Baseline platelet count and creatinine clearance rate predict the outcome of neutropenia-related invasive aspergillosis.

BACKGROUND

Invasive aspergillosis (IA) is a life-threatening infection for immunocompromised patients. Improvement in IA outcome has been hampered by lack of early prognostic factors, namely, those available before starting chemotherapy (baseline) or early in the course of IA (nonbaseline). We hypothesized that prognostic factors can be identified before chemotherapy, ≤7 days from the first positive serum Aspergillus galactomannan index (s-GMI).

METHODS

We analyzed 98 patients with multiple myeloma who developed neutropenia-related IA and had a positive s-GMI. Three response criteria were used: kinetics of s-GMI, European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) definitions, and 6-week survival. Baseline and nonbaseline variables were analyzed separately.

RESULTS

Independent response predictors at baseline were a platelet count ≥65,000 platelets/mm(3) (odds ratio [OR], 1.009; 95% confidence interval [CI], 1.001-1.017; P = .03) by s-GMI kinetics, and a platelet count ≥65,000 platelets/mm(3) (OR, 1.009; 95% CI, 1.002-1.017; P = .01) and a creatinine clearance rate ≥53 mL/min (OR, 1.024; 95% CI, 1.006-1.042; P = .009) by EORTC/MSG criteria, with response rates of 83% and 28% when both variables were above or below these cutoffs, respectively (P < .001). Only baseline creatinine clearance rate ≥53 mL/min predicted 6-week survival (P = .003). Normalization of the s-GMI ≤7 days after the first positive s-GMI and neutrophil recovery were the nonbaseline factors associated with positive outcomes.

CONCLUSIONS

Two simple, inexpensive to measure, widely available, and routinely collected prechemotherapy values, platelet count and creatinine clearance rate, predict IA outcome and stratify patients into low-, intermediate-, and high-risk categories, while early evaluation of s-GMI allows timely treatment modification. These findings may improve patient outcomes by optimizing management strategies for this serious infection and may prove valuable in designing clinical trials of interventions to improve IA outcomes.