Comparing the findings and diagnostic sensitivity of cardiovascular magnetic resonance in biopsy confirmed acute myocarditis with infarct-like vs. heart failure presentation.

BACKGROUND: Cardiovascular magnetic resonance (CMR) is considered the reference imaging modality in providing a non-invasive diagnosis of acute myocarditis (AM), as it allows for the detection of myocardial injury associated with AM. However, the diagnostic sensitivity and pattern of CMR findings appear to differ according to clinical presentation. METHODS: This is a retrospective cross-sectional study. Consecutive adult patients presenting to a single tertiary centre in South Africa between August 2017 and January 2022 with AM confirmed on endomyocardial biopsy (EMB) were enrolled. Patients with infarct-like symptoms, defined as those presenting primarily with chest pain syndrome with associated ST-T wave changes on electrocardiogram, or heart failure (HF) symptoms, defined as clinical signs and symptoms of HF without significant chest discomfort, were compared using contrasted CMR and parametric techniques with EMB confirmation of AM as diagnostic gold standard. RESULTS: Forty-one patients were identified including 23 (56%) with infarct-like symptoms and 18 (44%) with HF symptoms. On CMR, the infarct-like group had significantly higher ejection fractions of both ventricles (LVEF 55.3 ± 15.3% vs. 34.4 ± 13.5%, p < 0.001; RVEF 57.3 ± 10.9% vs. 42.9 ± 18.2%, p = 0.008), without significant differences in end diastolic volumes (LVEDVI 82.7 ± 30.3 ml/m2 vs. 103.4 ± 35.9 ml/m2, p = 0.06; RVEDVI 73.7 ± 22.1 ml/m2 vs. 83.9 ± 29.9 ml/m2, p = 0.25). Myocardial oedema was detected more frequently on T2-weighted imaging (91.3% vs. 61.1%, p = 0.03) and in more myocardial segments [3.0 (IQR 2.0-4.0) vs. 1.0 (IQR 0-1.0), p = 0.003] in the infarct-like group. Despite the absence of a significant statistical difference in the prevalence of late gadolinium enhancement (LGE) between the two groups (95.7% vs. 72.2%, p = 0.07), the infarct-like group had LGE detectable in significantly more ventricular segments [4.5 (IQR 2.3-6.0) vs. 2.0 (IQR 0-3.3), p = 0.02] and in a different distribution. The sensitivity of the original Lake Louise Criteria (LLC) was 91.3% in infarct-like patients and 55.6% in HF patients. When the updated LLC, which included the use of parametric myocardial mapping techniques, were applied, the sensitivity improved to 95.7% and 72.2% respectively. CONCLUSION: The pattern of CMR findings and its diagnostic sensitivity appears to differ in AM patients presenting with infarct-like and HF symptoms. Although the sensitivity of the LLC improved with the addition of parametric mapping in the HF group, it remained lower than that of the infarct-like group, and suggests that EMB should be considered earlier in the course of patients with clinically suspected AM presenting with HF.

Prevalence of cardiotropic viruses in adults with clinically suspected myocarditis in South Africa.

OBJECTIVES: To determine the prevalence and types of viral pathogens in the myocardium of patients presenting with clinically suspected myocarditis in South Africa. METHOD: This is a prospective cross-sectional study. Consecutive adults presenting to a single tertiary centre in South Africa between August 2017 and January 2021 who fulfilled the European Society of Cardiology's diagnostic criteria for clinically suspected myocarditis and who had undergone the appropriate investigations, including cardiac MRI (CMR) and endomyocardial biopsy (EMB), were included. RESULTS: One hundred and two patients with clinically suspected myocarditis were enrolled. Acute myocarditis (AM) was confirmed by CMR or EMB in 82 (80.39%) patients. Viral genomes were detected by PCR in EMB specimens of 50 patients with AM. Parvovirus B19 (PVB19) was the most frequently detected virus, in 37 as monoinfection and 4 as coinfection. This was followed by Epstein-Barr virus (n=6), human herpesvirus 6 (n=2) and human bocavirus (n=1). PVB19 was also detected in 9 patients with no evidence of AM on CMR or EMB. CONCLUSION: Viral myocarditis is the most common form of myocarditis in South Africa. Local viral prevalence appears to be similar those of the developed world. The clinical significance and pathogenic role of PVB19 remains questioned, and its local background prevalence will have to be further investigated.

