Systemic nocardiosis following allogeneic bone marrow transplantation

Five cases of systemic Nocardia infection were diagnosed among 301 allogeneic bone marrow transplant recipients. A sixth case included in this report received her transplant at another institution. The cumulative annual incidence rate of this infection was 1.75%. All patients had been treated previously for acute graft-versus-host disease (GVHD). At the time of diagnosis of systemic Nocardia infection, a median of 198 (range 148-1121) days after transplantation, all patients had extensive chronic GVHD and were taking 2 to 3 immunosuppressive medications. Prior to diagnosis of Nocardia infection patients had experienced multiple opportunistic infections, including infections with Mycobacterium avium-intracellulare, Pneumocystis carinii, and cytomegalovirus antigenemia. Treatment with trimethoprim-sulfamethoxazole (TMP-SMX), ceftriaxone, or carbapenem antibiotics resulted in a median survival of 219 days from the time of diagnosis and an actuarial 1-year survival of 40%. All patients who received more than 2 weeks of therapy were cured of their infections. Notably, 5/6 patients in this cohort were unable to take TMP-SMX because of myelosuppression. In comparison with randomly selected control patients, the use of pentamidine for prevention of P. carinii infection was associated with a marginal increase in the risk of Nocardia infection. We postulate that the use of TMP-SMX may be of benefit in the prophylaxis of infections other than P. carinii in patients with chronic GVHD.