Objective To explore the feasibility of immunofluorescent staining (IF) in formalin-fixed and paraffin-embedded kidney tissue. Methods The formalin-fixed and paraffin-embedded renal biopsy specimens of 10 patients with membranous nephropathy, 25 IgA nephropathy and 10 lupus nephritis were selected for this study. First, the best working conditions including the deparaffinized duration with dimethylbenzene, the antigen restoring methods with enzyme or microwave, and the optimal concentrations of FITC-conjugated antibodies were investigated. Then, the direct IF was performed on the deparaffinized and antigen-restored sections (DARS) and compared to the direct IF on snap-frozen sections(SFS). Results In this study,the best deparaffinized duration with dimethylbenzene was 30 min, and the best antigen restoring method was incubation with pepsin (0.4%,pH2) for 10 min. The FITC-conjugated antibodies should be diluted to show the strongest specific fluorescence with weakest background of nonspecific fluorescence. The coincident rate of immunopathological diagnosis was 100% between the IF on the DARS and the SFS. In addition, the IF on DARS had the following benefits: easiness to judge results because of its better preserved tissue structure and clearer IF appearance; a longer IF fading time which will be propitious to observe IF results and take photographs.Conclusions The IF on DARS should become a complementary method of IF on SFS. Because the bother with long-distance transport of frozen tissue is avoided, it will be very convenient for the local hospitals to send the renal biopsy tissue to the big nephrology centers for IF examination, which has a greatly realistic significance in the current China.

Objective To analyze the clinical characteristics of renal involvement associated with antiphospholipid syndrome(APS). Methods Data of 91 cases with APS who were admitted to our hospital from 1983 to 2004 were reviewed. Results Thirteen cases (14.3%) were primary APS(PAPS) and 78 cases (85.7%) were secondary APS(SAPS) including 55 cases with systemic lupus erythematosus. Renal involvement were found in 82 APS cases (90.1%). 76.9% patients with PAPS and 92.3% with SAPS had renal involvement. The average age of renal involvement was(38±14) years old. The ratio of male to female was 1∶3.1 and the period of pre-renal damage was (4.9±6.8) years. The clinical manifestations included proteinuria (92.7%), gross hematuria (2.4%), microscopic hematuria (76.8%), hypertension (33.0%) and renal insufficiency(18.3%). Fourteen cases (15.4%)of acute renal insufficiency were caused by thrombotic microangiopathy, renal artery thrombosis, renal vein thrombosis and others. Kidney biopsy specimens were obtained from 8 patients with SLE,among them,5(62.5%)had APS nephropathy and exhibited thrombosis of renal capillaries and renal small vessels,and fibrous intimal hyperplasia of renal interlobular arteries. Onion-peeled renal interlobular arteries were also found. Concolusions Renal involvements in APS are quite common, mainly including proteinuria, hematuria and hypertension. Thrombotic microangiopathy, renal artery thrombosis, renal vein thrombosis may occur and progress to acute renal insufficiency.

Objective To analyze the pathological and clinical characteristics of patients with idiopathic IgA nephropathy accompanied by vasculitic/crescentic lesion (IgA-V/C). Methods Data of 222 patients diagnosed as idiopathic IgA nephropathy by renal biopsy, among them 87 cases with vasculitic/crescentic(V/C)lesion, from our department in 2004 were analyzed retrospectively. Clinical and pathological data from patients with IgA-V/C were compared to those of non-IgA-V/C patients and of lupus nephritis (LN) patients with V/C lesion. Results Vasculitic/crescentic lesion was found in 39.19% (87/222) patients with idiopathic IgA nephropathy.And about(14.08±12.75)% of the glomeruli was affected. It should be taken into account that there was no significant differences of clinical manifestations including blood pressure,urinary protein excretion between IgA-V/C group and non-IgA-V/C group,except serum creatinine(Scr)level which was significantly higher in IgA-V/C group. In addition, only 37.9% of IgA-V/C patients presented high Scr level,thus the lesion of V/C in idiopathic IgA nephropathy was easily overlooked. Patients with idiopathic IgA nephropathy were found to have higher percentage of glomerular sclerosis(64.86% vs 40.00%) and ratio of sclerostic glomeruli to total glomeruli [(26.98±24.68)% vs (16.10±18.80)%]as compared to LN group, which further predicated the progressing characteristics of IgA nephropathy.Conclusions Vasculitic/crescentic lesion is a quite common finding in idiopathic IgA nephropathy and often associated with no dramatically symptoms. It is possible for vasculitic/crescentic lesion to induce unmarked lose of nephron slowly and continually,so as to accelerate IgA nephropathy progression to end-stage renal failure.

Objective To investigate the role of transmission electron microscopy (TEM) on the diagnosis of cryoglobulinemia related glomerulonephritis. Methods Sixteen cases which showed glomerular organized deposits by TEM in the renal biopsy specimens were collected in our hospital during last six years. Their clinical data, renal pathological features and ultrastructural morphology were analysed. Results Four cases had positive serum cryoglobulin were diagnosed as cryoglobulinemia related glomerulonephritis. Serum cryoglobulin was not available in the other 12 cases, who were suspected as cryoglobulinemia related glomerulonephritis. All patients had proteinuria with microscopic hematuria,and some cases had nephrotic syndrome, hypertension and mild to moderate renal insufficency.The main pathological pattern was membranoproliferative glomerulonephritis.Endocapillary proliferation with an infiltration of monocytes was observed in these cases. Glomerular subendothelial deposits and intraluminal thrombi was their prominent features. Organized electron-dense deposits were identified by TEM, whose deposits organized into microtubular, fibrillary, crystalline-like and granular structures, and were demonstrated mainly in glomerular subendothelia and capillary lumen. Most of cases were considered as cryoglobulinemia related glomerulonephritis by the ultrastructural findings of glomerular organized deposits. Conclusion Glomerular organized deposits identified by TEM provide important diagnostic implications for cryoglobulinemia related glomerulonephritis.

Objective To analyze the clinical and pathologic characteristics of IgA or non-IgA mesangial proliferative glomerulonephritis associated with psoriasis. Methods Clinical and pathologic data from 6 patients suffered from IgA or non-IgA mesangial proliferative glomerulonephritis associated with psoriasis were reviewed. They were admitted to our hospital from 1983 to 2004 and diagnosed by renal biopsy. Results Two male and four female patients were average thirty-eight years old. Renal damages occurred at average sixteen years after diagnosis of psoriasis.Two patients presented asymptomatic hematuria or proteinuria, three with chronic glomerulonephritis and one with nephritic syndrome. All patients suffered from microhematuria and two from macrohematuria. The average 24 hours proteinuria was 2.05 g. Two had hypertension. All serum creatinine results were normal. Immunofluorescent examination of renal biopsy showed four cases with IgA deposited in mesangium, one with IgG deposited in mesangium, and one with negative immunofluorescent result. Microscopy examination showed three with mild and the others with moderate mesangial proliferation. No crescents and severe chronic tubulointerstitial lesions were found. Two cases showed intimal hyperplasia and stenosis of small renal arteries. Conclusions It is quite common that IgA or non-IgA mesangial proliferative glomerulonephritis in renal involvement is associated with psoriasis. Mesangial proliferative glomerulonephritis may be related to psoriasis.