Polycythaemia Vera among Sudanese Patients with Special Emphasis on JAK2 Mutations

Polycythemia vera disease profile in an African population-experience from a tertiary facility in Ghana

Objectives

The study describes the clinical and laboratory profile of the patients with polycythemia vera at Komfo Anokye Teaching Hospital in Kumasi, Ghana.

Methods and design

This was a retrospective hospital-based cohort study conducted from September 2020 to August 2022. Hematology clinic entry book was used to identify the patient's unique hospital code. Using these unique codes, retrospective data were collected using an Excel spreadsheet from the Hospital Lightwave health information management system (LHIMS) database.

Results

A total of 20 participants were recruited over the period of 2 years. The overall mean age was 51.53 ± 16.39 years. The hematological profile of the male participants revealed a mean hemoglobin of 18.25 ± 1.373 g/dl, mean hematocrit of 52 ± 3.47%, and a mean platelet of 345.5 ± 180.82. Comparatively, the mean hemoglobin, hematocrit, and platelet for the female participants were higher with figures of 19.26 ± 1.43 g/dl, 53 ± 3.61%, and 816 ± 935.32, respectively. Headache, tiredness, numbness, splenomegaly, and abnormal labs were the most common reasons why participants sought medical attention. Majority (60%) of the study participants had Janus Kinase 2 mutation. New-onset hypertension was identified in 45% of the study participants during follow-up. Thromboembolism was seen in 10% of the study population.

Conclusion

Polycythemia vera is an uncommon disease in Ghana mostly found in older males above 50 years. It is important to recognize it early to initiate therapy aimed at preventing common complications such as hypertension and thromboembolism. Polycythemia vera should be considered a differential diagnosis for patients with secondary hypertension.

Analysis of JAK2V617F Tyrosine Kinase Mutation in Blood Donors with Erythrocytosis - A Pilot Study in a Tertiary Care Teaching Hospital of South India

Purpose

Transfusion services and blood centers provide immediate medical evaluation to blood donors by physical examination and hemoglobin (Hb) screening. Screening for Hb value before every blood donation is mainly aimed to rule out anemia. However, it is not uncommon to defer the donors for high Hb value which can be due to primary or secondary polycythemia. This study aimed to analyze the frequency of JAK2V617F mutation among blood donors with a high Hb of >18 g/dl.

Patients and Methods

A prospective study was conducted over a period of 18 months involving blood donors with a persistently high Hb value of >18 g/dl. Complete blood count (CBC), JAK2V617F gene mutation and Serum Erythropoietin (EPO) levels in study donors were analyzed. Descriptive statistical analysis was performed using SPSS, version 24 (IBM, USA).

Results

Of 13,798 screened donors, 48 donors (0.34%) had persistent erythrocytosis with a high Hb value of >18 g/dl. Their age ranged between 20-50 years with a mean of 31.2 ± 6.66. The CBC parameters including red blood cell (RBC) count, Hb%, hematocrit (Hct), white blood cell (WBC) count and the platelet count ranged from 4.35-8.43 million/µL (6.2 ± 0.6), 18.6-24.4 g/dl (19 ± 0.94), 51.9-83.3% (58 ± 5.02), 3.99-10.8 × 103/µL (7.8 ± 1.5), and 120-450 × 103/µL (227 ± 57.2), respectively. Estimated mean EPO value was 8.29 mIU/± 0.04. JAK2V617F mutation was detected in 2 donors (4.1%).

Conclusion

The prevalence of persistent erythrocytosis among blood donors was 0.34% and among them, two donors (4.1%) harbored the JAK2V617F mutation. Thus, blood centers play an important role in the primary screening of donors with high hemoglobin leading to early detection and management of polycythemia vera (PV).

