The burden of silicosis, pulmonary tuberculosis and COPD among former Basotho goldminers

BACKGROUND

The burden of silicosis, pulmonary tuberculosis and COPD is described in 624 South African gold miners 18 months after cessation of work.

METHODS

This was a prevalence study. Questionnaires were administered, and spirometry, chest radiography, tuberculosis investigations, and urine HIV antibody assays were performed.

RESULTS

Attendance was 80.1% (624/779), mean age 49.4 years, and mean employment duration 25.6 years. Most subjects had had medium (26.5%) or high (65.4%) dust-exposure jobs. Current smoking rate was 35%, with ever smoking 61%. HIV antibodies were detected in the urine in 22.3%. Prevalences were: silicosis 24.6%, past tuberculosis 26%, current tuberculosis 6.2%, airflow obstruction 13.4%, and chronic productive cough 17.7%. Almost 50% of these miners had at least one of these respiratory conditions.

CONCLUSIONS

A heavy burden of silicosis, tuberculosis and COPD was present in this group of former goldminers. Intensification of work place dust control measures and TB and HIV prevention activities are needed on South African gold mines. In labor sending communities investment is needed in silicosis and tuberculosis surveillance as well as HIV treatment and care.

[Overexpression, purification of recombinant HIV-1 gp41 protein and detection of HIV antibody in urine]

OBJECTIVE

To establish a specific and sensitive Enzyme-linked immunosorbent Assay (ELISA) kit for detection of HIV-1 antibody in urine using Escherichia coli expression products as coating antigen.

METHODS

The truncated HIV-1 gp41 gene fragment of major antigenic epitopes was inserted into the plasmid pET22b to obtain expression plasmid pET22b-mgp41. The recombinant antigen was expressed in BL21 (DE3) strains of Escherichia coli and was purified by immobilized metal chelation and gel filtration chromatography. Using this antigen as coating antigen, a HIV-1 urine antibody ELISA kit was developed. In order to examine the clinical utility of the kit, 5437 urine samples were assayed, which consisted of 641 urine samples from HIV infected patients and 4796 samples from normal subjects. Results The purity of purified antigen is up to 95%. Anti-HIV antibodies were detected in all the urine samples from HIV infected patients, and the diagnostic sensitivity for HIV-1 infection was 100%. In healthy control group, 71 cases showed false positive, the specificity was 98.52%.

CONCLUSION

The HIV-1 urine antibody kit can be used in screening and diagnosing for HIV-1 infection.

[Urine HIV-1 antibody testing technology]

The conventional rapid detection method for AIDS is testing HIV-1 antibody in blood. Urine HIV-1 antibody testing is a new means with great potential for development because of its safe, convenient and low cost. In this paper, HIV-1 antibody in urine, the merits of urine HIV-1 testing and factors that effect the result of test were reviewed, the application and product actuality of urine testing production were briefly introduced, and the development prospect of urine HIV-1 testing was viewed.

[Oral fluid and urine as alternative samples in confirmatory testing of HIV-1 infection]

The objective of this report was to evaluate oral fluid and urine as optional samples for HIV-1 confirmatory test using DAVIH-BLOT system (Laboratorios DAVIH, La Habana, Cuba), for which they were compared with their corresponding serum samples in a group of 125 individuals. In band pattern analysis, predominant antibodies in positives oral fluid and urine samples against p34, p68, gp41, gp120, were no different from their corresponding sera according to the proportion comparison test (p < 0,001). Relative sensitivity and specificity of this system were 100% in oral fluid and 98, 75% and 100% in urine samples respectively. These results support optional use of oral fluid and urine that, with slight modifications in the diagnostic system, can be applied for HIV-1 antibody confirmation testing.

Performance of two commercial immunochromatographic assays for rapid detection of antibodies specific to human immunodeficiency virus types 1 and 2 in serum and urine samples in a rural community-based research setting (Rakai, Uganda)

Rapid detection of human immunodeficiency virus (HIV) antibodies is of great importance in developing and developed countries to diagnose HIV infections quickly and at low cost. In this study, two new immunochromatographic rapid tests for the detection of HIV antibodies (Aware HIV-1/2 BSP and Aware HIV-1/2 U; Calypte Biomedical Corporation) were evaluated in rural Africa to determine the tests' performance and comparability to commercially available conventional enzyme immunoassay (EIA) and Western blot (WB) tests. This prospective study was conducted from March 2005 through May 2005 using serum and urine from respondents in the Rakai Community Cohort Survey. Nine hundred sixty-three serum samples were tested with the Aware blood rapid assay (Aware-BSP) and compared to two independent EIAs for HIV plus confirmatory Calypte WB for any positive EIAs. The sensitivity of Aware-BSP was 98.2%, and the specificity was 99.8%. Nine hundred forty-two urine samples were run using the Aware urine assay (Aware-U) and linked to blood sample results for analysis. The sensitivity of Aware-U was 88.7% and specificity was 99.9% compared to blood EIAs confirmed by WB analysis. These results support the adoption of the Aware-BSP rapid test as an alternative to EIA and WB assays for the diagnosis of HIV in resource-limited settings. However, the low sensitivity of the Aware-U assay with its potential for falsely negative HIV results makes the urine assay less satisfactory.

