Peter C. Kolbeck

Renal Disease in Type I Glycogen Storage Disease

Although kidney enlargement occurs in Type I glycogen storage disease, renal disease has not been considered a major problem. Death from renal failure in three patients known to us prompted a study of renal function in this disorder. Of the 38 patients with Type I glycogen storage disease under our care, the 18 children under 10 years old had normal renal function. Fourteen of the 20 older patients (13 to 47 years) had disturbed renal function, manifested by persistent proteinuria; many also had hypertension, hematuria, or altered creatinine clearance. Progressive renal insufficiency developed in 6 of these 14 patients, leading to three deaths from renal failure. At the onset of proteinuria, creatinine clearance was increased in seven patients (3.05 +/- 0.68 ml per second per 1.73 m2 of body-surface area; range, 2.47 to 4.13 [normal range, 1.33 to 2.33 ml per second per 1.73 m2]). Renal biopsies were performed in three patients after an average of 10 years of proteinuria. All three biopsies demonstrated focal segmental glomerulosclerosis in various stages of progression. Our data suggest that chronic renal disease is a frequent and potentially serious complication of Type I glycogen storage disease. In addition to treating hypoglycemia vigorously, physicians should monitor renal function carefully in patients with this disorder.

Hepatic transplantation into sensitized recipients Demonstration of hyperacute rejection

Hepatic transplantation into immorally presensitized patients has occasionally been performed without reported accelerated rejection. To study survival of orthotopic hepatic transplants in sensitized recipients a series of studies in rats were performed. Lewis rats sensitized by three successive skin grafts from fully allogeneic ACI strain donors then underwent orthotopic hepatic transplantation from ACI donors. Nine of ten recipients died within 4 hr with bleeding from the liver surface. By comparison, nine unsensitized recipients survived a mean of 10.7±0.5 days before succumbing with cellular rejection. Death of the sensitized recipients was not due to coagulopathy or technical failure. Histological studies of hyperacuteiy rejected livers demonstrated marked hemorrhage, edema, congestion, and necrosis within the hepatic parenchyma. There was a relative lack of cellular infiltrate compared with livers rejected by unsensitized recipients. Immunofluorescent staining showed IgG bound to perivascular tissues and sinusoids, and complement bound to perivascular tissue. Serum from presensitized, but not control, recipients showed a high titer of donor-specific, complement-dependent cytotoxic activity. It is concluded that hyperacute rejection of hepatic transplants can occur in sensitized rats and is mediated by a humoral mechanism. The immunohistopathology of this process is described.

Associations between cyclosporine therapy and interstitial fibrosis in renal allograft biopsies

No significant difference in any measure of IF was found between all CsA+ vs. CsA- patients, although both groups showed a highly significant increase in IF compared with control pretransplant donor biopsies. Similarly, no differences in tubular changes or the patterns of fibrosis were identified between CsA groups. However, since the mean interval between transplantand biopsy was significantly (p<0.04) greater for the CsA- group, measures of creatining and If were nonrmalized by the time interval between transplant and biopsy, and were stratified into biopsies obtained before or after 6 months posttransplant. By this stratification and normalization, both the baseline creatinine (P<0.01) and the degree of IF as measured by morphometry (P<0.04) were significantly higher in the CsA+ group, but only for biopsies obtained >6 months posttransplant. Evaluation of biopsies > months posttransplant normalized by interval showed no suggested differences between the CsA+ and CsA- groups in terms of creatinine levels or any measure of IF. tubular epithelial changes were not different in the CsA+ and CsA- groups within either period. These results suggest that CsA therapy is not associated with increased interstitial fibrosis in renal allografts prior to 6 months posttransplant, after which there is a signivicant increase in fibrosis relative to patients not receiving CsA.

