhibitors in the culture supernatant decreased the sensitivity of Non-RI RTA more significantly than that of RI RTA. It was demonstrated that higher concentrations (> 20%) of fetal calf serum in RPMI-1640 culture medium inhibited the hybridization of poly rA template with immobilized primer, resulting in reducing the sensitivity of Non-RI RTA. Then we identified the isolated retroviruses using specific RT-inhibiting (RTI) antibodies against HIV-1 and HIV-2. HIV-1 RTI antibody specifically inhibited RTs of isolated retroviruses and HIV-1 strain, LAV-1, but not HIV-2 and Rous-associated virus 2 (RVA-2) RT. Conversely, HIV-2 RTI antibody specifically inhibited HIV-2 RT, but not HIV-1 and RAV-2 RT. These findings agreed with previously reported results showing the type-specificity of HIV-1 and -2 RTI antibodies, and suggest the possibility that isolated retroviruses could be identified by these antibodies.

Occupational blood exposure among health care workers: I. Frequency and reporting

The frequency and reporting rate concerning occupational blood exposure were investigated among former and currently employed medical staff at a Department of Infectious Diseases (DID) having a high prevalence of HIV-positive patients. Subjects were asked to complete an anonymous questionnaire describing occupational percutaneous exposure (PCE) and mucocutaneous exposure (MCE) to blood, experienced during their employment at the DID. 135 out of 168 (80%) subjects responded. 45 subjects described 37 incidents of PCE and 15 of MCE. 44 of the exposures (85%) involved HIV-positive blood and 6 (11.5%) involved blood from a patient with hepatitis B. Annual incidence rates of PCE and MCE were: for A) interns and residents, 0.51 PCE/year and 0.17 MCE/year; B) for senior residents and senior physicians, 0.13 PCE/year and 0.21 MCE/year; C) for registered nurses, 0.11 PCE/year and 0.03 MCE/year; D) for auxiliary nurses, 0.09 PCE/year and 0.11 MCE/year. 35% of PCE and 87% of MCE were not reported to the security representative, the major reason being that the subject felt it to be unnecessary. We conclude that medical employment, especially as interns and residents at clinics for infectious diseases, carries a real and serious risk of contracting infectious diseases due to occupational exposure to blood. The importance of reporting needs to be emphasized.

Extrachromosomal human immunodeficiency virus type 1 DNA forms in fresh peripheral blood lymphocytes and in two interleukin-2-independent T cell lines derived from peripheral blood lymphocytes of an asymptomatic seropositive subject

Two immature T cell lines (FT1 and FT4) were established after in vitro cloning of peripheral blood lymphocytes (PBLs) from an asymptomatic human immunodeficiency virus type 1 (HIV-1) seropositive, human T cell-lymphotropic virus type 1 seronegative homosexual subject. Although derived from a limiting dilution cell cloning assay, these cell lines were not recloned for this study. Their growth was independent of exogenous interleukin-2. Both cell lines were able to form colonies when cloned in agar, but failed to form solid tumours when injected into nude mice. FT lines belong to the very immature T cell lineage as they exhibit rearranged TCR genes but no expression of T cell membrane antigens, including CD2, CD3, CD4, CD6, CD7 and CD8. They also contain an HIV-1 genome that was detected only in an extra-chromosomal DNA form, even after several passages in vitro. The presence of unintegrated viral DNA was also detected by polymerase chain reaction analysis in the same sample of fresh uncultured PBLs. Furthermore, despite the absence of CD4 expression, both T cell lines were susceptible to CD4-independent HIV-1 superinfection (lack of superinfection inhibition in the presence of OKT4A monoclonal antibodies).

A new approach to estimating AIDS incubation times: results in homosexual infected men

STUDY OBJECTIVE

The aim was to develop a new approach for estimating the incubation period of acquired immunodeficiency syndrome (AIDS), based on age distributions.

DESIGN

Incubation period was expressed as the difference between age at time of diagnosis and age at time of contamination. Assuming independence between age at time of infection and incubation period, the age distribution of newly diagnosed AIDS cases is thus the convolution product between the distributions of the age of freshly infected patients and of the incubation times. AIDS incubation time can therefore be estimated from the age distribution of newly HIV infected subjects and newly diagnosed AIDS cases.

