C3 Deposition in IgA Nephropathy in Children and Adolescents

The aim of this study was to assess the significance of C3 deposition in IgA nephropathy in children and adolescents. One hundred and two patients aged 5–21 years (57 male and 45 female) were studied. The findings of C3 deposition were classified into 8 groups by immunofluorescent (IF) pattern and intensity as follows: group MC3+ (N = 12): mesangiocapillary pattern and 3+ in intensity; group MC2+ (N = 13): mesangiocapillary and 2+; group MC1 + (N = 4): mesangiocapillary and 1 +; group M3+ (N = 11): mesangial and 3+; group M2+ (N = 24): mesangial and 2+; group M1 + (N=18): mesangial 1 +; group S (N = 12): only segmentally positive; and group N (N = 8): negative. Histological changes were scored semiquantitatively as an activity index (cellular proliferation, necrosis, interstitial cell infiltration, and cellular crescents) and a chronicity index (mesangial sclerosis, segmental and global glomerular sclerosis, fibrous crescents, adhesion and tubulo-interstitial change). IF findings were scored semiquantitatively and laboratory findings were also studied. The following results were obtained: 1) The scores of total activity index in MC groups were higher than in the M, S or N groups, and the greater the degree of C3 deposition, the higher the score; 2) Such result was not evident in the chronicity index; 3) High IF scores of IgG and IgM were found in the MC3+ and MC2+ groups; 4) Hematuria was more severe in MC3+ and MC2+ than in other groups, and proteinuria was more prominent in the MC than other groups. Thus the degree of C3 deposition was parallel with histological activity and urinary findings.     

Pattern of renal dysfunction in analgesic nephropathy--comparison with glomerulonephritis.

Comprehensive renal function tests were performed in 84 patients with analgesic nephropathy, 33 glomerulonephritis patients matched for creatinine clearance, and 30 control subjects. A system of 1-day renal function tests including urine microscopy, creatinine clearance, phenolsulphonphthalein excretion, urine concentration and acidification, and electrolyte excretion, was used. Patients with analgesic nephropathy were found to have significant sterile pyuria and haematuria, even those with mild renal insufficiency, significantly reduced concentrating ability and a distal acidifying defect, and a tendency to impaired sodium conservation. These function defects are consistent with the primary lesion of renal papillary necrosis in analgesic nephropathy; the detection of these defects have implications in patient management.     

IgA肾病大鼠血清IgA-纤维连接蛋白的检测及意义

目的 检测IgA肾病大鼠血清IgA-纤维连接蛋白水平，探讨其在IgA肾小球系膜沉积中的作用。方法 肝叶切除后，尾静脉注射脂多糖，制作IgA肾病大鼠模型。应用ELISA法检测血清IgA-纤维连接蛋白聚合物水平，半定量法对系膜IgA免疫荧光强度评分，二者作相关性分析。结果 IgA肾病时，血清IgA-纤维连接蛋白聚合物水平升高，并与系膜IgA沉积呈正相关。结论 IgA肾病时，血清IgA-纤维连接蛋白聚合物水平是升高的，且可能是导致IgA系膜沉积的原因之一。     

补体对免疫沉淀的抑制作用与小儿肾脏疾病的关系

以辣根过氧化物酶（PO）和抗-PO作为免疫沉淀中的抗原和抗体，用光电比色法，对78例小儿肾脏疾病血清补体对免疫沉淀的抑制作用（IIPC）进行了研究，并同时检测补体成分C3、C4。结果，正常对照IIPCOD值为0．505±0．085，急性肾小球肾炎（0．137±0．108）显著降低（P＜0．001）；慢性肾小球肾炎（0．470±0．053）改变不明显（P＞0．05）；肾病综合征（0．401±0．038）明显低下（P＜0．05）。IIPC低下的发生率依次为急性肾小球肾炎（83％）、肾病综合征（43％）、慢性肾小球肾炎（32％）。表明小儿肾小球疾病时IIPC大多降低并与疾病的活动性有关。因此认为IIPC低下在肾脏病的发生和发展中起一定作用。     

A study of factors governing fluid filtration in the diabetic foot

Abstract. The effect of lowering the foot on the factors governing fluid filtration in the foot were studied in 12 male insulin-dependent diabetic subjects and 10 controls. Toe skin blood flow, measured by laser Doppler flowmetry, was significantly higher during dependency in the diabetic group. In the control subjects, the colloid osmotic pressure of venous blood sampled from the foot rose to 47·7 mmHg (range 45·1–53·8) after 50 min of foot dependency. In the diabetic group, colloid osmotic pressure failed to rise to the same extent (median 36·7 mmHg; range 28·6–43·0; P < 0·001). Capillary pressure, measured directly by the Landis microinjection technique, was significantly higher in the diabetic group (85·3±1·7 ( n = 6) vs. 92·2±4·6 cm H₂O ( n = 6); P < 0·007), as was foot swelling rate determined by mercury strain gauge plethysmography (0·069±0·022 vs. 0·099±0·025 ml min^-1 100ml^-1; P < 0·02). These results suggest an impairment of the oedema-preventing mechanisms in diabetic subjects which may contribute to the risks of ulceration in the diabetic foot.     

