Research of Predictive Factors to Immune Thrombopenic Purpura (PREDI-PTI)

Research of Predictive Factors to Immune Thrombopenic Purpura in Front of a Thrombopenia in Appearance Isolated in the Elderly

It is about a multicentric study prospective of more than patients' 60 years with a thrombopenia isolated of less than 100 G/L blood platelet without cause found to estimate so certain examinations realized in the diagnosis (medullary cytogenetics, dosage of the TPO, the Anti-platelet antibodies, isotopic lifetime of platelet) are in favour of the diagnosis of PTI.

It is about a multicentric study prospective of more than patients' 60 years with a thrombopenia isolated of less than 100 G/L blood platelet without cause found to estimate so certain examinations realized in the diagnosis (medullary cytogenetics, dosage of the TPO, the Anti-platelet antibodies, isotopic lifetime of platelet) are in favour of the diagnosis of PTI. The principal endpoint is to evaluate if the medullary cytogenetics is the predictive factor of the diagnosis of PTI in front of a thrombopenia isolated in elderly. The secondary endpoints are : to identify at the time of the diagnosis, the factors and/or predictive markers correlated in the final diagnosis of PTI or SMD to study the respective frequency of the PTI and the SMD in front of a thrombopenia seemingly isolated of the subject of more than 60 years. 200 patients will be included. 160 patients should be assessable at the end of study by considering the excluded patients, the dead and the lost sight.They will be followed every 4 months, during two years. In every visit, will be realized a clinical examination, a blood film, a haemogram. If the haemogram is abnormal, a bone marrow biopsy is realized. The patient who presents a myelodysplastic syndrome is excluded.

Patients of 60 years old and more presenting a thrombopenia isolated with a rate of platelet < 100 G/l Blood tests and bone marrow biopsy repeated

Blood tests are realized for the dosage of the TPO, the dosage of the antiplatelet antibodies, to measure isotopic lifetime of platelet. The test in corticoids by the prednisone per os is realized too. The bone marrow biopsy is realized at the inclusion and during follow-ups if the haemogram is abnormal.

1 mg / kg / day for 3 weeks The therapeutic test is considered as positive if a number of platelets is > 50 G/l with at least a doubling of the platelet rate before treatment

Inclusion Criteria: Rate of platelet < 100 G/l for less than 12 months , age = ou > 60 years, haemoglobin > ou = 12 g / dl at the woman, > ou = 13 g/dl at the man, polymorphonuclear neutrophil > ou = 1.7 G/l, monocytes < ou= 1 G/l, lymphocytes < ou = à 4 G/l, VGM < 100 fL, blood film normal, informed consent, expectation of life > 6 months Exclusion Criteria: hepatomegaly, splenomegaly, hepatic abnormality, blood coagulation abnormality, antecedent of auto-immune disease, drug thrombopenia, HIV, VHB or VHC positive, antecedent of malicious tumor in the 5 years before inclusion