The Clinical and Prognostic Significance of Ribonucleotide Reductase Subunits RRM1 and RRM2 mRNA Levels in Patients with Chronic Lymphocytic Leukemia

Ribonucleotide Reductase (RNR) converts ribonucleotides to deoxyribonucleotides required for DNA replication and repair. RNR consists of subunits M1 and M2. It has been studied as a prognostic factor in several solid tumors and in chronic hematological malignancies, but not in chronic lymphocytic leukemia (CLL). Peripheral blood samples were collected from 135 CLL patients. M1/M2 gene mRNA levels were measured and expressed as a RRM1-2/GAPDH ratio. M1 gene promoter methylation was studied in a patients' subgroup. M1 mRNA expression was higher in patients without anemia (p = 0.026), without lymphadenopathy (p = 0.005) and 17p gene deletion (p = 0.031). Abnormal LDH (p = 0.022) and higher Rai stage (p = 0.019) were associated with lower M1 mRNA levels. Higher M2 mRNA levels were found in patients without lymphadenopathy (p = .048), Rai stage 0 (p = 0.025) and Trisomy 12 (p = 0.025). The correlation between RNR subunits and clinic-biological characteristics in CLL patients demonstrate RNR's potential role as a prognostic factor.

JAK2V617F positive polycythemia vera with paroxysmal nocturnal hemoglobinuria and visceral thromboses: a case report and review of the literature

Background

Polycythemia vera (PV) is characterized by red cell mass expansion in the peripheral blood and can be complicated with thrombosis, bleeding, evolution to acute myeloid leukemia (AML) or a fibrotic phase. Paroxysmal nocturnal hemoglobinuria (PNH) in an acquired clonal haematopoietic stem cell disorder associated with chronic intravascular hemolysis, venous thrombosis, defective hematopoiesis, frequent episodes of infection and, rarely, leukemic transformation. Herein, we report an interesting case of a patient with coexistence of PNH clones and a JAK2V617F positive PV, with unusual thromboses without hemolysis.

Case presentation

A 51-year-old woman presented with increased levels of hematocrit, multiple liver, spleen, and left kidney infarctions and ascites; further investigation revealed a JAK2V617F-positive polycythemia vera and the presence of a significant PNH population (more than 90% CD55– CD59– cells among both granulocytes and red blood cells). Interestingly, the patient has experienced severe thrombotic events without any signs or symptoms of hemolysis.

Conclusions

This case raises questions over uncharted aspects of the PNH etiopathogenesis and its potential association with myeloproliferative neoplasms (MPN) and highlights the difficulty of diagnosing and managing patients with more than one potentially thrombophilic conditions, especially with established and severe thromboses.