Derangements of immunological proteins in HIV-associated diffuse large B-cell lymphoma: the frequency and prognostic impact.

Introduction: Diffuse large B-cell lymphoma (DLBCL) is an aggressive malignancy of B-cells frequently encountered among people living with HIV. Immunological abnormalities are common in immunocompetent individuals with DLBCL, and are often associated with poorer outcomes. Currently, data on derangements of immunological proteins, such as cytokines and acute phase reactants, and their impact on outcomes in HIV-associated DLBCL (HIV-DLBCL) is lacking. This study assessed the levels and prognostic relevance of interleukin (IL)-6, IL-10 and Transforming Growth Factor Beta (TGFß), the acute phase proteins C-reactive protein (CRP) and ferritin; serum free light chains (SFLC) (elevation of which reflects a prolonged pro-inflammatory state); and the activity of the immunosuppressive enzyme Indoleamine 2,3-dioxygenase (IDO)in South African patients with DLBCL. Methods: Seventy-six patients with incident DLBCL were enrolled, and peripheral blood IL-6, IL-10, TGFß, SFLC and IDO-activity measured in selected patients. Additional clinical and laboratory findings (including ferritin and CRP) were recorded from the hospital records. Results: Sixty-one (80.3%) of the included patients were people living with HIV (median CD4-count = 148 cells/ul), and survival rates were poor (12-month survival rate 30.0%). The majority of the immunological proteins, except for TGFß and ferritin, were significantly higher among the people living with HIV. Elevation of IL-6, SFLC and IDO-activity were not associated with survival in HIV-DLBCL, while raised IL-10, CRP, ferritin and TGFß were. On multivariate analysis, immunological proteins associated with survival independently from the International Prognostic Index (IPI) included TGFß, ferritin and IL-10. Conclusion: Derangements of immunological proteins are common in HIV-DLBCL, and have a differential association with survival compared to that reported elsewhere. Elevation of TGFß, IL-10 and ferritin were associated with survival independently from the IPI. In view of the poor survival rates in this cohort, investigation of the directed targeting of these cytokines would be of interest in our setting.

Hepatitis C Virus Genotype 5 Variability in Treatment-Naïve Patients in South Africa.

INTRODUCTION: Hepatitis C virus (HCV) genotype 5 was originally identified in South Africa, where it represents 35-60% of all HCV infections. There are limited data on resistance-associated variants (RAVs) in South Africa. Thus, we investigated variability within the NS3/NS4A, NS5A, and NS5B genes of treatment-naïve individuals with HCV genotype 5 infection at the Dr. George Mukhari Academic Hospital (DGMAH) in Pretoria, South Africa. METHODS: Nested PCR was performed to amplify the NS3/4A, NS5A, and NS5B genes. RAVs were evaluated using the Geno2pheno tool. RESULTS: In the NS3/4A gene, F56S and T122A were detected in one sample each. The D168E mutation was detected in 7 samples. Within the NS5A gene, the T62M mutation was detected in 2 individuals. In the NS5B gene, 8 of 12 individuals (67%) had the A421V mutation, while all 12 individuals (100%) had the S486A mutation. DISCUSSION: RAVs were detected frequently among treatment-naïve individuals with HCV genotype 5 infection in South Africa. Thus, resistance testing may be prudent when initiating treatment of patients with genotype 5 infection. Additional population-based studies are needed to understand the prevalence of these RAVs during HCV genotype 5 infection.

The Association between Symptomatic Rotavirus Infection and Histo-Blood Group Antigens in Young Children with Diarrhea in Pretoria, South Africa.

