Background: The aim of the study was to investigate the levels of a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13), total bilirubin (TBIL), and D-dimer (D-D) in thrombotic thrombocytopenic purpura (TTP) and their values for predicting the prognosis.
Methods: The clinical data of 89 TTP patients admitted from March 2018 to December 2021 were collected for retrospective analysis. They were assigned to remission group (n = 61) and death group (n = 28) according to clinical outcomes. General clinical data were compared between the two groups. Predictors with non-zero coefficients were screened by LASSO regression analysis, and influencing factors were identified by logistic regression analysis. Then the risk factors were incorporated to construct a nomogram model, which was validated subsequently. Bivariate Pearson's correlation analysis was employed to analyze the correlations. The receiver operating characteristic curves were plotted to analyze the values of ADAMTS13, TBIL, and D-D for predicting the prognosis of TTP.
Results: TBIL ≥ 72.74 μmol/L, D-D ≥ 4.17 mg/L, PLASMIC score < 6 points, and absence of plasma exchange (PEx) were risk factors affecting the prognosis, and ADAMTS13 ≤ 25.04% was a protective factor for the prognosis of TTP patients (p < 0.05). ADAMTS13, TBIL, and D-D were significantly associated with death (p < 0.05). The areas under the curves of TBIL, ADAMTS13, D-D and their combination were 0.796 (95% confidence interval CI: 0.729 - 0.860), 0.721 (95% CI: 0.648 - 0.788), 0.820 (95% CI: 0.756 - 0.880), and 0.872 (95% CI: 0.823 - 0.920), respectively.
Conclusions: TBIL, D-D, ADAMTS13, PLASMIC score, and absence of PEx are factors influencing the prognosis of TTP patients, among which TBIL, D-D, and ADAMTS13 are of high predictive values.