Diagnostic detection of human immunodeficincy virus type-1 antibodies in urine, Jimma Hospital, south west Ethiopa

BACKGROUND

Testing for human immunodeficiency virus (HIV) specific antibodies continues to be the most important measure in diagnosis and HIV intervention. Detection of anti-HIV antibodies in serum or plasma samples are common strategies. However, body fluids such as urine and saliva could serve as an alternative sample for diagnosis of HIV infection.

OBJECTIVE

To determine the diagnostic accuracy of Calypte HIV-1 urine EIA test kits for detection of HIV antibodies in urine sample.

METHODS

Urine and serum samples were collected from a total of 365 subjects (HIV suspected (n=156), VCT clients (n=129) and 80 known HIV positive individuals at Jimma Hospital VCT center, OSSA, Red Cross and Mekaneyessus Jimma cohort sites in unlinked anonymous testing method. Urine sample were tested using Calypte HIV-1 urine EIA kits parallel to the golden standard method of testing serum samples by combination of Determine and Vironostica (Rapid test followed by ELISA) test algorithm. All discordant samples (by urine serum tests) were resolved using urine western blot (Calypte HIV-1 urine Western Blot).

RESULT

Comparing the results obtained with a golden standard (HIV test algorithm) the sensitivity and specificity of urine EIA test kit were 99.5% (187/188) and 98.3% (174/177) respectively. Beside to this kappa's test of agreement showed perfect agreement with kappa 0.98.

CONCLUSION

The result showed the utility of urine test as an alternative method for HIV antibody detection. Since the method of collection of urine specimen is non-invasive, it reduces occupational exposure for health professionals involved in collecting samples. Furthermore patient's stronger acceptance to give urine samples will make this test more applicable than serum or whole blood test.

Evaluation of a commercial enzyme immunoassay for HIV screening in urine

A cross-sectional study was conducted to evaluate the utility of a commercial enzyme immunoassay (EIA) as a screening test for detecting HIV-1 antibody in urine in a population at risk for HIV infection in Catalonia, Spain. Paired urine and serum samples were collected consecutively from 99 patients who attended two drug-dependency treatment centres and 151 patients who attended a sexually transmitted diseases (STD) clinic in Barcelona. Antibodies against HIV in urine samples were detected using the Calypte HIV-1 Urine EIA (Calypte Biomedical Corporation, Berkeley, CA, USA) and confirmed by urine-based Western blot (WB) analysis. Sera were analysed using Bioelisa HIV-1+2 EIA (Biokit Laboratories, Barcelona, Spain), and the results were verified using serum-based WB analysis. Results of both urine and serum testing were available for 246 of 250 participants. For 52 individuals the results of both urine and serum testing were positive and for five the results were discordant (2 with urine-negative/serum-positive results and 3 with urine-positive/serum-negative results). The respective sensitivity and specificity values obtained for the urine EIA were 100% and 96.2% for intravenous drug users (IDUs) and 80% and 99.3% for persons attending the STD clinic. According to the 1997 UNAIDS/WHO strategy I recommendations, these values are acceptable for surveillance purposes, particularly in populations with a high prevalence of HIV infection.

Screening for HIV infection in high-risk communities by urine antibody testing

OBJECTIVES

To evaluate the effectiveness of urine screening to detect HIV-infected individuals in high-prevalence communities.

METHODS

Urine HIV testing was performed at 16 discrete events and four ongoing testing sites in Baltimore communities with a high incidence of HIV infection. When possible, positive urine test results were confirmed by blood testing. In addition, we attempted to obtain blood samples from subjects who reported a possible exposure to HIV but did not have a positive urine test.

RESULTS

From February 1998 to August 2001, we screened 1718 persons. Overall, 210 persons (12%) were HIV-positive, of whom 169 (80%) had never previously tested positive; 87% of those who tested positive received their results, and most were referred for medical care.

CONCLUSIONS

Urine-based screening for HIV infection in high-prevalence inner city communities can be an effective tool for identifying and treating infected persons who are unaware of their infection.

