Presence of HTLV-III antibodies in immune serum globulin preparations

The authors tested 15 immune serum globulin pharmaceutical preparations for antibody reactivity to human T cell lymphotrophic virus type III (HTLV-III) by the Abbott immunoenzymometric assay (IEMA). Although no evidence of HTLV-III infectivity has appeared after injection of similar preparations into humans, the authors found all samples IEMA reactive. Upon dilution, the authors demonstrated parallel decreases of antibody reactivity among two samples of gamma globulin, the Abbott-positive control, and a markedly reactive patient specimen. Gamma globulin isolated from sera of six animal species was nonreactive in the Abbott assay. All samples were nonreactive with the H-9 cell line antigen. Antibody reactivity to HTLV-III was confirmed in 13 of 15 gamma globulin samples when tested by the Electro-Nucleonics IEMA, and 14 samples contained at least the p24 band on Western blot analysis. Although false positivity occurs in IEMA assays possibly because of elevated protein concentrations and nonspecific binding, the authors, results show that in most circumstances immune serum globulin preparations tested do contain true reactivity to HTLV-III.     

Counterimmunoelectrophoresis for detection of human serum antibody to HTLV-III

We examined the usefulness of a counterimmunoelectrophoresis (CIE) technique for detecting antibodies to HTLV-III using sera that previously had been assessed for antibodies to HTLV-III by the standard enzyme-linked immunosorbent assay (ELISA). We selected a subset of 53 sera from patients with the acquired immune deficiency syndrome (AIDS) or the generalized lymphadenopathy syndrome (GLS) in which 81.1% were initially ELISA-positive, and 96.2% were positive by Western blot technique. In our standard HTLV-III CIE technique, 58.5% were positive and repeat testing increased the yield to 67.9%. Varying several parameters of the standard CIE assay did not improve sensitivity. We also studied 20 ELISA-negative and 10 ELISA-borderline sera from normal controls; all were negative by CIE. These results indicate that CIE may be used for detection of human serum antibodies to HTLV-III, but that the present assay was less sensitive than the HTLV-III ELISA.     

Anti-arbovirus antibodies positive serum screening in population of Saratov

Seroepidemiological studies revealed the existence of a population stratum immune to West Nile and Sindbis viruses in the Saratov region. Screening of 218 sera showed that the stratum immune to arboviruses increased from 1998 to 2000. The incidence of antibodies to Batai and Sindbis viruses was the highest. Activation of natural foci of these arboviruses can lead to exacerbation of the epidemic situation in the region.     

Predictive value of a screening test for antibodies to HTLV-III

A test for the detection of antibodies to HTLV-III is available and will be widely used to screen donated blood to prevent transfusion-associated acquired immunodeficiency syndrome (AIDS). Based upon the sensitivity and specificity, the authors calculated the expected predictive values for different groups of asymptomatic individuals using Bayes' theorem. The prevalence of HTLV-III infection has great impact upon the positive and negative predictive values of the test. For a member of the general population there is a less than 3% chance that a positive test represents a true positive. High-risk patients, such as hemophiliacs, with a positive test will have a greater than 95% chance of actually having antibodies to HTLV-III, but the negative predictive value of the test in this group is less than ideal. The authors recommend that all positive tests for HTLV-III be confirmed by more specific methods when obtained in low-risk people. Members of high-risk groups for AIDS should continue to refrain from donating blood, despite the availability of the screening test.     

Lymphadenopathy and antibodies to HTLV-III in homosexual men

Summary The study provides information on the epidemiology of HTLV-III infection and the lymphadenopathy syndrome (LAP) in 374 German homosexual men. Sexual contacts in the USA and rectal enemas before receptive anal intercourse are the main risk factors associated with virus transmission. HTLV-III seropositivity is significantly correlated with LAP. Prominent clinical signs are infreqquent. Immunological and haematological abnormalities are prevalent, and the retrovirus infection is frequently associated with serological markers of other viruses (hepatitis B, herpes group viruses). Lymphadenopathy as a manifestation of HTLV-III infection is discussed within the context of AIDS-related disorders.Abbreviations AIDS Acquired Immunodeficiency Syndrome - CMV Cytomegalovirus - EBV Epstein-Barr virus - HBV Hepatitis B virus - HTLV-III Human leukaemia retrovirus type III - LAP Lymphadenopathy     

