Advances in laboratory testing for HIV

Clinical, epidemiological, and drug resistance insights into HIV-positive patients in Meizhou, China

The acquired immunodeficiency syndrome (AIDS) epidemic, resulting from human immunodeficiency virus (HIV) infection, exhibits distinct regional characteristics. This study undertakes a retrospective analysis of the epidemiological and clinical features of 195 HIV-positive cases in Meizhou, China, from May 1, 2018 to December 31, 2019. Western blotting (WB) confirmed and assessed these cases. Notably, the majority of cases emanated from socio-economic groups with comparatively lower levels of education, with 80% being male. Strikingly, 90% of the cases were found to be in the middle to late stages of infection based on CD4+ T cell counts. Among the 30 different serum antibody profiles examined, reactivity with seven bands (p24, p31, gp41, p51, p66, gp120, and gp160) emerged as the most commonly observed WB pattern. The absence of specific bands, specifically p55 (17.44%), p39 (32.31%), and p17 (25.64%) were most frequent, with the detection frequency of p17 bands significantly reduced among cases in the AIDS and middle stages. An analysis of drug resistance genotypes indicated that, despite viral mutations conferring resistance to certain reverse transcriptase inhibitors, the first-line treatment regimen remained effective for patients in Meizhou. Notably, mutations resistant to protease inhibitors were infrequent (2.7%), suggesting that incorporating protease inhibitors into the treatment regimen may enhance therapeutic outcomes for local patients. These findings provide essential insights into the specific epidemiological patterns, serum antibody profiles, and drug resistance genotypes of HIV-infected patients in Meizhou. Significantly, this research contributes to the formulation of future treatment strategies tailored to the local context.

Western Blot-Based Logistic Regression Model for the Identification of Recent HIV-1 Infection: A Promising HIV-1 Surveillance Approach for Resource-Limited Regions

Objectives

Identifying recent infections is necessary to monitor HIV/AIDS epidemic; however, it needs to be further developed.

Methods and Results

Participants were defined as having recent infection or older infection according to the estimated duration of HIV-1 infection and further assigned into training set and validation set according to their entering time points. Western blot (WB) confirmatory test and BED-CEIA were performed. The performance of the two methods on recent HIV-1 diagnosis was evaluated and compared. 81 subjects were enrolled in the training set and 72 in the validation set. Relative grey ratios of p24, p39, p31, p66, gp41, and gp160 were significantly higher in older infected patients of the training set. The present status of p55 was more frequently missing in recently infected patients in both sets. The logistic stepwise regression analysis of WB method shows sensitivity, specificity, and accuracy of 93.02%, 92.11%, and 92.59%. For BED-CEIA, they were 76.74%, 86.84%, and 81.48%. In the validation set, overall agreement rate, sensitivity, and specificity were 88.46%, 84.78%, and 86.11% in the WB-based method and 50.00%, 84.78%, and 72.22% in the BED-CEIA method.

Conclusions

WB-based method is a promising approach to predict recent HIV-1 infection, especially in resource-limited regions.

Evaluation of an external quality assessment program for HIV testing in Haiti, 2006-2011

OBJECTIVES

To evaluate an external quality assessment (EQA) program for human immunodeficiency virus (HIV) rapid diagnostics testing by the Haitian National Public Health Laboratory (French acronym: LNSP). Acceptable performance was defined as any proficiency testing (PT) score more than 80%.

METHODS

The PT database was reviewed and analyzed to assess the testing performance of the participating laboratories and the impact of the program over time. A total of 242 laboratories participated in the EQA program from 2006 through 2011; participation increased from 70 laboratories in 2006 to 159 in 2011.

RESULTS

In 2006, 49 (70%) laboratories had a PT score of 80% or above; by 2011, 145 (97.5%) laboratories were proficient (P < .05).

CONCLUSIONS

The EQA program for HIV testing ensures quality of testing and allowed the LNSP to document improvements in the quality of HIV rapid testing over time.

Diagnostic assays used to control small ruminant lentiviruses

The serologic diagnostic tests, such as the agar gel immunodiffusion assay and various types of enzyme-linked immunosorbent assays (ELISAs), have contributed to the reduction of small ruminant lentivirus (SRLV) infections worldwide. Because there are no treatments or efficacious vaccines, the serologic diagnostic tests have supported most of the eradication efforts by testing and removal or separation of adult animals that generate antibodies to SRLVs. With the advent of molecular diagnostics, standard and quantitative polymerase chain reaction (PCR)-based assays for the detection of provirus in peripheral blood cells are becoming more common and aid in the detection of infected goats and sheep before antibody detection by ELISA in some animals. Performance of the serologic and molecular diagnostic tests is dependent upon a number of factors, including the format of the assay, the percentage of identity between the viral nucleotide sequences in a flock or herd of a certain geographic region and the sequences used to generate SRLV test reagents, and the intrinsic pathogenesis or amount of provirus and SRLV antibody generated in a species or individual small ruminant. In addition, small ruminant genomics may help with establishing genetic markers of SRLV infection and disease, which could also aid eradication or reduction of SRLVs from herds and flocks throughout the world.