Diagnostic detection of human immunodeficiency virus type 1 antibodies in urine: a brazilian study

We evaluated, for the first time in Latin America, the performance of a commercial enzyme immunoassay (EIA) (Calypte Biomedical Corporation, Berkeley, Calif.) that detects human immunodeficiency virus type 1 (HIV-1)-specific antibodies in urine in comparison to standard serological assays (two commercial EIAs and a commercial Western blot [WB] assay). Paired serum and urine specimens were collected from two different groups of Brazilian patients: 225 drug users with unknown HIV status who attended drug treatment centers in Rio de Janeiro, Brazil, and 135 subjects with known HIV status. Patients showing positive results in the serum EIAs and/or in the urine EIA were serologically confirmed by WB assay. For 135 individuals with known HIV status, the urine EIA showed 100% sensitivity (74 positive samples) and 95.1% specificity (58 of 61 negative specimens). For 225 drug users, the test showed 100% sensitivity (2 positive samples) and 98.7% specificity (220 of 223 negative samples) compared to WB-confirmed serological EIA results. Thus, in a total of 360 samples, the urine EIA correctly identified all 76 HIV-positive samples and 278 of 284 negative samples (100% sensitivity and 97.9% specificity). Detailed analysis of the urine EIA results indicates that an increase of the recommended cutoff value might raise the specificity of the assay without affecting its sensitivity. Our results suggest that the HIV-1 urine EIA is a good screening test suitable for developing countries like Brazil. However, as for all other HIV screening tests on the market, it is not specific enough to be used as a one-step test and therefore requires confirmation.

Evaluation of youth preferences for rapid and innovative human immunodeficiency virus antibody tests

OBJECTIVE

To determine youth preferences for Food and Drug Administration (FDA)-approved and investigational human immunodeficiency virus (HIV) antibody collection and testing methods before and after subjects learned of test result response times; to determine how influential test result response times are on participants' preferences.

DESIGN

After health educators explained and demonstrated 6 different HIV antibody collection and testing strategies (3 saliva, 1 urine, and 2 fingerstick methods), participants completed a confidential survey about test method preference and tried the different testing methods. The participants had an opportunity to re-rank their test method preference after learning about each test's result response time.

SETTING

Health education sessions in both clinical and community settings.

PARTICIPANTS

Youths aged 12 to 24 years.

RESULTS

An oral collection device with a rapid saliva test was the most highly preferred test method. The preference for this method and the rapid response test methods via fingerstick procedures improved significantly after subjects learned of the rapid result response time, while the other methods were given significantly lower preference rankings after subjects learned of the longer result response times. Shifts in preference rankings were not related to sex, age, ethnic group, experience with HIV testing, or practice of risk behaviors.

CONCLUSIONS

Our research supports the use of noninvasive and rapid HIV testing methods with rapid response times for adolescents to assist in the early identification of HIV status, while offering HIV prevention opportunities and immediate linkage to care.

Comparison of three assays for HIV antibodies detection in urine to be applied to epidemiological setting

Three immune-enzymatic tests for urinary HIV antibodies were examined in order to assess their sensibility, specificity and delta value. The highest sensibility was noticed for the Seradyn test (98.8%), followed by the Wellcozyme test (98.1%) and finally the SUDS rapid test (56.8%). The resultant specificity was 98.5% for the Seradyn test, 91.3% for the Wellcozyme test and 97.3% for the SUDS test. The measurement of delta value showed a higher capability of discrimination for Seradyn test, that could be considered the most reliable for epidemiological purposes.

Prevalence of HIV-1 among recent arrestees in Los Angeles County, California: serial cross-sectional study, 1991-1995

Injection drug users (IDU), crack smokers, and commercial sex workers engage in illegal activities that place them at risk for HIV infection. The marginalized nature of these groups often limits use of customary sampling methods to assess HIV prevalence. We tested urine samples of recent arrestees to evaluate HIV prevalence of at-risk populations that are difficult to access using standard surveillance methods. We tested for HIV-1 antibodies in urine specimens of recent Los Angeles County (California, U.S.A.) arrestees as part of the Drug Use Forecasting (DUF) Program funded by the U. S. National Institute of Justice. Data are presented for 5 years of a serial cross-sectional study of arrestees. Results from 1991 through 1995 indicate a slight HIV prevalence increase among crack smokers (from 4% to 6%). Prevalence estimates were relatively stable for IDU (6%), male (3%) and female arrestees (3%), arrestees who share needles (9%), and commercial sex workers (6%). HIV status was independently associated with injection drug use, crack smoking, and ever having exchanged sex for money or drugs. Prevalence of HIV among arrestee subgroups may reflect prevalence in the community. However the benefit of using the DUF sample must be weighed against bias introduced from using nonrandom samples to estimate prevalence.