Routine use of fluoroscopic and real-time transthoracic echocardiographic guidance to ensure safety of right ventricular endomyocardial biopsy in a low-volume center.

To determine whether the routine use of real-time transthoracic echocardiographic (TTE) guidance in addition to fluoroscopy would ensure the safety of right ventricular endomyocardial biopsy (RV EMB) in a low-volume center. RV EMB is a valuable tool and plays an important role in the diagnosis and management of patients with myocardial diseases. However, it has yet to gain widespread acceptance due to its perceived low diagnostic yield and concerns regarding its invasive nature and potential complications. Although the safety of EMB when performed by experienced operators in high-volume centers is well established, the complication rate in low-volume centers is less well defined but appears to be higher. This is a retrospective single-center cross-sectional study. Consecutive adult patients who underwent RV EMB procedures at Tygerberg Hospital (Cape Town, South Africa) between August 2017 and December 2020 were included. RV EMB was successfully performed in 85 patients. No major complications were reported. Five (5.88%) patients experienced minor complications: three transient right bundle branch blocks and two hemodynamically stable ventricular tachycardia. A definitive biopsy diagnosis was made in 37 (43.54%) patients. The average procedural time was 27.06 min, which equated to 4.09 min per specimen taken. The routine use of real-time TTE guidance in addition to fluoroscopy ensured the safety of RV EMB in a low-volume center without unnecessarily prolonging procedural time.

Early Emergence and Long-Term Persistence of HIV-Infected T-Cell Clones in Children.

Little is known about the emergence and persistence of human immunodeficiency virus (HIV)-infected T-cell clones in perinatally infected children. We analyzed peripheral blood mononuclear cells (PBMCs) for clonal expansion in 11 children who initiated antiretroviral therapy (ART) between 1.8 and 17.4 months of age and with viremia suppressed for 6 to 9 years. We obtained 8,662 HIV type 1 (HIV-1) integration sites from pre-ART samples and 1,861 sites from on-ART samples. Expanded clones of infected cells were detected pre-ART in 10/11 children. In 8 children, infected cell clones detected pre-ART persisted for 6 to 9 years on ART. A comparison of integration sites in the samples obtained on ART with healthy donor PBMCs infected ex vivo showed selection for cells with proviruses integrated in BACH2 and STAT5B Our analyses indicate that, despite marked differences in T-cell composition and dynamics between children and adults, HIV-infected cell clones are established early in children, persist for up to 9 years on ART, and can be driven by proviral integration in proto-oncogenes.IMPORTANCE HIV-1 integrates its genome into the DNA of host cells. Consequently, HIV-1 genomes are copied with the host cell DNA during cellular division. Pediatric immune systems differ significantly from adults, consisting primarily of naive T cells, which have low expression of the HIV-1 coreceptor CCR5. This difference may result in variances in the number or size of infected cell clones that persist in children on ART. Here, we provide the most extensive analysis of the integration landscape of HIV-1 in children. We found that, despite the largely naive cell populations in neonatal immune systems, patterns of HIV-1 integration and the size of infected cell clones are as large and widespread as those in adults. Furthermore, selection for integration events in proto-oncogenes were observed in children despite early ART. If such cell clones persist for the life span of these individuals, there may be long-term consequences that have yet to be realized.

HIV false positive screening serology due to sample contamination reduced by a dedicated sample and platform in a high prevalence environment.

