Detection of immunoglobulins and other serum proteins in the dermal and glomerular capillary walls from patients with diabetes mellitus

Deposition of immunoglobulins or acute phase reactant (APR) proteins in the dermal and glomerular capillary walls from patients with diabetes mellitus was examined to determine whether development of microangiopathy in such patients was related to exudation and/or entrapment of these proteins. Skin and renal biopsy specimens were obtained from patients with diabetic nephropathy and diabetes mellitus without nephropathy. These biopsy samples were stained with FITC-labeled anti-human IgG, IgA, IgM, C3, APR proteins, and beta-lipoprotein antisera. Linear depositions of IgA, IgG, and/or APR proteins were observed in the dermal and/or glomerular capillary walls from some patients with diabetic nephropathy or diabetes mellitus without nephropathy. It is indicated that deposition of such immunoglobulins in the dermal and glomerular capillary walls might be due to exudation and/or entrapment of these substances in patients with diabetes mellitus.     

DETECTION OF IMMUNOGLOBULINS AND OTHER SERUM PROTEINS IN THE DERMAL AND GLOMERULAR CAPILLARY WALLS FROM PATIENTS WITH DIABETES MELLITUS

Deposition of immunoglobulins or acute phase reactant (APR) proteins in the dermal and glomerular capillary walls from patients with diabetes mellitus was examined to determine whether development of microangiopathy in such patients was related to exudation and/or entrapment of these proteins. Skin and renal biopsy specimens were obtained from patients with diabetic nephropathy and diabetes mellitus without nephropathy. These biopsy samples were stained with FITC-labeled anti-human IgG, IgA, IgM, C3, APR proteins, and β-Hpoprotein antisera. Linear depositions of IgA, IgG and/or APR proteins were observed in the dermal and/or glomerular capillary walls from some patients with diabetic nephropathy or diabetes mellitus without nephropathy. It is indicated that deposition of such immunoglobulins in the dermal and glomerular capillary walls might be due to exudation and/or entrapment of these substances in patients with diabetes mellitus.     

Detection of polymeric IgA in glomeruli from patients with IgA nephropathy.

A study on the detection of polymeric IgA in glomeruli from renal biopsy specimens in patients with IgA nephropathy is described. Renal biopsy specimens were obtained from patients with IgA nephropathy. These specimens were stained with FITC-labelled anti-human J chain antisera and then examined with a fluorescent microscope. The J chain was observed in the glomerular mesangium by immunofluorescent staining. In parallel studies, renal biopsy specimens were treated with citrate buffer (pH 3.2) and the 'eluate' was neutralized by sodium hydroxide. The eluate was labelled with iodine-125, and the radiolabelled 'eluate' was fractionated by sucrose density-gradient ultracentrifugation. Polymerized IgA in the 'eluate' obtained from patients with IgA nephropathy was found to sediment predominantly as 9S to 11S using a sucrose density gradient analysis. Polymeric IgA in the fractions of the density gradient analysis was determined by anti-human IgA and anti-human J chain antisera. It was demonstrated that IgA and J chain were eluted from the glomeruli in some patients with IgA nephropathy. It is concluded that IgA deposited in the glomeruli is composed of dimers and/or larger polymers of circulating IgA in some patients with IgA nephropathy.     

Evaluation of the staining findings of immunofluorescence in unfixed or fixed renal biopsy specimens from patients with IgA nephropathy and membranous nephropathy

A study on the evaluation of staining findings of immunofluorescence in unfixed or fixed renal biopsy specimens is described. Renal biopsy specimens obtained from ten patients with IgA nephropathy and membranous nephropathy were embedded in gelatin or paraffin matrix. Renal biopsy specimens embedded in paraffin matrix were digested with 0.05% protease. The specimens were stained with FITC-conjugated anti-human IgA, IgG, IgM or C3 antisera at 4 degrees C overnight. IgA, IgG or IgM were markedly observed in glomeruli using unfixed materials embedded in gelatin matrix or 10% neutral buffered formalin fixed materials embedded in paraffin matrix from patients with IgA nephropathy and membranous nephropathy. There was no significant difference in the intensity or distribution of IgA, IgG or IgM deposition among the two different conditions of immunofluorescence in patients with such diseases. Although the deposition of IgA using unfixed materials embedded in gelatin matrix was prominently coarse granular or lumpy in glomeruli from patients with IgA nephropathy, that of IgA using 10% formalin fixed materials embedded in paraffin matrix was fine granular and/or interrupted linear in glomeruli. It was suggested that the immunofluorescence in renal biopsy specimens embedded in paraffin matrix after digestion with protease is useful for the evaluation of immunoglobulins in glomeruli from patients with IgA nephropathy or membranous nephropathy.     

