A multihousehold study reveals a positive correlation between age, severity of ocular toxoplasmosis, and levels of glycoinositolphospholipid-specific immunoglobulin A.
A cross-sectional household study involving 499 individuals was undertaken in an area of Minas Gerais state, Brazil, where infection with Toxoplasma gondii is endemic. Nearly 50% (n=247) of the sample had T. gondii-specific antibodies, even individuals in the 5-9-year-old age group. Approximately 12.5% (n=28) of a random subsample of participants who were positive for T. gondii antibodies had ocular lesions associated with T. gondii infection. The frequency of ocular toxoplasmosis increased significantly with age, with approximately 50% of individuals >60 years of age having lesions. The size of the ocular lesion correlated positively (r=0.85; P=.01) with the serum level of immunoglobulin A specific for tachyzoite-derived glycoinositolphospholipids. We found that sharing the same residence accounted for 30% of the variation in infectivity among residents in the sample, whereas age was the main risk factor for development of ocular toxoplasmosis in patients who were positive for T. gondii antibodies.
Portela
Ricardo W D
RW
Department of Biochemistry and Immunology, Federal University of Minas Gerais, and Laboratory of Immunopathology, René Rachou Research Center, Oswaldo Cruz Foundation, Brazil.
Bethony
Jeffrey
J
Costa
Maria I
MI
Gazzinelli
Andréa
A
Vitor
Ricardo W A
RW
Hermeto
Flavio M
FM
Correa-Oliveira
Rodrigo
R
Gazzinelli
Ricardo T
RT
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000913:Antibodies, Protozoan / Q000097:blood; D000918:Antibody Specificity; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D005260:Female; D006017:Glycolipids / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007223:Infant; D008297:Male; D008875:Middle Aged; D010743:Phospholipids / Q000276:immunology*; D012720:Severity of Illness Index; D017678:Sex Distribution; D014122:Toxoplasma / Q000276:immunology*; D014126:Toxoplasmosis, Ocular / Q000453:epidemiology* / Q000469:parasitology / Q000503:physiopathology
D000913:Antibodies, Protozoan; D006017:Glycolipids; D007070:Immunoglobulin A; D010743:Phospholipids