Automated testing of HIV serology on clinical chemistry analysers has become common. High sample throughput, high HIV prevalence and instrument design could all contribute to sample cross-contamination by microscopic droplet carry-over from seropositive samples to seronegative samples resulting in false positive low-reactive results. Following installation of an automated shared platform at our public health laboratory, we noted an increase in low reactive and false positive results. Subsequently, we investigated HIV serology screening test results for a period of 21 months. Of 485 initially low positive or equivocal samples 411 (85%) tested negative when retested using an independently collected sample. As creatinine is commonly requested with HIV screening, we used it as a proxy for concomitant clinical chemistry testing, indicating that a sample had likely been tested on a shared high-throughput instrument. The contamination risk was stratified between samples passing the clinical chemistry module first versus samples bypassing it. The odds ratio for a false positive HIV serology result was 4.1 (95% CI: 1.69-9.97) when creatinine level was determined first, versus not, on the same sample, suggesting contamination on the chemistry analyser. We subsequently issued a notice to obtain dedicated samples for HIV serology and added a suffix to the specimen identifier which restricted testing to a dedicated instrument. Low positive and false positive rates were determined before and after these interventions. Based on measured rates in low positive samples we estimate that before the intervention, of 44 117 HIV screening serology samples, 753 (1.71%) were false positive, declining to 48 of 7 072 samples (0.68%) post-intervention (p<0.01). Our findings showed that automated high throughput shared diagnostic platforms are at risk of generating false-positive HIV test results, due to sample contamination and that measures are required to address this. Restricting HIV serology samples to a dedicated platform resolved this problem.

High positive HIV serology results can still be false positive.

The consequences of falsely reactive HIV test results can be significant, for patients and healthcare providers. This case describes a diagnostic investigation of a patient with pronounced discordant HIV serological results, to determine HIV status. The fourth generation serological screening assay (Roche COBAS Elecsys HIV combiPT) had high positive results but confirmatory testing was negative (Abbott HIV Ag/Ab Combo). Five separate samples over 13 days were tested using multiple fourth generation HIV immunoassays and molecular tests for HIV-1 and HIV-2. Potential causes of falsely reactive serological results were investigated. Samples were sent to the manufacturer for analysis. The screening assay was positive on all samples with a very high signal to cut-off ratio (S/CO) of greater than 400. However, multiple serological and molecular assays did not detect HIV-1 or HIV-2 specific antibodies, antigen or nucleic acid. A recombinant immunochromatographic assay had faint reactivity to gp41 peptide and the manufacturer investigation reported cross-reactivity to one of the screening assay's synthetic peptides. Possible causes of the false positive result include cross reactivity to other antigens, including prior schistosomiasis infection, or the patient's previously excised ameloblastoma (a rare germ cell tumor of the jaw). This is a rare case of false high positive results on fourth-generation HIV serology testing due to high level non-specific reactivity to an isolated synthetic peptide component of the assay. It highlights the need for confirmatory testing even in settings with HIV high prevalence and awareness that false-positive serological results may have a high S/CO.

Better Virological Outcomes Among People Living With Human Immunodeficiency Virus (HIV) Initiating Early Antiretroviral Treatment (CD4 Counts ≥500 Cells/µL) in the HIV Prevention Trials Network 071 (PopART) Trial in South Africa.

BACKGROUND: There have been concerns about reduced adherence and human immunodeficiency virus (HIV) virological suppression (VS) among clinically well people initiating antiretroviral therapy (ART) with high pre-ART CD4 cell counts. We compared virological outcomes by pre-ART CD4 count, where universal ART initiation was provided in the HIV Prevention Trials Network 071 (PopART) trial in South Africa prior to routine national and international implementation. METHODS: This prospective cohort study included adults initiating ART at facilities providing universal ART since January 2014. VS (<400 copies/mL), confirmed virological failure (VF) (2 consecutive viral loads >1000 copies/mL), and viral rebound were compared between participants in strata of baseline CD4 cell count. RESULTS: The sample included 1901 participants. VS was ≥94% among participants with baseline CD4 count ≥500 cells/µL at all 6-month intervals to 30 months. The risk of an elevated viral load (≥400 copies/mL) was independently lower among participants with baseline CD4 count ≥500 cells/µL (3.3%) compared to those with CD4 count 200-499 cells/µL (9.2%) between months 18 and 30 (adjusted relative risk, 0.30 [95% confidence interval, .12-.74]; P = .010). The incidence rate of VF was 7.0, 2.0, and 0.5 per 100 person-years among participants with baseline CD4 count <200, 200-499, and ≥500 cells/µL, respectively (P < .0001). VF was independently lower among participants with baseline CD4 count ≥500 cells/µL (adjusted hazard ratio [aHR], 0.23; P = .045) and 3-fold higher among those with baseline CD4 count <200 cells/µL (aHR, 3.49; P < .0001). CONCLUSIONS: Despite previous concerns, participants initiating ART with CD4 counts ≥500 cells/µL had very good virological outcomes, being better than those with CD4 counts 200-499 cells/µL. CLINICAL TRIALS REGISTRATION: NCT01900977.

