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Biomedical subjects

N Lapointe

Publications and source records attributed to N Lapointe.

At least 37 records · Page 2Linked to original sources
PubMed1998

Sexual behavior and pregnancy outcome in HIV-infected women. Canadian Women's HIV Study Group.

Sexual behavior and pregnancy outcome data for 392 HIV-infected women were analyzed. During the 6 months before study entry, 71.2% (279 of 392 women) were sexually active. In multivariate regression, women with baseline CD4+ > or = 200/microl were more likely than women with CD4+ < 200/microl to be sexually active (adjusted odds ratio [OR] = 1.75; 95% confidence interval [CI], 1.06-2.88; p = .03). Consistent condom use was reported with 58.4% (149 of 255) of steady male partners and 65.7% (23 of 35) of casual partners. Overall, 90.3% of 279 sexually active women were using contraception. Among women aged between 15 and 44 years (n = 320), the incidence of pregnancy in the year before HIV diagnosis was 27.5 per 100 person-years (PY) (95% CI, 22.1-33.9) compared with 8.3/100 PY (95% CI, 6.8-10.2) in the time since HIV diagnosis (p < .001). The incidence of therapeutic termination of pregnancies conceived in the 20 weeks before HIV diagnosis (10.6/100 PY) was more than triple that after diagnosis (3.1/100 PY; p = .001). After publication of results of zidovudine prophylaxis of mother-to-child transmission, pregnancy rates did not increase, but the incidence of therapeutic abortion dropped from 4.3/100 PY to 1.4/100 PY (p = .009). Knowledge of sexual behavior, including pregnancy frequency and outcome, can assist in tailoring counseling for HIV-infected women concerning sexual and reproductive health.

Abortion, Therapeutic↗
PubMed1998

Natural history of Epstein-Barr virus infection in a prospective pediatric cohort born to human immunodeficiency virus-infected mothers.

To determine whether Epstein-Barr virus (EBV) constitutes a contributing factor in AIDS and, conversely, whether the human immunodeficiency virus (HIV) alters the course of primary EBV infection in a pediatric population, 62 children born to HIV-infected mothers and prospectively followed were evaluated. EBV infection was documented by EBV-specific serology and polymerase chain reaction and by clinical history. HIV infection status was determined according to the Centers for Disease Control and Prevention pediatric classification system. Demographics from HIV-infected and HIV-uninfected children were comparable. The data suggest that HIV-infected children may acquire primary EBV infection earlier in life. The incidence of accompanying splenomegaly or hepatomegaly (or both) around the time of EBV seroconversion was higher among HIV-infected children than among HIV-uninfected children. In contrast, HIV disease progression and HIV-1 RNA load did not seem to be influenced by primary EBV infection.

AIDS-Related Opportunistic Infections↗
PubMed1998

Antiribonucleoprotein antibodies in children with HIV infection: a comparative study with childhood-onset systemic lupus erythematosus.

A number of clinical and laboratory features of HIV infection are found in systemic lupus erythematosus (SLE). The objective of this study was to analyze the presence of circulating antibodies to small nuclear ribonucleoproteins (snRNP) in both diseases. Sera from 44 HIV-infected children, from 22 patients with childhood-onset SLE, and from 50 healthy children were studied. Anti-snRNP antibodies were detected by ELISA using recombinant and affinity-purified nuclear antigens, by counterimmunoelectrophoresis (CIE), and by immunoblotting using extractable nuclear antigens. Results included the detection of anti-snRNP antibodies by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE patients (86.3%). These antibodies were directed against U1-RNP (61.3% and 77.2%, respectively), Sm (29.5% and 54.5%, respectively), 60 kDa Ro/SS-A (47.7% and 50%, respectively), and La/SS-B proteins (18.1% and 9%, respectively). None of the HIV-infected children and 11 SLE patients (50%) showed anti-snRNP antibodies by CIE. None of the HIV-infected patients showed anti-70 kDa U1-RNP or anti-D-Sm antibodies by immunoblotting. No differences between the two groups were noted on the presence of nonprecipitating anti-snRNP antibodies. No such reactivities were observed among the normal sera tested. The authors concluded that nonprecipitating anti-snRNP antibodies in HIV-infected children are as frequent as in childhood-onset SLE. The significance of these antibodies is not clear at present. Although polyreactive and low-affinity antibodies and a mechanism of molecular mimicry may explain these results, a specific stimulation of B cells by nuclear antigens could not be excluded.

