
Methods: A retrospective cohort study was conducted among 70 consecutive patients (pts) who received LZD therapy (1200mg/day) between July 2003 and August 2012 at St. Luke’s International Hospital (530 beds, acute care teaching hospital in Tokyo). Pts who received LZD repeatedly and pts with hematologic malignancy or DIC were excluded. TP was defined as decreased platelet counts (more than 50% decrease from baseline). Laboratory data were obtained for each pt followed from baseline to 14 days after discontinuation of LZD. Bivariate analyses and multivariate logistic regression were performed categorizing BMI into the three groups: 1. BMI less than 20, 2. BMI equal to or more than 20 and less than 25, 3.BMI equal to or more than 25.
Results: The mean age of the 70 pts was 66±17 years and 42 (60%) were male. The median period of LZD therapy was 16 days (range 3-63 days). LZD induced TP was found in 30 of 70 pts (43%). When evaluated by BMI category, 59% (13/22), 40% (12/30), and 28% (5/18) of pts with BMI less than 20, BMI equal to or more than 20 and less than 25, BMI equal to or more than 25, respectively, developed TP. Low BMI was significantly associated with TP in bivariate analyses (p<0.01). Results of the multivariate analysis showed evidence of an association with increasing age [adjusted odds ratio (OR)=1.02, 95% confidence intervals (CI), 0.99-1.05] and increase in serum creatinine (OR=1.53, 95%CI, 0.99-2.65], and a significant association with BMI less than 20 (versus BMI equal to or more than 25 ,OR=6.93, 95% CI, 1.69-36.12).
Conclusion: BMI less than 20 was independently associated with LZD induced TP. Our results indicate that the platelet counts of pts with low BMI treated with LZD should be monitored closely due to a potential increased risk of TP.

B. Natsumoto,
None
F. Omata, None
K. Furukawa, None