Evaluation of the Performance of Three Biomarker Assays for Recent HIV Infection Using a Well-Characterized HIV-1 Subtype C Incidence Cohort.

Biomarkers for detecting early HIV infection and estimating HIV incidence should minimize false-recent rates (FRRs) while maximizing mean duration of recent infection (MDRI). We compared HIV subtypes B, E and D (BED) capture enzyme immunoassay (BED), Sedia limiting antigen (LAg) avidity enzyme immunoassay, and Bio-Rad avidity incidence (BRAI) assays using samples from Zimbabwean postpartum women infected with clade C HIV. We calculated MDRIs using 590 samples from 351 seroconverting postpartum women, and FRRs using samples from 2,825 women known to be HIV positive for >12 months. Antibody kinetics were more predictable with LAg and had higher precision compared with BED or BRAI. BRAI also exhibited more variability, and avidity reversal in some cases. For BED, LAg, and BRAI, used alone or with viral load, MDRI values in days were: BED-188 and 170 at normalized optical density (ODn) 0.8; LAg-104 and 100 at ODn cutoff 1.5; BRAI-135 and 134 at avidity index cutoff 30%. Corresponding FRRs were: BRAI 1.1% and 1.0% and LAg 0.57% and 0.35%: these were 3.8-10.9 times lower than BED values of 4.8% and 3.8%. BRAI and LAg have significantly lower FRRs and MDRIs than in published studies, and much lower than BED and could be used to estimate incidence in perinatal women and to measure population-level HIV incidence in HIV control operations in Africa.

PhyloPi: An affordable, purpose built phylogenetic pipeline for the HIV drug resistance testing facility.

INTRODUCTION: Phylogenetic analysis plays a crucial role in quality control in the HIV drug resistance testing laboratory. If previous patient sequence data is available sample swaps can be detected and investigated. As Antiretroviral treatment coverage is increasing in many developing countries, so is the need for HIV drug resistance testing. In countries with multiple languages, transcription errors are easily made with patient identifiers. Here a self-contained blastn integrated phylogenetic pipeline can be especially useful. Even though our pipeline can run on any unix based system, a Raspberry Pi 3 is used here as a very affordable and integrated solution. PERFORMANCE BENCHMARKS: The computational capability of this single board computer is demonstrated as well as the utility thereof in the HIV drug resistance laboratory. Benchmarking analysis against a large public database shows excellent time performance with minimal user intervention. This pipeline also contains utilities to find previous sequences as well as phylogenetic analysis and a graphical sequence mapping utility against the pol area of the HIV HXB2 reference genome. Sequence data from the Los Alamos HIV database was analyzed for inter- and intra-patient diversity and logistic regression was conducted on the calculated genetic distances. These findings show that allowable clustering and genetic distance between viral sequences from different patients is very dependent on subtype as well as the area of the viral genome being analyzed. AVAILABILITY: The Raspberry Pi image for PhyloPi, source code of the pipeline, sequence data, bash-, python- and R-scripts for the logistic regression, benchmarking as well as helper scripts are available at http://scholar.ufs.ac.za:8080/xmlui/handle/11660/7638 and https://github.com/ArmandBester/phylopi. The PhyloPi image and the source code are published under the GPLv3 license. A demo version of the PhyloPi pipeline is available at http://phylopi.hpc.ufs.ac.za/.

The effect of interventions on the transmission and spread of HIV in South Africa: a phylodynamic analysis.

The epidemic in South Africa is characterized by high genetic diversity driven by multiple independent introductions. The bulk of these introductions occurred between 1985-2000 during which time HIV prevalence increased exponentially. Epidemic growth has stabilized in recent years with the implementation of several interventions. Here we identified distinct HIV clades from a large sequence dataset of southern African HIV sequences (n = 15,332). Each clade was characterized using phylodynamic and phylogeographic methods to infer their growth through time and space. The estimated date of origin for the 18 clades that were found, fell between 1979-1992 with strong growth during the 1990's. Phylogeographic reconstruction revealed wide dispersal of clades throughout the country with the city of Johannesburg as the focal point of viral dispersal. We found clear signs of decreasing growth rate in four of the clades since the advent of interventions, while other clades have continued to growth and expand. Our results demonstrate that interventions do not affect the HIV epidemic universally with major difference between different clades over time and space. Here we demonstrate the utility and flexibility of molecular epidemiological methods and demonstrate how they can potentially be a powerful tool in HIV epidemic monitoring in South Africa.

