Platelets are essential blood component involved in primary hemostasis. A platelet count of less than 150 × 109/L is considered to be thrombocytopenia The causes of thrombocytopenia can be divided into two major groups, a decreased production of platelets or an under proliferative BM and an over-destruction of platelets. Under proliferative BM defects most common cause is aplastic anemia, On the contrary, peripheral destruction of platelets may be as a result of an immune-mediated process namely immune thrombocytopenia (ITP)

ITP is a common auto-immune disease in which platelet count is reduced in peripheral blood leading to petechiae and hemorrhage. The platelet count is decreased because there are auto-antibodies in circulation against platelets that bind to platelets surface and destroy them in the spleen . Aplastic anemia is characterized by suppression of bone marrow function resulting in progressive pancytopenia. The hematology analyzers can now give us certain parameters that can give information about platelets. These parameters are referred to as platelet indices in literature. Platelet indices include mean platelet volume (MPV), platelet distribution width (PDW) and platelet large cell ratio (P-LCR) . They are sensitive, non-invasive, inexpensive biomarkers. MPV is the most commonly investigated platelet parameter, signifies the average size of platelets in the blood. PDW is a marker of platelet anisocytosis, which describes distribution of platelets produced by megakaryocytes and increases upon platelet activation. P-LCR is another marker of platelet activity, is a percentage of all platelets with a volume measuring over 12 fl circulating in the bloodstream .

Inclusion Criteria:

• Age more than 18 years old regardless of gender.
• Platelet count below 100000/cu mm.
• Confirmed diagnosis aplastic anaemia.
• Confirmed diagnosis immune thrombocytopenia

Exclusion Criteria:

• Patient who received a platelet or blood transfusion within two weeks prior MPV analysis.
• Splenectomized patients
• Patients with chronic infection or inflammations.
• Diabetics and patients with coronary artery disease.
• Patients on anti- platelet or anti-inflammatory drugs.

Participants of the study will be confirmed as thrombocytopenic patients.