Ocular toxoplasmosis in the fetus. Immunohistochemistry analysis and DNA amplification.
OBJECTIVE
Ocular toxoplasmosis is often the result of a congenital infection. However, the earlier stages of the ocular lesions in the fetus have not been well studied. The purpose of the present study is to analyze the ocular findings in four aborted fetuses that were infected congenitally with Toxoplasma gondii.


METHODS
Eight eyes from four fetuses of 22 to 27.5 weeks with T. gondii infection were studied by routine and immunohistochemical techniques. Two of the four were also examined by polymerase chain reaction (PCR).


RESULTS
In two cases, the results of gross and histopathologic of the eyes were normal; marked retinal necrosis was present in the other two cases. Although no toxoplasmic cysts were identified by routine histopathologic examination, antigens of the tachyzoite were detected by immunohistochemistry analysis in the areas of retinal necrosis. In one of the cases with ocular lesions, the presence of T. gondii was confirmed by PCR. The presence of ocular lesions correlated with the severity of pathologic changes in the central nervous system. Large numbers of T cells were observed in the retinal lesions and in the choroid.


CONCLUSIONS
Retinal necrosis, neovascularization, and marked chorioretinal inflammations despite the absence of bradyzoites are characteristic findings in the fetal eyes infected with T. gondii, and infiltrating T lymphocytes play a role in early recognition of the toxoplasma organism.
Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892.
A P
AP
Brézin
L
L
Kasner
P
P
Thulliez
Q
Q
Li
F
F
Daffos
R B
RB
Nussenblatt
C C
CC
Chan
D000328:Adult; D000818:Animals; D015139:Blotting, Southern; D005260:Female; D005315:Fetal Diseases / Q000469:parasitology / Q000473:pathology*; D006801:Humans; D007124:Immunoenzyme Techniques; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000175:diagnosis; D014126:Toxoplasmosis, Ocular / Q000151:congenital* / Q000473:pathology*