[The human spleen in idiopathic thrombocytopenic purpura]

Idiopathic (autoimmune) thrombocytopenic purpura (ITP, AITP) represents a relatively frequent impairment. It involves a syndrome of various diseases with a shortened thrombocytes survival caused by anti-platelet antibodies. The majority of cases are of secondary character. Spleenectomy often evokes a complete remission of thrombocytopenia. The study describes morphologic findings in spleens of 30 patients with the clinical diagnosis of ITP/AITP. The findings were gained by light microscopy from formol-paraffin blocks and histochemical findings from cryostat sections of non-fixed tissue. The alcaline and acidic phosphatases, nonspecific esterase, chloracetate esterase, and dipeptydilpeptidase IV were investigated enzymohistochemically. Immunoglobulins were examined immunohistochemically and T lymphocytes by means of monoclonal antibodies. The affinity HPA--Helix pomatia agglutinin, PHA--phytohemagglutinin from Phaseolus vulgaris, SBA--soy-bean agglutinin from Glycine max. and PSA--peas bean agglutinin from Pisum sativum were investigated by means of specific antilectin antibodies. The human spleen during idiopathic thrombocytopenic purpura accumulates neutrophilic polymorphonuclear granulocytes; platelets-stagnate and are destroyed. These processes can be identified in histologic sections e.g. also by means of anti-fibrinogen antibodies. The red pulp contains foam cells to various extent. Besides generally known processes, the white pulp also displays alterations in composition of cellular compartment of the periarterial lymphatic sheaths. Human spleen distinguishes modified blood platelets as alien corpuscles, and thus eliminates them from the blood circulation system by its immunologic and other mechanisms, the details of which still remain to be clarified. (Fig. 6, Ref. 44.)