C-Tb skin test to diagnose Mycobacterium tuberculosis infection in children and HIV-infected adults: A phase 3 trial.

BACKGROUND: C-Tb, an ESAT-6/CFP-10-based skin test, has similar sensitivity for active TB compared to tuberculin skin test (TST) and QuantiFERON-TB-Gold-In-Tube (QFT). However, data are limited in children and HIV-infected persons. METHODS: Asymptomatic South African contacts <5 years (n = 87; HIV-uninfected), or symptomatic individuals of all ages presenting to clinics with suspected TB (n = 1003; 30% HIV-infected) were recruited from eight South African centres. C-Tb and TST were allocated to either forearm double blinded. Samples for QFT were collected in parallel, and test-positivity rates were compared. RESULTS: In participants with microbiologically confirmed TB (n = 75; 45% HIV-infected) sensitivity of C-Tb, TST and QFT were similar (72% versus 75% versus 73%; p>0.5). All 3 tests had similar positivity rates in HIV-infected participants with active TB, however, positivity rates were reduced when CD4 counts were <100 cells/µL. In participants where active TB was excluded (n = 920), C-Tb (41%), TST (43%), and QFT (44%) also had similar test-positivity rates. Among asymptomatic contacts aged below five, 32% (28/87) tested positive with C-Tb and 32% (28/87) with TST (concordance 89%). Overall, C-Tb and TST showed a similar safety profile. CONCLUSION: C-Tb was safe and showed similar test-positivity rates, compared to TST and QFT, in children and HIV-infected persons with active or latent M. tuberculosis infection. These data inform the utility of C-Tb in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov NCT01642888. EudraCT 2011-005078-40.

A randomized, double-blind, parallel-group, placebo-controlled trial of Extract Sceletium tortuosum (Zembrin) in healthy adults.

OBJECTIVES: The objective of the study was to evaluate the safety and tolerability of two doses (8 mg and 25 mg once daily) of a 2:1 standardized extract of the South African medicinal plant Sceletium tortuosum (L.) N.E. Br., trademarked Zembrin,(®) in healthy adult volunteers over a three-month period. DESIGN: This was a randomized, double-blind, parallel-group, placebo-controlled single center study. SETTING: Tiervlei Trial Centre, Karl Bremer Hospital, Bellville, Cape Town, South Africa. PARTICIPANTS: The study took place between February 2 and July 27, 2009. Thirty-seven healthy adults were recruited from the general population. INTERVENTION: Participants were randomized to receive either one of two doses of study medication, or an identical placebo, taken once daily for 3 months. Of the 37 subjects, 12, 12, and 13 subjects received 8 mg extract Sceletium tortuosum (Zembrin), 25 mg extract Sceletium tortuosum (Zembrin), and placebo treatment, respectively. OUTCOME MEASURES: No efficacy variables were assessed. The safety and tolerability variables comprised of vital signs, physical examination, 12-lead electrocardiogram (ECG), laboratory assessments (hematology, biochemistry, and urinalysis), and the recording of adverse events (AEs). RESULTS: There were no apparent differences between the three treatments with regard to vital signs, 12-lead ECG, body weight, and physical examination from screening to the end of the 3-month treatment period. No significant changes were observed in hematology or biochemistry parameters between initial screening and the end of the study. Both doses of extract Sceletium tortuosum (Zembrin) were well-tolerated. The most commonly reported AE was headache, followed by abdominal pain and upper respiratory tract infections, all with greater incidence in the placebo group than in the treatment groups. Unsolicited positive effects on well-being were noted in patient diaries by some participants taking extract Sceletium tortuosum (Zembrin), including improved coping with stress and sleep. CONCLUSION: Both doses of extract Sceletium tortuosum (Zembrin) (8 mg and 25 mg) were well tolerated when used by healthy human subjects once daily for 3 months.