Anti-HIV indeterminate western blot in dialysis patients: a long-term follow-up

False positive viral marker results in blood donors and their unintended consequences

False positive (FP) viral marker results in blood donors continue to pose many challenges. Informing donors of FP results and subsequent deferral can result in stress and anxiety for donors and additional complexity and workload for blood services. Donor management strategies need to balance the requirement to minimise donor anxiety and inconvenience while maintaining sufficiency of supply. Decisions about how and when to inform donors of FP results and determine deferral periods can be difficult as FP results, while often transitory, can take up to several years to resolve. Additional complexities include the interpretation of indeterminate serological confirmatory testing without detectable viral RNA or non-discriminated NAT results with concomitant anti-HBc reactivity - both may be due to FP results, but the former may also represent past infection and the later may represent occult hepatitis B infection. In this review we discuss strategies to minimise indeterminate serological confirmatory results, possible donor deferral policies and the impact on donors when notified of FP results. We also provide some new data from Australia that address the challenge of interpreting non-discriminated NAT results with concomitant anti-HBc reactivity. Ultimately, the challenge is for each blood service to develop appropriate strategies for donor management, taking into account local information and requirements.

Prevalence and risk behaviour for human immunodeficiency virus 1 infection in Marajó Island, Northern Brazil

BACKGROUND

Human immunodeficiency virus 1 (HIV-1) infection is a global public health problem, but, so far, there is no published information regarding the epidemiology of HIV-1 in Marajó Archipelago (Pará, Brazil).

AIM

The present study reports the occurrence of infection by HIV-1 in four municipalities of the Marajó Island, Pará, Brazil.

SUBJECTS AND METHODS

A total of 1877 samples were collected from volunteer blood donors (1296 women and 551 men) living in the municipalities of Anajás, Chaves, Portel and São Sebastião da Boa Vista. Information about risk behaviour assessment was obtained from a questionnaire. Plasma samples were tested for the presence of anti-HIV antibodies using serological tests. The infection was confirmed by nucleic acid amplification assays.

RESULTS

Twelve samples were seropositive for HIV by ELISA. Western blot analysis showed four positive samples, eight indeterminate patterns and one found to be negative. Molecular analysis revealed three positive samples. Risk factors for HIV-1 infection included absence of condoms during sexual intercourse (41.3%, São Sebastião da Boa Vista), use of illicit drugs (5.8%, Anajás) and early initiation of sexual activities, from 10-15 years (30.7%).

CONCLUSION

Although the study indicates a low HIV-1 prevalence in Marajó Island, some factors may increase the risk for HIV-1 and these include early sexual initiation, unprotected sexual intercourse and the use of illicit drugs.

Use of rapid HIV assays as supplemental tests in specimens with repeatedly reactive screening immunoassay results not confirmed by HIV-1 Western blot

BACKGROUND

An alternate HIV testing algorithm has been proposed which includes a fourth-generation immunoassay followed by an HIV-1/HIV-2 antibody differentiation supplemental test for reactive specimens and a nucleic acid test (NAT) for specimens with discordant results.

OBJECTIVE

To evaluate the performance of five rapid tests (Alere Clearview, Bio-Rad Multispot, OraSure OraQuick, MedMira Reveal, and Trinity Biotech Unigold) as the supplemental antibody assay in the algorithm.

STUDY DESIGN

A total of 3273 serum and plasma specimens that were third-generation immunoassay repeatedly reactive and Western blot (WB) negative or indeterminate were tested with rapid tests and NAT. Specimens were classified by NAT: (1) HIV-1 infected (NAT-reactive; n=184, 5.6%), (2) HIV-status unknown (NAT nonreactive; n=3078, 94.2%) or by Multispot, (3) HIV-2 positive (n=5), and (4) HIV-1 and HIV-2 positive (n=6). Excluding HIV-2 positive specimens, we calculated the proportion of reactive rapid tests among specimens with reactive and nonreactive NAT.

RESULTS

The proportion of infected specimens with reactive rapid test results and negative or indeterminate WB ranged from 30.4% (56) to 47.8% (88) depending on the rapid test. From 1% to 2% of NAT-negative specimens had reactive rapid test results.

