6. Analysis of late infections in 89 long-term survivors of bone marrow transplantation

Abstract

Eighty-nine patients with aplastic anaemia or acute leukaemia treated by either syngeneic (13 patients) or allogeneic (76 patients) marrow transplantation who had survived for more than 6 mth were surveyed to determine the incidence of late infections. Most patients (72%) had either no or very few late infections and only a minority (28%) had 3 or more infections. Eight patients (9%) died from infection. Bacterial infections of lung, respiratory tract, skin and blood represented more than half of the 152 infections encountered. Gram-positive cocci represented one-third of the documented infecting organisms. Varicella-zoster (VZ) infections were seen in 22% of all patients. Each affected patient had only a single episode of VZ infection. Fungal infections and interstitial pneumonia were uncommon. By the use of a proportional hazards regression model we attempted to identify clinical and immunological factors predictive of and predisposing to late infections. Only 2 factors were significantly associated with late non-VZ infections; chronic graft-versus-host disease (C-GVHD) and inability to respond to cutaneous dinitrochlorobenzene (DNCB). Other factors analysed, e.g. underlying disease, conditioning regimen, type of transplant, age and sex, did not not show significant associations. In contrast, VZ infections were not associated with C-GVHD. Negative DNCB skin test reactivity appeared to be the only factor correlating with VZ infections. The recurrent (and occasionally fatal) infections seen in a minority of long-term survivors after syngeneic and allogeneic marrow transplantation are most likely the result of immunologic deficits—as indicated by the failure to respond to DNCB—which in turn are most often associated with C-GVHD.