Future technologies for monitoring HIV drug resistance and cure.

PURPOSE OF REVIEW: Sensitive, scalable and affordable assays are critically needed for monitoring the success of interventions for preventing, treating and attempting to cure HIV infection. This review evaluates current and emerging technologies that are applicable for both surveillance of HIV drug resistance (HIVDR) and characterization of HIV reservoirs that persist despite antiretroviral therapy and are obstacles to curing HIV infection. RECENT FINDINGS: Next-generation sequencing (NGS) has the potential to be adapted into high-throughput, cost-efficient approaches for HIVDR surveillance and monitoring during continued scale-up of antiretroviral therapy and rollout of preexposure prophylaxis. Similarly, improvements in PCR and NGS are resulting in higher throughput single genome sequencing to detect intact proviruses and to characterize HIV integration sites and clonal expansions of infected cells. SUMMARY: Current population genotyping methods for resistance monitoring are high cost and low throughput. NGS, combined with simpler sample collection and storage matrices (e.g. dried blood spots), has considerable potential to broaden global surveillance and patient monitoring for HIVDR. Recent adaptions of NGS to identify integration sites of HIV in the human genome and to characterize the integrated HIV proviruses are likely to facilitate investigations of the impact of experimental 'curative' interventions on HIV reservoirs.

Tabula viva chirurgic: a living surgical document.

AIM: The purpose of this article is to present the results of a private cardiac surgical practice. This information could also serve as a hermeneutical text for new wisdom. METHODS: A personal database of 1 750 consecutive patients who had had coronary artery bypass graft (CABG) surgery was statistically analysed. Mortality and major morbidity figures were compared with large registries. Risk factors for postoperative death were determined. RESULTS: Over a period of 12 years, 1 344 (76.8%) males and 406 (23.2%) females were operated on. The observed mortality rate was 3.03% and the expected mortality rate (EuroSCORE) was 3.87%. After stepwise logistic regression, independent risk factors for death were urgency (intra-aortic balloon pump), renal impairment (chronic kidney disease, stage III), re-operation and an additional procedure. Apart from the 53 deaths, another 91 patients had major complications. CONCLUSION: Mortality and morbidity rates compared favourably with other international registries. Mortality was related to co-morbidities. This outcome contributes to a hermeneutical understanding focusing on new spiritual wisdom and meaning for the surgeon.

Virologic failure among children taking lopinavir/ritonavir-containing first-line antiretroviral therapy in South Africa.

OBJECTIVE: To report the outcomes, clinical management decisions and results of resistance testing among a group of children who developed virologic failure on first-line lopinavir/ritonavir (LPV/r)-based therapy from a large cohort of antiretroviral therapy-treated children in Soweto. DESIGN: Historical cohort study. METHODS: Children with virologic failure were identified from a group of 1692 children <3 years who had initiated first-line LPV/r-containing therapy since 2000 up to the end November 2011. Genotyping was conducted in some children, and outcomes, management decisions and resistance results were described. RESULTS: A total of 152 children with virologic failure on first-line LPV/r-containing antiretroviral therapy were included. Resistance testing was performed in 75/152 (49%), and apart from a younger age (11.1 vs. 15.1 months, P = 0.04), the children with versus those without resistance testing were similar for baseline characteristics (weight, CD4, viral load and time to failure). Genotyping revealed that 8/75 (10.7%) had significant LPV/r-associated resistance mutations, including 2 with intermediate darunavir resistance. Among 63/75 (84%) children remaining on LPV/r-based therapy, 32/63 (51%) achieved virologic suppression, and 2 of these children with significant LPV mutations. In accordance with the local guidelines at the time, 12/152 (8%) children were switched to non-nucleoside reverse-transcriptase inhibitors-based therapy. Of these, 4/12 (33%) resuppressed, and the rest did not achieve virologic suppression including the 2 with lopinavir mutations. CONCLUSIONS: Virologic failure of LPV/r-containing first-line regimens is associated with accumulation of LPV/r mutations in children. The implications are unclear, and surveillance at selected sites is warranted for long-term virologic outcomes and development of resistance.

