Determination of RF and anti-CCP positivity rate in patients with hematological malignancies and solid organ malignancies

Paraneoplastic syndromes may mimic many rheumatic diseases. Paraneoplastic arthritis is one of these syndromes. In case reports and studies published to date, RF and anti-CCP have been studied as markers in differentiating paraneoplastic arthritis from other rheumatic disease. Although these studies have demonstrated increased levels of these markers in arthritis with rheumatoid origin, there is no study showing the prevalence of RF and anti-CCP in patients with hematological malignancy or solid organ tumors. In the present study, we aimed to evaluate the prevalence of RF and anti-CCP in patients with hematological malignancy and solid organ tumors. The study included a total of 102 patients who were admitted to the Hematology and Oncology outpatient clinics at Gaziantep University Sahinbey Training and Research Hospital and who were recently diagnosed with a hematological or solid organ malignancy. The control group comprised of a total of 84 patients without a history of malignancy who were admitted to the internal medicine outpatient clinics of the same healthcare center. Female to male ratio was 47/55 in the study group and 42/42 in the control group, indicating no statistically significant difference (p>0.05). The mean age was 52.44±17.24 years in the study group and 46.46±19.15 in the control group. There was no statistically significant difference in age between the groups (p>0.05). All participants were anti-CCP negative. A total of 22 patients including 12 in the study group (hematological malignancy=3, solid organ tumor=9) and 10 in the control group tested positive for RF. There was no significant difference in RF positivity between the groups (p>0.05). The rate of RF positivity was 11.76% in the study group. The prevalence of RF and anti-CCP positivity in this group of patients with hematological malignancy or solid organ tumor was not significantly different, compared to the healthy population. These findings may suggest that these markers which are used in the differential diagnosis of paraneoplastic arthritis and examined for more extensive utility may not be related to malignancies in the absence of arthritis. However, further large-scale studies conducted in the clinical setting are required to confirm these findings.