Q: My niece is battling a blood disorder ITP. She is 8 and currently her count is at 27,000. They are considering using a new AIDS fighting injection called IVIg, which is well tolerated by children. What is your opinion of ITP and do you agree they should try the new shot? They live in a highly toxic city called Houston, which is a large chemical and gasoline producing area. If she temporarily left Houston, would 30 days in a different city be enough time for her body to show a different count? I can't help but think this problem exists because of where they live. Is this true?

A:Platelets (thrombocytes) are a type of blood cells, which are derived in the bone marrow from large cells called megakaryocytes. They are critical for the clotting of blood and have life-span of about 10 days. The normal platelet count ranges from 150,000 - 400,000/ml and a reduction in platelets is referred to as thrombocytopenia. This may be mild (100,000 - 150,000/ml), moderate (50,000 - 100,000/mlƒw) or severe (less than 50,000/ml). Platelets may be low due to: a) increased destruction (immunologic ¡V infections, drugs; gestational thrombocytopenia) or utilization (disseminated intra-vascular coagulation; abnormal vasculature as seen in hemolytic uremic syndrome & thrombotic thrombocytopenic purpura), b) decreased production (leukemia, aplastic anemia, megaloblastic anemia, drugs, infections or c) sequestration in the spleen (cirrhosis of liver). Even though there is a diverse list of potential underlying causes of thrombocytopenia, most cases fall within two major categories: impaired platelet production or accelerated platelet destruction. Idiopathic thrombocytopenic purpura (ITP) is the presence of isolated thrombocytopenia with a normal bone marrow and the absence of other causes to account for it. ITP is caused by increased peripheral platelet destruction, with most patients having antibodies to specific platelet membrane glycoproteins while relative marrow failure may contribute to this. There are two distinct types - acute ITP in children which has an abrupt onset and chronic ITP in adults which is gradual in its appearance. There may be a history of recent live virus immunization or a recent viral illness (childhood ITP). Drugs can cause platelet destruction by a variety of mechanisms. No treatment is required when the platelet counts are more than 50,000/ml. Treatment is indicated a) when platelets are less than this and there is significant mucous membrane bleeding; b) in patients with hypertension, peptic ulcer disease or vigorous lifestyle who have a risk factor for bleeding and c) when platelet count <20,000-30,000/ml. Glucocorticoids and intra-venous gammaglobulins (I.V. Ig) are the mainstays of medical therapy. Their use and dose is dictated by the symptoms, patients clinical condition and the platelet count. Platelet transfusion is indicated for controlling severe hemorrhage. Platelet survival is increased if the platelets are transfused immediately after I.V. Ig infusion. The prognosis is good with about 83% children having a spontaneous remission and nearly 90% children eventually recovering.