Activation of mRNA expression of collagen,collagenase and its inhibitor on renal biopsy specimens in patients with IgA nephropathy

Summary: In situ hybridization of mRNA for collagen IV, collagen VI, stromelysin (MMP-3) and TIMP1 was examined in renal biopsy specimens from patients with IgA nephropathy (IgAN) or diabetic nephropathy with various degrees of tissue damage. The majority of cells in the glomeruli expressed these mRNA almost simultaneously, but a few cells demonstrated positive expression for only one of these probes. There was a parallel relationship between the degree of tissue damage and that of mRNA expressions of these probes in patients with IgAN, while patients with diabetic nephropathy showed a reverse relationship between these two parameters. It is concluded that patients with mesangial proliferative glomerulonephritis expressed mRNA for collagen collagenase and its inhibitor in the glomeruli in parallel with the progress of tissue damage. In contrast, glomerular samples from patients with diabetic nephropathy showed that there was an inverse relationship between tissue damage and expression of mRNA. It is concluded that expression of collagen, collagenase and its inhibitor parallels the progression of glomerular changes in IgAN, but such parallel expression was not observed in patients with diabetic nephropathy.     

Sequential occurrence of IgA nephropathy and Henoch-Schönlein purpura: support for common pathogenesis

We report a patient who developed Henoch-Schönlein purpura (HSP) 13 years after he presented with IgA nephropathy (IgAN). In both HSP and IgAN renal biopsy most commonly reveals focal proliferative glomerulonephritis on light microscopy and immunofluorescence displays mesangial IgA deposits. In addition, patients with HSP or IgAN have elevated serum IgA levels, circulating IgA immune complexes, IgA-bearing lymphocytes, immunoglobulin-producing cells, and binding of IgG to glomerular components of similar molecular weight. The occurrence of both diseases in the same patient or the same families and the presence of immune abnormalities compatible with HSP or IgAN in relatives of patients with these diseases suggest a common pathogenesis.     

Increased recognition of IgA nephropathy in African-American children

Based upon the percentage of cases of IgA nephropathy (IgAN) in biopsy series, a lower prevalence has been assumed for African-Americans compared with Americans of European descent. This may be due to a racial difference in the basic underlying pathology of IgAN or to racial differences in patterns of referral and biopsy selection practices. Over the past decade (1985 – 1994), we have found similar incidences of IgAN in Caucasian and African-American children from Shelby County, Tennessee. The incidence was 3.0 cases per million per year for Caucasian and 5.7 cases per million per year for African-American children. IgAN may be more common in African-American children than previously appreciated. Population-based incidence studies will be necessary to determine whether or not our experience has become a more widespread phenomenon. Received August 21, 1996; received in revised form and accepted December 18, 1996     

Aldose reductase inhibition with imirestat — effects on impulse conduction and insulin-stimulation of Na+/K+-adenosine triphosphatase activity in sciatic nerves of streptozotocin-diabetic rats

Summary This study describes reduced motor nerve conduction velocity and increased resistance to hypoxia-induced conduction failure in sciatic nerves of rats after four weeks of streptozotocin-induced diabetes (both effects were significant at p <0.05). These changes occurred in the absence of any deficit in the steady-state ouabain-sensitive adenosine triphosphatase (ATPase) activity of sciatic nerve endoneurial homogenates. The addition of 10 nmol/l insulin to endoneurial homogenates from control animals resulted in a 34% increase in ouabain-sensitive ATPase activity and a 19% reduction in ouabain-insensitive ATPase activity (both p <0.01). This stimulation of ouabain-sensitive ATPase activity by insulin did not occur in homogenates from diabetic rats. Treating diabetic rats daily with the aldose reductase inhibitor, imirestat (1 mg/kg) improved nerve conduction velocity (p <0.05) but was without effect upon the resistance to hypoxic conduction blockade or the deficit in insulin-stimulated oubain-sensitive ATPase activity. These data suggest that in streptozotocin-diabetic rats the functional disorders of reduced motor nerve conduction velocity and increased resistance to hypoxic conduction blockade do not share a common aetiology and that impaired nerve conduction is not related to reduced maximal potential oubain-sensitive ATPase activity.