EVALUATION OF THE STAINING FINDINGS OF IMMUNOFLUORESCENCE IN UNFIXED OR FIXED RENAL BIOPSY SPECIMENS FROM PATIENTS WITH IGA NEPHROPATHY and MEMBRANOUS NEPHROPATHY

A study on the evaluation of staining findings of immunofluorescence in unfixed or fixed renal biopsy specimens is described. Renal biopsy specimens obtained from ten patients with IgA nephropathy and membranous nephropathy were embedded in gelatin or paraffin matrix. Renal biopsy specimens embedded in paraffin matrix were digested with 0.05% protease. The specimens were stained with FITC-conjugated anti-human IgA, IgG, IgM or C3 antisera at 4°C overnight. IgA, IgG or IgM were markedly observed in glomeruli using unfixed materials embedded in gelatin matrix or 10% neutral buffered formalin fixed materials embedded in paraffin matrix from patients with IgA nephropathy and membranous nephropathy. There was no significant difference in the intensity or distribution of IgA, IgG or IgM deposition among the two different conditions of immunofluorescence in patients with such diseases. Although the deposition of IgA using unfixed materials embedded in gelatin matrix was prominently coarse granular or lumpy in glomeruli from patients with IgA nephropathy, that of IgA using 10% formalin fixed materials embedded in paraffin matrix was fine granular and/or interrupted linear in glomeruli. It was suggested that the immunofluorescence in renal biopsy specimens embedded in paraffin matrix after digestion with protease is useful for the evaluation of immunoglobulins in glomeruli from patients with IgA nephropathy or membranous nephropathy. ACTA PATHOL. JPN. 35 : 315–321, 1985.     

Increase of Peripheral Blood B Cells with Fc Receptor for IgA in Patients with IgA Nephropathy

A B-cell subset with Fc receptors for IgA (B alpha cells) has been observed in human peripheral blood. To investigate aberrations of B cells in a diseased state, the percentages of B alpha cells were enumerated in peripheral blood from patients with IgA nephropathy, which is characterized by preponderant deposition of IgA-dominant immune complexes in the glomerular mesangial area. The present study showed a significant increase in B alpha cells in peripheral blood from patients with IgA nephropathy but not in those with chronic proliferative glomerulonephritis without mesangial IgA deposition. Most Fc alpha R-bearing cells were observed in surface IgA bearing lymphocytes. No linear correlation was observed between the levels of serum IgA and the percentages of B alpha cells. The addition of aggregated IgA to cultures did not induce Fc alpha R-bearing B cells in vitro. It is postulated that B alpha cells might have some pathogenetic role in the development of IgA nephropathy and that some antigenic stimuli might play a role in the increase of peripheral blood B alpha cells in patients with IgA nephropathy.     

Detection of IgA-class circulating immune complexes (CIC) in sera from patients with IgA nephropathy using a solid-phase anti-C3 Facb enzyme immunoassay (EIA)

The detection of circulating immune complexes (CIC) in sera from patients with IgA nephropathy is described. A solid-phase anti-C3 Facb enzyme immunoassay (EIA) was employed for detection of IgA-, IgG- and IgM-CIC in sera. The C1q-binding enzyme assay was also used for the detection of CIC in sera from these patients and healthy adults. Twenty-two patients with IgA nephropathy, 14 patients with other glomerular diseases and 19 healthy adults were examined by anti-C3 Facb EIA. The levels of IgA-CIC in sera from patients with IgA nephropathy were significantly higher than those in sera from patients with other glomerular diseases and healthy adults. CIC measured by the C1q-binding enzyme assay was detected in some patients with IgA nephropathy. The levels of serum IgA in patients with IgA nephropathy were significantly higher than those in patients with other glomerular diseases and healthy adults. However, there was no significant correlation between the levels of IgA-CIC in sera and those of serum IgA in patients with IgA nephropathy. There was also no significant correlation between the levels of IgA-CIC in sera and the degree of histopathological injuries in the patients. It is concluded that the solid-phase anti-C3 Facb EIA is useful for the detection of IgA-CIC in sera from patients with IgA nephropathy.     