Human immunodeficiency virus antibody testing by enzyme-linked fluorescent and western blot assays using serum, gingival-crevicular transudate, and urine samples

The aim of the present study was to evaluate the possible utilization of saliva and urine as alternative samples to serum for the diagnosis of human immunodeficiency virus (HIV) infection. A total of 302 individuals participated in the study: 187 HIV-infected individuals (106 had Centers for Disease Control and Prevention [CDC] stage II infection, 19 had CDC stage III infection, and 62 had CDC stage IV infection) and 115 noninfected persons (46 of the noninfected persons were blood donors and 69 belonged to a group at high risk of HIV infection). Paired saliva and urine samples were taken from each of the participants in the study. The presence of HIV-specific antibodies was detected by an enzyme-linked fluorescent assay (ELFA), and the result was confirmed by Western blot analysis (WB). The ELFA with saliva gave maximum sensitivity and specificity values, while ELFA had lower sensitivity (95.2%) and specificity (97. 4%) values for detection of HIV antibody in urine samples. WB with all saliva samples fulfilled the World Health Organization criterion for positivity, while only 96.8% of the urine samples were confirmed to be positive by WB. Among the four reactivity patterns found by WB of these alternative samples, the most frequent included bands against three groups of HIV structural proteins (was ENV, POL, and GAG). The reactivity bands most frequently observed were those for the proteins gp160 and gp120. The least common reactivity band was the band for protein p17. The detection of HIV antibodies in saliva samples by means of ELFA with the possibility of later confirmation by WB makes saliva an alternative to serum for possible use in the diagnosis of infection. In contrast, HIV antibody detection in urine samples by the same methodology (ELFA) could be taken into consideration for use in epidemiological studies.

Sensitive enzyme immunoassay of antibodies to HIV-1 p17 antigen using indirectly immobilized recombinant p17 for diagnosis of HIV-1 infection

Recombinant p17 (rp17) antigen of HIV-1 and maltose binding protein-rp17 fusion protein (MBP-rp17) were immobilized onto polystyrene beads in different ways: rp17 and MBP-rp17 were immobilized directly onto polystyrene beads by physical adsorption; biotinyl-rp17 and biotinyl-MBP-rp17 were immobilized indirectly onto streptavidin-coated polystyrene beads; and 2,4-dinitrophenyl (DNP)-MBP-rp17 was immobilized indirectly onto (anti-DNP) IgG-coated polystyrene beads. These directly and indirectly immobilized antigens were incubated with urine samples containing antibody IgG to p17 antigen and subsequently with rp17-beta-D-galactosidase conjugate or (anti-human IgG gamma-chain) Fab'-beta-D-galactosidase conjugate. Beta-D-galactosidase activity bound to the polystyrene beads was assayed by fluorometry. When rp17-beta-D-galactosidase conjugate was used, signals (fluorescence intensities for bound beta-D-galactosidase activity) were much higher with the indirectly immobilized antigens than those with the directly immobilized antigens. By experiments using (anti-human IgG gamma-chain)Fab'-beta-D-galactosidase conjugate, the binding of rp17-beta-D-galactosidase conjugate to antibodies against p17 antigen bound to directly immobilized rp17 antigen was shown to be seriously limited as compared with that to antibodies against p17 antigen bound to indirectly immobilized DNP-MBP-rp17. When rp17-beta-D-galactosidase conjugate and serum samples were used, serum interference was much less with indirectly immobilized DNP-MBP-rp17 than with directly immobilized rp17 antigen, and the sensitivity of enzyme immunoassay for antibody IgG to p17 antigen using indirectly immobilized DNP-MBP-rp17 was 1,000- to 3,000-fold higher than that of enzyme immunoassay using directly immobilized rp17 antigen and Western blotting for p17 band. This sensitive enzyme immunoassay indicated positivity in HIV-1 seroconversion serum panels as early as conventional methods for antibodies to HIV-1 and earlier than Western blotting for p17 band.

More reliable diagnosis of infection with human immunodeficiency virus type 1 (HIV-1) by detection of antibody IgGs to pol and gag proteins of HIV-1 and p24 antigen of HIV-1 in urine, saliva, and/or serum with highly sensitive and specific enzyme immunoassay (immune complex transfer enzyme immunoassay): a review

