Eleven years of experience with dialysis associated tuberculosis.

BACKGROUND

The aim of this retrospective study was to evaluate the incidence of tuberculosis (TB) in dialysis patients and to determine its clinical features and results of short-course (6 months) chemotherapy, mortality and risk factors of mortality.

METHODS

The study included 48 TB patients among 330 patients on dialysis of whom 37 were on hemodialysis and 11 were on peritoneal dialysis at Security Forces Hospital in the period from October 1989 to October 2000. The diagnosis of TB was established by a combination of clinical, radiological, biochemical, microbiological and histological examinations. Treatment with anti-TB drugs, the results of therapy and the outcome of patients were noted.

RESULTS

There were 32 males and 16 females with age ranges of 18 -89 (mean = 53.4) and 40 - 70 (mean 57.9) years, respectively. Their duration on dialysis ranged from 1 month to 10 years (mean = 26 months). The presenting clinical features were fever (32), cough (16), weight loss (9), and anorexia (7). The organ systems involved were pulmonary (23), peritoneal (15), lymphadenopathy (11), pericardial (4), bone TB (3), bone marrow (2), epididimo-orchitis (1), right infraclavicular chest wall cold abscess (1), right infrascapular cold abscess (1) and right renal mass (1). Single organ system involvement was noted in 36 patients, 2 systems in 10 patients and 3 systems in 2 patients. Two patients were treated empirically with good response. Evidence of tuberculosis was obtained from chest X-rays (23), bone X-rays (3), spinal MRIs (1), AFB (stain and culture) of sputum and fluid (15), ascitic fluid examination with exudate and raised adenine deaminase (ADA) levels (12), lymph node biopsy (8), pleural fluid examination with exudate and raised ADA levels (5), bone marrow aspiration (2), exudative pericardial fluid with raised ADA levels (2), nephrectomy and histopathology (1), dorsal spine biopsy (1) and laparotomy and biopsy ofperitoneum (1). Thirty-two patients received 4 anti-TB drugs: isoniazid (INH), rifampicin (Rif), pyrazinamide (Pyra) and ethambutol (Eth), 10 received 3 drugs (INH, Rif and Pyra or Eth), 2 received 2 drugs (INH + Rif) and a modified regimen was used in 3. The drug toxicities noted were hepatoxicity (5) and INH encephalopathy prior to the routine use of pyridoxine 100 mg daily (3), INH-induced SLE (1) and pyrazinamide-induced thrombocytopenia (1). The outcome of the patients was cured (35), expired (13), and 1 patient expired before starting therapy. Tuberculosis was not the direct cause of death in any of the patients.

CONCLUSION

The incidence of TB in dialysis patients is 26 times more common than in the general Saudi population and a high index of suspicion is needed for early diagnosis and treatment. Extrapulmonary TB was noted in 52% of the patients. Short-course (6 months) chemotherapy is effective. INH-induced CNS toxicity is significant.