No abstract

To clarify the early involvement of cellular adhesion molecules in human glomerulonephritis, we investigated P-selectin and high endothelial venules' (HEVs) marker MECA-79 expression in kidney specimens by immunohistochemical and in situ hybridization analyses, and measured serum and urinary soluble P-selectin levels by enzyme-linked immunosorbent assay. In normal controls, P-selectin and MECA-79 expression were negative in glomeruli (N = 4), and serum soluble P-selectin levels were 114.3 +/- 36.8 ng/ml (mean +/- SEM, N = 12). Soluble P-selectin was not detectable in urine of all cases. In proliferative glomerulonephritis involving rapidly progressive glomerulonephritis (N = 6), IgA nephropathy (N = 26), lupus nephritis (N = 7) and acute glomerulonephritis (N = 2), both glomerular and interstitial P-selectin expression were up-regulated. Glomerular P-selectin expression correlated positively with local cellular accumulation, endocapillary proliferation and CD41b (platelet) staining. Interstitial P-selectin expression showed a positive correlation with the grade of local cellular infiltrates. P-selectin mRNA signals detected by in situ hybridization were only observed on capillary or venous endothelium in the interstitium, but not in glomeruli. In addition, MECA-79 was expressed on the plump endothelial cells at the cortico-medullary junction (outer medulla). Serum soluble P-selectin levels were significantly higher in patients with proliferative glomerulonephritis, especially in glomerular and interstitial P-selectin positive staining, and correlated with glomerular endocapillary proliferation. These observations suggested that P-selectin was associated with both glomerular and interstitial leukocyte accumulation in human glomerulonephritis, and might be expressed by two distinct mechanisms that are the activated platelets in glomeruli and the de novo expression in the interstitial lesions that correlated with MECA-79 expression as HEVs like vessels, and serum soluble P-selectin may be a useful marker for predicting in situ P-selectin expression associated with glomerular endocapillary proliferation in nephritis.

Our results suggest that short-term relatively low-dose intravenous Glb therapy has a beneficial effect in the earlier induction of remission in a subgroup of MN, the homogeneous type with EM findings of synchronous electron-dense deposits, but does not alter the long-term outcome of human MN.

Expression of MHC-class II molecules (HLA-DR and -DQ), serum gamma-interferon (gamma-IFN) and soluble interleukin-2 receptor (sIL-2R) levels were studied in 35 Japanese patients with lupus nephritis (LN) to clarify intraglomerular cellular activation and cytokine involvement in human LN. In 11 normal kidney specimens, HLA-DR(Ia1) was noted in glomerular tufts, but HLA-DQ was either not or was faintly detected in glomeruli by the indirect immunofluorescence technique. HLA-DR and -DQ were observed mainly on the surface of glomerular endothelial cells in 100% and 50% of 28 lupus kidney specimens except for necrotic or sclerotic lesions. HLA-DQ was expressed in a high incidence of 67%, 86% in patients with proliferative LN (WHO Class III-IV) and active lesions, respectively. Serum gamma-IFN and sIL-2R levels were 1.2 +/- 0.2 U/ml and 190 +/- 24 U/ml (mean +/- SEM; N = 30) in normal controls, and elevated in patients with proliferative LN (4.1 +/- 1.0 U/ml, 383 +/- 81 U/ml, N = 25), especially with active lesions (6.2 +/- 1.5 U/ml, 500 +/- 110 U/ml, N = 14). Overall, glomerular lesions such as HLA-DQ expression, the activity index and leukocyte infiltration correlated positively with serum gamma-IFN levels (r = 0.55; P less than 0.01 for HLA-DQ, r = 0.68; P less than 0.001 for activity index, r = 0.38; P less than 0.05 for leukocyte infiltration), but not with serum sIL-2R levels, anti-DNA antibody titers and CH50 titers.(ABSTRACT TRUNCATED AT 250 WORDS)

In order to clarify intraglomerular cellular activation and cytokine involvement in IgA nephropathy, the glomerular expression of MHC class II antigens (HLA-DR and DQ) and cellular proliferative nuclear antigen (Ki-67), and serum γ-interferon (γ-IFN) levels were evaluated in 49 patients with IgA nepropathy. HLA-DR was detected in all but 4 patients in whom glomerular sclerosis was present. HLA-DQ and Ki-67 were observed in 51 and 38% of the patients, respectively. Proteinuria, recent macroscopic hematuria, mesangial proliferation, and extracapillary and endocapillary lesions were more frequent and more severe in HLA-DQ-positive than in HLA-DQ-negative patients. In 10 patients with acute exacerbation, endocapillary lesions and HLA-DQ and Ki-67 expression were present in 70,80 and 88%, respectively. Serum γ-IFN levels were high in the patients (2.0 ± 0.3 U/ml, n = 40), especially during acute exacerbation (3.4 ± 1.1 U/ml, n = 9). Glomerular HLA-DQ and Ki-67 expression correlated with serum γ-IFN levels (r = 0.73, p < 0.01 for HLA-DQ; r = 0.75, p < 0.01 for Ki-67). Renal biopsy specimens taken before and after prednisolone and/or urokinase therapy were available from 4 patients. There was strong reactivity to HLA-DQ in the glomerular tufts of all 4 pretreatment samples. However, HLA-DQ reactivity disappeared after treatment in 3 samples, concomitant with normalization of serum γ-IFN levels. We conclude that serum γ-IFN levels are related to glomerualr HLA-DQ and Ki-67 expression and acute exacerbation in patients with IgA nephropathy. These data suggest that γ-IFN and MHC class II antigens play an important role in the immune-mediated glomerular injury of IgA nephropathy.