Renal lesions in IgG4-related systemic disease.
ABSTRACT Recently, a new concept of IgG4-related systemic disease including autoimmune pancreatitis, characterized by a high serum IgG4 level and tissue infiltration by IgG4-positive plasma cells, has been proposed. Our aim was to investigate the renal involvement in this condition.
We investigated the results of laboratory and imaging studies of the kidneys in 7 patients with IgG4-related systemic disease, and examined the renal histology in four of them. All patients showed elevated serum IgG4 levels, and 4 had autoimmune pancreatitis. The other three patients showed involvement of various extrapancreatic organs (lymphadenopathy, sialadenitis or renal insufficiency), and abundant IgG4-positive plasma cell infiltration was confirmed in their affected tissues.
Six of the 7 patients showed some renal abnormalities. In one patient, hydronephrosis was observed accompanied by retroperitoneal fibrosis. Another patient showed multiple low-density areas in both kidneys by computed tomography, and gallium citrate scintigraphy showed gallium-67 accumulation in both kidneys, although renal function was normal. Four patients had tubulointerstitial nephritis. In two of them, the tubulointerstitial nephritis was diffuse. In one patient, marked diffuse but patchily distributed lymphoplasmacytic infiltration of the renal interstitium was observed. In another patient, computed tomography showed a tumor-like low-density mass; open biopsy of the mass showed aggregates of lymphocytes and plasma cells in the renal interstitium.
Renal parenchymal lesions in IgG4-related systemic disease are due to dense lymphoplasmacytic infiltration of the renal interstitium, and the lesions vary from diffuse tubulointerstitial nephritis to tumor-like masses according to the distribution patterns of the infiltrating cells.
SourceAvailable from: Masafumi Moriyama[Show abstract] [Hide abstract]
ABSTRACT: IgG4-DS patients showed strong infiltration of M2 macrophages, whereas it was rarely detected in controls, CS, and SS patients.•The expression of pro-fibrotic factors such as CCL18 and IL-10 were almost consistent with that of M2 macrophages in SMGs from IgG4-DS patients.•The fibrosis scores were positively correlated with the frequency of M2 macrophages only in IgG4-DS patients.•IL-10 and CCL18 secreted by preferential M2 macrophages play a key role in the development of severe fibrosis in IgG4-DS.Clinical Immunology 10/2014; DOI:10.1016/j.clim.2014.10.008 · 3.99 Impact Factor
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ABSTRACT: Immunoglobulin G4-related disease (IgG4-RD) is a new clinical entity. Characteristic features of IgG4-RD are elevated serum IgG4 levels, infiltration of IgG4-positive cells, mass-forming lesions with fibrosis and good response to corticosteroids. The variable imaging features of IgG4-RD and the overlap with other differential diagnoses often pose a diagnostic challenge, as they frequently mimic malignant tumors or other inflammatory diseases in the abdomen. A 54-year-old woman visited our hospital with left flank discomfort and palpebral edema. Computed tomography, magnetic resonance imaging, retrograde pyelography and positron emission tomography/computed tomography indicated renal pelvic cancer. However, after a left-sided nephroureteral cystectomy was performed, the mass was pathologically confirmed as an IgG4-related lesion. Her elevated serum IgG4 level and a past history of sicca complex supported the diagnosis of IgG4-RD. It is critical to recognize the importance of laboratory examinations such as serum IgG4 level if a patient has a past history of rheumatic disease.World Journal of Surgical Oncology 12/2014; 12(1):395. DOI:10.1186/1477-7819-12-395 · 1.20 Impact Factor
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ABSTRACT: IgG4-related disease is a recently established systemic condition. Tubulointerstitial nephritis is the most common renal manifestation. Glomerular lesions, particularly membranous glomerulonephritis, can develop simultaneously. Some patients present with serological renal dysfunction associated with elevated IgG or IgE levels and hypocomplementemia, while others are incidentally found to have abnormalities in kidneys on imaging. A majority of patients with IgG4-related kidney disease have similar lesions at other anatomical sites, which help us to suspect this condition. Serum IgG4 elevation (>135 mg/dL) is the most, although not entirely, specific marker for the diagnosis. Imaging findings varies from small nodules to bilateral diffuse abnormalities. In addition to the renal parenchyma, the renal pelvis and perirenal adipose tissue can be affected. Histological features include dense lymphoplasmacytic infiltration, storiform or "bird's eye" fibrosis (highlighted by PAM stain), and IgG4-positive plasma cell infiltration (>10 cells/high-power field and IgG4/IgG-positive cell ratio >40%). Immune complex deposition is detectable in the tubular basement membrane by immunofluorescence and/or electron microscopy. Patients usually respond well to corticosteroids, but highly active diseases may require other immunosuppressive therapies. Further investigations will be required to fully understand pathophysiology underlying this emerging condition.