The epidemiology and clinical characteristics of myeloproliferative neoplasms in Malaysia

Abstract

BackgroundThe evolution of molecular studies in myeloproliferative neoplasms (MPN) has enlightened us the understanding of this complex disease consisting of polycythaemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF). The epidemiology is well described in the western world but not in Asian countries like Malaysia.Materials and methodsThis retrospective national registry of MPN was conducted from year 2009 to 2015 in Malaysia.ResultsA total of 1010 patients were registered over a period of 5 years. The mean age was 54 years with male predominance. The ethnic distribution revealed that Chinese had a relatively high weighted incidence proportion (43.2%), followed by Indian (23.8%), Malay (15.8%) and other ethnic groups (17.2%). The types of MPN reported were 40.4% of ET (n = 408), 38.1% of PV (n = 385), 9.2% of PMF (n = 93), 3.1% of hypereosinophilic syndrome (HES) (n = 31) and 7.9% of unclassifiable MPN (MPN-U) (n = 80). Splenomegaly was only palpable clinically in 32.2% of patients. The positive JAK2 V617F mutation was present in 644 patients with 46.6% in PV, 36.0% in ET, 9.0% in PMF, and 7.4% in MPN-U, and had significantly lower haemoglobin (p < 0.001), haematocrit (p < 0.001) and white blood cells (WBC) (p < 0.001) than those with negative mutation. Significant differences in platelet and WBC count were detected in ethnic groups and MPN sub-types. There were more arterial thrombosis events seen in those with JAK2 V617F mutation as compared to venous thrombosis events (23.1% vs 4.4%). The bleeding rate was only 6.6%. Among the risk factors, previous thrombosis, old age (≥ 60 years) and hypertension were significantly correlated to positive JAK2 V617F mutation. The arterial thrombosis event is associated with higher presenting HB, HCT and PLT while the bleeding event is associated with lower presenting HB, HCT but higher PLT. The presence of JAK2 V617F mutation is associated with higher risk of arterial thrombosis.ConclusionChinese ethnicity is associated with higher rates of MPN. The history of thrombosis, age ≥ 60 years and hypertension are risk factors that can be correlated to JAK2 V617F mutation. This study is instrumental for policy makers to ensure preventive strategies can be implemented in future.

Clinical and Laboratory Features of JAK2 V617F, CALR, and MPL Mutations in Malaysian Patients with Classical Myeloproliferative Neoplasm (MPN)

“…It is postulated that MPN clonal cells induce the release of inflammatory cytokines, which results in procoagulant states. This finding is supported by blood-clotting markers, i.e., thrombin antithrombin complex, thrombomodulin, von Willebrand factor/factor V111, and prothrombin fragment 1 + 2 [ 45 ]. The majority of our MPN patients had thrombotic events that were commonly due to arterial thrombosis compared to venous thrombosis; this is consistent with most studies [ 42 ].…”

Delayed diagnosis of polycythaemia vera in an adult female with non-cirrhotic portal hypertension

“…5,6 Palpable splenomegaly as in the index case, has also been reported in 1/3 of PV patients in Malaysia. 7 Whiles Hb > 16 and 16.5 in women and men respectively should raise suspicion for PV diagnosis, the presence of splenomegaly can mask high Hb and delay diagnosis. Even though this did not occur in our case, clinicians must be mindful of this fact when interpreting Hb results as part of the evaluation for PV.…”

The mortality outcomes and survival pattern of patients of Myeloproliferative Neoplasms in Malaysia

“…There is a similar nding to the previous paper of epidemiology of this MPN cohort in which Chinese seems to have a relatively higher incidence of death in MPN compared to Malay considering the racial distribution of 21.2% for Chinese and 61.8% for Malay in Malaysia. [41] Despite the statistical insigni cance, geography and ethnicity are found to in uence the survival in other countries [13]. Maynadie et al revealed that the survival rates of 74% in Northern Europe in comparison to only 27% survival rates in Eastern Europe [21].…”