Human Immunodeficiency Virus (HIV) types Western blot (WB) band profiles as potential surrogate markers of HIV disease progression and predictors of vertical transmission in a cohort of infected but antiretroviral therapy naïve pregnant women in Harare, Zimbabwe

Background

Expensive CD4 count and viral load tests have failed the intended objective of enabling access to HIV therapy in poor resource settings. It is imperative to develop simple, affordable and non-subjective disease monitoring tools to complement clinical staging efforts of inexperienced health personnel currently manning most healthcare centres because of brain drain. Besides accurately predicting HIV infection, sequential appearance of specific bands of WB test offers a window of opportunity to develop a less subjective tool for monitoring disease progression.

Methods

HIV type characterization was done in a cohort of infected pregnant women at 36 gestational weeks using WB test. Student-t test was used to determine maternal differences in mean full blood counts and viral load of mothers with and those without HIV gag antigen bands. Pearson Chi-square test was used to assess differences in lack of bands appearance with vertical transmission and lymphadenopathy.

Results

Among the 64 HIV infected pregnant women, 98.4% had pure HIV-1 infection and one woman (1.7%) had dual HIV-1/HIV-2 infections. Absence of HIV pol antigen bands was associated with acute infection, p = 0.002. All women with chronic HIV-1 infection had antibody reactivity to both the HIV-1 envelope and polymerase antigens. However, antibody reactivity to gag antigens varied among the women, being 100%, 90%, 70% and 63% for p24, p17, p39 and p55, respectively. Lack of antibody reactivity to gag p39 antigen was associated with disease progression as confirmed by the presence of lymphadenopathy, anemia, higher viral load, p = 0.010, 0.025 and 0.016, respectively. Although not statistically significant, women with p39 band missing were 1.4 times more likely to transmit HIV-1 to their infants.

Conclusion

Absence of antibody reactivity to pol and gag p39 antigens was associated with acute infection and disease progression, respectively. Apart from its use in HIV disease diagnosis, WB test could also be used in conjunction with simpler tests like full blood counts and patient clinical assessment as a relatively cheaper disease monitoring tool required prior to accessing antiretroviral therapy for poor resource settings. However, there is also need to factor in the role of host-parasite genetics and interactions in disease progression.

Immunoassays for the diagnosis of HIV: meeting future needs by enhancing the quality of testing

Immunoassays for detecting HIV infection perform better than other serological assays. HIV immunoassays are presented in a number of different formats: instrument-based, plate, rapid assays and as immunoblots. HIV immunoassays for screening and diagnosis are now in their fourth generation; an assay generation meaning that significant modifications to the assay format have led to a significant enhancement in quality. Although still not perfect, they are now of exceptionally high quality if conducted properly. Most problems relate to how the assays are performed. Many laboratories, especially in high human development index (HDI) countries, manage testing within functioning quality-management systems, but this is not true of laboratories in low HDI countries or in many medium HDI countries. Simple rapid tests for HIV are being used increasingly, and create special challenges for assuring quality. Users of HIV immunoassays are learning that a poorer assay used well has better outcomes than a splendid assay performed poorly. Experience highlights the importance of conducting HIV testing within quality-managed systems and according to international standards, but testing quality and laboratory quality management must be funded adequately.

Assessing proficiency of interpretation of rapid human immunodeficiency virus assays in nonlaboratory settings: ensuring quality of testing

Rapid antibody tests for the detection of human immunodeficiency virus (HIV) offer an effective means of providing a timely result of HIV serostatus to individuals. The increased use of rapid HIV antibody tests outside the laboratory has highlighted the need for new, cost-effective quality assurance methods to be developed for use in nonlaboratory-based and resource-limited settings. Photographed rapid HIV test results were used in a modified external quality assessment scheme to assess the interpretation proficiency and, therefore, to assess the feasibility of using this method as a basis for a quality assessment program for nonlaboratory-based testing. Participants (n = 148), both experienced and inexperienced in the performance and interpretation of rapid HIV testing, interpreted the photographed results of five rapid HIV assays. These were scored according to the degree of technical discordance. Error scores were grouped according to each participant's technical experience. The accuracy of interpretation for four of the five assays was between 80 and 97%, indicating that the photographed results of samples, including those difficult to read or borderline difficult to read, can be used to assess the proficiency of test operators in interpreting results. Participants had greater difficulty in interpreting samples of weak reactivity; this was consistent across the five assays. Experience played an important role in accurate interpretation, with experienced laboratory participants exhibiting greater proficiency (P < 0.05) in interpreting the results of three of the five rapid HIV assays. It was established that photographed results of rapid HIV assays could be interpreted with accuracy and demonstrated that prior experience resulted in a more accurate interpretation performance.

Biomarker discovery using protein microarray technology platforms: antibody-antigen complex profiling

Protein microarrays represent an important new tool in proteomic systems biology. This review focuses on the contributions of protein microarrays to the discovery of novel disease biomarkers through antibody-based assays. Of particular interest is the use of protein microarrays for immune response profiling, through which a disease-specific antibody repertoire may be defined. The antigens and antibodies revealed by these studies are useful for clinical assay development, with enormous potential to aid in diagnosis, prognosis, disease staging and treatment selection. The discovery and characterization of novel biomarkers specifically tailored to disease type and stage are expected to enable personalized medicine by facilitating preventative medicine, predictive diagnostics and individualized curative therapies.

