Salazosulfapyridine-induced agranulocytosis in a patient on chronic hemodialysis with seronegative spondyloarthropathy: a case report

Background Salazosulfapyridine is a generally safe drug often used to treat rheumatoid arthritis and ulcerative colitis. However, agranulocytosis is a rare but serious adverse effect of this drug. To date, there have been no reports describing the clinical course of salazosulfapyridine-induced agranulocytosis in a chronic hemodialysis patient. Case presentation The patient was a 64-year-old man with IgA nephropathy who had been on chronic hemodialysis for about 3 years. For 1 month, he had general fatigue, mild fever, and pain in multiple joints of the upper extremities. He was hospitalized and underwent detailed examinations in our department. Laboratory investigations revealed an erythrocyte sedimentation rate of 67 mm/h and a C-reactive protein level of 7.73 mg/dL. Rheumatoid factor and anti-cyclic citrullinated peptide antibody were negative. Musculoskeletal ultrasonography showed inflammation of the tendon sheath in both wrists and the right shoulder joint. Computed tomography scans revealed osteosclerosis and narrowing of the sacroiliac joint. The diagnosis was seronegative spondyloarthropathy. He was started on salazosulfapyridine. Four weeks later, he had a high fever and low granulocyte count. Treatment with granulocyte colony-stimulating factor was started. The agranulocytosis could not be ascribed to any other cause and was considered an adverse effect of salazosulfapyridine, which was then stopped. Nine days later, the granulocyte count had recovered and the fever had resolved. Conclusions Currently, there are no guidelines on the use of salazosulfapyridine in chronic hemodialysis patients. The starting dosage should be smaller for these patients than for patients without renal impairment. Also, the laboratory monitoring interval for complete blood count should be shorter than usual.