X-linked juvenile retinoschisis associated with an RS1 in-frame deletion and bilateral central serous chorioretinopathy.

PURPOSE: To report the case of a patient with X-linked juvenile retinoschisis (XLRS), caused by an in-frame deletion of the RS1 gene, who presented visual loss due to bilateral central serous chorioretinopathy (CSC).Methods: Observational case report. RESULTS: A 34-year-old man, with type-A personality, presented with a one-month history of decreased visual acuity and metamorphopsia in his right eye. Funduscopic examination showed a dome-like foveal elevation in both eyes (OU), as well as subtle pigmentary changes of the retinal pigment epithelium with a tapetal reflex in the fovea. Spectral-domain optical coherence tomography revealed intraretinal cystic foveal changes and serous retinal detachment in OU. Fundus fluorescein angiography of OU showed a focal area of intense hyperfluorescence with leakage in late phases. Electroretinogram revealed a markedly attenuated b-wave and a diminished a-wave in photopic and scotopic phases. Genetic testing revealed a hemizygous c.282_284delCTT deletion in the RS1 gene, predicting a p.Ser95del change at the protein level. The patient was diagnosed with XLRS and central serous chorioretinopathy as a coexisting condition. Patient was observed during a 3-month period but showed no improvement. Therefore, subthreshold micropulse laser was applied, achieving complete resolution of signs and symptoms of CSC. CONCLUSION: CSC can be a cause of acute or subacute visual loss in patients with XLRS when other complications such as vitreous hemorrhage and retinal detachment have been excluded.

Inhibition of B cell death causes the development of an IgA nephropathy in (New Zealand white x C57BL/6)F(1)-bcl-2 transgenic mice.

Little is known about the pathogenic mechanisms of IgA nephropathy, despite being the most prevalent form of glomerulonephritis in humans. We report in this study that in (New Zealand White (NZW) x C57BL/6)F(1) mice predisposed to autoimmune diseases, the expression of a human bcl-2 (hbcl-2) transgene in B cells promotes a CD4-dependent lupus-like syndrome characterized by IgG and IgA hypergammaglobulinemia, autoantibody production, and the development of a fatal glomerulonephritis. Histopathological analysis of glomerular lesions reveals that the glomerulonephritis observed in these animals resembles that of human IgA nephropathy. The overexpression of Bcl-2 in B cells selectively enhances systemic IgA immune responses to T-dependent Ags. Significantly, serum IgA purified from (NZW x C57BL/6)F(1)-hbcl-2 transgenic mice, but not from nontransgenic littermates, shows reduced levels of galactosylation and sialylation and an increased ability to deposit in the glomeruli, as observed in human patients with IgA nephropathy. Our results indicate that defects in the regulation of B lymphocyte survival associated with aberrant IgA glycosylation may be critically involved in the pathogenesis of IgA nephropathy, and that (NZW x C57BL/6)F(1)-hbcl-2 Tg mice provide a new experimental model for this form of glomerulonephritis.

Inhibition of B-cell death does not restore T-cell-dependent immune responses in CD40-deficient mice.

Signalling through CD40 is essential for the development of immunoglobulin G (IgG) antibody responses, germinal centres and B-cell memory against T-dependent antigens. In addition, engagement of CD40 in B cells promotes cell survival by inducing the expression of anti-apoptotic members of the bcl-2 family of cell-death regulators. In the present study we analysed whether T-dependent immune responses can be developed in mice deficient in CD40 if the anti-apoptotic activity mediated by the engagement of CD40 in B cells is compensated by the constitutive over-expression of anti-apoptotic genes of the bcl-2 family. We showed that the over-expression of either hbcl-2 or hbcl-xL transgenes in B cells is not sufficient to restore IgG antibody responses and germinal centre formation in CD40-deficient mice. These results indicate that CD40 functions, other than those mediated through survival, are required for the establishment of T-dependent B-cell responses.