Adolescent↗
PubMed1998

Socioeconomic geographical links to human immunodeficiency virus seroprevalence among childbearing women in Montreal, 1989-1993.

BACKGROUND: To describe the socioeconomic profiles of geographical areas on Montreal Island in which human immunodeficiency virus (HIV) seropositive women delivering live births between 1989 and 1993 reside. METHODS: Leftover dried blood spot filter paper specimens collected from newborns were irretrievably unlinked from identifying information prior to testing. Seroprevalence estimates were calculated based on Western blot confirmed positive samples. Using data from the Canadian census, Revenue Canada, and provincial birth records, the socioeconomic characteristics of postal zones in which seropositive mothers reside were described. RESULTS: Montreal Island had an overall 5-year HIV seroprevalence rate estimate of 16.6 (95% CI: 14.1-19.3) per 10000 childbearing women. Areas in which at least one seropositive woman gave birth had lower mean infant birthweights and higher percentages of single mothers and single-parent families. The HIV-positive neonatal blood specimens were more likely to originate from areas where a higher proportion of residents reported less education, greater unemployment, and lower income. CONCLUSIONS: Higher HIV infection rates were found among childbearing women from lower socioeconomic areas of Montreal. Increased understanding of the relationship between socioeconomic status and HIV acquisition and transmission is required to inform the development of targeted HIV prevention programmes.

Adult↗
PubMed1997

Comparison between vaginal tampon and cervicovaginal lavage specimen collection for detection of human papillomavirus DNA by the polymerase chain reaction. The Canadian Women's HIV Study Group.

The aim of the study was to compare the accuracy of self-administered vaginal tampon (VT) specimens for the detection of human papillomaviruses (HPVs) with that of cervicovaginal lavage specimens (CVL). Two hundred seventy-four paired VT and CVL specimens were collected prospectively from women at risk of sexually transmitted diseases. Specimens were treated and amplified with the polymerase chain reaction (PCR). Each woman served as her own control. One hundred and forty-four of 272 (52.9%) CVLs and 159 of 271 (58.7%) VTs contained HPV DNA sequences (correlation of 88%). The sensitivity and specificity of vaginal tampons reached 93.9% (138/147) and 80.5% (99/123), respectively. HPV typing results were concordant for 99 negative paired samples and 114 paired samples positive for the same type(s) (correlation of 78.9%). It is concluded that these sampling methods collect cells from different areas of the genital epithelium, highlighting the importance of further assessment of the comparative predictive value of HPV detection in each sample.

Adult↗
PubMed1997

Evaluation of a non-isotopic polymerase chain reaction assay for detection in clinical specimens of herpes simplex virus type 2 DNA. Canadian Women's HIV Study Group.

BACKGROUND: PCR assays for detection of herpes simplex virus DNA sequences in clinical specimens are more sensitive than cell culture. OBJECTIVE: A non-isotopic PCR assay (glycoprotein B HSV-2 assay, Roche Molecular Systems) for detection of HSV-2 DNA sequences was evaluated on 234 clinical specimens. STUDY DESIGN: A total of 125 patients (73 women, 40 men, 12 unknown) provided 162 samples contained in viral transport medium. Samples were first inoculated in cell culture, centrifuged at 12,000 x g, lyzed and kept frozen. A total of 77 women provided 42 cervicovaginal lavages and 30 vaginal tampons that were lyzed, tested with two isotopic HSV-2 PCR assays and kept frozen. All these samples were subsequently thawed and amplified with the glycoprotein B HSV-2 assay using generic primers for HSV glycoprotein B gene. Amplicons were captured on microplates with a HSV-2-specific probe and were detected with avidin-peroxidase and substrate. RESULTS: Of the 162 samples submitted to viral culture, HSV-2 was isolated from 73 while 89 did not contain HSV-2. All the 73 specimens with culture-proven HSV-2 infections tested positive with glycoprotein B HSV-2 assay (sensitivity of 100%). Herpesviruses other than HSV-2 were isolated from 34 samples that were negative with glycoprotein B HSV-2 assay. Two culture-negative samples tested positive in the glycoprotein B HSV-2 assay (specificity of 98.7%). The latter samples could not be retested in confirmatory isotopic HSV-2 PCR tests. HSV-2 DNA sequences could also be detected directly in cervical lavages or vaginal tampons from 13 women with the glycoprotein B HSV-2 assay. CONCLUSION: Detection and typing of HSV-2 in clinical samples, including those collected in viral transport medium, can be accomplished with PCR assays using the AMPLICOR format.

