title: Flow cytometric detection of platelet-associated immunoglobulin in patients with immune thrombocytopenic purpura and nonimmune thrombocytopenia.
abstract: We increased the specificity of flow cytometric detection of platelet-associated immunoglobulin (PAIg) by a combination of platelet gating and cutoff for positivity determined by the use of receiver operating characteristic (ROC) curve analysis, and we evaluated the significance of elevated PAIg in non-immune thrombocytopenic purpura (ITP) patients. Blood samples from 118 patients with a platelet count <100 x 10(9)/L were used in this study. Flow cytometric detection of PAIg was performed. To obtain the cutoff of the surface-bound immunoglobulin for the discrimination of ITP and non-ITP, ROC curve analysis was used. The sensitivity of a positive PAIgG and PAIgM test for ITP in thrombocytopenic patients was 74.6%; the specificity was 79.7%; the positive predictive value 78.6%; and the negative predictive value 75.8%. Among 3 patients with myelodysplastic syndrome, 2 showed increased PAIg. Six of 20 patients with benign disease showed positivity for PAIg. Among these patients, 4 with elevated PAIg were diagnosed with liver disease. This study demonstrates that flow cytometric detection of PAIg combined with ROC curve analysis is a convenient, sensitive, and specific test, compared to previous methods, and it is useful for the differential diagnosis of thrombocytopenic patients.
authors: Department of Laboratory Medicine, University of Ulsan, Asan Medical Center, Seoul, Korea.
authors: Hee Jin
authors: HJ
authors: Huh
authors: Chan Jeoung
authors: CJ
authors: Park
authors: Sang We
authors: SW
authors: Kim
authors: Sang Hee
authors: SH
authors: Han
authors: Seongsoo
authors: S
authors: Jang
authors: Hyun Sook
authors: HS
authors: Chi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001792:Blood Platelets / Q000276:immunology* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D007136:Immunoglobulins / Q000097:blood / Q000276:immunology*; D007223:Infant; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011237:Predictive Value of Tests; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000097:blood / Q000175:diagnosis* / Q000276:immunology; D012372:ROC Curve; D012680:Sensitivity and Specificity; D012712:Serum Globulins / Q000032:analysis; D013921:Thrombocytopenia / Q000097:blood / Q000175:diagnosis* / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007136:Immunoglobulins; D012712:Serum Globulins