Pediatria pre prax 5/2004

Možnosti využití anti-D globulinu v léčbě dětí s chronickou formou ITP

THE USE OF ANTI-D GLOBULIN IN THE TREATMENT OF CHILDREN WITH CHRONIC IMMUNE (IDIOPATHIC) THROMBOCYTOPENIC PURPURA The authors analyzed the results of anti-D globulin treatment in a group of 12 patients, aged 5–18 years (median age 11 years), with a chronic form of immune (idiopathic) thrombocytopenic purpura. Anti-D globulin was administered in a dose of 50 ?g/kg by short intravenous infusion. Platelet count before the start of the therapy was 3–19 × 109/l (median 7,5 × 109/l). Complete blood count and laboratory markers of hemolysis were measured in all patients, and antiplatelet antibodies before and after administration of anti-D globulin in 9 patients. Treatment response was divided into four grades according to platelet count values: grade 1: normalization of platelet count, grade 2: good response – platelet increase to 50–149 × 109/l, grade 3: partial response: platelet increase to 20–50 × 109/l, grade 4: poor response – platelet increase to less than 20 × 109/l. The time of platelet decrease under 50, 30 and 20 × 109/l was evaluated in patients with responses of grade 1 and 2. Grade 1 response was observed in 6/12 (50 %) patients, type 2 in 4/12 (33,3 %) patients, type 3 and 4 in one patient (8,3 %). The effect was transient in all patients. The period of platelet count increase above 50 × 109/l was longer than 21 days in only one patient. Platelet decrease under 20 × 109/l was observed between 14–49 days after anti-D administration. After a repeated therapy course, two patients had a durable platelet count increase above 30 × 109/l, and both are off treatment. In all patients, a decrease in haemoglobin level in the range 3–27 g/l (median 12 g/l) as a result of Coombs-positive haemolytic anaemia was observed. The haemoglobin decrease was not clinically significant. In three patients, a brief increase in body temperature without chills, despite preventive antipyretic administration, was observed. No other side effects of therapy appeared. Grade 1 and 2 responses were seen in all 7 patients with a previously good response to HDIVID. The only one poor responder to anti-D had had no response to HDIVIG in the past. Anti-D globulin has no effect on the ITP pathogenetic mechanism. Its effect is only transient; a cure of the disease cannot be expected after its adminstration. Howewer, in patients with clear indication for therapy, anti-D globulin can serve as another treatment option appart from corticosteroids and HDIVIG. Repeated courses of anti-D globulin can give the time to overcome critical periods with significant bleeding until partial or complete remission of the disease is achieved. Its use is suitable for the planned improvement of platelet count before surgery or intervention in the mouth cavity. One of its advantages is the possibility of short infusion in an outpatient setting and lower cost in comparison with HD IVIG. For the definitive evaluation of efficacy, optimal dose and side effects of anti-D in children with the chronic form of ITP, further systematic studies in a larger cohort of patients are needed. Key words: immune (idiopathic) thrombocytopenic purpura, chronic form, children, treatment, anti-D globulin, hemolytic anaemia.