Toxocariasis might be an important cause of atopic myelitis in Korea

Abstract

Atopic myelitis is defined as myelitis with atopic diasthesis but the cause is still unknown. Toxocariasis is one of the common causes of hyperIgEaemia that may lead to neurologic manifestations. The purpose of this study was to evaluate the sero-prevalence of Toxocara specific IgG Ab among the atopic myelitis patients. We evaluated the medical records of 37 patients with atopic myelitis whose conditions were diagnosed between March 2001 and August 2007. Among them, the 33 sera were analyzed for specific serum IgG Ab to Toxocara excretory-secretory antigens (TES). All of 37 patients had hyperIgEaemia. Specific IgE to D. pteronyssinus and D. farinae was detected in 22 (64.7%) and 34 (100%) patients, respectively, of the 34 patients. Thirty-one of 33 patients (93.9%) were found to be positive by TES IgG enzyme-linked immunosorbent assay (ELISA). Based on the image findings of eosinophilic infiltrations in the lung and liver, 8 patients had positive results. These results inferred that the prevalence of toxocariasis was high in patients with atopic myelitis. Our results suggest that toxocariasis might be an important cause of atopic myelitis and Toxocara ELISA is essential for evaluating the causes of atopic myelitis.

Keywords: Atopy; Myelitis; Toxocariasis.

Fig. 1

IgE binding to TES Antigens on blotting strips. Serum of A, B were obtained from toxocariasis patients with liver abscess. Serum C was obtained from AM patient with Toxocara-IgG positivity. Serum of D, E, and F were obtained from D. farinae specific allergic rhinitis patients. Lane A, B, and C revealed a typical pattern of Toxocara specific bands in low molecular weight fractions.

Fig. 2

Radiologic images from 45-yr-old man whose first symptoms were chest tightness and progressive lower extremities weakness. He used to eat uncooked cow liver one or two times a month. The peripheral blood showed leukocytosis (11,090/µL) with 33% eosinophils and hyperIgEaemia (2,724 U/mL). The values of specific IgE to D. pteronyssinus and D. farinae were 1.4 U/mL and 4.98 U/mL, respectively although he showed negative skin-prick test results to common aeroallergens. The ELISA test for Toxocara canis was strongly positive (absorbance 2.195). (A-D) Initial transverse CT scan showing a lung nodule with halo sign and multiple low attenuating nodules in the liver. (E-H) One month follow up transverse CT scan showing migrating nodules in the lung and liver. (I, J) T2-weighted MRI images with high signal intensity lesions at the cervical spinal cord.

Fig. 3

Treatment response. All patients had conventional supportive therapy with systemic corticosteroid and some had additive albendazole therapy. The outcome score was determined according to a score system and patients with outcome score 5 were defined as non-responders. Two of 20 patients in additive albendazole group and 5 of 11 patients in corticosteroid group were non-responders (P=0.032).