Infectious arthritis in patients with rheumatoid arthritis.

Eleven cases of infectious arthritis occurring in patients with rheumatoid arthritis are reported. Staphylococcus aureus was the causative organism in eight patients. Streptococcus anginosus and Streptococcus agalactiae in one patient each, and Mycobacterium tuberculosis in two patients. The mean duration of symptoms before diagnosis was 16 days in patients with pyogenic arthritis. The diagnosis of joint infection caused by Mycobacterium tuberculosis was especially delayed (57 days). Four patients died; they were found to have a longer time to diagnosis and two of them had multiple joint infection. Although Staphylococcus aureus is the microorganism most often affecting patients with rheumatoid arthritis, infection caused by Mycobacterium tuberculosis must also be considered in such patients

Rheumatoid factor in patients with systemic lupus erythematosus.

SIR, In the report by Helin et al in the Annals' the authors suggest that rheumatoid factor (RF) protects against nephropathy in patients with systemic lupus erythematosus (SLE). We have reviewed our series of 78 patients with SLE fulfilling the criteria of the above report for evaluating nephropathy and assaying RF. The Waaler-Rose sensitised sheep cell agglutination test was used to measure RF, with titres equal or greater than 1/64 considered positive. Both groups with and without renal disease were comparable for age and sex. A renal biopsy was performed in 38 out of 40 patients with nephropathy..