Limits...
IgG4-related kidney disease--an update.

Kawano M, Saeki T - Curr. Opin. Nephrol. Hypertens. (2015)

Bottom Line: Clinically, decreased renal function, or characteristic imaging findings such as multiple low-density lesions on contrast-enhanced computed tomography or diffuse thickening of the renal pelvic wall, are typical presenting features.TIN with characteristic imaging findings is a typical manifestation of IgG4-RKD in the interstitium, while MGN is a representative manifestation of the glomerular lesions.Although IgG4 is a central feature of IgG4-RD, the recent discovery of IgG4-negative IgG4-RD raises questions about the causative role of the IgG4 molecule in this context.

View Article: PubMed Central - PubMed

Affiliation: aDivision of Rheumatology, Kanazawa University Hospital, Kanazawa, Japan bDepartment of Internal Medicine, Nagaoka Red Cross Hospital, Nagaoka, Japan.

ABSTRACT

Purpose of review: IgG4-related disease (IgG4-RD) is a recently recognized systemic inflammatory disorder that can affect most organs/tissues such as sarcoidosis. The kidney is a frequently affected organ with tubulointerstitial nephritis (TIN), the representative lesion of IgG4-RD. This review focuses on the latest knowledge of IgG4-related kidney disease (IgG4-RKD).

Recent findings: A wide range of renal manifestations of IgG4-RD, that is TIN, membranous glomerulonephritis (MGN) and other glomerular lesions, and pyelitis, are collectively referred to as IgG4-RKD. Clinically, decreased renal function, or characteristic imaging findings such as multiple low-density lesions on contrast-enhanced computed tomography or diffuse thickening of the renal pelvic wall, are typical presenting features. Although a rapid response to corticosteroid therapy is a very important feature of IgG4-TIN, in cases in which renal function is moderately to severely decreased before therapy, only partial recovery of renal function is obtained.

Summary: TIN with characteristic imaging findings is a typical manifestation of IgG4-RKD in the interstitium, while MGN is a representative manifestation of the glomerular lesions. Although IgG4 is a central feature of IgG4-RD, the recent discovery of IgG4-negative IgG4-RD raises questions about the causative role of the IgG4 molecule in this context.

Show MeSH

Related in: MedlinePlus

Typical histological features of IgG4-related tubulointerstitial nephritis. Upper: Histopathological examination in a patient with IgG4-related kidney disease (IgG4-RKD) shows plasma cell rich tubulointerstitial nephritis with different stages of fibrosis intermingled within different areas (periodic acid-methenamine-silver staining x100). Lower: Immunostaining for IgG4 shows many IgG4-positive plasma cells in the area of inflammation just outside the renal capsule, probably corresponding to the rim-like lesion of the kidney noted on imaging study (x400).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4318645&req=5

Figure 2: Typical histological features of IgG4-related tubulointerstitial nephritis. Upper: Histopathological examination in a patient with IgG4-related kidney disease (IgG4-RKD) shows plasma cell rich tubulointerstitial nephritis with different stages of fibrosis intermingled within different areas (periodic acid-methenamine-silver staining x100). Lower: Immunostaining for IgG4 shows many IgG4-positive plasma cells in the area of inflammation just outside the renal capsule, probably corresponding to the rim-like lesion of the kidney noted on imaging study (x400).

Mentions: Plasma cell rich TIN with fibrosis and sometimes numerous infiltrating eosinophils are typical pathological findings of IgG4-RKD (Fig. 2) [4,30–32]. Histologic findings are mandatory for the definite diagnosis of IgG4-RKD. However, several situations such as inaccessible regional lesion distribution (e.g. lesions distributed in only the upper pole of the kidney) hamper histologic examination of the kidney. In such cases, histologic findings from other organs could support typical renal imaging findings and clinical features of IgG4-RKD to allow the diagnosis of IgG4-RKD. Although Sjögren's syndrome sometimes shows plasma cell rich TIN, IgG4 immunostaining clearly differentiates these two diseases. Usually, more than 10 infiltrating IgG4 and plasma cells per high-power field or at least 40% of the ratio of IgG4 and plasma cells to IgG and plasma cells are employed as the cutoff values. However, the specificity of IgG4 immunostaining is not high because ANCA-associated vasculitis, particularly eosinophilic granulomatosis with polyangiitis [33–35] and granulomatosis with polyangiitis (GPA) [36], sometimes show lymphoplasmacytic infiltrates with copious IgG4 and plasma cells in the interstitium. Moreover, serum IgG4 levels have been reported to be sometimes elevated in such cases. Therefore, special caution is needed to differentiate IgG4-RD from ANCA-associated vasculitis. Elevated serum CRP levels and a partial response to corticosteroid therapy seem to be helpful in differentiating these diseases.