Deficiency of natural killer activity, but not of natural killer binding, in patients with lymphoadenopathy syndrome positive for antibodies to HTLV-III

Blood lymphocytes (BL) of eleven patients with lymphoadenopathy syndrome (LAS) were studied for natural killer (NK) activity against the K562 cell line (using both the standard 51Cr release assay and the single-cell cytotoxicity assay on poly-L-lysine-coated coverslips) and for surface phenotype (employing OKT4, OKT8 and Leu7 monoclonal antibodies). A significant reduction in NK activity and in NK active cells was detected, while the percentage of target binding cells was not affected. Furthermore, the OKT4/OKT8 ratio was found to be inverted, and the Leu7+ subpopulation expanded. The patients had high titers of anti-HTLV-III antibodies. This study indicates that defective NK activity in LAS is secondary to an abnormality in the lytic event itself and not in target binding.     

Detection of antibodies to HTLV-III in commercially available immunoglobulin preparations

Summary Samples of 96 polyvalent and virus-specific immunoglobulin batches commercially available in West-Germany were tested by enzyme-linked immunoassay and immunoblot for the presence of anti-HTLV-III antibodies. 37% of the polyvalent and 87% of the virus-specific batches were positive. It was concluded that these preparations are still safe and because of their reportedly low titer neutralizing antibodies possibly beneficial in certain cases, such as newborns of HTLV-III positive mothers or after accidental exposure to infectious material in clinics or laboratories.Abbreviations AIDS acquired immunodeficiency syndrome - ARC AIDS-related complex - CMV cytomegalovirus - ELISA enzyme-linked immuno adsorbent assay - HTLV-III human T-cell lymphotropic virus, type III     

Sensitive assay for neutralizing antibodies against AIDS-related viruses (HTLV-III/LAV)

A sensitive assay for neutralizing antibodies (NA) against AIDS-related viruses (HTLV-III and LAV) was developed, using human T-cell lymphotropic virus type-I (HTLV-I)-bearing and HTLV-III-susceptible MT-4 cells. NA to HTLV-III in 21 patients with acquired immune deficiency syndrome (AIDS), 10 individuals with AIDS-related complex (ARC), 20 healthy male homosexuals, and 10 healthy male controls were titrated. Antibodies to HTLV-III were also detected by indirect immunofluorescence (IF). The assay was sensitive up to a dilution of 1:10 000. Sera from patients with AIDS showed a geometric mean titer (GMT) of NA of 1:475, whereas much higher GMTs (1:1318 and 1:1009) were observed in patients with ARC and healthy male homosexuals, respectively. Moreover, titers of NA significantly correlated with the levels of anti-HTLV-III antibodies detected by IF.     

Evaluation of two commercially available immunoassays for the detection of hantavirus antibodies in serum samples.

BACKGROUND: hantaviruses are members of the family Bunyaviridae and the spectrum of clinical symptoms in humans may vary from sub-clinical to severe haemorrhagic fever with renal syndrome (HFRS) or pulmonary syndrome (HPS). Several serotypes have been described from which at least five are pathogenic to humans. Each serotype has a different animal reservoir and geographical distribution. In the acute phase of the disease the clinical diagnosis may be confirmed by serology or by polymerase-chain reaction (PCR). OBJECTIVE: to evaluate two commercially available immunoassays using sera from hantavirus suspected and non-hantavirus patients: an enzyme immunoassay (EIA) developed by MRL Diagnostics, for the detection of immunoglobulins M (IgM) and G (IgG) against several hantavirus serotypes and an indirect immunofluorescence assay (IFA) from Progen, based on slides coated with Hantaan virus (HNTV) and Puumala virus (PUUV), infected cells. STUDY DESIGN: a total of 145 serum samples were used for this study. The serum panel included serum samples from patients suspected of mild (n=91), severe (n=10) HFRS and patients with other viral infections (n=44). RESULTS: the agreement between the MRL EIA and the Progen IFA for the detection of IgM and IgG serum antibodies ranged from 87 to 91%, respectively. In the non-hantavirus group one out of 44 samples was positive by the Progen HNTV IgM IFA, none in the Progen PUUV IFA and two samples in the MRL IgM EIA, resulting in specificities of 98, 100 and 95%, respectively. The sensitivities and specificities of the MRL EIAs compared to the Progen overall PUUV and HNTV IFAs were 90 and 91% for IgM, respectively, and 96% for IgG in both immunoassays. CONCLUSIONS: the MRL EIA proved to be relatively sensitive and specific assay for the serological diagnosis of mild and severe HFRS.     

