Endogenous erythroid colony formation in patients with retinal vein occlusion.

PURPOSE: The pathophysiology and causes of retinal vein occlusion (RVO) remain largely unknown. Latent forms of myeloproliferative disorders, which are diagnosed by the presence of in vitro endogenous erythroid colony (EEC) formation, are a well-known cause of intraabdominal vein thrombosis. The suspected diagnosis of a latent myeloproliferative disorder in a patient with RVO, based on the presence of EEC formation, led us to evaluate the association between latent myeloproliferative disorders and RVO.

DESIGN

Observational case series in a national eye center.

PARTICIPANTS

Forty-four patients, with a mean age of 46 years (range, 21-62) and central (n = 38) or peripheral (n = 6) RVO responsible for visual acuity decreased to 6/12 or less.

METHODS

In vitro bone marrow culture.

MAIN OUTCOME MEASURE: Endogenous erythroid colony formation in cytokine-free culture medium. Conventional diagnostic criteria for myeloproliferative disorders and the JAK2 V617F mutation (which is strongly associated with myeloproliferative disorders) were assessed in RVO patients showing EECs.

RESULTS

Endogenous erythroid colony formation was observed in 12 of 44 (27%) patients with RVO, 13 of 35 (37%) patients with Budd-Chiari syndrome, and 52 of 53 (98%) patients with primary polycythemia (positive control groups) but not in 22 healthy bone marrow donors (negative controls) evaluated at the same time and by the same hematology laboratory. Neither conventional nor genetic diagnostic criteria for myeloproliferative disorders were observed in any patient with both RVO and an EEC at the time of diagnosis or during follow-up.

CONCLUSIONS

Endogenous erythroid colony formation is frequently observed in patients with RVO independently of any detectable myeloproliferative disorder. This opens a new aspect of research on the pathophysiology of this sight-threatening disease.