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Biomedical subjects

J C Wilber

Publications and source records attributed to J C Wilber.

12 recordsLinked to original sources
PubMed1992

Prevalence of hepatitis C virus RNA in organ donors positive for hepatitis C antibody and in the recipients of their organs.

BACKGROUND: There is a high prevalence of liver disease among the recipients of organs from donors with antibodies to hepatitis C virus (HCV). We undertook a study to determine the frequency of persistent HCV infection, as indicated by the presence of HCV RNA, among both cadaveric organ donors positive for antibodies to HCV (anti-HCV) and the recipients or organs from these donors. METHODS: Serum samples from donors and recipients were tested for HCV RNA with the reverse transcriptase polymerase chain reaction, with use of primers from the 5' untranslated region of the HCV genome, and for anti-HCV with the first-generation enzyme-linked immunosorbent assay (ELISA) and two second-generation tests. RESULTS: HCV RNA was detected in 9 of the 11 organ donors (82 percent) with a positive first-generation ELISA for anti-HCV. Among the organ recipients, the prevalence of HCV RNA increased after transplantation: 7 of 26 patients (27 percent) had positive samples before transplantation, as compared with 23 of 24 patients (96 percent) after transplantation (P less than 0.001). Among 13 recipients who were HCV RNA-negative before receiving organs from the nine HCV RNA-positive donors, HCV infection was detected in all 13 after transplantation, and anti-HCV developed in 8 (62 percent). On the basis of a positive test for HCV RNA, the maximal sensitivity of the three anti-HCV tests was 57 percent (positive in 4 of 7 patients with end-stage organ failure) before transplantation and 70 percent (positive in 16 of 23 patients) after transplantation. CONCLUSIONS: Nearly all the recipients of organs from anti-HCV-positive donors become infected with HCV. The current tests for anti-HCV antibodies underestimate the incidence of transmission and the prevalence of HCV infection among immunosuppressed organ recipients.

Base Sequence↗
PubMed1992

Impact of specimen handling and storage on detection of hepatitis C virus RNA.

Direct detection of hepatitis C virus (HCV) RNA in serum or plasma is useful for validating the performance of anti-HCV assays and for the discrimination of persons with persistent HCV infections from those with resolved infections. Quantitation of HCV RNA may also be useful for disease prognosis and therapeutic monitoring. Previous studies have reported detection of HCV RNA in 50 to 70 percent of blood donors who were positive on anti-HCV supplemental tests. There is concern that specimen processing and storage conditions might influence the stability, and hence the detectability, of HCV RNA. To address this concern, the rate of detection of HCV RNA by the polymerase chain reaction (PCR) using donor pilot tube sera (PTS) previously subjected to routine donor screening and supplemental testing was compared with HCV PCR results obtained with fresh-frozen plasma (FFP) derived from the same donations. All 16 anti-HCV supplemental test-positive donations evaluated were HCV RNA positive with FFP, whereas only 10 (62.5%) were positive with PTS (p = 0.024). None of 11 FFP or PTS samples from HCV enzyme immunoassay-reactive donations not confirmed by supplemental anti-HCV assays tested positive for HCV RNA. Direct comparison of sample type (serum vs. plasma) and various storage conditions using specimens from two seropositive donors showed that room-temperature storage results in marked reduction in HCV RNA signal, while replicate freezing and thawing caused a moderate reduction. These data indicate that well-controlled sample processing and storage conditions are critical to the sensitive and potentially quantitative analysis of HCV RNA.

Blood Preservation↗
PubMed1991

Long-term human immunodeficiency virus infection in asymptomatic homosexual and bisexual men with normal CD4+ lymphocyte counts: immunologic and virologic characteristics.

From a prospective cohort study, 24 asymptomatic men were identified who had been antibody positive for human immunodeficiency virus (HIV) for at least 5 years (median = 9.1) with CD4+ lymphocyte counts greater than or equal to 400 cells/mm3. Of these "nonprogressors", 23 (96%) had evidence of HIV infection by either HIV culture or the polymerase chain reaction (PCR) for HIV DNA, although only 1 (4%) had a positive assay for HIV RNA (by PCR) and no one was positive for p24 antigen. Compared with 24 antibody-negative men and 14 men with AIDS, nonprogressors had higher CD8+ counts and lower natural killer cell activity. Nonprogressors had higher beta 2-microglobulin levels than did seronegative controls, suggesting some degree of immune system activation. Compared with men with AIDS, nonprogressors seemed to have a stronger antibody response to six different HIV-related proteins but did not differ significantly in neutralizing antibody or antibody-dependent cellular cytotoxic activity.

