Evaluating inflammatory markers in distinguishing polycythemia Vera from secondary polycythemia: a prospect for novel diagnostic marker

Polycythemia vera (PV) is a myeloproliferative neoplasm. The presence of JAK2 mutations is a major diagnostic criterion for PV. PV is linked to chronic inflammation and an increased risk of thrombosis, and inflammation plays a significant part in the pathophysiology of PV. Testing for JAK2 mutations is expensive and is not available in all laboratories. Simple inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII), are evaluated in this study as potential diagnostic markers for differentiating patients with PV from other patients with polycythemia. We conducted a retrospective study of the clinical and laboratory data from 281 patients with polycythemia (110 with PV and 181 with secondary polycythemia (SP)) who attended Ghaem Hospital. The diagnosis of PV was established based on the World Health Organization criteria. Individuals who did not meet the criteria were classified as having SP. The median NLR, PLR, and SII in the PV group were considerably elevated compared to the SP group (NLR: 5.00 vs. 1.86, PLR: 261.3 vs. 94.0, SII: 2432.9 vs. 368.8, p < 0.001 for all). The receiver operating characteristic analysis revealed that NLR, PLR, and SII were highly effective in differentiating PV patients from the SP group. Each of these tests showed sensitivities and specificities over 85% and an area under the curve of more than 0.9. SII, NLR, and PLR were all higher in PV than SP, suggesting that these biomarkers, particularly SII, might be helpful in the diagnosis of PV.