OBJECTIVES: Recently, histo-blood group antigens (HBGAs) have been identified as receptors or attachment factors of several viral pathogens. Among rotaviruses, HBGAs interact with the outer viral protein, VP4, which has been identified as a potential susceptibility factor, although the findings are inconsistent throughout populations due to HBGA polymorphisms. We investigated the association between HBGA phenotypes and rotavirus infection in children with acute gastroenteritis in northern Pretoria, South Africa. METHODS: Paired diarrheal stool and saliva samples were collected from children aged ≤ 59 months (n = 342) with acute moderate to severe diarrhea, attending two health care facilities. Rotaviruses in the stool samples were detected by commercial EIA and the rotavirus strains were characterized by RT-PCR targeting the outer capsid VP7 (G-type) and VP4 (P-type) antigens for genotyping. Saliva-based ELISAs were performed to determine A, B, H, and Lewis antigens for blood group typing. RESULTS: Blood type O was the most common blood group (62.5%) in this population, followed by groups A (26.0%), B (9.3%), and AB (2.2%). The H1-based secretors were common (82.7%) compared to the non-secretors (17.3%), and the Lewis antigen positive phenotypes (Le(a+b+)) were predominant (54.5%). Blood type A children were more likely to be infected by rotavirus (38.8%) than any other blood types. P[4] rotaviruses (21/49; 42.9%) infected only secretor individuals, whereas P[6] rotaviruses (3/49; 6.1%) only infected Le(a-b-), although the numbers were very low. On the contrary, P[8] rotaviruses infected children with a wide range of blood group phenotypes, including Le(a-b-) and non-secretors. CONCLUSIONS: Our findings demonstrated that Lewis antigens, or the lack thereof, may serve as susceptibility factors to rotaviral infection by specific VP4 genotypes as observed elsewhere. Potentially, the P[8] strains remain the predominant human VP4 genotype due to their ability to bind to a variety of HBGA phenotypes.

Intestinal fatty acid binding protein (I-FABP) and CXC3L1 evaluation as biomarkers for patients at high-risk for coeliac disease in Johannesburg, South Africa.

Coeliac disease (CD) is an autoimmune disorder and one of the few gastroenteropathies with accurate serological testing. CD serology has decreased accuracy for patients on a gluten-free diet and for monitoring mucosal healing. New ancillary tests would, therefore, be useful. Intestinal Fatty Acid Binding Protein (I-FABP) and CX3CL1 (Fractalkine) are two promising biomarkers for CD but haven't been examined in patients who are at a high-risk for CD such as patients with type one diabetes (TID). This study, therefore, aimed to investigate serum levels of I-FABP and CX3CL1 in a cohort of South African patients with TID at a high-risk of developing CD. The serum I-FABP levels were significantly higher in CD-positive patients compared to CD-negative individuals (p = 0.03). No significant differences in the serum CX3CL1 levels were detected although this may reflect the impact of the comorbid autoimmune diseases had on the serum CX3CL1 levels. In conclusion, this study is the first to assess the levels of these biomarkers in a multiethnic population with comorbid autoimmune disease and determined I-FABP to be the more promising biomarker in such clinical contexts. Future research should focus on a diverse biomarker panel and longitudinal follow-up of patients at a high-risk for CD.

SARS-CoV-2 Host Immunogenetic Biomarkers.

SARS-CoV-2 causes generally mild symptoms, with approximately 10-20% of cases progressing to severe disease. The pathophysiologic mechanisms by which SARS-CoV-2 causes severe disease are largely unknown. Data have indicated the involvement of different immunogenetic markers such as HLA, T, and B cells, to be associated with disease outcome. This has led to interest in these genes as potential biomarkers of SARS-CoV-2 susceptibility and for predicting prognosis and response to vaccines and other therapeutic strategies. In this chapter, we discussed outline protocols for characterizing these potential biomarkers and methods for identifying SARS-CoV-2 biomarkers using the Luminex® 100/200 technology and next-generation sequencing.

Evaluation Protocol for SARS-CoV-2 Serological Assays.

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has been identified as the causative agent of COVID-19. Accurate detection of SARS-CoV-2 infection is not only important for management of infected individuals but also to break the chain of transmission. Although the polymerase chain reaction (PCR) is the gold standard for diagnosis of acute SARS-CoV-2 infection, there are a number of limitations of these assays, which include the inability to detect past infection and decline in sensitivity 14 days post-symptom onset. There are several serology tests developed for the detection of SARS-CoV-2 antibodies including high-throughput serology platforms and lateral flow immunoassays. These tests should be evaluated for their performance to meet local regulations acceptance criteria. To optimize the diagnostic algorithm for SARS-CoV-2, this protocol describes the evaluation of serological antibody testing using various automated serology platforms and lateral flow immunoassays. This protocol was evaluated in both serum and plasma samples. The sample preparation, procedure, and data analysis are described. The protocol can be adapted for any serological testing.

