We found that morphological features of fibrosis in this disease are largely depending on the anatomical location wherein the lesion developed. Interstitial fibrosis located at intracapsule in 1, subcapsule in 3, cortex in 3, perivasculature in 5, perinerve in 2 cases and medulla in no case. The components of extra cellular matrices in the fibrosis are followings. In perivascular and perineural lesions, collagen type I (67%), III (100%) and VI (100%) were the major components,

while collagen type IV (27%) and V (0%) were scant. In subcapsular and cortical lesions, collagen type III (83%), IV (32%) and VI (50%) were the major components, although collagen type I (14%) and V (0%) were less dominant. Three cases revealed storiform fibrosis and all distributed only in the cortex. Storiform fibrosis was negative for collagen type Selleckchem Target Selective Inhibitor Library I. Fibronectin accumulated between collagen Trichostatin A fibers and increased as stage advanced. In conclusions, renal pathology in IgG4-related kidney disease reveals several distinct morphology, useful to discriminate TIN from other causes. Interstitial fibrosis mainly distributes along perivasculature, whereas storiform fibrosis is formed only in the cortex. The main components of interstitial fibers may be dependent on the locations

which are formed of interstitial fibrosis in IgG4-RKD. SAEKI TAKAKO Department of Internal Medicine, Nagaoka Red Cross Hospital, Japan IgG4-related kidney disease (IgG4-RKD) is a comprehensive term for renal lesions associated with IgG4-related disease (IgG4-RD). The most dominant feature of

IgG4-RKD is plasma cell-rich tubulointerstitial nephritis (TIN) with increased IgG4-positive plasma cells and fibrosis (namely IgG4-related TIN), although some glomerular lesions such as membranous nephropathy are sometimes evident concurrent with IgG4-related TIN. Clinical features: IgG4-RKD shows a striking male predominance (73–87%) and the average patient age is about 65 years. Systemic symptoms are relatively mild and the condition usually comes clinically apparent when renal 4��8C dysfunction and/or renal radiographic abnormalities occur. Most patients have accompanying IgG4-related extra-renal lesions such as sialadenitis, lymphadenopathy or type 1 autoimmune pancreatitis. Although nearly half of all patients with IgG4-RKD have proteinuria (and some have hematuria), it is mild in the majority. Nephrotic range proteinuria is rarely detected, except when glomerular lesions are also present. Kidney function varies from normal to renal failure, and the development of renal dysfunction also varies from relatively acute to slowly progressive. Serology usually demonstrates high levels of serum IgG and IgG4. A high level of serum IgE and hypocomplementemia are also frequent features. Although antinuclear antibodies and rheumatoid factor are often positive, anti-DNA, anti-SS-A and anti-SS-B antibodies are usually negative.