A prospective evaluation of normal mean platelet volume in discriminating hyperdestructive thrombocytopenia from hypoproductive thrombocytopenia.

Bone marrow (BM) examination is the gold standard test in discriminating between hyperdestructive thrombocytopenia and hypoproductive thrombocytopenia. However, this procedure is invasive. Mean platelet volume (MPV) is simple and may be used as an alternative diagnostic test in distinguishing these two types of thrombocytopenia. All thrombocytopenic patients (platelet count: <150.0 x 10(9)/l), except those with congestive splenomegaly, thrombotic thrombocytopenic purpura, and disseminated intravascular coagulopathy, were enrolled into the study prospectively. The mean MPV of normal Thais (7.9 fl) was tested as a cutoff value. Any thrombocytopenic patient with MPV of >7.9 fl would be presumptively diagnosed as hyperdestructive thrombocytopenia, whereas one with MPV of <or= 7.9 fl would be presumptively diagnosed as hypoproductive thrombocytopenia. One hundred two patients were completely evaluated. When compared with the BM examination, the MPV of >7.9 fl could predict hyperdestructive thrombocytopenia with a sensitivity of 82.3% (95% CI: 70.5-90.8), a specificity of 92.5% (95% CI: 79.6-98.4), a positive predictive value of 94.4% (95% CI: 84.6-98.8), a negative predictive value of 77.1% (95% CI: 62.7-88.0), and a likelihood ratio of 11.0. In conclusion, the mean MPV of normal Thais may be used as a cutoff value in distinguishing these two types of thrombocytopenia.