Thrombotic thrombocytopenic purpura in HIV-infected patients: new twists on an old disease.

OBJECTIVE: Investigate the presence of inflammation, endothelial dysfunction and complement activation in patients with HIV-associated thrombotic thrombocytopenic purpura (HIV-TTP) to support the hypothesis that these processes probably contribute to the development of this thrombotic microangiopathy. DESIGN: A prospective, investigational cohort study of 35 consecutive patients diagnosed with HIV-associated TTP presenting to three academic, tertiary care hospitals in Johannesburg, South Africa over 2 years. METHODS: The patients with HIV-TTP received therapeutic plasma therapy and supportive treatment. Demographic data, the results of routine investigations and patient outcomes were recorded. Peripheral blood samples were collected prior to and on completion of plasma therapy and the following additional parameters were assessed at both time points: activity of the von Willebrand factor (VWF) cleaving protease, a-disintegrin-and-metalloproteinase-with-thrombospondin-motifs 13 (ADAMTS-13) and the presence of ADAMTS-13 autoantibodies, levels of pro-inflammatory cytokines, interleukin-6 and tumour necrosis factor-alpha, and two endothelial cell adhesion molecules. Complement activation was assessed by sequential measurement of C3 and C4 as well as levels of the complement inhibitor, factor H. RESULTS: The inflammatory and endothelial activation markers were significantly ( P  < 0.001) elevated in the cohort of patients prior to plasma therapy compared with levels on discharge. Complement was activated and normalized with therapy. The ADAMTS-13 levels were reduced with significant auto-antibodies to this protease at presentation. CONCLUSION: Inflammation in HIV mediates endothelial damage and complement activation. This study proposes that these processes are probably contributory to the development of HIV-TTP, which can therefore be characterized in part as a complementopathy, resembling TTP-like syndrome.

Performance of the Abbott SARS-CoV-2 IgG serological assay in South African 2 patients.

In late December 2019, pneumonia cases of unknown origin were reported in Wuhan, China. This virus was named SARS-CoV2 and the clinical syndrome was named coronavirus disease 19 (COVID-19). South Africa, despite strict and early lockdown has the highest infection rate in Africa. A key component of South Africa's response to SARSCoV2 was the rapid scale-up of diagnostic testing. The Abbott SARS-CoV2 assay detects IgG antibodies against the Nucleocapsid (N) protein of the SARS-CoV2 virus. This study undertook to validate and evaluate performance criteria of the Abbott assay and to establish whether this assay would show clinical utility in our population. Positive patients (n = 391) and negative controls (n = 139) were included. The Architect-i and Alinity-i systems were analyzers that were used to perform the SARS-CoV-2 IgG assay. In-house ELISA was incorporated into the study as a confirmatory serology test. A total of number of 530 participants was tested, 87% were symptomatic with infection and 13% were asymptomatic. When compared to RT-qPCR, the sensitivity of Architect and Alinity SARS-CoV2 assays was 69.5% and 64.8%, respectively. Specificity for Architect and Alinity assays was 95% and 90.3%, respectively. The Abbott assay was also compared to in house ELISA assay, with sensitivity for the Architect and Alinity assays of 94.7% and 92.5%, respectively. Specificity for Abbott Alinity assays was 91.7% higher than Abbott Architect 88.1%. Based on the current findings testing of IgG after 14 days is recommended in South Africa and supports other studies performed around the world.

Biomarkers of Endothelial Activation in Black South African HIV-Positive Subjects are Associated with Both High Viral Load and Low CD4 Counts.

