HIV-Associated Tuberculosis

Comorbidities in Black South Africans with established rheumatoid arthritis

Objective

Comorbidities contribute both to morbidity and mortality in rheumatoid arthritis (RA). The aim of the current study was to investigate the prevalence and spectrum of comorbidities in South Africans with established RA.

Methods

A retrospective, consecutive case record review of 500 Black South African patients with established disease of ≥5 years attending a tertiary rheumatology service was performed. Common comorbidities including those listed in the Charlson Comorbidity Score (CCS) were documented.

Results

Most patients, 463 known alive (AG) and 37 known deceased (DG), were female (87%). Mean (SD) age and disease duration were 60 (11.1) and 10.7 (5.0) years respectively, and 98% had ≥1 comorbidities. Median CCS was 2, significantly higher in DG than AG (4 vs 2, P < .0001). Despite hypertension (70%) and hypercholesterolemia (47%) being the commonest comorbidities overall and type 2 diabetes (T2D) occurring in 15.4%, clinical cardiovascular events were rare (0.6%). Peptic ulcer disease (odds ratio [OR] = 8.67), congestive cardiac failure (OR = 7.09), serious infections (OR = 7.02) and tuberculosis (OR = 2.56) were significantly more common in DG than AG. Multivariate analysis showed that American College of Rheumatology functional class 3/4 was associated with increased risk for serious infections (OR = 3.84) and tuberculosis (OR = 2.10).

Conclusion

Despite the high burden of cardiometabolic comorbidities in South Africans with established RA, cardiovascular events were rare. Serious infections and tuberculosis, both associated with severe functional disability, are a major cause of morbidity and mortality.

Immune correlates of Mycobacterium Tuberculosis patients in Zambia stratified by HIV serostatus and level of immunity-a cross-sectional analytical laboratory based study

BACKGROUND

People living with HIV (PLHIV) co-infected with tuberculosis (TB) have a distinct clinical presentation and poorer treatment outcomes compared to HIV-seronegative TB patients. Excluding low CD4 count, innate immune factors associated with TB are not fully elucidated. We, therefore, characterised and compared the expression of IL-6, TNF-α, IFN-γ, and IL-10 in whole blood of treatment naïve TB patients stimulated with heat-killed Mycobacterium tuberculosis stratified by HIV status and the level of CD4 count.

RESULTS

We recruited 39 HIV seropositive and 31 HIV seronegative TB patients. Median (IQR) age was 35(28-42) years and 31(25-36) years respectively, and a majority had pulmonary tuberculosis i.e. 38(95%) and 30(97%), respectively. The two groups were significantly different in the distribution of CD4 count, 563 [465-702.5 cells/mm3] vs 345 [157-483 cell/mm3] in HIV negative vs HIV positive respectively p = <0.001. Post stimulation, the expression of IL-6 in HIV negative TB patients was significantly higher than in the HIV positive 16,757366 [8,827-23,686 pg/ml] vs. 9,508 [5,514-15,008 pg/ml], respectively; p = 0.0360. TNF-α and IFN-γ were highly expressed in HIV negative TB patients compared to the HIV positive though not statistically significant. We only observed higher expression of IL-6 in HIV negative patients in comparison to the HIV positive when stratified by level of CD4 counts as < 500 and ≥ 500 cell/mm3 for both cohorts. 21,953 [8,990-24,206 pg/ml] vs 9,505 [5,400-15,313 pg/ml], p value = 0.0585 in patients with CD4 count < 500 cell/mm3 and 13,168 [7,087-22,584 pg/ml] vs 10,413 [7,397-14,806 pg/ml], p value = 0.3744 for patients with CD4 count of ≥ 500 cell/mm3 respectively. We found a positive pairwise correlation between TNF-α -alpha and IL-6 in both HIV positive and HIV negative patients, r = 0.61 (95% CI 0.36-0.72; p < 0.0001) and r = 0.48 (95% CI 0.15-0.68; p = 0.005) respectively. The IFNγ/IL-10 ratio was higher in HIV negative when compared to HIV positive individuals, 0.052 [0.0-0.28] vs 0.007 [0-0.32] respectively; p = 0.05759. IL-6 independently reduced the probability of TB/HIV, Adjusted odds ratio 0.99, p value 0.007.

