Our data suggest that EM may be a more sensitive method of detecting immune deposits as the electron dense granular material was found in the TBM of 27 cases overall compared with 12 cases by IF. routine laboratory assessment. This work was carried out in due regard for the provisions of the Declaration of Helsinki. Results A survey of renal biopsies received during a single calendar year has been carried out to assess the prevalence of immune complex deposition associated with the proximal and distal tubules. This cohort comprised 87 native renal biopsy cases diagnosed by routine histology, IF, and EM. The patients ages ranged from 23 to 85 years comprising 48% male and Rabbit Polyclonal to Gab2 (phospho-Tyr452) 52% female cases. At the time of examination, detail of any pathology affecting tubules of the kidney cortex was noted. Deposition of immune complex in proximal tubules by IF and abnormality of the TBM by EM were the main assessment criteria. Screening of all 87 cases by immunofluorescence was based on a standard antibody panel to identify IgA, IgG, IgM, KLC, LLC, C1q, C3c, and fibrinogen. Positive glomerular staining for immunoglobulin or light chain was found in 65 cases (74%) and positive staining for complement was found in 51 cases (58%). The tubules demonstrated less positive staining for both immunoglobulin/light chain and complement with only 12 cases (14%) and 11 cases (12%) respectively Orphenadrine citrate (Table 1). This staining was found either in a granular pattern with positivity randomly distributed in the cytoplasm and TBM or linear surrounding the Orphenadrine citrate tubule perimeter and corresponding to the TBM (Figure 1). Open in a separate window FIGURE 1. Immunofluorescence microscopy showing examples of staining patterns for immune deposits associated with proximal and distal tubules. (A) Granular staining of the TBM with anti-C3c (arrows) from a case of immune complex tubular Orphenadrine citrate basement membrane disease. (B) Linear staining of the TBM with anti-KLC (arrows) from a case of KLC disease. (C) Diffuse cytoplasmic staining of the epithelium with anti-LLC (arrows) from a case of lupus. (D) Focal staining of the apical cytoplasm and desquamated debris with anti-C3c (arrows) from a case of lupus. TABLE 1. Numbers of cases with positive immunostaining with corresponding EM findings. thead th rowspan=”1″ colspan=”1″ /th th rowspan=”1″ colspan=”1″ /th th align=”center” rowspan=”1″ colspan=”1″ Glomeruli IF /th th align=”center” rowspan=”1″ colspan=”1″ Glomeruli IF /th th align=”center” rowspan=”1″ colspan=”1″ Tubules IF /th th align=”center” rowspan=”1″ colspan=”1″ Tubules IF /th th align=”center” rowspan=”1″ colspan=”1″ Tubules EM /th th align=”center” rowspan=”1″ colspan=”1″ Tubules EM /th th align=”center” rowspan=”1″ colspan=”1″ Tubules EM /th th rowspan=”1″ colspan=”1″ Primary diagnosis /th th align=”center” rowspan=”1″ colspan=”1″ Cases /th th align=”center” rowspan=”1″ colspan=”1″ Immunoglobulin or light chain /th th align=”center” rowspan=”1″ colspan=”1″ Complement /th th align=”center” rowspan=”1″ colspan=”1″ Immunoglobulin or light chain /th th align=”center” rowspan=”1″ colspan=”1″ Complement /th th align=”center” rowspan=”1″ colspan=”1″ Granular deposits in TBM /th th align=”center” rowspan=”1″ colspan=”1″ Vesicular deposits in TBM /th th align=”center” rowspan=”1″ colspan=”1″ Vacuolar changes in TBM /th /thead Normal aged (within normal limits)52210051Amyloid11100010Diabetes76422241Focal and segmental glomerulosclerosis, necrotising glomeruolonephritis115511362Immunoglobulin deposition (including IgA, IgG, and IgM), Orphenadrine citrate light chain disease, immune complex tubular basement membrane disease41402966895Lupus nephritis (SLE)88811843Minimal change nephropathy50000012Scleroderma11000010Tubulointerstitial nephritis, tubular atrophy, and transplant glomerulopathy62211600Drug toxicity20000000TOTAL8765511211273114 Open in a separate window Renal biopsy cases grouped into main disease entities based on the primary diagnosis. Types of deposits seen in the glomerulus and tubules by immunofluorescence (IF) with corresponding deposits associated with tubular basement membrane (TBM) identified by transmission electron microscopy (EM). Examination by EM revealed 58 cases to have some changes evident in the TBM including deposition of vesicular, vacuolar or granular material, and/or thickening of the lamina densa region (Figure 2). Of these, only Orphenadrine citrate 12 cases had corresponding positive tubular staining for immunoglobulin, light chains, or complement by IF. Electron dense granular TBM deposits were found in 27 cases mainly with immune complex disease, SLE, and tubulointerstitial nephritis. Vesicular material was found in 31 cases spread across most groups and vacuolar changes were found in 14 cases likewise dispersed through.