Conjunctival epithelial cells (CEC) morphology in hematological patients before and after hematopoietic stem cell transplantation (HSCT). A Cytological and Confocal Microscopy Study

Abstract

Purpose: To analyze CEC morphology in hematological patients before and after HSCT and to correlate possible modifications to HSCT parameters and ocular surface impairment

Methods: Prospectively collected data from 33 patients (20 F; 13 M) who had received HSCT were retrospectively analyzed upon local ethical committee authorization. CEC collected before the pre-op conditioning regimen (V0) and 1 month (V1), 3 months (V2), 6 months (V3) and 12 months (V4) post- op were analyzed by in vivo confocal microscopy (IVCM), scraping and impression cytology, immunocytochemistry (ICC) and interphase FISH analysis with X and Y chromosome probes in donor/recipient sex-mismatched cases. Data were related to recipient age, donor type and age, HSC source, T-cell depletion intensity, sex mismatch, Dry Eye (DE) onset, systemic and ocular graft versus-host disease (GVHD)

Results: No patient developed ocular GVHD. DE was diagnosed in 13 patients already at V0 and in 7 patients after HSCT (medium interval 3.8±3.1 months from HSCT to DE onset). Squamous metaplasia with decrease/absence of goblet cells was found already at V0. Giants polyploid (GP) cells were never observed at V0 but were detected in 18 patients only at V1 with density 10-45% vs total CEC. GP cells reached a density peak at V2 and V3 and were found up to V4 in 7 of 26 surviving patients who were living without disease relapse. GP cells were also detected by IVCM as randomly grouped enlarged superficial cells. No polyploid cell was observed in bone marrow aspirate at the same post-op intervals. FISH analysis did not show any donor chromosome; ICC showed a CK19 positivity suggesting a conjunctival recipient origin. GP cell density was found to be related to squamous metaplasia degree (r=0.572,p<0.01) and T-cell depletion intensity (r=0.43,p<0.05)

Conclusions: This is the first study diagnosing DE in hematological patients already before HSCT and conditioning regimen. Further, GP cells were detected after HSCT in conjunctiva for the fisrt time by IVCM. These cells have been shown to increase in number as a response to adverse circumstances as chemotherapy but their role has been poorly investigated in human conjunctiva. In this study GP cells appeared to be related to conditioning regimen and squamous metaplasia representing a possible marker of post-HSCT ocular surface dryness