CONCLUSIONS

In these diagnostically challenging specimens, all rapid tests identified infections that were missed by the Western blot, but only Multispot could differentiate HIV-1 from HIV-2. Regardless of which rapid test is used as a supplemental test in the alternative algorithm, false-positive algorithm results (i.e., reactive screening and rapid test in uninfected person) may occur, which will need to be resolved during the baseline medical evaluation.

HBV, HCV and HIV seroprevalence among blood donors in Istanbul, Turkey: how effective are the changes in the national blood transfusion policies?

The national blood transfusion policies have been changed significantly in recent years in Turkey. The purpose of this study was to determine the prevalence of HBV, HCV, and HIV in blood donors at the Red Crescent Center in Istanbul and to evaluate the effect of changes in the national blood transfusion policies on the prevalence of these infections. The screening results of 72695 blood donations at the Red Crescent Center in Istanbul between January and December 2007 were evaluated retrospectively. HBsAg, anti-HCV, and anti-HIV-1/2 were screened by microparticle enzyme immunoassay (MEIA) method. Samples found to be positive for anti-HIV 1/2 and anti-HCV were confirmed by Inno-Lia HCV Ab III and Inno-Lia HIV I/II Score, respectively. The seropositivity rates for HBsAg, anti-HCV, and anti-HIV-1/2 were determined as 1.76%, 0.07%, and 0.008%, respectively. Compared to the previously published data from Red Crescent Centers in Turkey, it was found that HBV and HCV seroprevalances decreased and HIV seroprevalance increased in recent years. In conclusion, we believe that the drop in HBV and HCV prevalence rates are likely multifactorial and may have resulted from more diligent donor questioning upon screening, a higher level of public awareness on viral hepatitis as well as the expansion of HBV vaccination coverage in Turkey. Another factor to contribute to the decreased prevalence of HCV stems from the use of more sensitive confirmation testing on all reactive results, thereby eliminating a fair amount of false positive cases. Despite similar transmission routes, the increase in HIV prevalence in contrast to HBV and HCV may be linked to the increase in AIDS cases in Turkey in recent years.

Management of HIV-infected patients with ESRD

Patients infected with human immunodeficiency virus (HIV) often progress to ESRD. In the era of highly active antiretroviral therapy, the care of these patients has become increasingly complex as survival has improved. Patients infected with HIV who also have ESRD are at risk for critical interactions between medication regimens to treat both of these conditions. Within this population, hemo- and peritoneal dialysis as well as kidney transplantation are life sustaining but present a host of obstacles related to HIV monitoring and risk of transmission, access thrombosis, infection, and rejection. Knowledge of antiretroviral regimens, drug interactions, and HIV resistance as well as the management of ESRD in the presence of HIV infection will improve the care of these unique patients.

Human Immunodeficiency Virus (HIV) Infection Screening in a Dialysis Unit

BACKGROUND

Human immunodeficiency virus (HIV) screening is a routine for long-term hemodialysis patients because of a high risk for infection. Enzyme-immunoassay (EIA) is a simple tool for screening HIV, but clinically false-positive EIA is a frequent result. Other tests such as Western blot analysis (WB) and HIV DNA and RNA by polymerase chain reaction have better specificity and sensitivity, but they cannot be accessible in many dialysis units.

METHODS

Four hundred and four patients with end stage renal disease on long-term hemodialysis were screened with EIA for HIV antibodies. Repeated EIA was performed if the first test was positive result. WB was used as the confirmatory test.

RESULTS

Two persons initially showed a positive EIA pattern among the 404 patients, but nobody had positive WB test result later.

CONCLUSION

The ratio of false-positive EIA results for screening HIV is relatively high in long-term hemodialysis patients. Further tests should be employed to confirm the diagnosis.

Can we improve the management of blood donors with nonspecific reactivity in viral screening and confirmatory assays?

Donors with nonspecific reactivity in viral screening or confirmatory assays are problematic for blood services because of donor management issues and product loss. Considerable experience has now accumulated in the use of screening and confirmatory assays; therefore, it is timely to examine the ways in which donors with nonspecific reactivity are managed. In this review, we summarize the causes and characteristics of nonspecific reactivity in blood donors and approaches for reducing the number of nonspecific reactive results and we offer some suggestions for improving the management of these donors.

