Post-transplantation morphological and functional changes in kidneys from expanded criteria donors.

Introduction Despite an increase in the number of cadaver donors and overall organ transplantations, the dramatic increase in the waiting list makes it necessary to reconsider donor criteria. The authors wanted to examine whether differences could exist in the function and/or morphology of transplanted kidneys originated from expanded criteria donors (ECDs) and ideal donors 1 and 5 years after transplantation. Methods Kidney function and histopathologic findings were analyzed and compared 1 and 5 years after transplantation in 97 patients having ECD kidneys and in 178 patients who received ideal donor kidneys (IDK). Results Serum creatinine level was significantly higher (p = 0.001) and estimated glomerular filtration rate was significantly lower (p = 0.003) in patients having ECD kidneys as compared with those with IDK 5 years after transplantation. Morphological changes in the transplanted kidneys, such as tubulitis (p = 0.025) and interstitial inflammation (p = 0.002), were significantly more frequently present in patients with ECD kidneys than in those with IDK 1 year after transplantation. Conclusion Despite an absence of differences in kidney function 1 year after kidney transplantation between patients having ECD and IDK, morphological differences in the transplanted kidneys can be detected between the two groups of patients.

Side effects of the calcineurin inhibitor, such as new-onset diabetes after kidney transplantation.

New-onset diabetes after transplantation (NODAT) is one of the frequent complications following kidney transplantation. Patients were randomized to receive cyclosporine A- or tacrolimus-based immunosuppression. Fasting and oral glucose tolerance tests were performed, and the patients were assigned to one of the following three groups based on the results: normal, impaired fasting glucose/impaired glucose tolerance (IFG/IGT), or NODAT. NODAT developed in 14% of patients receiving cyclosporine A-based immunosuppression and in 26% of patients taking tacrolimus (p = 0.0002). Albumin levels were similar, but uric acid level (p = 0.002) and the age of the recipient (p = 0.003) were significantly different comparing the diabetic and the normal groups. Evaluation of tissue samples revealed that acute cellular rejection (ACR) and interstitial fibrosis/tubular atrophy (IF/TA) were significantly different in the NODAT group. The pathological effect of new-onset diabetes after kidney transplantation can be detected in the morphology of the renal allograft earlier, before the development of any sign of functional impairment.

Functional and morphological changes in kidneys from marginal donors.

Despite the increased number of cadaver donors and overall organ transplantations, we have observed a dramatic increase in the waiting list. We evaluated transplantations performed using marginal (n = 63) and "ideal" or optimal donors (n = 86). Donor and recipient functional and histopathological data were studied at 1 and 5 years after transplantation. Among the marginal donor group, we investigated whether the age or pre-existent hypertension in the donor showed a strong impact on the functional deterioration of the grafts. Twenty-three graftectomies were performed in marginal, and 39 in ideal recipients (P = .002). Evaluating graft function, at 5 years, we observed the serum creatinine level (P = .0001) and the estimated glomerular filtration rate (P = .003) are significantly different between the two groups. At this time there was a significant difference in the serum creatinine level of patients who were older than the age of 55 years compared with those who showed hypertension (P = .0003). Evaluating morphological changes in the kidneys, acute rejection episodes (P = .0004) and interstitial fibrosis/tubular atrophy (P = .002) were significantly greater among the marginal versus the ideal groups. At 1 year after kidney transplantation, despite no significant difference regarding renal function, they were significant in the histology of marginal versus ideal donor kidneys.

Treatment of subclinical injuries detected by protocol biopsy improves the long-term kidney allograft function: a single center prospective randomized clinical trial.

BACKGROUND: The long-term benefit of early treatment of subclinical disorders detected in kidney allografts by protocol biopsy is controversial. We collected 145 protocol biopsies from 113 recipients for comparison with 51 control patients in a single-center, prospective, randomized trial. METHODS: Ultrasound-guided biopsies were performed in recipients with stable renal function. Samples were taken at 3 (n=66) and/or 12 months (n=79) after transplantation. The biopsies were evaluated according to the Banff scheme, and patients were treated based on the diagnosis. Changes in glomerular filtration rate (GFR) were compared with 51 patients who were randomized as a control group. RESULTS: The findings on 38 samples (29%) were considered to be normal. Based on the pathology findings, such as subclinical acute rejection (n=23), calcineurin inhibitor toxicity (n=28), chronic rejection (n=6), and other specific pathologies (n=23), including polyoma virus nephropathy (n=2), induced treatment among 82 recipients (57%). Significantly better graft function was observed at 3-year follow-up among the biopsy group, compared with controls: GFR = 46.0 ± 13.8 vs 35 ± 15 mL/min (P=.002). The 5-year graft survival was significantly higher in the biopsy (81%) than in the control (55.6%) group (P=.0012). CONCLUSION: Early detection and treatment of subclinical pathologies improved graft function and long-term survival. Protocol biopsies were a valuable tool for posttransplantation management.

Peritubular capillary damage in acute humoral rejection: an ultrastructural study on human renal allografts.