Ultrasensitive enzyme immunoassays (immune complex transfer enzyme immunoassays) were developed for antibody IgGs to HIV-1 using recombinant reverse transcriptase (rRT), p17 (rp17), and p24 (rp24) as antigens. Antibody IgGs were reacted with 2,4-dinitrophenyl-recombinant antigens and recombinant antigen-beta-D-galactosidase conjugates, and the immune complexes formed, comprising the three components, were trapped onto polystyrene beads coated with (anti-2,4-dinitrophenyl group) IgG. After washing, the immune complexes were eluted from the polystyrene beads with excess of epsilon N-2,4-dinitrophenyl-L-lysine and were transferred to clean polystyrene beads coated with (antihuman IgG gamma-chain) IgG. beta-D-Galactosidase activity bound to the last polystyrene beads was assayed by fluorometry. By transfer of the immune complexes from one solid phase to another, the nonspecific binding of the beta-D-galactosidase conjugates was minimized and the sensitivity was markedly improved. The immune complex transfer enzyme immunoassays using rRT, rp17, and rp24 as antigens were 300-1,000-fold, 1,000-3,000-fold, and 30-100-fold, respectively, more sensitive than Western blotting for the corresponding antigens and 10-300-fold more sensitive than a conventional ELISA and a gelatin particle agglutination test. For urine (100 microliters), whole saliva (1 microliter), and serum (1 microliter) samples, the sensitivity and specificity of the immune complex transfer enzyme immunoassay using rRT as antigen were both 100%. However, for urine samples in which the specific activities of antibody IgG to RT, p17, and p24 were much lower than those in serum samples probably due to degradation by the kidney, a longer assay of bound beta-D-galactosidase activity or/and a concentration process for urine was required. The use of more than 1 microliter of whole saliva was recommended for reliable diagnosis of the infections, whereas 1 microliter of serum was sufficient for the purpose. The positivity with rRT as antigen could be confirmed by demonstration of antibody IgGs to p17 and p24 in most of the urine, whole saliva, and serum samples. In HIV-1 seroconversion serum panels, antibody IgG to p17 was detected as early as or even earlier than antibodies to HIV-1 by a conventional ELISA or/and a gelation particle agglutination test, whereas antibody IgGs to RT and p24 were detected as early as or later than antibody IgG to p17. Thus the uses of rRT and rp17 as antigens were advantageous over that of the other antigens for randomly collected serum samples probably long after the infection and serum samples at early stages of the infection, respectively. On the basis of these results and other reports, the immune complex transfer enzyme immunoassay was developed for simultaneous detection of p24 antigen and antibody IgGs to RT and p17 in a single assay tube, and the window period (8 weeks, although widely variable), during which diagnosis of HIV-1 infection is not possible due to the absence of detectable antibodies to HIV-1, was shortened by 2 weeks. As a result, the simultaneous detection made possible not only as early diagnosis as that by detection of p24 antigen, but also as reliable diagnosis as that by detection of antibodies to HIV-1. Finally, the immune complex transfer enzyme immunoassay has been recently improved so as to be performed within shorter periods of time (2-3 hr) with higher sensitivity, and testing many samples has become easy.

Urinary HIV-1 antibody patterns by western blot assay

Diagnosis of human immunodeficiency virus infection (HIV-1) is normally carried out by serum testing for HIV-1 antibody. Recently, antibody testing in other body fluids such as saliva and urine have been attempted. In this study, we examined HIV-1 antibody patterns in urine by Western blot assay as compared to that found in serum. Out of 44 sero-positive samples by Western blot assay we found 43 to be HIV-1 antibody positive in the urine, whereas all 40 sero-negative samples were negative in urine. Thus the sensitivity of urine testing was 97.7% with 100% specificity when compared to serum testing by the Western blot assay. In the analysis of the antibody pattern in urine, we found 6.8% of p17, 68% of p24, and 47.7% of p39 in the core proteins; 72.7% of p31, 61.4% of p51, and 68.2% of p66 in the polymerase; and 63.6% of gp41, 75% of gp120, and 97.7% of gp160 in the envelope proteins. The data obtained supports the selection of the HIV-1 antigen subtype-E to develop a home test kit using urine. Urine testing for HIV-1 antibody is convenient, non-invasive, safe, and easily performed at home. However, if the urine is positive, the confirmation test on serum is needed.

Urinary IgG antibody capture particles adherence test for detecting HIV antibodies: a preliminary report

It is known that antibodies to HIV are secreted in urine and saliva. IgG antibody capture particle adherence test (GACPAT) has been shown to provide accurate results for antibodies in urine. The aim of the study was to study the sensitivity and specificity of this test in our settings. 114 urine samples were collected from both HIV positive and HIV negative patients and were analysed using GACPAT. The test has a sensitivity of 92.3% and specificity of 100%. We feel that this test has a definite role in our country especially for surveillance purposes.

HIV infection among family planning clinic attenders in Glasgow: why prevalence has remained low in this general population group

OBJECTIVE

During 1991-2, unlinked anonymous testing of dried blood spots from neonatal metabolic screening cards showed the prevalence of HIV among childbearing women from Glasgow to be extremely low at 0.01%. A study was conducted to determine if non-pregnant sexually active women who engaged in unprotected sexual intercourse were more likely to be infected than those who were pregnant.

