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.
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.