Body composition of rheumatoid arthritis patients in the City of Cape Town, South Africa.

Patients with rheumatoid arthritis (RA) tend to have a poor nutritional status. This study aimed to gather information on body composition in patients with RA in private and public health settings in the City of Cape Town, South Africa (SA). This cross-sectional study evaluated adults with RA. Information on demographics, comorbidities and medication was gathered. Anthropometrical measurements included weight, height, waist circumference and skinfolds and were used to calculate, interpret and classify body mass index (BMI), percentage body fat, waist circumference, fat mass index (FMI) and fat-free mass index (FFMI). Ethics approval for the execution of the study was obtained from the Health Research Ethics Committee of Stellenbosch University. The study included 251 participants [mean age, 54.7 years; ±standard deviation (SD) 13.6]. The mean BMI was 30.3 kg/m(2) (±SD 6.7) and 26.6 kg/m(2) (±SD 6.1) for women and men, respectively. BMI was used to classify obesity (45.9 %), overweight (26.8 %), normal weight (25.6 %) and underweight (1.6 %). Waist circumference classifications showed a substantially increased risk for metabolic complications in 127 participants (51.8 %) and an increased risk in 52 participants (21.2 %). Low fat-free mass (FFMI of <10th percentile) was seen in 24 participants (21 %), and obesity (FMI of >90th percentile) was seen in 31 (27 %). Rheumatoid cachexia was identified in 12 participants (10.3 %). Results indicate suboptimal nutritional status in patients with RA in the current setting. It highlights the importance of involving dietitians in the management of RA, with a view to reduce symptoms, improve quality of life, prevent cardiovascular disease and decrease overall medical costs.

Cloning of B7-2: a CTLA-4 counter-receptor that costimulates human T cell proliferation.

Although presentation of antigen to the T cell receptor is necessary for the initiation of an immune response, additional molecules expressed on antigen-presenting cells deliver essential costimulatory signals. T cell activation, in the absence of costimulation, results in T cell anergy. The B7-1 protein is a costimulator molecule that regulates interleukin-2 (IL-2) secretion by signaling through the pathway that uses CD28 and CTLA-4 (hereafter referred to as the CD28 pathway). We have cloned a counter-receptor of CD28 and CTLA-4, termed B7-2. Although only 26 percent identical to B7-1, B7-2 also costimulates IL-2 production and T cell proliferation. Unlike B7-1, B7-2 messenger RNA is constitutively expressed in unstimulated B cells. It is likely that B7-2 provides a critical early costimulatory signal determining if the T cell will contribute to an immune response or become anergic.