METHODS

Unlinked anonymous HIV testing of urine specimens submitted by attenders of the family planning clinic in Glasgow for pregnancy testing.

RESULTS

Of 11,990 urine specimens tested, 7664 were from women with a negative pregnancy test and two of these were HIV positive (0.026%); none of the remainder from those with a positive pregnancy test had HIV antibodies.

CONCLUSION

No hidden epidemic was unearthed among a population which had engaged in unprotected sexual intercourse and was not pregnant. Other data from Glasgow strongly suggest that the control of HIV transmission among the city's population of current injectors (HIV prevalence, 1% of 8500) has prevented the spread of infection into its wider heterosexual population. It is essential that preventive measures which have been responsible for this public health success should be maintained.

Urine-based diagnostic technologies

The worldwide dissemination of infectious agents has created a demand for simple diagnostic tests. Urine-based testing makes use of non-invasive collection of specimens, and there is no need for expensive facilities and equipment, or for highly trained personnel. As urine antibodies retain activity under normal conditions of transport and storage, such tests appear to have widespread application. Urine-based antibody tests have also indicated a compartmentalized antibody response to HIV-1 infection. Urine studies suggest that antibodies to the products of endogenous viral genes may be involved in the pathogenesis of chronic diseases of suspected viral etiology.

[Clinical usefulness of urinary anti HIV antibody test--a large scale study from 11 institutes in Japan]

An enzyme immuno assay kit has been developed to detect anti-HIV antibody in urine. In order to examine the clinical utility of the kit, 1333 urine samples were assayed. These samples consisted of 233 urine samples from HIV infected patients, 472 samples from HIV uninfected patients including 203 samples from patients with urogenital diseases, and 628 samples from normal subjects. Anti-HIV antibodies were detected in all the urine samples from HIV infected patients, and the diagnostic sensitivity for HIV infection was 100% with no false negative cases. A variety of anti-HIV antibody titers were found in the urine samples from HIV infected patients. However, no significant differences were found in the distribution patterns of urinary anti-HIV antibody titers among AC, ARC and AIDS patients. False positives were determined in only five samples in 628 healthy subjects (0.8%), one in 19 patients with hepatitis (5.3%), one in 45 patients with hemophilia (2.2%) and two in 105 pregnant women (1.9%). The antibody titers of all the false positive samples in these groups were less than the cut-off index multiplied by two. However, relatively high positive rates were demonstrated in the samples from urogenital diseases (11.8%), diabetes mellitus (20.0%) and auto-immune diseases (7.3%). False positive results were found to be directly correlated to the protein concentration of urinary protein, especially the immunoglobulin concentration in urine. The assay system was also evaluated by various reproducibility tests performed by different operators at different laboratories. The test results were satisfactory.(ABSTRACT TRUNCATED AT 250 WORDS)

Screening for human immunodeficiency virus antibody in urine

OBJECTIVE

To determine the diagnostic accuracy of an investigational test for human immunodeficiency virus (HIV) envelope antibodies in urine.

DESIGN

Matched blood and urine specimens were tested for HIV by two independent laboratories, both of which were blinded to all results at the other site. Duplicate positive enzyme-linked immunoassay (EIA) results were confirmed by immunofluorescent antibody or western blot.

SETTING

Six alcohol treatment centers in the San Francisco metropolitan area.

PATIENTS

Five hundred ninety-two recovering alcoholics.

MAIN OUTCOME MEASURES

Diagnosis of HIV infection by blood and urine EIA and western blot.

RESULTS

The experimental urine EIA, when confirmed by urine western blot, led to a correct diagnosis in all samples. One sample was negative by urine EIA screening, positive by blood EIA, and exhibited an indeterminate blood western blot pattern (p24 band only).

CONCLUSIONS

We encountered no false positive or false negative results using an investigational HIV antibody test for urine samples. There are several important advantages to HIV testing of urine versus serum or blood; however, there are also cogent reasons for limiting the use of alternative specimens for HIV testing.

Detection of anti-human immunodeficiency virus type 1 (HIV-1) immunoglobulin G in urine by an ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) with recombinant reverse transcriptase as an antigen

Anti-human immunodeficiency virus type 1 immunoglobulin G in urine was detected by an immunoassay with reverse transcriptase as the antigen and beta-D-galactosidase as the label; this immunoassay was 30-fold more sensitive than the previous immunoassay with peroxidase as the label. The sensitivity and specificity were both 100%. The lowest signal for asymptomatic carriers was 20-fold higher than the highest signal for seronegative subjects.

