Immunofluorescence detection of gb3 in conjunctival biopsies of hemizygotes and heterozygotes patients with Fabry?s disease

ROZENFELD P; CROXATTO O; EBNER R; FOSSATI CA

Sevilla, España

Congreso; 4th. International Symposium on Lysosomal Storage Diseases; 2004

?Immunofluorescence detection of gb3 in conjunctival biopsies of hemizygotes and heterozygotes patients with Fabry?s disease?. Rozenfeld P, Croxatto O, Ebner R, Fossati CA. Cátedra de inmunología, universidad Nacional de La Plata. Fundación Oftalmológica Argentina. Hospital Británico, Buenos Aires Fabry?s disease is an X-linked inborn metabolic error caused by a deficiency of lysosomal a-galactosidase A. Globotriaosylceramide (Gb3) accumulates in lysosomes of various tissues. In hemizygous males, Fabry?s disease is currently diagnosed by decreased a-galactosidase A activity. However, enzyme assays do not always distinguish between heterozygous females and normal controls. Renal or cardiac biopsies are useful for the diagnosis of hetereozygotes, but requires hospitalization of the patients. The aim of this study was to develop a method for the specific demonstration of Gb3 by immunofluorescence (IF) with a monoclonal antibody in conjunctival biopsies of patients with Fabry?s disease. Conjunctival biopsies were obtained from five hemizygous males and five heterozygous females. The specimens were processed for direct IF using a monoclonal mouse IgM anti-Gb3 antibody, light microsocopy and electron microscopy. Positive IF was observed in the wall of conjunctival blood vessels in 5/5 hemizygous male patients and in 4/5 heterozygous females. Positive and negative results correlated with electron microscopic findings. No fluoresence was detected in conjunctival specimens from controls subjects without Fabry?s disease. IF study of Gb3 deposits in conjunctival biopsies may be a useful and simple method for screening and diagnosis of patients with Fabry?s disease. In addition, this method may be applicable to the follow-up of patients under enzyme replacement therapy.