Pancytopenia in a patient with Lyme disease

Abstract

Lyme disease, caused by Borrelia burgdorferi, is the most common vector-borne disease in USA [1]. Its most frequent clinical features include skin manifestations and fever [2]. Hematologic manifestations are unusual in solitary infections with B burgdorferi. We report what we believe is the first documented case of pancytopenia triggered by Lyme disease. An 86-year-old Caucasian woman residing in rural Connecticut was hospitalized with generalized weakness leading to a fall at home. She had no other medical problems and was independent for all activities of daily living. She reported a tick bite while gardening about 2 months before and had received prophylaxis with single-dose doxycycline. Examination showed normal vital signs and a large 10 9 10 cm bruise on her left buttock attributed to the fall. No other skin lesions were apparent. Cardiovascular examination showed a systolic murmur loudest at the apex. Examination of the respiratory system, abdomen, and central nervous system were normal. Laboratory evaluation at admission showed: WBC 3900/mm (neutrophils 3500/mm, lymphocytes 200/mm); Hb 12.9 g/dL; platelets 60,000/mm; PT 11.9 s; INR 0.95; PTT 28.0 s; sodium 142 meq/L; potassium 3.9 meq/L; chloride 99 meq/L; bicarbonate 23 meq/L; BUN 21 mg/dL; creatinine 1.32 mg/dL; glucose 123 mg/dL; CPK 4515 u/L; AST 326 u/L; ALT 116 u/L; alkaline phosphatase 110 u/L; and LDH 1495 u/L. Blood reticulocytes was 0.2% suggesting suppression of RBC production. She was hospitalized with a diagnosis of rhabdomyolysis and acute kidney injury. Over the next two days, she developed worsening pancytopenia (Fig. 1). Given the history of tick bite, she was started on doxycycline on day 2, following which her cell lines showed improvement. The patient’s Lyme titer was positive at 2.84 [normal range 0–0.99]. IgG Lyme Western blot showed p18, p23, p28, p30, p31, p34, p39, p41, p45, p58 and p66 (diagnostic if C5 of: 18, 23, 28, 30, 39, 41, 45, 58, 66 and 93 kDa bands are present), and IgM Lyme Western blot showed bands p23, p31, p34, p41 and p66 (diagnostic if C2 of: 23, 39 and 41 kDa bands are present). IgG and IgM for Anaplasma phagocytophila and Ehrlichia chaffensis and blood smear for Ehrlichia were negative. Hepatitis A, B, and C serologies were negative. EBV IgG was positive, and IgM was negative. Antibodies to Coxsackie viruses B1B6 were non-diagnostic. Legionella antigen, Enterovirus PCR, and blood smear for Babesia microti were negative. ANA and platelet PF4 antibody assays were also negative. By the 6th hospital day her cell lines had recovered and renal functions normalized, and she was discharged home. While it is well-recognized that B. burgdorferi causes systemic disease, its hematologic manifestations are not widely reported. During the initial dissemination phase, B. burgdorferi seeds the bone-marrow [3]. Various reports have recognized thrombocytopenia and bone marrow granulomas as hematologic manifestations of Lyme disease [4–6], although pancytopenia has not previously been described. Making a diagnosis of Lyme-related pancytopenia is dependent on ruling out alternative diagnoses, especially A. phagocytophila, and B. microti, both of which are also transmitted by Ixodes dammini, and can cause hematologic manifestations. In our patient, these and other V. Babu S. Sukumarannair Z. Saul Bridgeport Hospital/Yale University Internal Medicine Residency Program, Bridgeport, CT, USA