Abstract:

Objective: To analyze and summarize the clinical features, diagnosis, treatment and prognosis of 61 patients with thrombotic thrombocytopenic purpura (TTP),so as to improve the ability of diagnosis and treatment.Methods: The clinical data of 61 TTP patients admitted to Peking University People’s Hospital from January 2004 to March 2019 were retrospectively analyzed, and the clinical manifestations, blood routine, hemolysis indicators, and von Willebrand factor lyase (von Willebrand factor-cleaving protease, vWF-CP, also known as ADAMTS13) of these patients were observed. According to the outcome at the time of discharge, they were divided into survival group and death group, and the differences in clinical characteristics, neutrophil to lymphocyte ratio (NLR) and plasma exchange between the two groups were compared. The PLASMIC scores were calculated and compared with ADAMTS13 to determine the accuracy of the PLASMIC score in predicting ADAMTS13.Results: Among the 61 TTP patients, 22 were males and 39 were females, with an average age of (48±17) years. In the study, 48 cases had pentalogy, only 9 had triad, and the remaining 4 had no neuropsychiatric symptoms. Twenty-seven cases (44.3%) died and 34 cases (55.7%) survived. Among the 61 TTP patients, the platelet count was (12.9±9.5)×10⁹/L, the hemoglobin (66.5±20.7) g/L, the percentage of erythrocyte fragments 3% (2%, 7%), and the plasma free hemoglobin increased to 360 (200, 457) mg /L, and the lactate dehydrogenase 1 508 (811, 2 133.8) U/L. The blood clotting was basically normal. The ADAMTS13 value of 30 patients was 49.0 (40.8, 61.3) μg/L, the ADAMTS activity of 10 patients was<5%, and the remaining 21 patients were not checked. The PLASMIC score was 6-7 in 58 cases, 5 in 2 cases, and 4 in 1 case. The PLASMIC score predicted the decreased activity or the reduction of ADAMTS with a sensitivity as high as 97.5%. The NLR in the death group was higher than that in the survival group, but the difference was not statistically significant (P>0.05). The total amount and frequency of plasma exchange (PEX) in the death group were significantly less than those in the survival group, and the difference was statistically significant (P<0.05). There was no significant difference in the treatment of glucocorticoids and human immunoglobulin between the two groups (P>0.05). Conclusion: PEX can significantly improve the survival rate of TTP patients. PLASMIC score can easily and quickly predict the possibility of ADAMTS13 activity reduction, which is beneficial to the early diagnosis of TTP and PEX treatment. NLR can reflect the systemic inflammatory process, but its significance in TTP needs further study.

Key words: Thrombotic thrombocytopenic purpura, Von willebrand factor-cleaving protease, Plasma exchange