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To estimate the weight deficit and body composition of cases of pulmonary TB (PTB), and assess the roles of HIV and the acute-phase response, a cross-sectional study was carried out in Tanzania. Weight, body mass index (BMI), arm muscle area (AMA), arm fat area (AFA) and the serum concentration of the acute-phase protein alpha(1)-antichymotrypsin (serum ACT) were evaluated for each of 532 cases of PTB and 150 'non-TB' controls. On average, the female cases of PTB not only weighed 7.8 kg less but also had BMI that were 3.1-kg/m(2) lower, AMA that were 14.8-cm(2) lower, and AFA that were 7.6-cm(2) lower than those seen in the female subjects without TB. Similarly, on average, the male cases of PTB weighed 7.1 kg less and had BMI that were 2.5-kg/m(2) lower, AMA that were 18.8-cm(2) lower and AFA that were 1.6-cm(2) lower than those seen in the male subjects without TB. Although HIV infection was associated with a 1.7-kg lower weight and a 0.6-kg/m(2) lower BMI (with deficits in both AMA and AFA) among males, it was not associated with any such deficits among the female subjects. Elevated serum ACT was found to be a negative predictor of BMI, AMA and AFA, partially explaining the effects of the PTB but not those of the HIV. There is need for a better understanding of the determinants and effects of loss of fat and lean body mass in HIV-positive tuberculosis.

Fe status is difficult to assess in the presence of infections. To assess the role of the acute- phase response (APR) and other predictors of serum ferritin and transferrin receptor, we conducted a cross-sectional study among pulmonary tuberculosis (PTB) patients in Mwanza, Tanzania. The acute- (serum ferritin) phase protein, serum alpha1-antichymotrypsin (ACT) and serum ferritin and serum soluble transferrin receptor (sTfR) were measured, and data on smoking, soil and alcohol intake, and infection status were collected. Linear regression analysis was used to assess the role of elevated serum ACT and other predictors of serum ferritin and serum sTfR. Of 655 patients, 81.2 % were sputum positive (PTB+) and 47.2 % HIV+. Mean serum ACT was 0.72 g/l, with 91.1 % above 0.4 g/l. Among females and males, respectively, geometric mean serum ferritin was 140.9 and 269.1 microg/l (P < 0.001), and mean serum sTfR 4.3 and 3.8 mg/l (P < 0.001). Serum sTfR was increased 0.5 mg/l and log serum ferritin increased linearly with serum ACT >0.4 g/l. PTB+ and HIV infection, alcohol drinking and smoking were the positive predictors of serum ferritin, and female sex, soil eating, Schistosoma mansoni and hookworm infection were the negative predictors. Similarly, smoking and HIV infection were the negative predictors of serum sTfR, and female sex, soil eating and PTB+ were the positive predictors. Serum ferritin and serum sTfR are affected by the APR, but may still provide information about Fe status. It may be possible to develop algorithms, based on the markers of the APR and Fe status, to assess the Fe status among the patients with tuberculosis or other infections eliciting an APR.

Vitamin D is essential to immune function, but little is known about the vitamin D status in equatorial populations. A cross-sectional study was conducted among pulmonary tuberculosis (PTB) patients in Mwanza, Tanzania to identify the predictors of their vitamin D status. Data on sociodemography, season, and intake of food, alcohol, tobacco, and soil were collected, anthropometric measurements taken, and serum alpha(1)-antichymotrypsin (ACT), ferritin and soluble transferrin receptor (sTfR), and serum 25-hydroxy-(ergocalciferol+cholecalciferol) [25(OH)D] determined. Of the 655 patients studied, 79.7% (508/637) were culture-positive (PTB+) and 47.2% HIV infected. Mean serum ACT, an acute phase reactant, was 0.73 +/- 0.25 g/L with 69.2% >0.6 g/L. Mean serum 25(OH)D was 86.6 +/- 32.9 nmol/L, with 41.2% <75 nmol/L. Serum 25(OH)D was highest during the harvest season, May to July, compared with the remaining year. Single subjects had lower [10.4 (95% CI 4.0; 16.9) nmol/L] serum 25(OH)D concentrations than married subjects and PTB+ patients had concentrations lower [8.2 (95% CI 1.5; 14.9) nmol/L] than PTB- patients. Serum 25(OH)D increased with consumption of a large freshwater fish but not of small dried fish or other foods. BMI and serum TfR were positive predictors of serum 25(OH)D, whereas neither elevated serum ACT nor HIV were predictors. In conclusion, serum 25(OH)D is a valid measure of vitamin D status during the acute phase response. The lower concentrations in PTB+ patients may reflect lower sun exposure or increased utilization. The health consequences of hypovitaminosis D in low-income equatorial populations, at risk for both infectious and chronic diseases, should be studied.