Immunofluorescent studies on alpha 2-plasmin inhibitor (alpha 2-PI) in glomeruli from patients with IgA nephropathy.

Detection of alpha 2-plasmin inhibitor (alpha 2-PI) and/or fibrinogen in glomeruli by immunofluorescence in 26 patients with IgA nephropathy was described. The present study showed that glomerular injuries such as glomerular adhesion to Bowman's capsule and the cellular and/or fibrous crescent were predominantly observed in glomeruli with alpha 2-PI and/or fibrinogen deposits in patients with IgA nephropathy. Alpha 2-PI coexisted with fibrinogen in glomeruli from patients with IgA nephropathy. It was postulated that the deposition of alpha 2-PI in vivo might lead to the accumulation of glomerular fibrinogen deposits in patients with IgA nephropathy. It was suggested that the depositions of alpha 2-PI and/or fibrinogen in glomeruli may be one of the exacerbative factors in glomeruli from patients with IgA nephropathy.     

STUDIES ON GLOMERULAR IMMUNE SOLUBILIZATION BY COMPLEMENT IN PATIENTS WITH IgA NEPHROPATHY

A study of the solubilization of glomerular immune deposits by serum or complement in patients with IgA nephropathy is described. Renal biopsy specimens were obtained from 15 patients with IgA nephropathy. These specimens were incubated with fresh and heated sera from healthy adults or with lyophilized complement components, i.e., C3 and C4, at 37°C for one hour in plastic tubes. The sections were then stained with fluorescein isothiocyanate (FITC)-labelled anti-human IgA antisera and examined by fluorescence microscopy. Normal sera showed a marked capacity to solubilize the glomerular immune deposits characteristic of IgA nephropathy. The solubilization capacity was reduced after inactivation and absorption of sera with anti-human C3 antiserum. Lyophilized C3 or C4 did not show any ability to solubilize such deposits. It was concluded that the solubilization of glomerular immune deposits may require whole active (fresh) components of complement related to the alternative pathway. ACTA PATHOL. JPN.     

Studies on glomerular immune solubilization by complement in patients with IgA nephropathy

A study of the solubilization of glomerular immune deposits by serum or complement in patients with IgA nephropathy is described. Renal biopsy specimens were obtained from 15 patients with IgA nephropathy. These specimens were incubated with fresh and heated sera from healthy adults or with lyophilized complement components, i.e., C3 and C4, at 37 degrees C for one hour in plastic tubes. The sections were then stained with fluorescein isothiocyanate (FITC)-labelled anti-human IgA antisera and examined by fluorescence microscopy. Normal sera showed a marked capacity to solubilize the glomerular immune deposits characteristic of IgA nephropathy. The solubilization capacity was reduced after inactivation and absorption of sera with anti-human C3 antiserum. Lyophilized C3 or C4 did not show any ability to solubilize such deposits. It was concluded that the solubilization of glomerular immune deposits may require whole active (fresh) components of complement related to the alternative pathway.     

DOUBLE IMMUNOFLUORESCENCE STUDIES OF IMMUNOGLOBULINS, COMPLEMENT COMPONENTS AND THEIR CONTROL PROTEINS IN PATIENTS WITH IgA NEPHROPATHY

A study on double immunofluorescent staining of immunoglobulins, complement components, and their control proteins in renal tissues from patients with IgA nephropathy is described. Renal biopsy specimens were obtained from patients with IgA nephropathy. These biopsy specimens were stained with anti sera to human C1q, C4-binding protein, and β1H globulin by indirect immunofluorescent staining. These samples were then stained with rhodamine-conjugated anti human IgG, IgM, and IgA. Although C1q and C4-binding protein do not combine with IgA, they ubiquitously combine with IgG and/or IgM. β1H gobulin also combine with IgG, IgM and/or IgA. It was demonstrated that the complement system activated in IgA nephropathy was via both alternative and classical pathways. The presence of C4-binding protein in glomeruli appeared to be a more sensitive indicator of classical pathway activation than the presence of C4.     