The prevalence of cardiovascular death in the HIV-infected population is higher than in uninfected individuals. Growing evidence suggests that HIV infection itself is directly linked to endothelial activation and dysfunction. Therefore, the aim of this study was to investigate whether endothelial activation is present in African subjects with HIV infection and identify its possible determinants. Eighty HIV-infected treatment-naive cases, categorized into two groups based on CD4 count (38 subjects with CD4 count ≤350 cells/mm3 and 42 subjects with CD4 count >350 cells/mm3), were compared with 60 HIV-uninfected controls. A small subgroup of the HIV-infected participants (n = 13) were followed up for 18 months following initiation of antiretroviral therapy (ART). Anthropometric data, fasting lipid and glucose levels, viral load, and CD4 counts were measured as were serum levels of intercellular adhesion molecule-1 (ICAM-1), endothelial leukocyte adhesion molecule-1, vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein-1, von Willebrand factor (vWF), tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and interleukin-8 (IL-8). The HIV-infected low CD4 group had higher levels of ICAM-1 (p < .05), VCAM-1 (p < .0005), TNF-α (p < .005), and vWF (p < .005), compared with the controls. In the HIV-infected cohort, VCAM-1 levels were negatively associated with CD4 counts (ß = -0.474; p < .0005), whereas vWF levels were positively associated with viral load (ß = 0.344; p < .01). Levels of ICAM-1 and VCAM-1 were reduced by ART (p < .05 vs. baseline for both), however, levels of IL-6, IL-8, and TNF-α increased (p < .005 vs. baseline for all). Endothelial activation and inflammation are evident in African ART-naive HIV-infected patients; the former is attenuated, and the latter is increased after 18 months of ART. In HIV-infected subjects, both immunological dysregulation and viral load are associated with biomarkers of endothelial activation.

Human Leukocyte Antigen Typing with Sequence Specific Oligonucleotides for Renal Transplantation in South Africa.

BACKGROUND: Kidney transplants are the only curative therapeutic intervention for end-stage kidney disease (ESKD). The current organ shortage in South Africa makes recipient risk assessments and effective laboratory workup crucial to assist in better organ assignment and increase the likelihood of better transplant outcomes. HLA typing is a step in the pre-transplant workup for performing virtual crossmatches and matching donors and recipients. Sequence Specific Oligonucleotide (SSO) PCR is a relatively fast and inexpensive method for determining genotypic HLA types at a 2- to 4-digit resolution. This study aimed to validate the SSO technique for achieving a 4-digit resolution when determining HLA types to improve virtual crossmatches. METHODS: DNA was extracted from 33 samples. After PCR amplification, the samples were hybridized to oligonu-cleotide probes and the HLA A, B, C, DRB1, DQA1/B1, DRB3, DRB4, DRB5, and DPA1/B1 types were identified. These results were compared to results from external laboratories. RESULTS: The kappa coefficient calculated for the low-resolution comparison suggested a perfect agreement between the two results (p = 0.32). CONCLUSIONS: SSO was successfully validated for HLA typing in the Johannesburg kidney transplant setting. This will improve the specificity of virtual crossmatches on an automated system by matching the resolution of the HLA typing and the HLA antibody testing. Additionally, common HLA types were identified in this donor cohort. Future research into these common HLA types and haplotypes in a South African population will inform the feasibility of reintroducing HLA matching into the pretransplant workup.

In silico analysis of mutations associated with occult hepatitis B virus (HBV) infection in South Africa.

Occult hepatitis B virus (OBI) infection is defined by the presence of viral DNA in the liver and/or serum in absence of hepatitis B surface antigen (HBsAg). While multiple studies have identified mutations that are associated with OBI, only a small portion of these mutations have been functionally characterized in vitro. Using complementary in silico approaches, the effects of OBI-associated amino acid mutations on HBV protein function in HBV/HIV-positive ART-naïve South Africans were evaluated. Two OBI-associated mutations in the PreS1 region, one in the PreS2 region, and seven in the surface region of subgenotype A1 sequences were identified as deleterious. In subgenotype A2 sequences, 11 OBI-associated mutations in the PreS1 region, seven in the PreS2 region, and 31 in the surface region were identified as deleterious. In the polymerase region, 14 OBI-associated mutations in subgenotype A1 and 71 OBI-associated mutations in subgenotype A2 were identified as deleterious. This study utilized in silico approaches to characterize the likely impact of OBI-associated mutations on viral function, thereby identifying and prioritizing candidates and reducing the significant cost associated with functional studies that are essential for mechanistic studies of the OBI phenotype.