IgG4-related kidney disease--an update.

Kawano M, Saeki T - Curr. Opin. Nephrol. Hypertens. (2015)

Typical histological features of IgG4-related tubulointerstitial nephritis. Upper: Histopathological examination in a patient with IgG4-related kidney disease (IgG4-RKD) shows plasma cell rich tubulointerstitial nephritis with different stages of fibrosis intermingled within different areas (periodic acid-methenamine-silver staining x100). Lower: Immunostaining for IgG4 shows many IgG4-positive plasma cells in the area of inflammation just outside the renal capsule, probably corresponding to the rim-like lesion of the kidney noted on imaging study (x400).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4318645&req=5

Figure 2: Typical histological features of IgG4-related tubulointerstitial nephritis. Upper: Histopathological examination in a patient with IgG4-related kidney disease (IgG4-RKD) shows plasma cell rich tubulointerstitial nephritis with different stages of fibrosis intermingled within different areas (periodic acid-methenamine-silver staining x100). Lower: Immunostaining for IgG4 shows many IgG4-positive plasma cells in the area of inflammation just outside the renal capsule, probably corresponding to the rim-like lesion of the kidney noted on imaging study (x400).
Mentions: Plasma cell rich TIN with fibrosis and sometimes numerous infiltrating eosinophils are typical pathological findings of IgG4-RKD (Fig. 2) [4,30–32]. Histologic findings are mandatory for the definite diagnosis of IgG4-RKD. However, several situations such as inaccessible regional lesion distribution (e.g. lesions distributed in only the upper pole of the kidney) hamper histologic examination of the kidney. In such cases, histologic findings from other organs could support typical renal imaging findings and clinical features of IgG4-RKD to allow the diagnosis of IgG4-RKD. Although Sjögren's syndrome sometimes shows plasma cell rich TIN, IgG4 immunostaining clearly differentiates these two diseases. Usually, more than 10 infiltrating IgG4 and plasma cells per high-power field or at least 40% of the ratio of IgG4 and plasma cells to IgG and plasma cells are employed as the cutoff values. However, the specificity of IgG4 immunostaining is not high because ANCA-associated vasculitis, particularly eosinophilic granulomatosis with polyangiitis [33–35] and granulomatosis with polyangiitis (GPA) [36], sometimes show lymphoplasmacytic infiltrates with copious IgG4 and plasma cells in the interstitium. Moreover, serum IgG4 levels have been reported to be sometimes elevated in such cases. Therefore, special caution is needed to differentiate IgG4-RD from ANCA-associated vasculitis. Elevated serum CRP levels and a partial response to corticosteroid therapy seem to be helpful in differentiating these diseases.

Bottom Line: Clinically, decreased renal function, or characteristic imaging findings such as multiple low-density lesions on contrast-enhanced computed tomography or diffuse thickening of the renal pelvic wall, are typical presenting features.TIN with characteristic imaging findings is a typical manifestation of IgG4-RKD in the interstitium, while MGN is a representative manifestation of the glomerular lesions.Although IgG4 is a central feature of IgG4-RD, the recent discovery of IgG4-negative IgG4-RD raises questions about the causative role of the IgG4 molecule in this context.

View Article: PubMed Central - PubMed

Affiliation: aDivision of Rheumatology, Kanazawa University Hospital, Kanazawa, Japan bDepartment of Internal Medicine, Nagaoka Red Cross Hospital, Nagaoka, Japan.

ABSTRACT

Purpose of review: IgG4-related disease (IgG4-RD) is a recently recognized systemic inflammatory disorder that can affect most organs/tissues such as sarcoidosis. The kidney is a frequently affected organ with tubulointerstitial nephritis (TIN), the representative lesion of IgG4-RD. This review focuses on the latest knowledge of IgG4-related kidney disease (IgG4-RKD).

Recent findings: A wide range of renal manifestations of IgG4-RD, that is TIN, membranous glomerulonephritis (MGN) and other glomerular lesions, and pyelitis, are collectively referred to as IgG4-RKD. Clinically, decreased renal function, or characteristic imaging findings such as multiple low-density lesions on contrast-enhanced computed tomography or diffuse thickening of the renal pelvic wall, are typical presenting features. Although a rapid response to corticosteroid therapy is a very important feature of IgG4-TIN, in cases in which renal function is moderately to severely decreased before therapy, only partial recovery of renal function is obtained.

Summary: TIN with characteristic imaging findings is a typical manifestation of IgG4-RKD in the interstitium, while MGN is a representative manifestation of the glomerular lesions. Although IgG4 is a central feature of IgG4-RD, the recent discovery of IgG4-negative IgG4-RD raises questions about the causative role of the IgG4 molecule in this context.

Show MeSH
Related in: MedlinePlus