Double immunofluorescence studies of immunoglobulins, complement components and their control proteins in patients with IgA nephropathy

A study on double immunofluorescent staining of immunoglobulins, complement components, and their control proteins in renal tissues from patients with IgA nephropathy is described. Renal biopsy specimens were obtained from patients with IgA nephropathy. These biopsy specimens were stained with anti sera to human C1q, C4-binding protein, and beta 1H globulin by indirect immunofluorescent staining. These samples were then stained with rhodamine-conjugated anti human IgG, IgM, and IgA. Although C1q and C4-binding protein do not combine with IgA, they ubiquitously combine with IgG and/or IgM. beta 1H globulin also combine with IgG, IgM and/or IgA. It was demonstrated that the complement system activated in IgA nephropathy was via both alternative and classical pathways. The presence of C4-binding protein in glomeruli appeared to be a more sensitive indicator of classical pathway activation than the presence of C4.     

不同性别IgA肾病患者相关临床指标及病理特点对比

目的 通过对不同性别IgA肾病患者临床指标及病理特点的对比,了解性别间相关指标的差异,为临床积极有效的治疗该病提供依据。方法 回顾性分析2017年1月1日~2018年8月30日我院经肾穿刺活检确诊的361例IgA肾病患者的临床资料,比较不同性别IgA肾病患者的临床资料、危险度分级、病理分级及免疫荧光分型。结果 不同性别IgA肾病患者年龄、病程、舒张压、水肿、血尿、蛋白尿、血尿+蛋白尿、白蛋白、IgA、IgG、IgM、IgE、C3、C4、IgA/C3、肾小球滤过率、血钾、血钙、血磷、APTT、PT、FIB、左肾及右肾大小比较,差异无统计学意义（P＞0.05）;男性收缩压、血压高、肾功异常占比、胱抑素、肌酐、尿素、尿酸、甘油三脂、胆固醇、血钠、尿蛋白定量高于女性,差异有统计学意义（P＜0.05）。不同性别IgA肾病患者在1~3级占比比较,差异无统计学意义（P＞0.05）;男性IgA肾病患者在4级占比多于女性,差异有统计学意义（P＜0.05）。不同性别IgA肾病患者病理分级比较,差异无统计学意义（P＞0.05）。不同性别IgA肾病患者在IgA+IgM+C3、IgA+IgM+IgG、IgA+IgM+IlgG+C3占比比较,差异无统计学意义（P＞0.05）;男性IgA肾病患者在IgA+IgG+C3、IgA+C3分型中占比多于女性,差异有统计学意义（P＜0.05）。结论 男性IgA肾病的发病人数多于女性,且在IgA肾病中,男性的肾功能较女性差,推测其预后可能较差,因此当男性确诊为IgA肾病后,应更加关注其临床指标及病理相关指标,及早干预、及早治疗,制定合理地个性化治疗方案,延缓其进展。     

Immunoelectron microscopy of IgA nephropathy

The distribution of IgA, IgG, IgM, C3, and albumin in kidney biopsy specimens from 11 children and adults with recurrent gross and microscopic hematuria and IgA nephropathy and 7 control specimens were evaluated by the direct peroxidase-labeled antibody method and electron microscopy. Granular masses of reaction product (RP), representing IgA, IgG, IgM, and C3, were observed within the mesangial matrix of glomeruli from all patients with IgA nephropathy. Occasional smaller masses of IgA-RP and C3-RP were noted along the peripheral glomerular capillary loops, the tubular basement membranes, and within the interstitial matrix of some patients. Large amounts of IgA-RP and C3-RP were present within the walls of small renal arterioles of several patients. These observations support the concept that immune-complex deposits are involved in the pathogenesis of IgA nephropathy and suggest that vascular deposits may have a more important role in the progression of the disease in some patients.     