Diagnosing coeliac disease: A literature review.

Coeliac disease (CD) is an autoimmune gastroenteropathy triggered by gliadin and gliadin-tissue transglutaminase (tTG) complexes. CD is one of the few autoimmune diseases with an accurate, non-invasive serological test. Anti-endomysial, anti-tTG and anti-deaminated gliadin peptides (DGP) antibodies are currently used for serological tests with tTG ELISAs being the superior test. Duodenal biopsy, although invasive, is the gold standard for CD diagnosis. HLA genotyping and flow cytometry can also be used as supplementary tests. The incidence of CD is rising globally although the reasons for this remain unclear. In addition, the true incidence of coeliac disease in African populations remains unknown although recent work suggests that South African populations express the alleles associated with this disease. This review examines the pathogenesis and diagnosis of coeliac disease and considers novel and innovative biomarkers in its diagnosis specifically in an African population.

Operational characteristics of 30 lateral flow immunoassays used to identify COVID-19 immune response.

Serology or antibody tests for COVID-19 are designed to detect antibodies (mainly Immunoglobulin M (IgM) and Immunoglobulin G (IgG) produced in response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS CoV-2) infection. In this study, 30 lateral flow immunoassays were tested using serum or plasma from patients with confirmed SARS CoV-2 infection. Negative serological controls were accessed from a well-characterised bank of sera which were stored prior to February 2020. Operational characteristics and ease of use of the assays are reported. 4/30 (13%) of kits (Zheihang Orient Gene COVID-19 IgG/IgM, Genrui Novel Coronavirus (2019-nCoV) IgG/IgM, Biosynex COVID-19 BSS IgG/IgM, Boson Biotech 2019-nCoV IgG/IgM) were recommended for SAHPRA approval based on kit sensitivity. Of these, only the Orientgene was recommended by SAHPRA in August 2020 for use within the approved national testing algorithm while the remaining three received limited authorization for evaluation. All kits evaluated work on the same basic principle of immunochromatography with minor differences noted in the shape and colour of cartridges, the amount of specimen volume required and the test duration. Performance of the lateral flow tests were similar to sensitivities and specificities reported in other studies. The cassettes of the majority of kits evaluated (90%) detected both IgG and IgM. Only 23% of kits evaluated contained all consumables required for point-of-care testing. The study highlights the need for thorough investigation of kits prior to implementation.

Performance of the EUROIMMUN Anti-SARS-CoV-2 ELISA Assay for detection of IgA and IgG antibodies in South Africa.

Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2) has been identified as the causative agent for causing the clinical syndrome of COVID -19. Accurate detection of SARS-CoV-2 infection is not only important for management of infected individuals but also to break the chain of transmission. South Africa is the current epicenter of SARS-CoV-2 infection in Africa. To optimize the diagnostic algorithm for SARS-CoV-2 in the South African setting, the study aims to evaluate the diagnostic performance of the EUROIMMUN Anti-SARS-CoV-2 assays. This study reported the performance of EUROIMMUN enzyme-linked immunosorbent assay (ELISA) for semi-quantitative detection of IgA and IgG antibodies in serum and plasma samples targeting the recombinant S1 domain of the SARS-CoV-2 spike protein as antigen. Samples were collected from 391 individuals who had tested positive for SARS-CoV-2 and 139 SARS CoV-2 negative controls. Samples were stratified by number of days' post-PCR diagnosis and symptoms. The sensitivity of EUROIMMUN IgG was 64.1% (95% CI: 59.1-69.0%) and 74.3% (95% CI: 69.6-78.6%) for IgA and the specificity was lower for IgA [84.2% (95% CI: 77-89.2%)] than IgG [95.2% (95% CI: 90.8-98.4%)]. The EUROIMMUN Anti-SARS-CoV-2 ELISA Assay sensitivity was higher for IgA but low for IgG and improved for both assays in symptomatic individuals and at later timepoints post PCR diagnosis.

SARS-CoV-2 Antigens Expressed in Plants Detect Antibody Responses in COVID-19 Patients.

