Ning Tang1, Xiong Wang1, Dengju Li2, Ziyong Sun3. 1. Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. 2. Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. 3. Department of Clinical Laboratory, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China. Electronic address: 18963949562@189.cn.
Abstract
BACKGROUND: The recently published PLASMIC score was shown to be an excellent diagnostic model to identify patients with severe ADAMTS-13 deficiency. However, it is unclear if this score is suitable for Chinese patients with suspected thrombotic thrombocytopenic purpura (TTP). METHODS: We retrospectively studied a Chinese cohort of 134 consecutively hospitalized patients with thrombotic microangiopathy, ADAMTS-13 test results, and clinical information between January 2015 and June 2018, the PLASMIC score's distinguishing ability in this cohort was evaluated. We also combined the lactate dehydrogenase (LDH)-to-aspartate aminotransferase (AST) ratio with the PLASMIC score to determine its predictive value for TTP in pregnancy. RESULTS: In this Chinese cohort, 39 patients were diagnosed with TTP using ADAMTS13 testing. When stratified at high (score, 6-7) vs. low-intermediate (score, 0-5) risk, the PLASMIC test predicted TTP with a positive predictive value of 51%, negative predictive value of 92%, sensitivity of 85%, and specificity of 58%. In pregnant patients, a combination of the PLASMIC score of 6-7 and LDH-to-AST ratio of ≥5.5 showed a higher positive predictive value for TTP compared with the PLASMIC score alone (71% vs. 35%, P < 0.001). Removing the component MCV < 90 fL from the PLASMIC score did not reduce its distinguishing power, as measured using the C statistic (0.837, 95%CI 0.767-0.907 vs. 0.797, 95%CI 0.718-0.877; P = 0.771). CONCLUSIONS: Combination with a higher LDH-to-AST ratio improves the positive predictive value of the PLASMIC score in pregnant patients. A simpler score without MCV < 90 fL can be used to identify TTP in Chinese patients.
BACKGROUND: The recently published PLASMIC score was shown to be an excellent diagnostic model to identify patients with severe ADAMTS-13 deficiency. However, it is unclear if this score is suitable for Chinese patients with suspected thrombotic thrombocytopenic purpura (TTP). METHODS: We retrospectively studied a Chinese cohort of 134 consecutively hospitalized patients with thrombotic microangiopathy, ADAMTS-13 test results, and clinical information between January 2015 and June 2018, the PLASMIC score's distinguishing ability in this cohort was evaluated. We also combined the lactate dehydrogenase (LDH)-to-aspartate aminotransferase (AST) ratio with the PLASMIC score to determine its predictive value for TTP in pregnancy. RESULTS: In this Chinese cohort, 39 patients were diagnosed with TTP using ADAMTS13 testing. When stratified at high (score, 6-7) vs. low-intermediate (score, 0-5) risk, the PLASMIC test predicted TTP with a positive predictive value of 51%, negative predictive value of 92%, sensitivity of 85%, and specificity of 58%. In pregnant patients, a combination of the PLASMIC score of 6-7 and LDH-to-AST ratio of ≥5.5 showed a higher positive predictive value for TTP compared with the PLASMIC score alone (71% vs. 35%, P < 0.001). Removing the component MCV < 90 fL from the PLASMIC score did not reduce its distinguishing power, as measured using the C statistic (0.837, 95%CI 0.767-0.907 vs. 0.797, 95%CI 0.718-0.877; P = 0.771). CONCLUSIONS: Combination with a higher LDH-to-AST ratio improves the positive predictive value of the PLASMIC score in pregnant patients. A simpler score without MCV < 90 fL can be used to identify TTP in Chinese patients.
Authors: Nicolas Fage; Corentin Orvain; Nicolas Henry; Chloé Mellaza; François Beloncle; Marie Tuffigo; Franck Geneviève; Paul Coppo; Jean François Augusto; Benoit Brilland Journal: Kidney Int Rep Date: 2021-11-16