[The preliminary research in paroxysmal nocturnal hemoglobinuria with thrombosis]

[Role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria]

Objective: This study aimed to investigate the role and clinical significance of MUC4 gene mutations in thrombotic events in patients with classic paroxysmal nocturnal hemoglobinuria (PNH) patients. Methods: A retrospective analysis was conducted on the clinical data and gene sequencing results of 45 patients with classic PNH admitted to the Department of Hematology, Tianjin Medical University General Hospital, from June 2018 to February 2022. MUC4 gene mutations in patients with classic PNH were summarized, and the risk factors for thrombotic events in these patients were analyzed. Additionally, the effects of MUC4 gene mutations on the cumulative incidence and survival of thrombotic events in patients with classic PNH were determined. Results: The detection rate of MUC4 gene mutations in patients with classic PNH who experienced thrombotic events (thrombotic group) was 68.8% (11/16), which was significantly higher than that in the non-thrombotic group [10.3% (3/29) ] (P<0.001). All mutations occurred in exon 2. MUC4 mutation (OR=20.815, P=0.010) was identified as an independent risk factor for thrombotic events in patients with classic PNH. The cumulative incidence of thrombotic events was 78.6% (11/14) in the MUC4 gene mutation group (mutation group) and 16.1% (5/31) in the non-mutation group, showing a statistically significant difference between the two groups (P<0.001). Survival analysis showed a lower overall survival (OS) rate in the thrombotic group compared with that in the non-thrombotic group [ (34.4±25.2) % vs. (62.7±19.3) % ] (P=0.045). The OS rate of patients was (41.7±29.9) % in the mutation group and (59.1±18.3) % in the non-mutation group (P=0.487) . Conclusion: MUC4 gene mutations are associated with an increased incidence of thrombotic events in classic PNH patients, highlighting their role as independent risk factors for thrombosis in this population. These mutations can be considered a novel predictive factor that aids in evaluating the risk of thrombosis in patients with classic PNH.

Analysis of clinical characteristics of 92 patients with paroxysmal nocturnal hemoglobinuria: A single institution experience in China

Objectives

We performed a retrospective analysis to investigate the clinical characteristics and therapeutic strategies of Chinese paroxysmal nocturnal hemoglobinuria (PNH) patients, and assessed the efficacy and safety of glucocorticoid in PNH patients.

Methods

The clinical data of 92 PNH cases in our hospital were analyzed, including clinical manifestation, laboratory examination, treatment efficacy, and survival.

Results

The main clinical manifestations of these patients included hemoglobinuria, anemia, fatigue, dyspnea, headache, abdominal pain, and erectile dysfunction. Glucocorticoid is still the first‐line treatment for PNH patients to control hemolytic attack, and the short‐term remission rate (12 months) is 79.01% (64/81). Meanwhile, the overall survival (OS) of 10 years after diagnosis was estimated as 70.77% (46/65). Moreover, Cox proportional risk model for multivariate analysis showed that the increase in LDH multiple, thrombosis complications, and complicated with bone marrow failure were the independent adverse prognostic factors affecting the survival of PNH patients.

Conclusion

Paroxysmal nocturnal hemoglobinuria patients in mainland China have various clinical features, while lower incidences of thrombosis and renal damage. Thrombosis and bone marrow failure are two complications with worse prognosis.

Prediction of thrombosis risk in patients with paroxysmal nocturnal hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hemolytic disease with thrombosis as a major complication. The mechanism of thrombosis and related risk factors in PNH patients are still not well characterized. We retrospectively enrolled 99 patients with newly diagnosed PNH at our institute from 2011 to 2016. According to binary logistic regression model analysis, we first identified four baseline clinical risk factors which may be associated with incidence of thrombosis in the PNH cohort, including PNH clone sizes (fluorescent aerolysin of neutrophil) ≤ 80 (OR 1.056, 95%CI 1.016-1.097, P = 0.005), hemoglobin ≤ 75 g/L (OR 4.202, 95%CI 0.984-17.954, P = 0.053), platelet > 100 × 10⁹/L (OR 6.547, 95%CI 1.490-28.767, P = 0.013) and rs495828 = G (OR 5.243, 95%CI 1.314-20.916, P = 0.019). These independent risk factors were combined together to develop a risk model to evaluate thrombosis risk (AUC = 0.756, 95%CI 0.607-0.905, P < 0.001). Our risk model revealed a higher cumulative incidence of thrombosis and an earlier thrombosis events in PNH patients with high risk (risk score ≥ 23) compared with those with low risk (risk score < 23, P < 0.001 and P = 0.043, respectively). Although with some limitations, we set up a prediction model for thrombosis risk in patients with PNH for the first time, but it needed to be verified in a prospective study with larger patients and longer follow-up time in the future.

[Purpura fulminans related to paroxysmal nocturnal haemoglobinuria: a case report and literatures review]

Objective: To improve the understanding of the rare clinical presentation and management of purpura fulminans (PF) in patients with paroxysmal nocturnal haemoglobinuria (PNH). Methods: A case of PF occurring in PNH is reported, while the related literature review is conducted. Results: A 49-year-old male patient suffered from one-week history of fever, greenish-brown colour urine, multiple well demarcated and painful purpura of the head and neck. He had been reported to have two thromboembolic events during the 22-year course of PNH. Skin biopsy displayed classic PF features. Laboratory testing showed a high PNH clone, intravascular hemolysis and coagulation system changes. After sufficient anticoagulation and short course of glucocorticoid therapy, the clinical conditions were improved correspondingly. During a follow-up period of 6 month, there was no recurrence of thrombosis. Conclusion: PF should be considered in PNH patients with unexplained, quickly developed painful purpura. Extensive work-up should be performed to find out other potential thrombophilic risk factors after diagnosis of PF. Early diagnosis, adequate anticoagulation therapy and control hemolysis were essential to PF treatment occurring in PNH. The survival of patients and the qualities of life can be improved. The PNH clone detection is needed to evaluate the status of procoagulation and predict the risk of recurrent thrombosis.