The impact of JAK2V617F mutation on Philadelphia-negative myeloproliferative neoplasms

BACKGROUND

JAK2V617F mutation is expressed in almost all polycthemia vera (PV), 55% of essential thrombocythemia (ET), and 65% of primary myelofibrosis (PMF) patients. Studies investigating phenotypic effects of JAK2V617F mutation on Philadelphianegative myeloproliferative neoplasms (Ph-negative MPNs) have reported controversial results. This study aims to determine the impact of JAK2V617F mutation on clinical phenotype and outcome in Ph-negative MPNs.

METHODS

Clinical correlates and long-term prognostic relevance of the JAK2V617F mutation were analyzed in 410 Phnegative MPNs-170 ET, 135 PV, 105 PMF- from two institutions and followed for a mean of 76.7 months (SD 62.1) (mean 87 months (SD 67.8), 70.4 months (SD 56.4), 68 months (SD 57.4), respectively for ET, PV, and PMF). Two hundred and twenty-eight patients were genotyped for JAK2V617F mutation using the JAK2 Ipsogen MutaScreen assay, which involves allele-specific polymerase chain reaction (PCR), and 182 patients were genotyped using melting curve analysis.

RESULTS

In PV patients, JAK2V617F mutation was associated with higher rate in females, lower hemoglobin (Hgb) level, higher leukocyte and platelet count and higher prevalence of thrombosis (p = 0.008, p = 0.018, p = 0.001, p = 0.001, and p = 0.035, respectively). In ET patients, JAK2V617F mutation was associated with higher Hgb and hematocrit (Hct) levels and lower platelet count (p = 0.001, p = 0.001, and p = 0.001, respectively). JAK2V617F-negative ET patients showed a trend towards higher rate of leukemic transformation (p = 0.061). JAK2V617F mutation-positive PMF patients had higher leukocyte count, greater spleen size and showed a trend towards higher Hgb level (p = 0.019, p = 0.042, and p = 0.056, respectively). Among PMF patients with JAK2V617F mutation, the rate of female patients was lower (p = 0.001). Overall survival (OS) in Dynamic International Prognostic Scoring System (DIPSS) - plus high risk PMF patients was shorter compared to the other risk groups (p = 0.001). Leukemia-free survival (LFS) was shorter in DIPSS - plus high risk PMF patients than the other risk groups (p = 0.005). In the entire cohort of Ph-negative MPN patients, JAK2V617F mutation was associated with higher leukocyte count, higher Hgb and Hct levels and lower platelet count, higher frequency of phlebotomies, a trend towards older age, a trend towards greater spleen size, a trend towards a higher prevalence of risk factors for cardiovascular diseases and thrombosis (p = 0.001, p = 0.005, p = 0.001, p = 0.003, p = 0.004, p =0.052, p = 0.056, p = 0.052, and p = 0.059, respectively).

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

Mutations of JAK2V617F, CALR, and MPL genes confirm the diagnosis of myeloproliferative neoplasm (MPN). This study aims to determine the genetic profile of JAK2V617F, CALR exon 9 Type 1 (52 bp deletion) and Type 2 (5 bp insertion), and MPL W515 L/K genes among Malaysian patients and correlate these mutations with clinical and hematologic parameters in MPN. Mutations of JAK2V617F, CALR, and MPL were analyzed in 159 Malaysian patients using allele-specific polymerase chain reaction, including 76 polycythemia vera (PV), 41 essential thrombocythemia (ET), and 42 primary myelofibrosis (PMF) mutations, and the demographics of the patients were retrieved. The result showed that 73.6% JAK2V617F, 5.66% CALR, and 27.7% were triple-negative mutations. No MPL W515L/K mutation was detected. In ET and PMF, the predominance type was the CALR Type 1 mutation. In JAK2V617F mutant patients, serum LDH was significantly higher in PMF compared to PV and ET. PV has a higher risk of evolving to post PV myelofibrosis compared to ET. A thrombotic event at initial diagnosis of 40.9% was high compared to global incidence. Only one PMF patient had a CALR mutation that transformed to acute myeloid leukemia. JAK2V617F and CALR mutations play an important role in diagnostics. Hence, every patient suspected of having a myeloproliferative neoplasm should be screened for these mutations.