HIV testing in 2006: issues and methods

Infection with HIV and subsequent development of AIDS is a pandemic. The Joint United Nations Program on HIV/AIDS together with the WHO and many relevant funding bodies demand that those infected should be reliably identified so that people who need, or will need, therapy may be provided for over time. This means that there is a renewed interest in testing for HIV and in laboratories' performances and quality. Whatever the conditions under which testing is performed, and whatever the levels of training, the tests and their outcomes must exhibit equivalent, high standards of performance and reliable results. This is regardless of whether testing is conducted in the most sophisticated laboratories (either diagnostic or transfusion screening) to voluntary testing and counseling centers where those conducting testing may not be technically trained. This is not currently the case, especially in some places where HIV is most prevalent. To achieve uniformly high performance standards, quality assurance programs are imperative, but currently not sufficiently valued to be well supported with adequate funding or human resources. Accurate HIV testing is a cornerstone of blood safety, diagnosis of infection, patient management and surveillance.

The evidence for a change in antenatal HIV screening policy in Australia

Australia is one of the few developed countries without routine antenatal HIV screening, despite having the resources to undertake such a screening program and the availability of antiretroviral therapy. National policy recommends that only women with identified risk factors should be offered testing; however, the Royal Australian and New Zealand College of Obstetricians and Gynaecologists recommends that all pregnant women be offered HIV testing as part of their antenatal care. Knowledge of a woman's HIV status during pregnancy allows interventions to improve her health and reduce the risk of transmission of HIV to her child. A universal antenatal HIV screening program meets many of the Wilson and Jungner criteria for population-based screening programs. This should be considered in the current review of Australia's HIV testing policy.

Ultrasensitive monitoring of HIV-1 viral load by a low-cost real-time reverse transcription-PCR assay with internal control for the 5' long terminal repeat domain

BACKGROUND

Current HIV-1 viral-load assays are too expensive for resource-limited settings. In some countries, monitoring of antiretroviral therapy is now more expensive than treatment itself. In addition, some commercial assays have shown shortcomings in quantifying rare genotypes.

METHODS

We evaluated real-time reverse transcription-PCR with internal control targeting the conserved long terminal repeat (LTR) domain of HIV-1 on reference panels and patient samples from Brazil (n = 1186), South Africa (n = 130), India (n = 44), and Germany (n = 127).

RESULTS

The detection limit was 31.9 IU of HIV-1 RNA/mL of plasma (> 95% probability of detection, Probit analysis). The internal control showed inhibition in 3.7% of samples (95% confidence interval, 2.32%-5.9%; n = 454; 40 different runs). Comparative qualitative testing yielded the following: Roche Amplicor vs LTR assay (n = 431 samples), 51.7% vs 65% positives; Amplicor Ultrasensitive vs LTR (n = 133), 81.2% vs 82.7%; BioMerieux NucliSens HIV-1 QT (n = 453), 60.5% vs 65.1%; Bayer Versant 3.0 (n = 433), 57.7% vs 55.4%; total (n = 1450), 59.0% vs 63.8% positives. Intra-/interassay variability at medium and near-negative concentrations was 18%-51%. The quantification range was 50-10,000,000 IU/mL. Viral loads for subtypes A-D, F-J, AE, and AG yielded mean differences of 0.31 log(10) compared with Amplicor in the 10(3)-10(4) IU/mL range. HIV-1 N and O were not detected by Amplicor, but yielded up to 180 180.00 IU/mL in the LTR assay. Viral loads in stored samples from all countries, compared with Amplicor, NucliSens, or Versant, yielded regression line slopes (SD) of 0.9 (0.13) (P < 0.001 for all).

CONCLUSIONS

This method offers all features of commercial assays and covers all relevant genotypes. It could allow general monitoring of antiretroviral therapy in resource-limited settings.

Perspectives on medical research involving men in schizophrenia and HIV-related protocols

Ethical issues in research on serious physical and mental illnesses have received great attention, and yet little is known about how the perspectives of clinical research participants with different diagnoses may compare. We conducted a preliminary study to examine the attitudes of men enrolled in schizophrenia-related protocols and in HIV-related protocols regarding the importance of medical research, key aspects of research participation, and the acceptability of research involvement by various groups. A total of 33 men enrolled in schizophrenia protocols and 15 men enrolled in HIV-related protocols volunteered for our study. Respondents affirmed the importance of medical research and endorsed many positive things about participation. Autonomy and altruism were identified as motivators for research involvement. Participation by diverse groups was seen as acceptable. Respondents expressed comfort and little stress with the interview process. Men in different diagnostic groups largely saw the issues the same. Our findings thus suggest that people with schizophrenia and HIV/AIDS who are enrolled in protocols may share a number of core attitudes or beliefs related to ethical aspects of research participation. Further study is needed to explore how research involvement may influence perspectives and whether differences in views exist across people with diverse physical and mental illnesses.