CONCLUSIONS

This study suggests that HIV seronegative TB patients have a higher pro-inflammatory response to MTB than HIV seropositive TB patients. Further, it also shows that the level of CD4 influences immunomodulation. The findings suggest that the difference in cytokine expression may be responsible for the distinct patterns of TB presentation between HIV positive and HIV negative patient.

Pediatric Tuberculosis in a Northeast State of Peninsular Malaysia: Diagnostic Classifications and Determinants

Objectives

We sought to determine the total proportion of pediatric tuberculosis cases, characterize tuberculosis by its anatomical location and pretreatment sputum smear status, and to determine the association of the sociodemographic and clinical factors with tuberculosis disease among pediatric patients in Kelantan from 2012 until 2015.

Methods

We conducted a comparative cross-sectional study between tuberculosis cases and tuberculosis contacts among pediatric patients using the Tuberculosis Information System as a source population. All notified cases that fulfilled the inclusion and exclusion criteria were included in the study. Descriptive statistics, simple and multiple logistic regressions were used for data analysis.

Results

Of 5412 tuberculosis cases, 456 (8.4%) were pediatric patients with a mean age of 15.9 years. The majority had the pulmonary form of tuberculosis (78.1%) followed by the extrapulmonary (14.9%) and pulmonary form with concomitant extrapulmonary (7.0%) forms. Of all pulmonary tuberculosis cases, 64.9% were sputum smear-positive, and 35.1% were sputum smear-negative. Among 322 pediatric patients with tuberculosis, the majority were Malay (90.7%), 8.4% were illiterate, and 79.5% resided in non-urban areas. Of all cases, 2.8% were HIV-positive, and 14.6% were cigarette smokers. Older age, Malay ethnicity, female gender, non-urban residence, good education level, and cigarette smoking were the significant associated factors for tuberculosis disease among pediatric patients with an adjusted odds ratio (aOR) of 1.41 (95% confidence interval (CI): 1.29–1.54; p < 0.001), 0.17 (95% CI: 0.07–0.44; p < 0.001), 1.88 (95% CI: 1.33–2.65; p < 0.001), 1.92 (95% CI: 1.33–2.79; p = 0.001), 0.20 (95% CI: 0.12–0.33; p < 0.001), and 3.35 (95% CI: 1.86–6.01; p < 0.001), respectively.

Conclusions

The study will assist practices of tuberculosis detection and control management in the local setting and may help other national tuberculosis programs to review their detection criteria with similar statistics.

Matrix Degradation in Human Immunodeficiency Virus Type 1-Associated Tuberculosis and Tuberculosis Immune Reconstitution Inflammatory Syndrome: A Prospective Observational Study

Background

Extensive immunopathology occurs in human immunodeficiency virus (HIV)/tuberculosis (TB) coinfection, but the underlying molecular mechanisms are not well-defined. Excessive matrix metalloproteinase (MMP) activity is emerging as a key process but has not been systematically studied in HIV-associated TB.

Methods

We performed a cross-sectional study of matrix turnover in HIV type 1 (HIV-1)-infected and -uninfected TB patients and controls, and a prospective cohort study of HIV-1-infected TB patients at risk of TB immune reconstitution inflammatory syndrome (TB-IRIS), in Cape Town, South Africa. Sputum and plasma MMP concentrations were quantified by Luminex, plasma procollagen III N-terminal propeptide (PIIINP) by enzyme-linked immunosorbent assay, and urinary lipoarabinomannan (LAM) by Alere Determine TB LAM assay. Peripheral blood mononuclear cells from healthy donors were cultured with Mycobacterium tuberculosis and extracellular matrix in a 3D model of TB granuloma formation.

Results

MMP activity differed between HIV-1-infected and -uninfected TB patients and corresponded with specific TB clinical phenotypes. HIV-1-infected TB patients had reduced pulmonary MMP concentrations, associated with reduced cavitation, but increased plasma PIIINP, compared to HIV-1-uninfected TB patients. Elevated extrapulmonary extracellular matrix turnover was associated with TB-IRIS, both before and during TB-IRIS onset. The predominant collagenase was MMP-8, which was likely neutrophil derived and M. tuberculosis-antigen driven. Mycobacterium tuberculosis-induced matrix degradation was suppressed by the MMP inhibitor doxycycline in vitro.