Cervix Uteri↗
PubMed1997

Sexuality in Montreal women living with HIV.

The impact of learning a positive HIV test result on the sexuality of 161 women (47 injection drug users (IDU), 53 non-IDU women of Haitian or African origin (non-IDU-HA), and 61 non-IDU Caucasian women (non-IDU-C) was assessed using closed and open-ended questions. Self-reported CD4+ count correlated with any post-test (p = 0.001) and past month sexual activity (p = 0.007). After learning their HIV status, 110 women (68%) were sexually active, 48 (44%) of these within 1 month. After resuming sexual activity, 84% underwent a sexual adjustment period (median duration 8.5 months). IDU women were more likely to have frequent sex, be anorgasmic, and prefer sex less often. Consistent partner condom use was low in general (19% for IDU, 30% for non-IDU-HA, and 62% for non-IDU-C) and by partner type (new regular partner 58%, same regular partner 36%, casual partner 29%). Sexual satisfaction tended to decline post-test and then increase to higher than pre-test levels. Counselling focused on the safe and satisfying aspects of sex may assist women with HIV infection in sexual decision-making. Facilitating the access of IDU women with HIV infection to medically supervised drug provision and to detoxification and rehabilitation programmes can weaken the link between drug use and sex work.

Adolescent↗
PubMed1996

Antibody responses to two Epstein-Barr virus (EBV) nuclear antigens (EBNA-1 and EBNA-2) during EBV primary infection in children born to mothers infected with human immunodeficiency virus.

A variety of antibody response patterns to the latent Epstein-Barr nuclear antigen (EBNA) family have been described in different groups of subjects infected with Epstein-Barr virus (EBV). The purpose of this study was to characterize the immune response to two EBNA proteins, EBNA-1 and EBNA-2, in a population of children who were born to mothers infected with HIV and who underwent EBV seroconversion. Serial serum specimens from 33 children (nine were infected with HIV, and 24 were not infected) were evaluated for the presence of antibodies to EBNA-1 and EBNA-2 by anticomplement immunofluorescence. All the EBNA serology profiles observed for children in our study who were not infected with HIV were consistent with those described for immunocompetent hosts with acute EBV infection, i.e., development of antibodies to EBNA-1, often preceded by the appearance of a humoral immune response to EBNA-2. In contrast, following EBV primary infection in HIV-infected children, antibodies to EBNA-2 arose after antibodies to EBNA-1 and tended to persist. Further studies are needed to investigate the role of EBNA-2 serology as a prognostic marker in HIV-infected children.

Antibodies, Viral↗
PubMed1996

Detection of a transforming fragment of herpes simplex virus type 2 in clinical specimens by PCR. The Canadian Women's HIV Study Group.

A PCR assay for the sensitive detection of a transforming fragment of herpes simplex virus type 2 (HSV-2) was developed. Oligonucleotide primers were selected in Xho-2, a transforming region of the BglII N fragment of HSV-2. The assay reached a sensitivity endpoint of 10 copies of the Xho-2 subfragment and did not show cross-reactivity with other herpesviruses, including HSV-1. All 42 HSV-2 isolates scored positive in the assay. The Xho-2 PCR assay was evaluated with 216 clinical specimens and the results were compared with those of cell culture. The best protocol for processing specimens contained in viral transport medium included a centrifugation step followed by cell lysis. Of the 107 specimens positive for HSV-2 by culture, 105 were PCR positive (sensitivity, 98.1%). For one of the two falsely negative samples, beta-globin as well as sequences from the HSV-2 DNA polymerase gene could not be amplified. The other sample scored positive in both of these reactions but was indeterminate in duplicate tests by Xho-2 PCR. Two of 109 HSV-2 culture-negative specimens tested positive in the PCR assay (specificity, 98.2%). The latter two samples tested positive in a PCR test for the HSV-2 DNA polymerase gene. This novel tool was shown to be sensitive and specific for HSV-2 sequences and should allow for the investigation of the role of HSV-2 in genital cancers.

