Infectious arthritis in renal transplant patients.

Infectious complications in the renal transplant patient are common, and infecting agents include opportunistic organisms as well as common pathogens. However, we were only able to document 6 patients who had septic arthritis from more than 800 who received a renal transplant at our institution over an 18-year period. Furthermore, only 16 other cases of infectious arthritis have been reported in the literature. All of our patients had an apparent predisposing factor and 3 patients had prior infection with the same organism. The knee was the most commonly infected joint. The initial synovial fluid white blood cell count was usually greater than 30,000 cells/mm3, but 1 patient with viral arthritis initially had noninflammatory fluid. The peripheral blood white blood cell count may not be elevated. All of our cases of initial joint infection occurred by 18 months posttransplant. Blood cultures were positive in 3 of 4 patients with bacterial infection. Followup of these 6 patients averaged 4.3 years. Numerous other rheumatologic syndromes and disorders peculiar to the posttransplant period may mimic a septic joint. Consequently, despite the low frequency of occurrence of septic arthritis, persistent attention to the locomotor system in the transplant patient is warranted.