Background: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has swept the world and poses a significant global threat to lives and livelihoods, with 115 million confirmed cases and at least 2.5 million deaths from Coronavirus disease 2019 (COVID-19) in the first year of the pandemic. Developing tools to measure seroprevalence and understand protective immunity to SARS-CoV-2 is a priority. We aimed to develop a serological assay using plant-derived recombinant viral proteins, which represent important tools in less-resourced settings. Methods: We established an indirect ELISA using the S1 and receptor-binding domain (RBD) portions of the spike protein from SARS-CoV-2, expressed in Nicotiana benthamiana. We measured antibody responses in sera from South African patients (n = 77) who had tested positive by PCR for SARS-CoV-2. Samples were taken a median of 6 weeks after the diagnosis, and the majority of participants had mild and moderate COVID-19 disease. In addition, we tested the reactivity of pre-pandemic plasma (n = 58) and compared the performance of our in-house ELISA with a commercial assay. We also determined whether our assay could detect SARS-CoV-2-specific IgG and IgA in saliva. Results: We demonstrate that SARS-CoV-2-specific immunoglobulins are readily detectable using recombinant plant-derived viral proteins, in patients who tested positive for SARS-CoV-2 by PCR. Reactivity to S1 and RBD was detected in 51 (66%) and 48 (62%) of participants, respectively. Notably, we detected 100% of samples identified as having S1-specific antibodies by a validated, high sensitivity commercial ELISA, and optical density (OD) values were strongly and significantly correlated between the two assays. For the pre-pandemic plasma, 1/58 (1.7%) of samples were positive, indicating a high specificity for SARS-CoV-2 in our ELISA. SARS-CoV-2-specific IgG correlated significantly with IgA and IgM responses. Endpoint titers of S1- and RBD-specific immunoglobulins ranged from 1:50 to 1:3,200. S1-specific IgG and IgA were found in saliva samples from convalescent volunteers. Conclusion: We demonstrate that recombinant SARS-CoV-2 proteins produced in plants enable robust detection of SARS-CoV-2 humoral responses. This assay can be used for seroepidemiological studies and to measure the strength and durability of antibody responses to SARS-CoV-2 in infected patients in our setting.

Genetic characterization of G12P[6] and G12P[8] rotavirus strains collected in six African countries between 2010 and 2014.

BACKGROUND: G12 rotaviruses were first observed in sub-Saharan Africa in 2004 and since then have continued to emerge and spread across the continent and are reported as a significant human rotavirus genotype in several African countries, both prior to and after rotavirus vaccine introduction. This study investigated the genetic variability of 15 G12 rotavirus strains associated with either P[6] or P[8] identified between 2010 and 2014 from Ethiopia, Kenya, Rwanda, Tanzania, Togo and Zambia. METHODS: The investigation was carried out by comparing partial VP7 and partial VP4 sequences of the African G12P[6] and G12P[8] strains with the available GenBank sequences and exploring the recognized neutralization epitopes of these strains. Additionally, Bayesian evolutionary analysis was carried out using Markov Chain Monte Carlo (MCMC) implemented in BEAST to estimate the time to the most recent ancestor and evolutionary rate for these G12 rotavirus strains. RESULTS: The findings suggested that the VP7 and VP4 nucleotide and amino acid sequences of the G12 strains circulating in African countries are closely related, irrespective of country of origin and year of detection, with the exception of the Ethiopian strains that clustered distinctly. Neutralization epitope analysis revealed that rotavirus VP4 P[8] genes associated with G12 had amino acid sequences similar to those reported globally including the vaccine strains in RotaTeq and Rotarix. The estimated evolutionary rate of the G12 strains was 1.016 × 10- 3 substitutions/site/year and was comparable to what has been previously reported. Three sub-clusters formed within the current circulating lineage III shows the diversification of G12 from three independent ancestries within a similar time frame in the late 1990s. CONCLUSIONS: At present it appears to be unlikely that widespread vaccine use has driven the molecular evolution and sustainability of G12 strains in Africa. Continuous monitoring of rotavirus genotypes is recommended to assess the long-term impact of rotavirus vaccination on the dynamic nature of rotavirus evolution on the continent.

A Retrospective Study on Human Leukocyte Antigen Types and Haplotypes in a South African Population.

