Botryoid nuclei of neutrophils and monocytes in autoimmune limbic encephalitis

Abstract

A 53-year-old woman with rapidly progressive consciousness disturbance and high fever for three days was brought to our emergency room by ambulance. Her temperature was 41.5 C, with systolic blood pressure of 60 mmHg and heart rate of 100 bpm. She had oral dyskinesia and muscle rigidity and tremor of the limbs. Laboratory data showed leukocytosis (18,200/lL), thrombocytopenia (1.8 9 10/lL), renal insufficiency (Cr 1.05 mg/dL), and SIADH (Na 117 mEq/L). Brain MRI revealed no abnormalities. Cerebral spinal fluid was clear, and HSV, EBV, and CMV DNA were not detected by PCR. Plasma exchange and methylprednisolone pulse were performed on the diagnosis of suspected thrombocytic thrombocytopenic purpura (TTP), which immediately reduced the high fever; however, unconsciousness was not improved. The diagnosis of TTP was eliminated three days afterward based on normal ADAMTS13 activity. Interestingly, peripheral blood smears on admission showed a large number of neutrophils with radially hypersegmented nuclei (Fig. 1a), a phenomenon first reported by Hernandez [1] and termed botryoid nuclei (BN). BN were observed in 92 % of neutrophils, and also in 25 % of monocytes (Fig. 1b). Furthermore, on the next day, no BN of neutrophils or monocytes was detected. She was transferred to Sapporo Medical University and diagnosed with autoimmune limbic encephalitis with voltage-gated potassium channel antibody. BN has been reported in patients with heat stroke and in children with acute encephalopathy. To our knowledge, this is the first case report of BN of neutrophils and Fig. 1 Botryoid nuclei of neutrophils (Fig. 1a) and monocytes (Fig. 1b) (May Grunwald Giemsa staining, 91000)