Evaluation of hypofibrinegenemia frequency and causes in rheumatology practice

Hypofibrinogenemia, may be congenital or acquired. This condition is characterized by decreased synthesis, increased consumption or hemodilution. The aim of this study was to investigate the frequency and causes of hypofibrinogenemia in rheumatology practice, to determine the demographic, laboratory, clinical findings and patient outcomes of patients with hypofibrinogenemia, also to evaluate their effects on mortality and to compare the obtained data with literature data. In our study, patients who were followed up in our rheumatology clinic and had low fibrinogen levels (≤ 200 mg/dL) were retrospectively screened for etiology. In a 10-year period, we found the frequency of hypofibrinogenemia as 28(1.78%) among 1573 patients. In our study, 19(67,9) of the patients were female. The mean age of the patients was 51.25±11.88 (28-75) years. In the study group, 10(35.7%) patients had rheumatoid arthritis (RA) and 4(14.3%) patients had systemic lupus erythematosus (SLE). The fibrinogen values of the patients were 134.25±44.80 mg/dL (46.50-194.80) when hypofibrinogenemia was detected and 272.28±121.61 mg/dL (51.40-503.49) after the treatment. Hypofibrinogenemia resolved in 15(53.6%) patients during follow-up. 4(14.3%) patients died after 5.25±4.64 (1-11) days. When the patients were analyzed for the causes of hypofibrinogenemia, tocilizumab side effect in 8(28.6%) patients, disseminated intravascular coagulation (DIC) in 7(25%) patients, chronic liver disease in 5(17.9%) patients, plasmapheresis in 3(10.7%) patients, macrophage activation syndrome (MAS) in 2(7.1%) patients and hemophagocytic lymphohistiocytosis (HLH) in 1(3.6%) patient were found as etiological causes. In 2 patients, the etiology could not be clarified. When the causes of hypofibrinogenemia were compared, it was observed that hypofibrinogenemia due to DIC developed in 4(100%) of the 4 patients who died (p=0,029). In conclusion, it is possible to encounter hypofibrinogenemia in rheumatology practice. Its frequency is not known. It should be known that underlying diseases including drugs may also cause hypofibrinogenemia.