Application of a rapid assay for detection of antibodies to human immunodeficiency virus in urine

The use of rapid, simple tests to detect antibodies to human immunodeficiency virus (HIV) in urine could be valuable for several testing situations, such as in private offices, for epidemiologic surveys, and in developing countries. The authors evaluated the performance of the SUDS HIV type 1 test to detect antibody to HIV-1 peptides in urine. Test performance and applicability of the SUDS test were compared with a routine Food and Drug Administration-licensed enzyme-linked immunosorbent assay (ELISA) and Western blot using 139 serum and urine pairs collected from autopsy cases. Using a modified procedure when testing urine by the SUDS test, results indicated that a total of 15 serum/urine pairs were HIV-1 antibody positive by both the SUDS test and ELISA; all could be confirmed positive by Western blot. One sample produced discrepant results. The SUDS test produced no false-positive results when testing serum or urine, as compared with ELISA, and no false-negative results when compared with the Western blot. For optimal accuracy of detection of antibodies using urine, at least 100 microL of sample was required. By Western blot analysis, antibody profiles in urine were generally weaker than in serum, but confirmation of positivity was not compromised when larger volumes were used. The authors concluded that this rapid HIV-1 test, when used to detect antibodies to HIV-1 in urine, is accurate, easy to perform, and appropriate for use in certain testing situations.

Diagnosis of HIV-1 infection by detection of antibody IgG to HIV-1 in urine with ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant proteins as antigens

Anti-HIV-1 IgG in urine was detected by an ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant reverse transcriptase (RT), p17 and p24 as antigens, and beta-D-galactosidase from Escherichia coli as label. Anti-HIV-1 IgG in urine was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-recombinant protein conjugate and recombinant protein-beta-D-galactosidase conjugate. The immune complex formed, consisting of the three components, was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG. After washing, the immune complex was eluted from the polystyrene balls with excess of epsilon N-2,4-dinitrophenyl-L-lysine and transferred to clean polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. Finally, the enzyme activity bound to the last solid phase was assayed by fluorometry. Using recombinant RT as antigen, the sensitivity and specificity for 83 seropositives and 100 seronegatives were both 100%, and the lowest signal for 60 asymptomatic carriers was 8.2-fold higher than the highest signal for the seronegatives. The positivity with recombinant RT as antigen could be confirmed by using recombinant p17 and p24 as antigens. The sensitivity could be improved by a longer assay of bound beta-D-galactosidase activity by using concentrated urine samples and by the combined use of recombinant RT, p17, and p24. Thus, reliable diagnosis of HIV-1 infection was possible for asymptomatic carriers.

Detection of antibody IgG to HIV-1 in urine by ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant p24 as antigen for diagnosis of HIV-1 infection

Anti-HIV-1 IgG in urine was detected by an ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant p24 gag protein (p24) of HIV-1 as antigen and beta-D-galactosidase from Escherichia coli as label. Anti-HIV-1 IgG in urine was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-recombinant p24 conjugate and recombinant p24-beta-D-galactosidase conjugate. The complex formed, consisting of the three components, was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG, eluted with epsilon N-2,4-dinitrophenyl-L-lysine, and transferred to polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. Bound beta-D-galactosidase activity was assayed by fluorometry. This assay was at least 3,000-fold more sensitive than conventional methods. The lowest signal among 49 asymptomatic carriers was 3.1-fold higher than the highest nonspecific signal among 100 seronegative subjects. The sensitivity and specificity were both 100%. The positivity could be confirmed by preincubation of urine samples with excess of the antigen. Thus, this assay would be a powerful tool for detecting IgG antibody to HIV-1 in urine.

HIV-1 antibody serum negativity with urine positivity

7 individuals who were negative for HIV-1 antibody in a licensed serum enzyme immunoassay (EIA) were positive in a urine EIA and western blot (WB). Follow-up in individuals by use of a cell-mediated immune response showed 1 positive and 1 negative for HIV-1 peptide reactivity. In a second study, 4 out of 5 subjects positive by urine EIA and indeterminate or negative by serum WB were HIV-1 peptide positive in the cell-mediated immune test. Comparison of cell-mediated responses with urine antibody responses may help to resolve discrepant HIV-1 results.

Novel assay for the detection of immunoglobulin G antihuman immunodeficiency virus in untreated saliva and urine

Epidemiological evidence and laboratory studies indicate that human immunodeficiency virus type 1 (HIV 1) is rarely, if ever, transmitted in saliva or urine. In that both specimens are easy to collect, each may be a useful alternative to serum specimens for anti-HIV screening. A rapid, simple, and robust IgG-capture enzyme-linked immunosorbent assay (GACELISA) suitable for the detection of anti-HIV 1 and 2 in saliva and urine was developed. Following optimisation of the assay, 177 salivary and 568 urine specimens collected from individuals of known serostatus were investigated. The assay was 100% sensitive on 50 salivary (median OD/CO = 8.9) and 126 urinary (median OD/CO = 8.6) specimens collected from anti-HIV-positive patients. The specificity was 100% on 127 salivary specimens (median OD/CO = 0.37) and 422 urinary specimens (median OD/CO = 0.39) collected from anti-HIV-negative individuals. These findings demonstrate that GACELISA HIV 1 + 2 tests on saliva or on urine are an accurate alternative to a conventional anti-HIV test of blood. This assay is satisfactory for surveillance purposes and, with appropriate precautions, could be used clinically.