Young age a predictor of weak reactivity in a rapid antibody test in infants infected with HIV.

In a resource-constrained African setting, children suspected of being infected with HIV are often screened with rapid antibody tests prior to definitive diagnosis with viral genome detection. It has previously been shown that a rapid antibody assay such as the Capillus HIV-1/HIV-2 test may have a high false-negative rate in infants. In this study CD(4) (+) count and percentage, HIV-1 viral load, antigen-specific reactivity, and age was explored as predictors of negative or low antibody reactivity by this assay. Young age was found to be the only factor associated significantly with low antibody reactivity. This phenomenon appeared to be specific to HIV since no such age association was found for antibody reactivity to tetanus toxoid. Rapid assays only validated in adults should therefore be used with utmost caution in young infants since this may lead to high rates of false-negative results.

Significantly diminished long-term specificity of the BED capture enzyme immunoassay among patients with HIV-1 with very low CD4 counts and those on antiretroviral therapy.

OBJECTIVE: To estimate the proportion who test as recent infections by the BED capture enzyme immunoassay (BED) among patients about to commence, and those receiving, antiretroviral therapy. DESIGN: Cryopreserved plasma samples from HIV patients on the national antiretroviral treatment (ART) rollout program at Tygerberg Hospital HIV clinic, South Africa, were tested using the BED assay. PARTICIPANTS: Five hundred five patients qualifying for ART were included in this study. METHOD: All plasma samples from each patient were tested by BED. Basic demographic data, HIV-1 viral load, and CD4 count results were obtained from the laboratory database. MAIN OUTCOME: The proportion presenting as false recently infected is reported. RESULTS: Among patients, with presumed long-term HIV-1 infections, about to commence ART, 11.2% [95% confidence interval (CI): 8.3 to 14.5%] tested recent by BED. The proportion was higher among patients with CD4 counts < 50 cells per microliter [odds ratio 2.63, 95% CI: 1.39 to 5.00] and log10 HIV-1 viral load less than 4 [odds ratio 3.03, 95% CI: 1.05 to 9.09]. Proportions testing false recent increased from 11.2% before ART to 17%, 25%, 38%, and 56% at 0.5, 1, 1.5, and 2 years, respectively, after ART initiation. CONCLUSIONS: If the BED method is to be used for the accurate estimation of HIV incidence from cross-sectional surveys, it will be essential, before other statistical adjustment methods, to identify, at least, all cases who are on ART and all those with CD4 counts < 50 cells per microliter. The more general remaining problem is the unequivocal identification of all persons with long-term HIV infections.

Protease inhibitor resistance in South African children with virologic failure.

BACKGROUND: In South Africa, first-line antiretroviral therapy for children younger than 3 years of age combines a protease inhibitor (PI) with 2 nucleoside reverse transcription inhibitors. In our study, some pediatric patients received ritonavir (RTV) as single PI (RTV-sPI) and others ritonavir-boosted lopinavir (LPV/r), which has a higher resistance barrier. We explored antiretroviral resistance mutations in pediatric patients failing PI-based antiretroviral therapy and the predictors of major PI resistance mutations (MPIRM) in these patients. MATERIALS AND METHODS: We studied pediatric HIV patients at Tygerberg Academic Hospital experiencing virologic failure on a PI regimen. Mixed-effects linear- and mixed-effect logistic regression modeling, were used to explore predictors of MPIRM. RESULTS: MPIRM were found in 12 of 17 patients exposed to RTV-sPI compared with 1 of 13 patients treated with LPV/r. Exposure to RTV-sPI was significantly associated with MPIRM, with both exposure time and estimated failing time on RTV-sPI being significant positive predictors of MPIRM. Neither CD4 count, viral load, age at first visit nor receiving rifampin predicted MPIRM. CONCLUSIONS: RTV-sPI in infants and children poses a significant risk of MPIRM which is dependent on the exposure time and time failing while receiving the regimen.