Adult↗
PubMed1996

Antiribonucleoprotein antibodies in children with human immunodeficiency virus infection: comparative study with childhood-onset systemic lupus erythematosus.

UNLABELLED: A number of clinical and laboratory features of human immunodeficiency virus (HIV) infection are found in systemic lupus erythematosus (SLE). OBJECTIVE: To analyze the presence of circulating antibodies to small nuclear ribonucleoproteins (snRNP) in both diseases. METHODS: We studied sera from 44 HIV-infected children, from 22 patients with childhood-onset SLE, and from 50 healthy children. Anti-snRNP antibodies were detected by (ELISA) using recombinant and affinity-purified nuclear antigens, by counterimmunoelectrophoresis (CIE), and by immunoblotting using extractable nuclear antigens. RESULTS: Anti-snRNP antibodies were detected by ELISA in 30 HIV-infected patients (68.1%) and 19 SLE patients (86.3%). These antibodies were directed against U1-RNP (61.3% and 77.2%), Sm (29.5% and 54.5%), 60kD-Ro/SS-A (47.7% and 50%), and La/SS-B proteins (18.1% and 9%), respectively. None of the HIV-infected children and 11 SLE patients (50%) showed anti-snRNP antibodies by CIE. None of the HIV-infected patients showed anti-70 kD U1-RNP or anti-D-Sm antibodies by immunoblotting. No differences between the two groups were noted relative to the presence of nonprecipitating anti-snRNP antibodies. No such reactivities were observed among the normal sera tested. CONCLUSIONS: Nonprecipitating anti-snRNP antibodies in HIV-infected children are as frequent as in childhood-onset SLE. The significance of these antibodies is not clear at present. Perhaps they are polyreactive and low-affinity antibodies and a mechanism of molecular mimicry may explain these results; however, we cannot exclude a specific stimulation of B-cells by nuclear antigens.

Adolescent↗
PubMed1994

Autoimmune phenomena in children with human immunodeficiency virus infection and acquired immunodeficiency syndrome.

We have studied sera from 44 children with Human Immunodeficiency Virus infection and Acquired Immunodeficiency Syndrome using immunoblotting, radioimmunoassay, enzymoimmunoassay and indirect immunofluorescence. We have detected a low incidence of antinuclear (2.9%), anti-reticulin (2.9%) and anti-smooth muscle (14.7%) antibodies by indirect immunofluorescence. By enzymoimmunoassay we have detected anti-dsDNA (20.5%) and anti-ENA [anti-nRNP (61.3%), anti-Sm (29.5%), anti-Ro (47.7%) and anti-La (18.1%)] antibodies. Tests for anti-dsDNA by radioimmunoassay were negative, suggesting the presence of low-avidity anti-DNA antibodies. By immunoblotting we have detected anti-C (nRNP) (33.3%), anti-BB' (Sm) (33.3%), anti-Ro (60 KD) (4.5%) and anti-La (11.3%) antibodies. The presence of anti-Ro antibodies was associated with progressive neurological disease. Long-term follow-up studies with larger numbers of patients are necessary to evaluate the clinical significance of the presence of anti-dsDNA and anti-ENA antibodies in children infected with Human Immunodeficiency Virus.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Rapid screening for early detection of mother-to-child transmission of human immunodeficiency virus type 1.

