A Case of Chronic Q Fever Endocarditis Mimicking Lymphoproliferative Disorders

Q fever is a zoonosis caused by Coxiella burnetii. In this report, a case of chronic Q fever endocarditis with pancytopenia and hypergammaglobulinemia mimicking a lymphoproliferative disease was presented. A 39-years-old male living in Çatalca and whose family is engaged in animal husbandry admitted with the complaints of weakness and fatigue. The patient had aortic valve replacement 29 years ago and had aortic valve re-replacement, and ascending aorta grafting because of endocarditis three years ago. It was revealed that the second operation of the patient was due to possible infective endocarditis, but no definitive agent could be identified. He was evaluated for massive hepatosplenomegaly, pancytopenia, hypergammaglobulinemia, presence of M-spike and elevated β-2 microglobulin levels and was referred to our hematology clinic with a preliminary diagnosis of lymphoproliferative disease. Lymphoplasmacytic lymphoma was excluded with the result of bone marrow biopsy and he was referred to our clinic for the investigation of possible infectious etiologies. We detected hepatosplenomegaly and finger clubbing. His blood analyses were normal except for the following: leukocyte count 3800/μl, platelet count 148000/μl, gamma globulin 5.9 gr/dl, rheumatoid factor (RF) and antinuclear antibody (ANA) positivity. Chronic Q fever endocarditis was suspected and C.burnetii Phase I IgG test was found positive in 1/132071 titers. Although transesophageal echocardiography showed no lesion of endocarditis, positron emission tomography/computed tomography revealed increased fluorodeoxyglucose uptake around the prosthetic heart valve and graft. The patient was diagnosed as having Q fever endocarditis and graft infection. He refused hospitalization and was started on hydroxychloroquine and doxycycline treatment. The patient stopped taking these antibiotics by himself seven days after the diagnosis. He was admitted with a headache to another hospital and operated for an intracranial hemorrhage and died shortly after. Apart from unfamiliarity, wide range of clinical presentations of disease could also lead to delayed diagnosis. Among patients with chronic Q fever, continuous bacteremia and antigenic stimulus causes inflammatory syndrome with hepatosplenomegaly, hypergammaglobulinemia and, presence of autoantibodies which leads to misdiagnoses of rheumatologic, autoimmune or hematologic diseases Chronic Q fever should be investigated in patients with known valvulopathy and chronic hepatomegaly or splenomegaly, pancytopenia, hypergammaglobulinemia, and unexplained autoantibody positivity.