Renal allograft cell infiltrates associated with irreversible rejection

All 74 renal transplant biopsies performed between 11/78 and 8/84 at Duke University and Durham VA Medical Centers having cellular infiltrates that could be phenotyped by immunoperoxidase labeling were examined to identify histologic and immunopathologic features which correlated with rejection. Monoclonal antibodies identifying hematopoietic cells, T cells, T helper cells, T cytotoxic-suppressor cells, macrophages, and B cells were used, and each phenotype population was graded separately based on pattern of infiltration: cortical-diffuse (CD), perviascular (PV), and cortical-aggregate (CA). Histologic and immunofluorescent studies were used to evaluate acute (humoral) and cellular types of vascular and interstitial inflammation. By univariate analysis, patients having irreversible rejection within 10 weeks postbiopsy (n=23) had significantly higher grades of both acute vascular (humoral) inflammation and Tc-s cell infiltrates in a CD pattern as compared with those who had good graft function. Multivariate (Cox regression) analysis was also performed considering biopsy changes, therapy before and after biopsy, and intervals between transplant, rejection onset, and biopsy—as well as other factors potentially affecting the biopsy or graft outcome. Of nine cell phenotype-pattern combinations, only Tc-s infiltrates in a CD pattern were associated with a significant (P<0.03) relative risk (RR) of subsequent failure from rejection (RR=8.2). When those cases with significant acute (humoral) inflammation (n=10) were excluded, the relative risk of Tc-s-CD infiltrates increased to 46.4 (P<0.04). These findings indicate that the location, as well as the number and type of cell infiltrates are critical in evaluating cellular forms of rejection, and that the extent of diffuse, cortical Tc-s infiltration on biopsy provides the greatest predictor of subsequent irreversible graft failure.

Relationships among the histologic pattern, intensity, and phenotypes of T cells infiltrating renal allografts

The evaluation of renal allograft rejection by routine histologic evaluation of transplant biopsy is often a diagnostic problem. Advances in monoclonal antibody and immunohistochemical technology have led to their application in characterizing the phenotype of peripheral blood lymphocytes in transplant recipients, as well as the infiltrating lymphocytes in renal biopsy specimens (both tissue and aspiration cytology samples). Recent reports suggest that the relative number of infiltrating T cells and the T cell phenotypic subset ratio may have some association with graft survival. However, most allograft biopsy studies have not examined the relationship of the intensity and phenotype of T cells to the histologic pattern of infiltration, while fine-needle aspiration cytology (FNAC) and peripheral blood analysis do not allow for this assessment. To examine the association of histologic pattern with the intensity and phenotype of T cell infiltrates, immunoperoxidase labeling of cells using monoclonal antibodies was evaluated in 66 renal allograft biopsies performed because of clinical suspicion of rejection. Our findings indicate that the ratio of T helper-inducer (Leu 3) cells to T suppressor-cytotoxic (Leu 2) cells is significantly lower in the pattern of diffuse renal cortex infiltration (cortical diffuse [CD] pattern) when compared with other histologic patterns (cortical aggregate or perivascular), regardless of the overall intensity of the T cell infiltrate. A significant difference in T cell phenotypes was also found among different histologic patterns as expressed by Leu 3/Leu 2 ratios and by the number of Leu 2 cells. An increase in the overall intensity of T cell infiltrate was not associated with significant changes in T cell phenotype seen in any pattern, but an increase in the intensity of the cortical diffuse T cell infiltrate was associated with a significant decrease in the Leu 3/Leu 2 ratio (P < 0.04), which was due to an increase in the population of Leu 2 cells (P < 0.002). Interestingly, increases in the intensity of either cortical aggregate or perivascular T cell infiltrates were associated with significant increases in both Leu 3 and Leu 2 cells, as well as a tendency towards higher Leu 3/Leu 2 ratios. These findings indicate that evaluation of T cell infiltrates by phenotype in renal allografts is dependent upon the pattern as well as the intensity of infiltrate.

Immunopathologic patterns of cyclosporine deposition associated with nephrotoxicity in renal allograft biopsies

Using antibody directed against cyclosporine (CsA-Ab) in an avidin-biotin-complex immunoperoxidase technique on routine formalin-fixed tissue specimens, 46 renal biopsies from CsA-treated renal allograft recipients and 23 biopsies from non-CsA-treated patients were examined to identify staining patterns potentially associated with CsA nephrotoxicity (CsA-NT). All specimens were examined independently in a masked fashion by two pathologists for the intensity of (CsA-Ab) specific staining for each of the four distinct patterns identified: diffuse interstitial staining (DIS, 0–3+); fine granular staining of tubular epithelium (FGS, 0–3+); coarse granular staining of tubular epithelium (CGS, 0–3+); and dark cellular staining of mononuclear inflammatory cells (DCS, 0–3+). Based on standard clinical criteria all CsA-treated patients were categorized according to the degree of CsA nephrotoxicity (grades 1—4).