False-positive human immunodeficiency virus antibody test in a dialysis patient

A patient developed end-stage renal disease secondary to p-anti-neutrophil cytoplasmic antibody (p-ANCA) positive rapidly progressive glomerulonephritis. He subsequently had human immunodeficiency virus (HIV)-1 antibody screening performed as part of a pre-transplant evaluation. The HIV-1 enzyme immunoassay (EIA) antibody test was repeatedly reactive. The HIV-1 western blot was indeterminate. The western blot pattern revealed "non-specific staining obscuring bands in that region." Another sample of serum was sent and the results were identical to the first result. An HIV-1 proviral qualitative polymerase chain reaction test was then performed several months later and no HIV-1 DNA was detected. One year later, an HIV-1 RNA test was negative. Thus, the positive antibody EIA test and the indeterminate western blot represent a false-positive result, most likely due to cross-reacting antigens in the patient's serum with various HIV antibodies. Throughout this period and thereafter, the patient has exhibited no symptoms of HIV infection.

Analysis of voluntary blood donors with biologic false reactivity on chemiluminescent immunoassays and implications for donor management

BACKGROUND

Biologic false-reactive (BFR) results in blood donors are problematic due to both component loss and donor-management issues. This report analyzes the results of a longitudinal study of BFR donors and the implications for donor management.

STUDY DESIGN AND METHODS

Donors who gave BFR results on HBsAg, HIV-1/HIV-2, HCV, or HTLV-I/HTLV/II chemiluminescent immunoassays (ChLIAs) (PRISM, Abbott) between May 1997 to March 1999 were analyzed. Donors were followed up for up to three donations after an index BFR episode. In addition, results of any negative donations before the index BFR result but within the study period were included in the analysis.

RESULTS

For donors who gave an index BFR result on the HBsAg ChLIA, 14.3 percent remained BFR at subsequent donations, whereas for the anti-HIV-1/HIV-2, anti-HCV, and anti-HTLV-I/HTLV-II ChLIAs, the figures were 66.0, 77.4, and 71.6 percent, respectively. For donors who gave a second BFR result, the percentage who remained BFR at subsequent donations was 75.0, 80.6, 84.6, and 74.5 percent for the four assays, respectively. The rate at which negative repeat donors became BFR during the study period was 0.02, 0.07, 0.12, and 0.02 percent for the HBsAg, anti-HIV-1/HIV-2, anti-HCV, and anti-HTLV-I/HTLV-II assays, respectively.

CONCLUSIONS

Our results indicate that donors who give an index BFR result on the ChLIAs (PRISM, Abbott) should be allowed to continue donating because most donors with a HBsAg BFR result were negative at subsequent donations, and between 22.6 and 34.0 percent of those with BFR results on the HIV-1/HIV-2, HCV, or HTLV-I/HTLV-II assays gave subsequent negative donations. However, donors who give a second BFR result should be counseled and deferred because they were very unlikely to give subsequent negative results.

Molecular aspects of T- and B-cell function in uremia

Chronic renal failure is associated with severe alterations of the immune system. Infections are responsible for a large part of the mortality in hemodialysis patients, and vaccination is mostly ineffective. Global tests of the immune function show greatly diminished activation of T cells. However, the intrinsic function of T and B cells is normal when they are provided with normal signaling from antigen-presenting cells (APCs). Patients with chronic renal failure show a defective function of costimulation derived from APCs leading to impaired activation of effector lymphocytes. Two major components of immune deviation are relevant: reduced signaling caused by impaired expression of the costimulatory molecule B7-2 (CD86) on monocytes leads to low activation of helper T cells. This dysfunction is associated with uremia and may be improved by high-efficiency renal replacement therapy. The other component is inflammatory activation of APCs mainly due to the hemodialysis procedure. Inflammation, characterized by overproduction of cytokines such as interleukin-1beta (IL-1beta) or IL-6, correlates with low effector activation. Furthermore, inflammatory cytokines such as IL-12 deviate the functional pattern of T-cell activation toward Th1 differentiation, thus leading to an additional reduction of Th2- and B-cell function. The individual severity of inflammatory alterations is partially controlled by the negatively regulating cytokine IL-10, which, on a genetic basis, can be up-regulated to a different extent in individual patients. Therapeutic interventions to improve immune dysfunction include the enhancement of dialysis efficiency and the reduction of inflammatory alterations by the use of highly biocompatible dialyzers.