Nephropathy associated with sickle cell anemia: an autologous immune complex nephritis. II. Clinicopathologic study of seven patients

A variety of renal structural and functional abnormalities have been associated with sickle cell disease. To define the relationship between the hemoglobinopathy and glomerular disease, clinicopathologic correlations, renal morphologic, ultrastructural immunohistologic and functional studies were performed on seven patients with clinical and laboratory evidence of glomerular disease. In addition, immunologic studies including isolation and characterization of cryoprecipitable immune complexes, and determination of immunoglobulin, total complement and complement component levels, and antibody titers to several antigens were performed in an attempt to define the etiologic and pathogenic mechanisms of the renal disease and its relationship to sickle cell anemia. Proteinuria was presnet in all patients. The nephrotic syndrome, hypertension, hematuria and renal insufficiency were found in more than one half the patients. All patients had membranoproliferative glomerulonephritis of varying degree; glomerular basement membrane splitting, electron dense deposits in the glomerulus; interstitial fibrosis, tubular atrophy and hemosiderin deposits were frequent. Immunoglobulin complement components (classif complement pathway) and renal tubular epithelial antigen were distributed in a granular pattern along the glomerular basement membranes of all patients studied by these methods. Cyroprecipitable complexes of renal tubular epithelial antigen-antibody to renal tubular epithelial antigen as well as antibody to renal epithelial antigen were detected in the circulation of some patients. There was no serologic evidence of activation of the alternate complement pathway. These studies demonstrated an immune deposit normocomplementemic nephritis associated with sickle cell anemia; they further support our hypothesis that the relationship is more then coincidental, and is mediated by glomerular deposition of immune complexes of renal tubular epithelial antigen-antibody to renal tubular epithelial antigen, the antigen possibly released after tubular damage secondary to oxygenation and hemodynamic alterations related to sickle cell disease.

Endogenous immune complex nephropathy associated with malignancy I. Studies on the nature and immunopathogenic significance of glomerular bound antigen and antibody, isolation and characterization of tumor specific antigen and antibody and circulating immune complexes

Three patients with clear cell renal carcinoma and one with another intrarenal malignancy were studied for the presence of glomerular localized immunoglobulins, complement components and tumor specific antigen and antibody by immunofluorescence. To determine the association and elucidate the pathogenic mechanisms involved in the relationship between tumors and glomerular deposits, antibody eluted from tumor tissue and renal glomeruli, cryoproteins, serum antibodies and rabbit antisera to tumor tissue were tested for specificity to antigen. The relationship between tumor antigens and the lipoprotein antigen localized in normal proximal tubular brush border (RTE) and the small bowel mucosa, was studied by immunofluorescence, absorption and blocking studies as well as complement fixation. Immunoglobulins and complement components were localized in the glomeruli and tumor membrane of all patients. Sera and glomerular fixed antibody from three patients with renal cell carcinoma localized to normal proximal tubular brush border and jejunal mucosa as well as to tumor membrane and the glomeruli and proximal tubules of all of these three patients. Anti RTE activity was also detected by complement fixation. Immunologic similarity between RTE and renal cell carcinoma antigen was confirmed by absorption studies. Furthermore, cryoprecipitable complexes of tumor antigen and specific antibody were isolated from the serum. The tumor antibody was immunologically similar to RTE. In the other case the rabbit anti-tumor antibody and the patient's serum fixed to the tumor membrane and kidney of the patient but did not show cross reactivity with the renal cell carcinoma or RTE. These studies suggest that the tumor antigen in renal cell carcinoma is similar to RTE and the glomerular deposits represent tumor antigen and antibody complexes. In addition these investigations support the hypothesis that tumor immune complexes are significant in the glomerular lesions, and that the origin of renal cell carcinoma is in the proximal tubule. The investigations also show that tumor antibodies are specific for tumors of the same morphological type but not for other tumors in the same tissue. Moreover, the renal glomerulus appears to be a chosen anatomic site for deposition of tumor antigens and antibodies and studies of the kidney may provide insight into the nature of tumor antigens and antibodies. Cryoprecipitation appears to be a valuable method in isolation of tumor complexes and characterization of tumor specific antigen and antibody.

Mechanism of the formation of megamitochondria induced by copper-chelating agents. III. Formation and some biochemical properties of megamitochondria induced by diethyldithiocarbamate (DDC)

Sodium diethyldithiocarbamate (DDC), a copper-chelating agent, has induced megamitochondria in mouse hepatocytes simply by feeding the animal with a diet containing the noxious agent. Megamitochondria have been isolated from the liver, specified above, in a medium containing albumin. Phosphorylating capacities of such megamitochondria have revealed that they are tightly coupled. Biochemical properties of megamitochondria, such as cytochrome contents, activities of copper-containing enzymes. and contents of Cu2+, strongly suggest that copper-chelating action of the agent may not be related to the formation of megamitochondria just as in the case of cuprizone-induced megamitochondria. Moreover, contents of divalent metals such as Ca2+ and Mg2+ were drastically decreased in the mitochondrial preparation specified above. Similarities in biochemical aspects of DDC-induced megamitochondria to those of cuprizone-induced megamitochondria together with ultrastructural changes in the liver and clinical appearances of the mouse treated with the agent would strongly suggest that the mechanism of the formation of megamitochondria induced either by DDC or by cuprizone may be the same.