Detection of antibodies to Mycoplasma gallisepticum in egg yolk versus serum samples.

Serum (n = 1,636) and egg yolk (n = 802) samples collected from hens on four commercial egg farms in Florida were tested for the presence of specific antibodies to Mycoplasma gallisepticum in a commercially available enzyme-linked immunosorbent assay. No significant differences were noted between serum and egg yolk samples with respect to distribution of positive, suspect, and negative test results or for the mean sample/positive control ratio values of positive, suspect, and negative test results. A linear relationship between the distribution of positive and negative results and the age of the birds was observed for results obtained with both serum and egg yolk samples. On the basis of the results of this study, egg yolk samples can be used in lieu of serum samples to screen flocks for antibodies to Mycoplasma gallisepticum.     

The use of enzyme-linked immunosorbent assay for detection of Mycoplasma hominis antibodies in infertile women serum samples

BACKGROUND: Besides Chlamydiae trachomatis and Mycoplasma genitalium, Mycoplasma hominis may also cause infertility due to damage of the Fallopian tubes. Therefore serum samples from infertile women were analyzed for antibodies to M. hominis. METHODS: Sera from 304 infertile women were investigated for seropositivity to M. hominis by immunoblotting and a developed ELISA. Women were classified into groups based on the type of infertility: infertile due to lack of passage in Fallopian tubes (TFI, tubal factor infertility), an infertile male partner (MFI, male factor infertility) and unexplained infertility (UFI, unexplained factor infertility). Three M. hominis isolates were used in the immunoblotting analysis and clear differences in patient immunoprofiles were observed between two isolates. For the ELISA we used a mixture of Triton X-114 extracted membrane proteins from those two M. hominis isolates as antigen. RESULTS: Ninety-seven sera (32%) were seropositive to M. hominis when tested by the ELISA. There was a significant correlation between TFI and seropositivity to M. hominis (P = 0.0015, OR = 2.21, CI = 1.35-3.61). We compared the seropositivity of 304 patients to M. hominis with the presence of antibodies against two other bacteria Chlamydiae trachomatis and Mycoplasma genitalium and there was no statistical correlation between those bacteria and M. hominis. CONCLUSION: Our results indicate that M. hominis may be an independent predictor of TFI.     

Evaluation of a new serotyping assay for detection of anti-hepatitis C virus type-specific antibodies in serum samples

The performance of a new version (HC03) of the hepatitis C virus (HCV) serotyping 1-6 assay (Abbott Murex Laboratories), a specific test for serological determination of HCV types, was evaluated using a selected panel of 180 HCV RNA-positive sera. HC03 was more sensitive than the current HC02 version, typing 53 (37.6%) of 141 samples which were not typable with HC02. Furthermore, the HC03 specificity was 94.1% as evaluated with a panel of 22 genotyped samples. This new version of the test improves the quality of the serological approach to HCV type determination.     

HTLV-III antibodies in hemodialysis patients — A consequence of blood transfusions?

Summary An investigation for HTLV-III antibodies in chronic hemodialysis patients revealed in four out of 276 patients a positive result using the ELISA and western blot techniques. All HTLV-III positive patients had received blood transfusions. As it has been shown that a needle stick could transmit the HTLV-III, it is suggested that hemodialysis patients who have received frequent blood transfusions should be screened.Abbreviations AIDS acquired immune deficiency syndrome - ELISA enzyme linked immunosorbent assay - HbSAg hepatitis surface antigen - HD hemodialysis - HTLV-III human T-cell lymphotropic virus type III     

An immunoassay for the determination of total IgA subclass antibodies in human serum

An enzyme immunoassay capable of determining total IgA1 and IgA2 concentrations in human serum has been developed. Subclass-specific monoclonal antibodies are bound to polyacrylamide bead-conjugated anti-mouse immunoglobulin antibodies. Bound IgA is detected with an anti-IgA peroxidase conjugate and the standard curve is linear in the region 0.25 - 2.0 micrograms/ml. Coefficient of variation values range from 0.24 - 5.77% for the IgA1 standard curve and from 0.86 - 5.92% for the IgA2 standard curve. Inter-assay variation for the IgA1 and IgA2 control sample values were 8.2% and 13.4%, respectively.