Incident Tuberculosis Diagnoses in Children at High Risk for Disease.

We followed 35 children meeting a research definition for unconfirmed tuberculosis (TB) but in whom a pediatric pulmonologist did not diagnose or treat TB. After a median follow-up of 16.4 months, most children were not diagnosed with TB following a comprehensive evaluation. However, 2 were diagnosed with TB, demonstrating high TB risk (6%; exact 95% CI, 1%-19%). In some contexts, researchers may wish to supplement these research definitions with clinical decision data and longitudinal follow-up in order to improve specificity.

A positively selected FBN1 missense variant reduces height in Peruvian individuals.

On average, Peruvian individuals are among the shortest in the world1. Here we show that Native American ancestry is associated with reduced height in an ethnically diverse group of Peruvian individuals, and identify a population-specific, missense variant in the FBN1 gene (E1297G) that is significantly associated with lower height. Each copy of the minor allele (frequency of 4.7%) reduces height by 2.2 cm (4.4 cm in homozygous individuals). To our knowledge, this is the largest effect size known for a common height-associated variant. FBN1 encodes the extracellular matrix protein fibrillin 1, which is a major structural component of microfibrils. We observed less densely packed fibrillin-1-rich microfibrils with irregular edges in the skin of individuals who were homozygous for G1297 compared with individuals who were homozygous for E1297. Moreover, we show that the E1297G locus is under positive selection in non-African populations, and that the E1297 variant shows subtle evidence of positive selection specifically within the Peruvian population. This variant is also significantly more frequent in coastal Peruvian populations than in populations from the Andes or the Amazon, which suggests that short stature might be the result of adaptation to factors that are associated with the coastal environment in Peru.

Efficacy and Safety of High-Dose Rifampin in Pulmonary Tuberculosis. A Randomized Controlled Trial.

RATIONALE: We examined whether increased rifampin doses could shorten standard therapy for tuberculosis without increased toxicity. OBJECTIVES: To assess the differences across three daily oral doses of rifampin in change in elimination rate of Mycobacterium tuberculosis in sputum and frequency of rifampin-related adverse events. METHODS: We conducted a blinded, randomized, controlled phase 2 clinical trial of 180 adults with new smear-positive pulmonary tuberculosis, susceptible to isoniazid and rifampin. We randomized 1:1:1 to rifampin at 10, 15, and 20 mg/kg/d during the intensive phase. We report the primary efficacy and safety endpoints: change in elimination rate of M. tuberculosis log10 colony-forming units and frequency of grade 2 or higher rifampin-related adverse events. We report efficacy by treatment arm and by primary (area under the plasma concentration-time curve [AUC]/minimum inhibitory concentration [MIC]) and secondary (AUC) pharmacokinetic exposure. MEASUREMENTS AND MAIN RESULTS: Each 5-mg/kg/d increase in rifampin dose resulted in differences of -0.011 (95% confidence interval, -0.025 to +0.002; P = 0.230) and -0.022 (95% confidence interval, -0.046 to -0.002; P = 0.022) log10 cfu/ml/d in the modified intention-to-treat and per-protocol analyses, respectively. The elimination rate in the per-protocol population increased significantly with rifampin AUC0-6 (P = 0.011) but not with AUC0-6/MIC99.9 (P = 0.053). Grade 2 or higher rifampin-related adverse events occurred with similar frequency across the three treatment arms: 26, 31, and 23 participants (43.3%, 51.7%, and 38.3%, respectively) had at least one event (P = 0.7092) up to 4 weeks after the intensive phase. Treatment failed or disease recurred in 11 participants (6.1%). CONCLUSIONS: Our findings of more rapid sputum sterilization and similar toxicity with higher rifampin doses support investigation of increased rifampin doses to shorten tuberculosis treatment. Clinical trial registered with www.clinicaltrials.gov (NCT 01408914) .