Early infection in bone marrow transplantation: Quantitative study of clinical factors that affect risk

Infections remain common life-threatening complications of bone marrow tran splantation. To examine clinical factors that affect infection risk, we ret rospectively studied patients who received bone marrow transplants (53 auto logous and 51 allogeneic). Over a median of 27 hospital days, 44 patients d eveloped documented infections. Both autologous transplantation and hematop oietic growth factor use were associated with less prolonged neutropenia an d decreased occurrence of infection (P less than or equal to .05). In a sur vival regression model, variables independently associated with infection r isk were the log(10) of the neutrophil count (hazard ratio [HR], 0.49; 95% confidence interval [CI], 0.32-0.75), ciprofloxacin prophylaxis (HR, 0.42; 95% CI, 0.19-0.95), empirical intravenous antibiotic use (HR, 0.09; 95% CI, 0.03-0.32), and an interaction between neutrophil count and intravenous an tibiotic use (HR, 1.86; 95% CI, 1.06-3.29). In this model, infection risk i ncreases steeply at low neutrophil counts for patients receiving no antibio tic therapy. Ciprofloxacin prophylaxis and particularly intravenous antibio tic therapy provide substantial protection at low neutrophil counts. These results can be used to model management strategies for transplant recipient s.