Clinical Features of Chinese Patients with Paroxysmal Nocturnal Hemoglobinuria Diagnosed By FLAER

Objective:

To summary the clinical features of Chinese patients with paroxysmal nocturnal hemoglobinuria (PNH) diagnosed by FLAER.

Methods:

The clinical data of 98 cases diagnosed by FLAER from September 2011 to March 2014 were analyzed retrospectively, including clinical features, laboratory examination results and complications. Patients were divided into three clinical groups according to the standard proposed by the International PNH Interest Group. This classification has been applied to each patient considering the clinical characteristics of the disease, bone marrow failure and PNH clone size. Statistical analysis: We presented continuous data as mean and standard deviation or median and interquartile range (IQR), with extreme values. The distributions of the presentation characteristics were compared among the three subcategories and between classic PNH and PNH-sc/AA by chi-square test or Fisher exact test when necessary for qualitative characteristics, and by Kruskal-Wallis (three subcategories) or Mann-Whitney (two groups) test for continuous characteristics. Spearman's rank correlation coefficient was used to measure correlations. Overall survival (OS) estimated by the Kaplan-Meier method was compared using the log-rank test. The Cox proportional hazards model was used to assess the risk factors for survival in both univariate and multivariate analyses. All of the analyses were performedusing statistical package SPSS 17.0. P<0.05 was considered as statistically significant.

Results:

There were 43 cases of classic PNH, 45 of PNH combined with other specific bone marrow disorders, 10 cases of subclinical PNH. 11 patients with PNH less than 18 years of age belong to adolescents, and other 87 PNH were adults. 70 patients were with fatigue, 41 patients with PNH manifested hemoglobinuria. Thrombosis in 6 cases, mostly formed in rare sites. 17 cases and 19 cases concurrented with renal and liver impairment respective. Only 2 cases of PNH were suffered with pulmonary hypertension simultaneously. Classic PNH was more susceptible to hemolysis, the bone marrow failure features of PNH combined with other specific bone marrow disorder was markedly obvious. The value of lactate dehydrogenase (LDH) level over normal range was related with the size of clone PNH-the GPI negative granulocyte, linearly (R=0.710, P<0.001). Patients with high PNH clone were specially prone to thrombosis. The incidence of hemoglobinuria in adolescent group was significantly lower than the adult group, but the rate of bleeding was higher than that of adult group.

Conclusion:

In Chinese patients with PNH, bone marrow failure, renal and liver impairment and thrombosis in rare sites was relatively common. But pulmonary arterial hypertension happened seldomly. Adult patients were more susceptible to hemolysis, but the megakaryocyte hematopoietic failure of adolescent patients combined with other specific bone marrow disorder was more obvious.