Study of the Alterations of Platelet Parameters and Functions in Children and Adolescent with Iron Deficiency Anemia and Response to Therapy

Abstract

Introduction: Iron deficiency anemia (IDA) is the commonest type of malnutrition. Several changes in platelets in IDA have been reported, so, a relationship between iron metabolism and thrombopoiesis should be considered. Aim of the study:to study the alterations of platelet functions in patients with IDA by assessment of platelet aggregation with epinephrine, ADP and ristocetin and by measuring platelet function analyzer (PFA-100) closure time together with the effect of iron therapy on the same tests. Patients and Methods: A case control study was conducted in Ain Shams University Children's hospital in the period from June 2011 to June 2012 including 20 patients with confirmed IDA and 20 healthy age and sex matched control. Their ages ranges between 2-18 years. Patients with coexisting chronic disease, decompensated severe IDA, thrombocytopenia and inherited platelet function defect were excluded. All patients and control were subjected to history taking with emphasis on socioeconomic standard according to Park classification, Dietetic history of iron intake with Food frequency questionnaire and Diet Analysis Program1995; Symptoms suggestive of anemia, history of blood transfusion, history of bleeding tendency, drug history and family history of similar condition with anemia or bleeding. Laboratory analysis included complete blood count to assess the erythrocyte indices (Hb, MCV, MCH, MCHC, RDW) and platelet parameters including (count, size and distribution width), assessment of iron status by measuring serum iron, total iron binding capacity and serum ferritin, assessment of platelet functions by PFA-100 closure time and platelet aggregation with epinephrine, ADP and ristocetin. Patients with IDA were treated by oral iron therapy 6mg/kg/day of ferrous sulphate for 12 weeks. Post therapeutic assessment of patients clinical improvement including bleeding, and laboratory iron status, erythrocyte indices, platelet functions after 48 hours of discontinuation of oral iron therapy. Results: Mean age of IDA patients was 5.7±4.2 years compared 7.6±4years in control group (p>0.05). Bleeding manifestations were more common in patients group. One patient was diagnosed as Glanzmannthrombasthenia and excluded from statistical analysis. Mean PFA-100 closure times (with epinephrine) were significantly longer in patients (186.2±90.35sec) compared to control group (115±28.5sec) (P <0.05). Platelet aggregation by ADP (38.1±22.2%), epinephrine (186.2±90.35) and ristocetin (58.8±21.4%) were significantly reduced in patients compared to control (62.7±6.2, 63.3±6.9, 73.8±8.3 respectively) (P<0.001). After treatment all hemoglobin parameters and iron profiles were improved, platelet aggregation tests induced by ADP (64.78±18.25%), and epinephrine (55.47±24%) were significantly increased in patients with IDA compared to before treatment (39.44±21.85%, 20.33±14.58%) (P<0.001). Similarly PFA 100 closure time as well showed significant decreased after treatment (118.4±27.242) compared to before treatment (186.2±90.35) (P<0.05). A negative correlation between platelet aggregation induced by ADP and mean values of serum ferritin before treatment (r= 0.042, P<0.05) and) was detected. Conclusion: A mutual effect is considered between iron deficiency and platelet functions. Subtle bleeding manifestations can occur in patients with IDA with delay in platelet aggregation and prolongation in PFA-100 closure times which can be reversed by iron therapy. Key words: Iron deficiency, Platelet aggregation, PFA 100