HIV and Associated TB: A Lethal Association for Kidney Health?

Human immunodeficiency virus (HIV) and tuberculosis (TB) are the leading infectious causes of death globally. The combined brunt of these diseases is experienced mainly in low-income and lower-middle-income countries. HIV/TB have devastating effects on the kidneys, leading to accelerated decline of kidney function as well as mortality. Managing the triad of TB/HIV and kidney disease is challenging. We discuss the epidemiology of HIV/TB coinfection and the kidney and the key mechanisms of kidney disease including genetic susceptibility. The clinical presentation and pathology, as well as the challenges of diagnosing CKD in these patients, also are discussed. The strategies to prevent and manage HIV/TB-related kidney disease such as proper assessment, avoiding nephrotoxic regimens, drug dose adjustments, kidney function monitoring, avoidance of drug-drug interactions, and other interventions are explored. We also briefly discuss the complexities around HIV/TB patients on dialysis and kidney transplantation. HIV/TB coinfection presents an increased risk for kidney-related morbidity and mortality; patients with this triad need to be given special consideration for future research and management.

Evaluation of Xpert MTB/RIF Versus AFB Smear and Culture to Identify Pulmonary Tuberculosis in Patients With Suspected Tuberculosis From Low and Higher Prevalence Settings

BACKGROUND

The Xpert MTB/RIF (Xpert) assay is a rapid nucleic acid amplification test widely used in settings of high tuberculosis prevalence to detect tuberculosis as well asrpoBmutations associated with rifampin resistance. Data are needed on the diagnostic performance of Xpert in lower-prevalence settings to inform appropriate use for both tuberculosis detection and the need for respiratory isolation.

METHODS

Xpert was compared to 2 sputum samples, each evaluated with acid-fast bacilli (AFB) smear and mycobacterial culture using liquid and solid culture media, from participants with suspected pulmonary tuberculosis from the United States, Brazil, and South Africa.

RESULTS

Of 992 participants enrolled with evaluable results, 22% had culture-confirmed tuberculosis. In 638 (64%) US participants, 1 Xpert result demonstrated sensitivity of 85.2% (96.7% in participants with AFB smear-positive [AFB(+)] sputum, 59.3% with AFB smear-negative [AFB(-)] sputum), specificity of 99.2%, negative predictive value (NPV) of 97.6%, and positive predictive value of 94.9%. Results did not differ between higher- and low-prevalence settings. A second Xpert assay increased overall sensitivity to 91.1% (100% if AFB(+), 71.4% if AFB(-)), with specificity of 98.9%. In US participants, a single negative Xpert result predicted the absence of AFB(+)/culture-positive tuberculosis with an NPV of 99.7%; NPV of 2 Xpert assays was 100%, suggesting a role in removing patients from airborne infection isolation. Xpert detected tuberculosis DNA and mutations associated with rifampin resistance in 5 of 7 participants with rifampin-resistant, culture-positive tuberculosis. Specificity for rifampin resistance was 99.5% and NPV was 98.9%.

CONCLUSIONS

In the United States, Xpert testing performed comparably to 2 higher-tuberculosis-prevalence settings. These data support the use of Xpert in the initial evaluation of tuberculosis suspects and in algorithms assessing need for respiratory isolation.

Prevalence and risk factors of undernutrition among antiretroviral-therapy-naïve subjects aged under 5 years old in Makurdi, Nigeria: a retrospective study

Background

Undernutrition is common in human immunodeficiency virus (HIV) infection and it contributes significantly to its morbidity and mortality. However, as far as we are aware, few studies have described the risk factors of undernutrition among HIV-infected Nigerian children. The study reported here aimed to determine the prevalence and risk factors of undernutrition among HIV-infected, antiretroviral therapy (ART)-naïve children aged under 5 years old in Makurdi, Nigeria.

Methods

A retrospective, cross-sectional study was undertaken at the Federal Medical Centre, Makurdi, between June 2010 and June 2011. Logistic regression modelling was used to determine the risk factors of undernutrition.

Results

Data on 182 HIV-infected children (88 males and 94 females), aged between 6 weeks and 59 months were studied. The prevalence of undernutrition was 12.1%, 33.5%, and 54.4% for underweight, wasting, and stunting, respectively. In multivariate regression analyses, being female (adjusted odds ratio [AOR] 0.292, 95% [confidence interval] CI 0.104–0.820, P=0.019), the child’s caregiver being on ART (AOR 0.190, 95% CI 0.039–0.925, P=0.04), and the absence of tuberculosis in the child (AOR 0.034, 95% CI 0.003–0.357, P=0.005) were independently protective against underweight. Subjects who were exclusively breastfed in the first 6 months of life were protected from stunting (AOR 0.136, 95% CI 0.032–0.585, P=0.007). No factor impacted significantly on wasting in multivariate analyses.

Conclusion

Undernutrition among HIV-infected, ART-naïve children aged under 5 years old may be reduced if programmatic interventions are guided toward early initiation of ART among eligible HIV-infected caregivers and the promotion of HIV/tuberculosis coinfection control efforts. Also, the importance of exclusive breastfeeding in reducing undernutrition cannot be overemphasized.