Toxocariasis: critical analysis of serology in patients attending a public referral center for ophthalmology in Brazil

• Published in: Japanese journal of ophthalmology Vol. 62; no. 1; pp. 77 - 83
• Main Authors: Rubinsky-Elefant, Guita, Yamamoto, Joyce H., Hirata, Carlos E., Prestes-Carneiro, Luiz E.
• Format: Journal Article
• Language: English
• Published: Tokyo Springer Japan 01-01-2018; Springer Nature B.V
• Subjects: Antibodies; Diagnosis; Enzyme-linked immunosorbent assay; Immunoglobulin G; Laboratory Investigation; Medicine; Medicine & Public Health; Ophthalmology; Patients; Serology; Signs and symptoms; Toxocara; Toxocariasis; Brazil; IgG anti; antibodies; species; Ocular toxocariasis; IgG anti-Toxocara antibodies; Toxocara species
• ISSN: 0021-5155; 1613-2246
• DOI: 10.1007/s10384-017-0543-8

Purpose
To analyze the contribution of IgG anti-
Toxocara
antibodies in the diagnosis of ocular toxocariasis (OT) in serum samples of patients attending a public referral center for ophthalmology in Brazil and to determine the most frequent ocular signs and symptoms.
Study design
This was a retrospective descriptive study of a cohort of outpatients followed from December 1989 to May 2006.
Methods
IgG anti-
Toxocara
antibody titers were determined by enzyme-linked immunosorbent assay. The results were correlated with the clinical and funduscopic findings.
Results
Of the diagnoses for the 126 patients, 42 were considered as probable OT, 48 as negative, and 36 as inconclusive. The median IgG anti-
Toxocara
antibody titers of the patients with probable OT were significantly higher than those of the patients in the negative or inconclusive groups (
P
 = 0.0001). Higher titers were observed more frequently in patients in the probable OT group (
P
 = 0.01) than in the negative group, in which titers were absent or lower in most patients (
P
 < 0.0001). The right eye was affected more in the OT group than in the negative group (
P
 = 0.01), and inflammation was located mostly in the intermediate and posterior poles. The mean age of the patients diagnosed with probable OT was significantly lower (mean, 8 years) than that of the negative patients (mean, 14.5 years) (
P
 = 0.006).
Conclusions
Higher levels of antibodies could help with the diagnosis of OT in patients with symptoms and clinical signs; however, negative results cannot exclude possible OT. Conversely, patients with negative serology or low titers make the diagnosis of OT less likely.