Adult↗
PubMed1990

Detection of human immunodeficiency virus DNA using the polymerase chain reaction in a well-characterized group of homosexual and bisexual men.

The polymerase chain reaction (PCR) for human immunodeficiency virus type 1 (HIV-1) DNA was performed on specimens from 197 homosexual and bisexual men enrolled in studies of HIV-1 infection. Thirty cycles of amplification were conducted, followed by detection with probes corresponding to two gag primer pairs (SK 38/39 and SK 101/145). Of 107 men who were HIV-1 antibody-negative, 105 (98%) were PCR-negative. Two who were initially PCR-positive antibody-negative were PCR- and antibody-negative on repeat testing of both the same specimen and specimens drawn 8-10 months later; this suggests that the first PCR results were false-positive. Of 90 men who were antibody-positive, PCR was positive in 87 (97%), including all 13 with AIDS, all 22 with AIDS-related conditions, all 11 with generalized lymphadenopathy only, and 41 (93%) of 44 without signs or symptoms of HIV-1 infection. On repeat testing, all 3 PCR-negative, antibody-positive men were PCR-positive. In this population and with this technique, PCR had excellent agreement with the HIV-1 antibody test.

Base Sequence↗
PubMed1990

Immunofluorescence for serodiagnosis of retrovirus infection.

Indirect immunofluorescence antibody testing is a mainstay of retrovirus serodiagnosis in the public health community, affording quick, inexpensive, and clear results with significant advantages over Western blot testing. Limitations regarding training of personnel and availability of reagents will probably continue and limit indirect immunofluorescence antibody testing to the present users.

Bibliographies as Topic↗
PubMed1987

Serologic testing of human immunodeficiency virus infection.

This article describes laboratory methods available for testing serum to determine whether a patient is infected with human immunodeficiency virus (HIV). Included is discussion of uses and limitations of the assays, patient counseling, laboratory safety, and interpretation of the test results.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Antibody to the retrovirus associated with the acquired immunodeficiency syndrome (AIDS). Presence in presumably healthy San Franciscans who died unexpectedly.

We performed autopsies and serologic tests in 189 subjects (152 men and 37 women) between 20 and 50 years of age with no history of immunosuppression who died unexpectedly and whose bodies were referred to the San Francisco coroner's office. Forty-eight of the 88 single men for whom addresses were available lived in areas of the city with a high incidence of the acquired immunodeficiency syndrome (AIDS). In addition, 36 of the subjects (30 men) were intravenous drug abusers. Antibody to the retrovirus associated with AIDS was present in 23 (18%) of the 121 subjects whose sera were tested. However, neither pathologic nor laboratory manifestations of AIDS were present in any of the 189 subjects who underwent autopsy. These results suggest that antibody to the retrovirus is common but subclinical manifestations of AIDS are uncommon in San Francisco, a city where the incidence of clinical AIDS is high.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Comparison of six methods for the detection of antibody to cytomegalovirus.

Five commercial assays were compared to a standardized complement fixation (CF) test for the detection of antibody to cytomegalovirus. Two hundred and thirty serum specimens were analyzed. In addition, nine pairs of acute- and convalescent-phase sera were tested by two of the commercial assays. The assays were compared as to sensitivity, specificity, and positive and negative predictive value, as well as incidence of false-positive and -negative results. Samples which did not agree in all the assays were retested and tested with an indirect fluorescent-antibody assay. Of 228 specimens, 103 (45.2%) were positive by CF. Of the 230 samples, 2 (0.9%) were inconclusive by CF and readable in the other assays. Of the 230 specimens, 97 (42.2%) were positive by an enzyme immunoassay (EIA; Litton Bionetics), 100 (43.5%) were positive by a second EIA (Abbott Laboratories), 104 (45.2%) were positive by a third EIA (M. A. Bioproducts). One hundred and eight (47.0%) were positive by indirect hemagglutination (IHA; Cetus Corporation), and 110 (47.8%) were positive by latex agglutination (LA; Hynson, Westcott and Dunning). Sensitivity and specificity were similar with all the assays (93 to 100%). The greater numbers of positive results by IHA and LA were confirmed by repeat CF testing at less than 1:8 dilution, and by indirect fluorescent-antibody assay. Acute- and convalescent-phase serum pairs showed a significant rise in antibody titer when tested by anticomplement immunofluorescence, IHA, and LA. There was good agreement among the assays, with LA having the highest sensitivity.

Antibodies, Viral↗