Association between thrombocytosis and iron deficiency anemia in inflammatory bowel disease

Abstract

Background: Thrombocytosis and iron deficiency anemia are frequent complications of inflammatory bowel disease (IBD). The aim of this study was to investigate the correlation between iron deficiency anemia and thrombocytosis in IBD patients.

Methods: A total of 198 consecutive IBD patients and 102 healthy controls participated in the study. The parameters investigated were: platelets (PLT), mean platelet volume, platelet distribution width, plateletcrit, hematocrit (HCT) levels, hemoglobulin (Hb) levels, mean corpuscular volume (MCV), red cell distribution width (RDW), ferritin levels, soluble transferrin receptor (sTfR) levels, the sTfR-F index (sTfR-F=sTfR/log10 ferritin), and vitamin B12 and folate levels. Thrombocytosis was defined as an absolute number of PLT greater than 400k/μl. Disease activity indices (Crohn's Disease Activity Index for Crohn's disease and Simple Clinical Colitis Activity Index for ulcerative colitis) as well as C-reactive protein (CRP) were also correlated with the study parameters.

Results: The IBD patients demonstrated decreased HCT levels, Hb levels, MCV, mean platelet volume, and ferritin levels and an increased absolute PLT count, RDW, platelet distribution width, plateletcrit, sTfR and sTfR-F index (P<0.0001) compared with healthy controls. Twenty-seven patients exhibited thrombocytosis (13.6%). The median value for PLT (interquartile range) was 289 (228-355)k/μl, for Hb levels was 13.4 (12.0-14.7) g/dl, for ferritin levels was 36.6 (19.7-80.7) ng/ml, and for sTfR-F was 0.82 (0.61-1.37) mg/l. The PLT in IBD patients correlated with HCT levels, Hb levels, MCV, RDW, Fe levels, ferritin levels, sTfR, sTfR-F, CRP levels, Simple Clinical Colitis Activity Index, and Crohn's Disease Activity Index (Spearman's ρ correlation). In the multivariate analysis, only Hb levels, RDW, CRP levels, ferritin levels, and sTfR-F remained significant (P<0.05). None of the aforementioned was observed in the control group.

Conclusion: The absolute PLT count seems to correlate with iron deficiency anemia parameters and disease activity in IBD patients. Controlling the inflammation and managing iron deficiency could lead to reversal of thrombocytosis in IBD patients.