Study of Conjunctival Flora in Patients after Peripheral Blood Stem Cell Transplantation and its Correlation with Tear Secretion

Abstract

Dry eye is a major ocular complication of peripheral blood stem cell transplantation (PBSCT) and may predispose bacterial colonization to the conjunctiva. To investigate the conjunctival bacterial flora in patients receiving PBSCT, we encompassed patients who received PBSCT at least 1 year from 2002 to 2008 in this cross-sectional study. Patients were divided into three groups in accordance to the result of the Schirmer Ia test. In the control group, we enrolled dry-eye patients with underlying disease other than hematopoietic stem cell transplantation of which the age range was similar to the study group. Thirty-six patients with 72 eyes were included in our study. The culture rates were 22% (8 in 36) in the first group (Schirmer Ia= 0-5 mm), 20% (4 in 20) in the second group (Schirmer Ia= 6-9 mm), and 0% (n=16) in the third group (Schirmer Ia ≥ 10 mm). The flora in patients receiving PBSCT were coagulase-negative Staphylococci, Staphylococcus aureus and Corynebacterium sp. The bacterial colonization rate in the post-PBSCT group was not higher than the control group (22.2% vs. 30.8% ), and coagulase-negative Staphylococci was the most common flora in the control group. In conclusion, despite not having statistical significance, there seems to be a positive correlation between the colonization rate and the severity of dry eye. However, bacterial profile isolated in post-PBSCT patients is not significantly different from other dry eye patients.