HIV drug resistance levels in adults failing first-line antiretroviral therapy in an urban and a rural setting in South Africa.

OBJECTIVES: Urban and rural HIV treatment programmes face different challenges in the long-term management of patients. There are few studies comparing drug resistance profiles in patients accessing treatment through these programmes. The aim of this study was to perform such a comparison. METHODS: HIV drug resistance data and associated treatment and monitoring information for adult patients failing first-line therapy in an urban and a rural programme were collected. Data were curated and managed in SATuRN RegaDB before statistical analysis using Microsoft Excel 2013 and stata Ver14, in which clinical parameters, resistance profiles and predicted treatment responses were compared. RESULTS: Data for 595 patients were analysed: 492 patients from a rural setting and 103 patients from an urban setting. The urban group had lower CD4 counts at treatment initiation than the rural group (98 vs. 126 cells/µL, respectively; P = 0.05), had more viral load measurements performed per year (median 3 vs. 1.4, respectively; P < 0.01) and were more likely to have no drug resistance mutations detected (35.9% vs. 11.2%, respectively; P < 0.01). Patients in the rural group were more likely to have been on first-line treatment for a longer period, to have failed for longer, and to have thymidine analogue mutations. Notwithstanding these differences, the two groups had comparable predicted responses to the standard second-line regimen, based on the genotypic susceptibility score. Mutations accumulated in a sigmoidal fashion over failure duration. CONCLUSIONS: The frequency and patterns of drug resistance, as well the intensity of virological monitoring, in adults with first-line therapy failure differed between the urban and rural sites. Despite these differences, based on the genotypic susceptibility scores, the majority of patients across the two sites would be expected to respond well to the standard second-line regimen.

Immunohistological characterization of spinal TB granulomas from HIV-negative and -positive patients.

Tuberculosis (TB) is mainly a disease of the lungs, but Mycobacterium tuberculosis (Mtb) can establish infection in virtually any organ in the body. Rising rates of extrapulmonary (EP) TB have been largely associated with the HIV epidemic, as patients co-infected with HIV show a four-fold higher risk of EPTB. Spinal TB (Pott's Disease), one of the most debilitating extrapulmonary forms of disease, is difficult to diagnose and can cause deformity and/or neurological deficits. This study examined the histopathology and distribution of immune cells within spinal TB lesions and the impact of HIV on pathogenesis. The overall structure of the spinal granulomas resembled that seen in lung lesions from patients with pulmonary TB. Evidence of efficient macrophage activation and differentiation were detectable within organized structures in the spinal tissue, irrespective of HIV status. Interestingly, the granulomatous architecture and macroscopic features were similar in all samples examined, despite a reversal in the ratio of infiltrating CD4 to CD8 T cells in the lesions from HIV-infected patients. This study provides a foundation to understand the mechanism of tissue destruction and disease progression in Spinal TB, enabling the future development of novel therapeutic strategies and diagnostic approaches for this devastating disease.

Use of dried blood spots for the determination of genetic variation of interleukin-10, killer immunoglobulin-like receptor and HLA class I genes.

Optimal methods for using dried blood spots (DBSs) for population genetics-based studies have not been well established. Using DBS stored for 8 years from 21 pregnant South African women, we evaluated three methods of gDNA extraction with and without whole-genome amplification (WGA) to characterize immune-related genes: interleukin-10 (IL-10), killer immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I. We found that the QIAamp DNA mini kit yielded the highest gDNA quality (P< 0.05; Wilcoxon signed rank test) with sufficient yield for subsequent analyses. In contrast, we found that WGA was not reliable for sequence-specific primer polymerase chain reaction (SSP-PCR) analysis of KIR2DL1, KIR2DS1, KIR2DL5 and KIR2DL3 or high-resolution HLA genotyping using a sequence-based approach. We speculate that unequal template amplification by WGA underrepresents gene repertoires determined by sequence-based approaches.

Cervical spine tuberculosis in children.

