RESUMO
German Shorthaired Pointer (GSHP) dogs with a UNC93B1 gene mutation develop exfoliative cutaneous lupus erythematosus (ECLE) and kidney disease resembling lupus nephritis in humans. The objective of this study was to characterize the kidney disease by light microscopy, immunofluorescence, and electron microscopy in a population of GSHP dogs with ECLE. Medical records were reviewed, and light microscopy of kidneys from 7 GSHP dogs with a previous histologic diagnosis of ECLE was performed. Immunofluorescence of fresh-frozen kidney from 1 dog and transmission electron microscopy of kidney from that dog and 2 additional dogs were performed. Five of 7 dogs had proteinuria diagnosed by urinalysis or urine protein-to-creatinine ratio. Two of 7 dogs were intermittently hypoalbuminemic, and none were azotemic. Histologic findings included early (2 dogs) to late (5 dogs) membranous glomerulonephropathy characterized by mild-to-severe glomerular capillary loop thickening and tubular proteinosis. In all 7 cases, trichrome staining revealed red granular immune deposits on the subepithelial surface of the glomerular basement membrane. Immunofluorescence revealed strong granular labeling for immunoglobulins and complement protein C3. Electron microscopy demonstrated subepithelial electron-dense immune deposits encircled by the remodeled glomerular basement membrane. These findings are diagnostic of immune-complex membranous glomerulonephropathy and are similar to class V lupus in humans. This cohort of GSHP dogs with ECLE developed immune-complex membranous glomerulonephropathy, which we hypothesize is a manifestation of systemic lupus erythematosus. GSHP dogs with ECLE should undergo clinical evaluation of renal function for early identification and treatment.
Assuntos
Doenças do Cão , Glomerulonefrite Membranosa , Nefropatias , Lúpus Eritematoso Cutâneo , Lúpus Eritematoso Sistêmico , Humanos , Cães , Animais , Glomerulonefrite Membranosa/diagnóstico , Glomerulonefrite Membranosa/veterinária , Glomerulonefrite Membranosa/patologia , Rim/patologia , Glomérulos Renais/patologia , Lúpus Eritematoso Cutâneo/tratamento farmacológico , Lúpus Eritematoso Cutâneo/genética , Lúpus Eritematoso Cutâneo/patologia , Lúpus Eritematoso Cutâneo/veterinária , Lúpus Eritematoso Sistêmico/patologia , Lúpus Eritematoso Sistêmico/veterinária , Nefropatias/patologia , Nefropatias/veterinária , Doenças do Cão/diagnóstico , Doenças do Cão/genéticaRESUMO
Subclinical stage of ehrlichiosis is characterized by absence of clinical or laboratory alterations; however, it could lead to silent glomerular/tubular changes and contribute significantly to renal failure in humans and animals. The aim of this study was to evaluate glomerular and tubular alterations in dogs with subclinical ehrlichiosis. We evaluated renal biopsies of 14 bitches with subclinical ehrlichiosis and 11 control dogs. Samples were obtained from the left kidney, and the tissue obtained was divided for light microscopy, immunofluorescence, and transmission electron microscopy. Abnormalities were identified by light microscopy in 92.9% of dogs with ehrlichiosis, but not in any of the dogs of the control group. Mesangial cell proliferation and synechiae (46.1%) were the most common findings, but focal segmental glomerulosclerosis and ischemic glomeruli (38.4%), focal glomerular mesangial matrix expansion (30.7%), mild to moderate interstitial fibrosis and tubular atrophy (23%), and glomerular basement membrane spikes (23%) were also frequent in dogs with ehrlichiosis. All animals with ehrlichiosis exhibited positive immunofluorescence staining for immunoglobulins. Transmission electron microscopy from dogs with ehrlichiosis revealed slight changes such as sparse surface projections and basement membrane double contour. The subclinical phase of ehrlichiosis poses a higher risk of development of kidney damage due to the deposition of immune complexes.
Assuntos
Doenças do Cão/patologia , Ehrlichiose/veterinária , Glomérulos Renais/patologia , Túbulos Renais/patologia , Animais , Biópsia/veterinária , Estudos de Casos e Controles , Cães , Ehrlichiose/imunologia , Ehrlichiose/patologia , Feminino , Imunoglobulinas/metabolismo , Masculino , Microscopia Eletrônica de TransmissãoRESUMO
The incidence and prevalence of paraneoplastic glomerulopathy, especially associated with carcinoma, are a matter of debate and the causal link between cancer and glomerular diseases remains unclear. The aim of this study was to evaluate renal biopsies of selected bitches with spontaneous mammary gland carcinoma. We hypothesized that dogs with mammary carcinomas would show histologic evidence of glomerular pathology. A prospective study was performed in dogs with naturally occurring mammary carcinoma that were undergoing tumor resection and ovariohysterectomy. We evaluated renal biopsies of 32 bitches with spontaneous mammary gland carcinoma and 11 control dogs without mammary gland neoplasia. Samples were obtained from the left kidney and the biopsy material was divided for light microscopy (LM), immunofluorescence (IF) and transmission electron microscopy (TEM). Light microscopy abnormalities were identified in 78.1% of dogs with mammary carcinoma (n = 25) and in none of the dogs in the control group. Focal glomerular mesangial matrix expansion was the most common alteration (n = 15, 60.0%), but mesangial cell proliferation (n = 9, 36.0%) and focal segmental glomerulosclerosis (n = 9, 36.0%), synechiae (n = 7, 28.0%), and globally sclerotic glomeruli (n = 6, 24.0%) were also frequent in dogs with malignancy. Immunofluorescence microscopy revealed strong IgM staining was demonstrated in 64.3% (n = 18) of carcinoma dogs. Transmission electron microscopy from dogs with carcinoma revealed slight changes, the most frequent of which was faint sub-endothelial and mesangial deposits of electron-dense material (78%). Mesangial cell interpositioning and segmental effacement of podocyte foot processes were identified in some specimens (45%). Changes in the glomerulus and proteinuria are common in dogs with naturally occurring mammary carcinoma and this condition appears to provide an excellent large animal model for cancer-associated glomerulopathy in humans.