A case of IgG4‐related autoimmune disease with multiple organ involvement

Abstract

A 52-year-old male was admitted with autoimmune pancreatitis (AIP), showing mononuclear cell infiltration in both the pancreas and salivary glands with both normal sialography and anti-SS-A/SS-B antibodies. Although the AIP improved with glucocorticoid treatment, subsequent abdominal computed tomography (CT) revealed a nodular shadow in the bilateral kidneys, which was confirmed as interstitial nephritis by renal biopsy. The patient's serum immunoglobulin G4 (IgG4) level was 10 times higher than the upper limit of the normal range. IgG4-positive mononuclear cell infiltration was detected in the salivary gland, pancreas, and kidney. A new entity proposed as 'IgG4-related autoimmune disease' was considered.

Membranoproliferative Glomerulonephritis-Like Glomerular Disease and Concurrent Tubulointerstitial Nephritis Complicating IgG4-Related Autoimmune Pancreatitis

“…Renal lesions of the disease have been reported recently, most commonly they consist of tubulointerstitial nephritis (6,23,(27)(28)(29) (28,30,31). Plasma cells infiltrating the interstitium show strong immunoreactivity to IgG4 (21, 28, 30-32).…”

“…Kamisawa et al (3) were the first to use the term "IgG4-related systemic disease" to describe the systemic nature of the disease (3,6,(21)(22)(23).…”

Renal Lesions in IgG4-Related Systemic Disease

“…However, immune complexes in the tubular basement membranes are sometimes observed in interstitial nephritis caused by other mechanisms (28), and the results of electron microscopy and immunostaining of the renal tubular basement membrane for IgG4 in patients with IgG4-related systemic disease are variable (8)(9)(10)(18)(19)(20)(21). Concerning the glomerular lesions, minor or mild abnormalities are dominant (8,9,(18)(19)(20)(21), however, membranous nephropathy has been described in two patients with AIP (10,18). In the present patients with TIN, immune deposits were not evident in the glomeruli or tubular basement membrane.…”

IgG4-related Kidney Disease in Which the Urinalysis, Kidney Function and Imaging Findings Were Normal

“…We believe that this is because (Table) (5)(6)(7)(8)(9)(10)(11). Most of the IgG4/IgG positive plasma cell ratios in these patients were only slightly higher than 40%.…”