The presentation and outcome of pediatric cervical spine tuberculosis are different from those of adult cervical spine tuberculosis. We retrospectively reviewed the clinical and radiographic outcome of 58 children with cervical spine tuberculosis treated nonoperatively and operatively between 1996 and 2004. The mean age was 3.7 years (range, 1.9-14 years). The cervicodorsal junction was affected in 27 children, the atlantoaxial complex in 19 children, and the mid-cervical spine in 12 children. Multifocal noncontiguous spinal lesions were observed in 21 patients. Surgery was performed in 25 children for: neurologic deficit (14); drainage of retropharyngeal abscesses (four); atlantoaxial fusion for late C1-C2 instability (three); and progressive deformity and pain (four). Neurologic recovery occurred in all patients. Seven patients were lost to followup within 2 years. The minimum followup was 2.4 years (mean, 3.5 years; range, 2.4-10 years). We attributed the improved functional outcome after anti-TB chemotherapy alone to the remodeling potential of the pediatric cervical spine. Surgery was performed only for neurologic deficit, an atlantodental interval greater than 5 mm on flexion/extension view, and progressive deformity. Four patients developed superficial wound infection, two patients had graft repositioning for a slipped graft, and seven children developed a grade 1 pressure sore over the scalp while on traction.

Histopathology and genotyping in infectious spondylitis of HIV- and HIV+ patients.

Approximately 2 million South Africans are HIV/TB coinfected, and many develop skeletal disease. The resurgence of spinal tuberculosis, including atypical forms, is due largely to HIV-associated immune suppression. We investigated the impact of HIV coinfection on the histological features of the disease and the occurrence of atypical opportunistic organisms in infectious spondylitis in an HIV/TB endemic region. We analyzed blood and tissue biopsies from 60 patients with tuberculous spondylitis. Investigations included full blood counts, CD4/CD8 counts, HIV-1 serology and RNA quantification (tissue and plasma), acid-fast bacilli localization and routine TB culture, histopathologic evaluation of biopsies, and bacterial genotyping using the 16S rDNA gene. Twenty-two patients (37%) were HIV positive with a mean age of 29 years (range, 2-65 years). Forty-one (68%) tissue specimens were culture negative for Mycobacterium tuberculosis (Mtb), although nontuberculous mycobacteria (NTM) were identified in three HIV-negative patients. Histopathologic features were characteristic of TB infection in 91.4% of all specimens tested and 100% of the HIV-infected group. Genotyping of 10 culture-positive isolates identified Mtb (3/10), NTMs (2/10), and environmental bacilli (3/10). Our observations suggest HIV-induced immune suppression impacts the histological and clinical features of infectious spondylitis but has no impact on the incidence of NTMs in this setting.

Atypical mycobacterial spondylitis in HIV-negative patients identified by genotyping.

Non-tuberculous mycobacterial infections pose a significant diagnostic and therapeutic challenge. We report two cases of such infection of the spine in HIV-negative patients who presented with deformity and neurological deficit. The histopathological features in both specimens were diagnostic of tuberculosis. The isolates were identified as Mycobacterium intracellulare and M. fortuitum by genotyping (MicroSeq 16S rDNA Full Gene assay) and as M. tuberculosis and a mycobacterium other than tuberculosis, respectively, by culture. There is a growing need for molecular diagnostic tools that can differentiate accurately between M. tuberculosis and atypical mycobacteria, especially in regions of the developing world which are experiencing an increase in non-tuberculous mycobacterial infections.

Prevalence, incidence, and mother-to-child transmission of HIV-1 in rural South Africa.

Simple, robust approaches are needed to monitor prevalence, incidence, and mother-to-child transmission of HIV-1 in rural Africa. We have designed a method that uses antibody and viral RNA testing of dried blood spots obtained from mother-infant pairs attending routine immunisation clinics. In our study, prevalence and incidence of HIV-1 was highest in young women in their late teens and early twenties. In children born to infected mothers, prevalence increased from 14% in infants younger than 6 weeks of age to 24% at 3-6 months. The blood-spot approach is an effective method for surveillance of HIV-1 in women and children, and for early identification of incidence of this infection in women of child-bearing age.