血清IgA、C3及IgA/C3比值在IgA肾病诊断中的应用价值

目的：探讨原发性IgAN和非IgAN原发性肾小球肾炎患者血清IgA、C3水平和IgA/C3比值的差异及与病理Lee氏分级的相关性。方法：选择上海交通大学医学院附属新华医院肾脏内科经肾穿刺组织活检确诊为原发性IgAN患者167例与非IgAN原发性肾小球肾炎患者105例,以透射免疫比浊法测定其血清IgA和C3浓度,按Lee氏分级标准评估IgAN的病理分级。结果：①原发性IgAN患者与非IgAN原发性肾小球肾炎患者血清IgA水平分别为[（2.98±1.27）vs（2.15±0.88）g/L,P〈0.01];血清C3水平分别为[（1.11±0.27）vs（1.12±0.29）g/L,P〉0.05];IgA/C3比值分别为[（2.83±1.34）vs（2.05±1.12）,P〈0.01];②Lee氏分级为Ⅰ和Ⅱ级与Lee氏分级为Ⅲ、Ⅳ、Ⅴ级的IgAN患者血清IgA水平分别为[（2.73±0.95）vs（3.12±1.41）g/L,P〈0.05];血清C3水平分别为[（1.94±0.32）vs（1.10±0.24）g/L,P〉0.05];IgA/C3比值分别为[（2.70±1.45）vs（2.90±1.26）,P〉0.05]。③IgAN患者不同临床起病表现组间IgA、C3水平和IgA/C3比值的差异均无统计学意义。结论：血清IgA水平及IgA/C3比值可作为鉴别IgAN与非IgAN的参考指标,血清C3水平的降低程度与IgAN患者病理严重程度相关。     

Cross-reactivity of IgA antibodies between renal mesangial areas and nuclei of tonsillar cells in patients with IgA nephropathy.

A study on autoradiographical analysis of antigenic sites in patients with IgA nephropathy is described. Renal biopsy specimens were obtained from patients with IgA nephropathy. These specimens were treated with citrate buffer (pH 3.2) and the 'eluate' was neutralized by sodium hydroxide. The 'eluate' was labelled with 125iodine by the chloramine-T method. 125I-labelled eluate was then applied to the tonsillar cells obtained from the same and other patients with IgA nephropathy as well as to those with other glomerular diseases. The tonsillar cells were dipped into the emulsion (NBT-2) and then examined with a light microscope. It was demonstrated that the antibodies eluted from renal tissues of patients with IgA nephropathy specificially bound with the nuclear regions of tonsillar cells. The binding of eluted antibodies and tonsillar cells was completely inhibited by the addition of anti-human IgA antisera, but not inhibited by human IgA myeloma proteins. The eluted antibodies bound with tonsillar cells from the same patients, but only 10% of them bound with the tonsillar cells obtained from other patients with IgA nephropathy. It is concluded that IgA antibodies deposited in glomeruli specifically bind with tonsillar cells obtained from patients with IgA nephropathy and these antibodies show some heterogeneity among those patients.     

Henoch-Schonlein purpura with hemorrhagic bullae in children: report of two cases.

Henoch-Schonlein purpura (HSP) is the most common form of acute vasculitis primarily affecting children. Clinical features include skin rashes, arthritis, abdominal pain and nephritis. Skin biopsy on immunofluorescence often reveals granular depositions of immunoglobulin A (IgA) and C3 within the walls of the dermal vessels as well as in the connective tissue of the upper dermis. The diversity of skin rashes produces confusion in diagnosis of HSP, especially in the presence of bullous lesions. Bullous lesions are very rare in children with HSP, whereas they often appear in adults with HSP. We report 2 cases of HSP in whom hemorrhagic bullae manifested predominantly. In our report, the skin biopsies of both patients revealed typical leukocytoclastic vasculitis without IgA and complement depositions on direct immunofluorescence studies. Dramatic improvement of clinical symptoms and signs was observed within a few days after corticosteroids were administered. There was neither recurrence nor nephritis in these 2 patients.     