Conclusions

MMP activity in TB differs by HIV-1 status and compartment, and releases matrix degradation products. Matrix turnover in HIV-1-infected patients is increased before and during TB-IRIS, informing novel diagnostic strategies. MMP inhibition is a potential host-directed therapy strategy for prevention and treatment of TB-IRIS.

Understanding HIV-Mycobacteria synergism through comparative proteomics of intra-phagosomal mycobacteria during mono- and HIV co-infection

Mycobacterium tuberculosis (Mtb) is the most common co-infection in HIV patients and a serious co-epidemic. Apart from increasing the risk of reactivation of latent tuberculosis (TB), HIV infection also permits opportunistic infection of environmental non-pathogenic mycobacteria. To gain insights into mycobacterial survival inside host macrophages and identify mycobacterial proteins or processes that influence HIV propagation during co-infection, we employed proteomics approach to identify differentially expressed intracellular mycobacterial proteins during mono- and HIV co-infection of human THP-1 derived macrophage cell lines. Of the 92 proteins identified, 30 proteins were upregulated during mycobacterial mono-infection and 40 proteins during HIV-mycobacteria co-infection. We observed down-regulation of toxin-antitoxin (TA) modules, up-regulation of cation transporters, Type VII (Esx) secretion systems, proteins involved in cell wall lipid or protein metabolism, glyoxalate pathway and branched chain amino-acid synthesis during co-infection. The bearings of these mycobacterial factors or processes on HIV propagation during co-infection, as inferred from the proteomics data, were validated using deletion mutants of mycobacteria. The analyses revealed mycobacterial factors that possibly via modulating the host environment, increased viral titers during co-infection. The study provides new leads for investigations towards hitherto unknown molecular mechanisms explaining HIV-mycobacteria synergism, helping address diagnostics and treatment challenges for effective co-epidemic management.

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.

Pulmonary resection for extensively drug resistant tuberculosis in Kwazulu-Natal, South Africa

BACKGROUND

Extensively drug resistant tuberculosis (XDR-TB) has been reported in 58 countries around the world and has emerged as a major public health challenge. Our objective was to determine the impact of pulmonary resection on XDR-TB treatment outcomes in a resource-constrained setting.

METHODS

We conducted a retrospective case review of 11 patients with XDR-TB who were referred for pulmonary resection between January 2007 and June 2010 at a tertiary care referral hospital in South Africa. Two pneumonectomies and three upper lobectomies were performed. Occurrence of surgical complications and TB treatment outcome were assessed.

RESULTS

No perioperative mortality or major morbidity was noted. All patients achieved sputum conversion, with 4 regarded as "cured." One patient defaulted on treatment, but subsequently returned and is regarded as a probable cure.

CONCLUSIONS

We describe pulmonary resection for XDR-TB management in Africa. Although the initial cohort of XDR-TB patients from Tugela Ferry demonstrated nearly complete mortality, our results demonstrate the potential of adjuvant surgical methods in XDR-TB treatment. With appropriate chemotherapy and timely adjuvant surgery, patients with XDR-TB localized to lobe or lung may achieve a "cure" with low morbidity and mortality. Consequently, this approach may be the most cost effective treatment for patients suitable for lung resection.

Pulmonary immune-compartment-specific interferon gamma responses in HIV-infected individuals with active tuberculosis (TB) in an area of high TB prevalence

There is a paucity of data on the pulmonary immune-compartment interferon gamma (IFNγ) response to M. tuberculosis, particularly in settings of high tuberculosis (TB) prevalence and in HIV-coinfected individuals. This data is necessary to understand the diagnostic potential of commercially available interferon gamma release assays (IGRAs) in both the pulmonary immune-compartment and peripheral blood. We used intracellular cytokine staining by flow cytometry to assess the IFNγ response to purified protein derivative (PPD) and early secretory antigen 6 (ESAT6) in induced sputa (ISp) and blood samples from HIV-infected, smear-negative, TB suspects. We found that individuals with active TB disease produced significantly less IFNγ in response to PPD in their induced sputa samples than individuals with non-active TB (control group). This difference was not reflected in the peripheral blood, even within the CD27- CD4+ memory T lymphocyte population. These findings suggest that progression to active TB disease may be associated with the loss of IFNγ secretion at the site of primary infection. Our findings highlight the importance of studying pulmonary immune-compartment M. tuberculosis specific responses to elucidate IFNγ secretion across the spectrum of TB disease.