CONTEXT.­: Human leukocyte antigen (HLA) is a polymorphic protein of the immune system with a central role in organ transplantation. Organ recipients can be sensitized against HLA from previous exposure, which increases the likelihood of antidonor immune responses and subsequently organ rejection. HLA matching represents an attractive option to improve graft function, reduce sensitization of recipients in first transplantations, and improve organ allocation. OBJECTIVE.­: To examine the feasibility of the reintroduction of HLA matching into the criteria in the Johannesburg program, we retrospectively assessed HLA types in our donor population. DESIGN.­: HLA types of 782 deceased and related living donors from 2015 until 2019 were recorded and analyzed to identify the most common HLA types and haplotypes. A virtual crossmatch was also done to examine the anti-HLA antibodies in the recipient population compared with the common HLA types identified in this study. RESULTS.­: Of the most common HLA types identified, at least 1 was present in 732 (93.6%) of the renal donors assessed. The virtual crossmatch confirmed that most recipients are sensitized against most donors, and this greatly impacts the number of recipients who can receive organ transplants. CONCLUSIONS.­: This study determined the most common HLA types and haplotypes in a South African organ donor population. This information, combined with the evidence suggesting the immunogenic potential of these common types, the high number of recipients with antibodies against common HLA types, and the ethnic distribution of the donor and recipient populations, informs the recommendation that the pretransplantation workup should not reinclude HLA matching.

Impact of Lamivudine-Based Antiretroviral Treatment on Hepatitis B Viremia in HIV-Coinfected South Africans.

This prospective study investigated the impact of lamivudine-containing antiretroviral therapy (ART) on HIV-positive patients in South Africa with baseline hepatitis B virus (HBV) infection. Follow-up samples from 56 HBV/HIV co-infected patients, 25 with occult HBV infection (OBI) and 31 with chronic HBV infection (CHB), were available for analysis. HBV viral loads were quantified at 6, 12, 18, and 24 months post-ART initiation by the COBAS TaqMan HBV Test 48 assay, and the HBV polymerase gene was amplified with an in-house nested polymerase chain reaction assay. During 24 months of lamivudine-based ART, 6 of 8 (75%) OBI and 4 of 6 (67%) CHB patients achieved undetectable levels of HBV DNA, while 2 patients had persistent HBV DNA levels ≥ 2 × 105 despite lamivudine-based ART for 24 months. HIV viremia was undetectable in all patients at 12 months, suggesting high adherence to ART. Several lamivudine-associated HBV resistance mutations, including L180M, A181T, M204I, and M204V, were observed. Sequence analysis also revealed a rare genotype G infection. While resource-limited settings may use lamivudine-based ART because of availability and low cost, antivirals with dual therapy against HBV and HIV (e.g., lamivudine and tenofovir) should always be recommended with the regular monitoring of HBV viremia levels.

Molecular characterization of hepatitis B virus X gene in HIV-positive South Africans.

Hepatitis B virus (HBV) infection is a major public health problem worldwide and the major cause of hepatocellular carcinoma (HCC) in South Africa. The role of HBV in HCC is not well understood, although the HBV X gene has been implicated as a critical factor. Data on the HBV X gene in HIV-positive South Africans are limited; thus, we investigated X gene variability in 24 HIV-infected treatment-naïve patients at Dr George Mukhari Academic Hospital. Quantitative and qualitative HBV DNA tests were conducted using real-time and in-house polymerase chain reaction (PCR) assays, respectively, targeting the complete HBV X gene. In-house PCR-positive samples were cloned using the P-Gem T-easy vector System II and sequenced. By phylogenetic analysis, X gene sequences were classified as subgenotype A1 (n = 15), A2 (n = 4), and D1 (n = 4), and one dual infection with subgenotypes as A1 and C. The basal core promoter mutations T1753C, A1762T, and G1764A were identified in the majority of sequences. Genotype D sequences had a 6-nucleotide insertion. In conclusion, subgenotype A1 was predominant, and a rare dual infection of HBV genotype A and C was detected. The 6-nucleotide insertion could represent a unique variant in the region and highlights the need for functional studies of HBV X gene variants, particularly from resource-limited settings.