Human immunodeficiency virus: GACPAT and GACELISA as diagnostic tests for antibodies in urine

Testing for antibodies to human immunodeficiency virus (HIV) in urine may be of use in epidemiological studies. We collected 336 paired urine and serum samples from subjects in Karonga District, northern Malawi: 86 (25.6%) of the serum samples were HIV positive. Serum results were compared with those from immunoglobulin (Ig) G antibody-capture particle adherence tests (GACPAT) and IgG antibody-capture enzyme-linked immunosorbent assay (GACELISA) on the corresponding urine samples performed independently in 2 laboratories. The minimum observed relative sensitivity and specificity of GACPAT were 96.5% and 98.8% respectively; the specificity could be raised by using a protocol involving re-testing of reactive samples to determine end-point titre. For GACELISA, the observed relative sensitivity and specificity were 98.8% and 99.2% respectively. Such assays may be useful either as a primary screen in populations where urine samples are considerably easier to obtain than serum samples, or as an alternative test for individuals unwilling to provide a serum sample.

Detection of antibody IgG to HIV-1 in urine by sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant proteins as antigens for diagnosis of HIV-1 infection

For diagnosis of HIV-1 infection, attempts were made to detect anti-HIV-1 IgG in urine by sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant reverse transcriptase (RT) and p17 as antigens. Anti-HIV-1 IgG in urine was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-recombinant protein conjugate and recombinant protein-enzyme conjugate. The enzymes used as labels were horseradish peroxidase for RT and Escherichia coli beta-D-galactosidase for p17. The complex formed, consisting of the three components, was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG, eluted with epsilon N-2,4-dinitrophenyl-L-lysine and transferred to polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. Finally, bound enzyme activity was assayed by fluorometry. Urine samples were collected from 100 seronegative subjects and 70 seropositive subjects. The sensitivity and specificity were both 100% with unconcentrated urine samples. The positivity was confirmed by preincubation of urine samples with excess of the antigens. The positivity and negativity with one of the two antigens could be confirmed with the other antigen. The positivity with low signals could be confirmed by concentration of urine samples. Detection of anti-HIV-1 IgG in urine by the immune complex transfer enzyme immunoassay using different antigens would make diagnosis of HIV-1 infection possible.

Salivary and urinary diagnosis of human immunodeficiency viruses 1 and 2 infection in Côte d'Ivoire, using two assays

This investigation, done at the Institut Pasteur de Cote d'Ivoire 'blind' of the previous serological findings, suggests that GACELISA, a commercial immunoglobulin G capture enzyme immunoassay for anti-human immunodeficiency virus antibody, can be successfully applied to unprocessed saliva and urine specimens. Its accuracy may be as high as that of conventional enzyme assays on serum tested under similar conditions. However, the role of GACPAT, a similar assay, as a cheap alternative screening test for urine remains in doubt unless its non-specificity can be controlled.

Testing for HIV in urine

The graph showing the number of National Science Foundation awards going to new investigators (Science, 18 May, p. 810) was inaccurate. The following table provides the correct numbers, as supplied by NSF. Total awards includes all active awards, single and multi-year, to individual investigators. New investigators are defined as any awardees who had not received an NSF award in the previous 5 years. See Table in the PDF File

Preliminary report: accurate assays for anti-HIV in urine

Untreated urine specimens from 358 patients (344 attending genito-urinary medicine clinics, 14 haemophiliacs) and 353 blood donors were tested blind by a simple IgG-capture particle-adherence test (GACPAT) and a rapid IgG-capture enzyme-linked immunosorbent assay (GACELISA) for antibody to human immunodeficiency virus (anti-HIV). All 158 urine specimens from seropositive subjects were anti-HIV positive by GACPAT and 157 of them (99.4%) were positive by GACELISA. Tests on 553 urine specimens from seronegative subjects gave two repeatable false-positive reactions by GACPAT (0.4%) and none by GACELISA. By means of a modified procedure anti-gp160 was detected by commercial western blot in the urine of 44 of 45 seropositive subjects examined. IgG-capture assays will detect anti-HIV in unconcentrated urine and so allow a diagnosis in circumstances when blood sampling is impracticable.