SUBJECTS

Subjects were 2220 AIDS cases diagnosed until 1987, reported to the Ministry of Health, France, and 172 subjects discovered to be HIV-1 seropositive during a blood donation in Paris between August 1985 and July 1988. In both groups, the only known risk factor was homosexuality.

MAIN RESULTS

The estimated median incubation time was 9.9 years (90% CI 9.0-10.9 years). Confidence intervals were narrow, even when taking into account the uncertainty in serodetection delay (90% CI 6.7-13.5 years).

CONCLUSIONS

The incubation estimate is as accurate as previous estimates based on other models. This technique could therefore be applied to other risk groups.

Detection of HIV-1 infections by PCR: evaluation in a seropositive subject population

To study the polymerase chain reaction (PCR) performance in detecting human immunodeficiency virus (HIV) infections, we tested 53 HIV-1 seropositive patients and 29 HIV-1 seronegative subjects for four different HIV-1 DNA regions. Fifty-one seropositive patients were found positive by PCR with at least one primer pair, but two were repeatedly negative for all primers. Weekly blood samples from 12 seropositive subjects all detected positive for at least one primer pair, but for three patients an irregular primer detection pattern was found. One additional HIV-1 seropositive sample, found negative for HIV DNA, was also negative for the beta-globin PCR control. The 29 seronegative specimens were HIV-1 DNA negative, as was a HIV-2 seropositive patient. This study demonstrates that PCR is almost as good as serological tests for detecting HIV infections, with a specificity of 100% and a sensitivity of 96% and that resampling the patients may improve detection performance.

[Detection of the HIV p24 antigen on lymphocyte membranes using flow cytometry]

The evaluation of the presence of p24 antigen on the membrane of peripheral blood mononuclear cells from 31 HIV infected individuals is presented. The study was performed by indirect immunofluorescence and flow cytometry and the data were analyzed by the Kolmogorov-Smirnov test. Values obtained [D/s(n)] result from the comparison of the fluorescence histograms of each sample with a control one. Cases showing p24 Ag on peripheral blood mononuclear cells also presented percentages of CD3, HLA-DR positive cells significantly higher than p24 negative ones. In addition, D/s(n) values were superior in symptomatic patients than in asymptomatic ones, which indicate the existence of a correlation between flow cytometry results, viral replication and clinical course. Nevertheless in this study, as well and in previous ones, a high degree of cross reactivity between the anti-p24 monoclonal antibody employed and normal lymphocytes has been observed. This reactivity is localized preferentially in the CD4 positive subset.

Molecular profile of human immunodeficiency virus type 1 infection in symptomless patients and in patients with AIDS

Recent molecular evidence indicates that active human immunodeficiency virus type 1 (HIV-1) infection is detectable in both symptomless and symptomatic infected patients. For this main reason, it has been pointed out that precise quantitative analysis of viral activity in vivo is necessary, firstly, for the pathogenetic investigation of the steps relevant to infection progression and, secondly, for better clinical management of HIV-1-infected patients. In this study, the presence of HIV-1 genomic RNA in plasma samples, specific HIV-1 transcripts in peripheral blood mononuclear cells, and proviral DNA sequences were assayed for 33 HIV-1-infected patients (including symptomless and symptomatic subjects) by using a competitive polymerase chain reaction method that allows quantitation of the RNA/DNA target sequences. The quantitative results obtained confirm that transcription of HIV-1 structural genes and complete viral replication occur in all the HIV-1-infected patients independently of the clinical stage. However, although sharp individual differences were detected, a high degree of correlation of the molecular parameters studied with both disease progression and a decrease in the number of CD4+ T lymphocytes was documented. Interestingly, despite the increasing viremia level associated with infection progression, the mean transcriptional activity of individual infected cells was found to be only moderately greater in AIDS patients than in asymptomatic infected subjects. In addition, it was noted that quantitation of HIV-1 genomic RNA in plasma samples and quantitation of specific HIV-1 transcripts in peripheral blood mononuclear cells appear to be more reliable and sensitive markers of viral activity than quantitative analysis of proviral HIV-1 sequences in peripheral lymphocytes.