The testing of dried blood spots (DBSs) for the presence of human immunodeficiency type 1 (HIV-1) proviral DNA by PCR was first described in 1991. The technology has proven to be particularly valuable for resolving the infection status in HIV-1-indeterminate infants born to HIV-1-seropositive mothers. To broaden the applicability of DBS PCR, we adapted it to a standardized, commercially available microwell plate amplification and detection kit, Amplicor HIV-1, produced by Roche Diagnostic Systems. The microwell assay is rapid and easy to perform and uses equipment that is readily available in routine diagnostic laboratories. The high level of performance of the assay was demonstrated in 1,168 duplicate tests performed on 584 DBSs from 178 uninfected and 100 HIV-1-infected individuals, including 56 children with perinatally acquired HIV-1. Of 12 infants who were followed prospectively from birth, 3 (25%) were infected in utero (PCR positive at birth) and 9 (75%) were infected intrapartum (PCR negative, culture negative at birth). Overall, HIV-1 DNA was identified in 3 of 11 (27.3%) DBSs collected from infected infants during the first 4 days of life, 8 of 9 (88.9%) DBSs collected between 10 and 15 days postpartum, and 166 of 167 (99.4%) DBSs collected after 15 days of age. All 320 DBSs from uninfected children were PCR DNA negative. These findings indicate that use of the Roche microwell DBS PCR assay provides a powerful new approach for large-scale perinatal screening programs and population-based studies of vertical transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Anticardiolipin antibodies in pediatric patients with human immunodeficiency virus.

OBJECTIVE: To study the presence of IgG and IgM anticardiolipin antibodies (aCL) in children with human immunodeficiency virus (HIV) infection and to determine their prevalence and clinical significance. METHODS: We studied 34 children with HIV infection: 26 patients were classified P-2, and 8 were P-1 according to the Centers for Disease Control classification. HIV transmission was from mother to child in 33 cases. aCL were measured by ELISA: RESULTS: IgG aCL were found in 28 (82%) and IgM aCL in 7 (20%). No difference in frequency and levels was found between class P-2 (85%, mean 54.5 PL units) and class P-1 (75%, mean 50.3 PL units). aCL were not related to the duration of the infection, clinical stage of disease, or with events like opportunistic infections. Children from sexually infected or intravenous drug user mothers showed no differences. CONCLUSION: As in adults, aCL are commonly found in children with HIV infection. The significance of this finding is still unclear.

Antibodies, Anticardiolipin↗
PubMed1994

[Clinical and serologic course of patients with mixed connective tissue disease].

The so called mixed connective tissue disease (MCTD), continues to be a controversial entity, while some authors considered it a good characterized disease, others think that is an undifferentiated connective tissue disease. OBJECTIVE. To analyse the clinical and serological evolution of a group of patients diagnosed of MCTD, with particular consideration to the meaning of anti-nRNP and anti-Sm antibodies. METHOD. We have studied 20 patients diagnosed of MCTD and 112 with systemic lupus erythematosus (SLE). Anti-nRNP and anti-Sm antibodies were detected through counter immunoelectrophoresis, immunoblotting and ELISA. RESULTS. After an average time of evolution of 10 years, 70% (14/20) of the patients diagnosed of MCTD fulfill criteria for SLE (6 cases), scleroderma (6 cases) or polymyositis (2 cases). Anti-nRNP response is persistent, directed mainly against the 70 Kd and A-nRNP polypeptides and qualitatively higher in MCTD in SLE (absorbencies 2.64 vs 1.25. The immunoblotting test detected anti-Sm antibodies in 5 patients (25%) and ELISA test in 14 (70%). CONCLUSIONS. Clinical and serological evolution suggest that MCTD is an undifferentiated connective tissue disease. Anti-nRNP antibodies are characteristic, although anti-Sm antibodies can be detected with ELISA regardless whether on not patients fulfill SLE criteria.

Adolescent↗
PubMed1993

Ontogeny of the humoral immune response to human immunodeficiency virus type 1 in infants.

In a cohort of infants born to human immunodeficiency virus type 1 (HIV-1)-infected mothers, changes in the levels of HIV-1 specific antibodies were measured during the first year of life. In uninfected children, the level of antibodies to six HIV-1 antigens (gp120, p66, p41, p31, p24, and p17) decreased continuously until becoming negative. In contrast, rising levels of one or more specific antibodies were detected in 9 of 12 infected children at a median age of 6 months. At 1 year of age, 8 infants were still asymptomatic and classified as P-1. All had serologic profiles consistent with de novo specific antibody production. In contrast, among the 4 infants who had early disease (class P-2), 3 had no significant rise in antibody to HIV-1. These results indicate that poor immune response, which could result from early infection of the infant, is often associated with rapid clinical progression.

Cohort Studies↗