Systemic immune activation as a potential determinant of wasting in Zambians with HIV-related diarrhoea

Wasting in African AIDS patients is severe, and its aetiology is probablymultifactorial: persistent diarrhoea, poverty and tuberculosis may allcontribute. We report a cross-sectional study of body composition measuredanthropometrically in 75 adult patients with HIV- related persistentdiarrhoea in Lusaka, and its relationship to gastrointestinal infection andsystemic immune activation assessed using serum neopterin and solubletumour necrosis factor receptor (sTNF- R55) concentrations. Patients as agroup were generally severely wasted (mean body mass index (BMI) 15.8kg/m2, range 11-22), but the severity of wasting was related neither tooesophageal candidiasis nor to intestinal infection. In men but not women,all measures of nutritional status were negatively related to serumsTNF-R55 concentration (fat- free mass in men, r = -0.64; 95% CI: -0.80,-0.41; p < 0.0001). Some wasted patients had cutaneous features ofmalnutrition, again associated with higher sTNF55 concentrations, and twohad peripheral oedema. The diarrhoea-wasting syndrome in this part ofAfrica seems to be associated with evidence of high cytokine activity inmen, rather than oesophageal candidiasis or any particular intestinalopportunistic infection. This immune activation requires furtherinvestigation in the context of the sex difference we have observed.