Hypersegmented neutrophils in peripheral smear –An etiological analysis

Abstract

Hypersegmentation of neutrophils is defined as presence of 5% or more neutrophils with five or more lobes or single neutrophil with 6 lobes. It is usually associated with deficiency of or failure to utilize cobalamin or folate and impaired DNA synthesis is the accepted mechanism for the morphological changes seen in megaloblastosis. Other causes of neutrophil hypersegmentation (NH) listed include microcytic hypochromic anemia(MHA) but the evidence for this is based mainly on a limited number of case studies in which MHAs with vit B12 and folic acid deficiency also were included. More studies are needed to establish itiological factors other than already established megaloblastic anemia.The present study was conducted in Department of Pathology in a tertiary care centre in Central Kerala, India. 100 cases peripheral smears with NH were evaluated. Aim of the study was to classify the itiological factors of NH in peripheral smears, study NH in microcytic hypochromic anemia and to check whether there is any connection between microcytic hypochromic anemia with NH and thrombocytosis. Complete blood count of all cases were taken using automated hematology analysers. Peripheral smear picture were correlated with the blood counts. Cases with MHA were examined for underlying vit B12 and folic acid deficiency. Study shows that 31% cases of peripheral smears with hypersegmentaion of neutrophils were pure microcytic hypochromic anemias with normal vitB12 and folic acid levels. Study also points to increased incidence thrombocytosis in pure MHA cases compared to other etiological factors.