Background Hereditary spherocytosis (HS) is a common inherited disorder that is characterised by anaemia, jaundice, and splenomegaly. Clinical severity is variable with most patients having a well-compensated hemolytic anaemia. The primary lesion in HS is loss of membrane surface area, leading to reduced deformability due to defects in the membrane proteins ankyrin, band 3, beta spectrin, alpha spectrin, or protein 4.2. Many isolated mutations have been identified in the genes encoding these membrane proteins; common hereditary spherocytosis-associated mutations have not been identified. The classic laboratory features of HS include minimal or no anaemia, reticulocytosis, an increased mean corpuscular haemoglobin concentration (MCHC), spherocytes on the peripheral blood smear, hyperbilirubinemia, and abnormal results on the osmotic fragility test.

Aim Of the study is to evaluate the role of MCV, MCHC as a screen test to diagnose spherocytosis

Methods In our study are included 60 subjects, 30 children with HS and 30 children-control groups. Our patients with anaemia, jaundice, and splenomegaly are diagnose with HS by incubated osmotic fragility test, performed after incubating RBCs for 18–24 h under sterile conditions at 37°C.

Results We found that 25% of pts. have mild HS, 20% moderate HS, 30% moderate to severe HS and 25% severe HS. In peripheral blood smear 7% of pts. had 0–5 spherocites for field, 30% had 5–10 spherocites for field and 63% had 10–15 spherocites for field. 70% of pts. With HS have MCHC > 38%.

There are a positive correlation between MCHC and spherocites in peripheral blood smear (r = 0,898, p < 0,001) and RDW (r = 0,647, p < 0.001), negative correlation between MCHC and MCV (r = -0,437 p < 0,001)

Conclusion The dedication of hiperdense erythrociyte today is used as a new tool in diagnosing HS. The determination of MCHC constantly growing with other red cell index, MCV < 80 fl, RDW > 15 obtained from an electronic cell counter usually is enough to suggest for HS.

Key Words Spherocytosis, MCHC, anaemia, children.