Immunopathological similarities between IgA nephropathy and Henoch-Schoenlein purpura (HSP) nephritis

A study on the immunopathological similarities between IgA nephropathy and Henoch-Schoenlein purpura (HSP) nephritis is described. Various examinations were performed as follows. (1) Pathological studies: light microscopic findings and immunofluorescent staining; (2) Measurement of the levels of IgA in pharyngeal washings and sera, and those of IgA quantitated by radial immunodiffusion; (3) Elution studies: renal biopsy specimens obtained from patients with IgA nephropathy and HSP nephritis were treated with citrate buffer (pH 3.2) and the "eluate" was neutralized by sodium hydroxide. The "eluate" was then applied to the acid-treated sections obtained from the same and other patients with IgA nephropathy as well as sections from patients with HSP nephritis and other glomerular diseases. The sections were stained with FITC-conjugated heavy chain specific antihuman IgA antisera and then examined with a fluorescent microscope. There were no differences in pathological findings of IgA nephropathy and HSP nephritis in the light microscopic and immunofluorescent examinations. The levels of IgA in pharyngeal washings and sera were significantly increased in patients with both diseases. IgA antibodies deposited in kidneys from patients with HSP nephritis crossreacted with kidneys from some patients with IgA nephropathy, and vice versa. However, antibodies from patients with IgA nephropathy and HSP nephritis did not react with normal glomeruli or other nephritic glomeruli. It is concluded that there are some immunopathological similarities between IgA nephropathy and HSP nephritis.     

IMMUNOPATHOLOGICAL SIMILARITIES BETWEEN IgA NEPHROPATHY and HENOCH-SCHOENLEIN PURPURA (HSP) NEPHRITIS

A study on the immunopathological similarities between IgA nephropathy and Henoch-Schoenlein purpura (HSP) nephritis is described. Various examinations were performed as follows. (1) Pathological studies: light microscopic findings and immunofluorescent staining; (2) Measurement of the levels of IgA in pharyngeal washings and sera, and those of IgA quantitated by radial immunodiffusion; (3) Elution studies: renal biopsy specimens obtained from patients with IgA nephropathy and HSP nephritis were treated with citrate buffer (pH 3.2) and the "eluate" was neutralized by sodium hydroxide. The "eluate" was then applied to the acid-treated sections obtained from the same and other patients with IgA nephropathy as well as sections from patients with HSP nephritis and other glomerular diseases. The sections were stained with FITC- conjugated heavy chain specific antihuman IgA antisera and then examined with a fluorescent microscope. There were no differences in pathological findings of IgA nephropathy and HSP nephritis in the light microscopic and immunofluorescent examinations. The levels of IgA in pharyngeal washings and sera were significantly increased in patients with both diseases. IgA antibodies deposited in kidneys from patients with HSP nephritis crossreacted with kidneys from some patients with IgA nephropathy, and vice versa. However, antibodies from patients with IgA nephropathy and HSP nephritis did not react with normal glomeruli or other nephritic glomeruli. It is concluded that there are some immunopathological similarities between IgA nephropathy and HSP nephritis.     

C3, C4, factor B and HLA-DR alpha mRNA expression in renal biopsy specimens from patients with IgA nephropathy.

The deposition of complement in the kidney mesangium is a constant finding associated with renal injury in IgA nephropathy, even though IgA does not bind complement. We have previously reported that complement gene expression in the kidney increases concurrently with the progression of immune complex disease in murine lupus nephritis. We have now studied the expression of C3, C4, factor B and HLA-DR alpha mRNA by in situ hybridization in renal biopsy specimens of patients with IgA nephropathy and compared these findings to those in patients with other immune-mediated diseases of the kidney, hereditary nephritis and normal kidney. In IgA nephropathy, C3 and factor B mRNA were expressed in the renal tubular epithelial cells, while no expression of either C3 or factor B mRNA was apparent in the glomerulus. Specimens from patients with other immune-mediated forms of chronic glomerulonephritis also showed a similar pattern of expression of C3 and factor B mRNA only in the tubules, but not in the glomerules. However, C3 and factor B mRNA were not found in normal kidney tissue or biopsy specimens from patients with hereditary nephritis. C4 mRNA was expressed in the tubular epithelial cells in all specimens examined, indicating that C4 mRNA is constitutively expressed in the human kidney. In IgA nephropathy HLA-DR alpha mRNA was observed in the interstitium, but not the tubules or glomerular cells. In contrast, HLA-DR alpha mRNA was present in the glomerulus and scattered in the interstitium in other immune-mediated kidney diseases. There was no expression of HLA-DR alpha mRNA in hereditary nephritis or normal kidney. Our findings, which reflect the immunopathogenic events in vivo, provide new insights as to the interpretation of the molecular immunology of this immune complex disease.