The ultrastructural features of peritubular capillary (PC) damage was studied in 12 kidney allografts with acute humoral rejection (AHR). AHR manifested in diffuse linear PC staining for C4d, and histology consistent with Banff grade III in 7 recipients and Banff grade II in 5. Allografts with acute tubular necrosis served as controls. First biopsies (post-transplantation day 16.2 +/- 2.2): The intra-capillary exudate comprised monocytes (59%), polymorphonuclears (14%), lymphocytes (12%) and not otherwise specified mononuclears (15%). Three patterns of focal PC endothelial injury were observed: lysis, an increased rate of apoptosis and fragmentation. No correlation was found between the respective damage types and the inflammatory cell types or the Banff grades. Controls revealed endothelial swelling, detachment from basement membrane and fragmentation. Follow-up biopsies: Monocytes transformed into macrophages intra-luminally. The reparative changes comprised endothelial cytoplasmic protrusions, binucleated endothelial cells and capillary sprouts. Early transplant capillaropathy and transplant glomerulopathy were noted in 2 recipients. Literature data indicate that lysis is mediated by anti-HLA alloantibodies; apoptosis, demonstrated first in the present study, may be induced by non-HLA-type anti-endothelial antibodies. Fragmentation is caused by ischemia. Ongoing endothelial injury leads to transplant capillaropathy and transplant glomerulopathy, the characteristic lesions of chronic rejection.

The value of electron microscopy in the diagnosis of chronic renal allograft rejection.

The main causes of the late dysfunction of renal allografts are chronic rejection and chronic transplant nephropathy. Both are clinicopathologic entities, with a similar clinical presentation, but different histologic appearances. Chronic rejection is characterized by the presence of alloantigen-induced lesions (transplant arteriopathy and transplant glomerulopathy), and chronic transplant nephropathy by nonspecific sclerosing changes. The incidence of transplant arteriopathy and transplant glomerulopathy is relatively low. Electron microscopy (EM) may overcome the limitations in the histologic diagnosis of chronic rejection, because it verifies alloantigen-induced chronic microvasculopathy in the peritubular capillaries (transplant capillaropathy), and identifies transplant glomerulopathy more precisely than does light microscopy. To assess the value of EM in chronic rejection diagnosis, a retrospective search for transplant capillaropathy and transplant glomerulopathy was performed in a consecutive series of 91 biopsies performed > or = 6 months after implantation (median: 26 months, range 6-186) and the diagnoses were reclassified on the basis of the ultrastructural findings. The definitions used were: transplant capillaropathy: a peritubular capillary profile with seven or more circumferential basement membrane layers, or at least three profiles with five or six circumferential layers; ultrastructurally verified transplant glomerulopathy: thickening of the capillary wall in at least three loops in consequence of the widening of the subendothelial space by abnormal basement membrane material, and the formation of a new layer(s) of basal lamina; and chronic rejection: the presence of transplant capillaropathy and/or transplant glomerulopathy and/or transplant arteriopathy. Histologically, chronic transplant nephropathy, chronic rejection, chronic cyclosporine nephrotoxicity, glomerulonephritis, acute rejection, "suspicious" for acute rejection, and "others" were diagnosed in 37%, 34%, 21%, 19%, 57%, 30%, and 5% of the specimens, respectively. The results of EM increased the diagnosis of chronic rejection to 69% of the cases, and decreased chronic transplant nephropathy to 15%. The individual incidence of transplant capillaropathy and transplant glomerulopathy was 79% and 57%, respectively, and their cumulative incidence was 92%. Five biopsies exhibited merely transplant arteriopathy. A late dysfunction typically had more than one cause; the most frequent combination was chronic rejection and acute rejection. In conclusion, the EM search for transplant capillaropathy and transplant glomerulopathy doubled the frequency of the diagnosis of chronic rejection. Currently, the evaluation of renal allograft biopsies from recipients with a late dysfunction relies on standard light microscopy. Because light microscopy per se proved to be insensitive in the diagnosis of chronic rejection, incorporation of EM into the evaluation of late dysfunction biopsies is strongly recommended.

Adhesion molecules and rejection of renal allografts.

Despite an increasing amount of immunohistochemical and molecular biology data relating to the pathogenesis of kidney transplant rejection, the pathological diagnosis of this condition still rests on routine light microscopy. The detection of changes in expression and distribution of adhesion molecules in renal allograft biopsies may open a new era of increased accuracy of rejection diagnosis. Of the various adhesion molecule reactivities, peritubular capillary VCAM-1 staining appears to be the most specific finding for chronic rejection. This same staining reaction is seen in acute rejection, but may have less specificity in that setting.

Distribution of podocyte protein (44 KD) in different types of glomerular diseases.

The podocyte protein, 44 KD (pp44), is a podocyte-specific antigen that is selectively distributed in the cytoplasm of foot processes. It has been suggested that the pp44 antigen is associated with the cytoskeleton and helps to maintain the complex architecture of podocytes. To answer the question as to whether changes in pp44 expression are associated with changes in podocyte morphology, we investigated the distribution of the pp44 antigen in different kidney diseases. Twenty-one kidney biopsies and one nephrectomy specimen were studied by indirect immunofluorescent technique and electron microscopy. The pp44-antigen is preserved in cases associated with foot process fusion. In contrast, the antigen could not be detected in areas of capillary wall necrosis, cellular crescents or early and advanced stages of focal segmental glomerulosclerosis--even in the presence of podocytes. Our results show that the pp44 antigen is preserved in diseases associated with reversible loss of foot processes (in cases with foot process fusion associated with proteinuria). In contrast, the pp44 antigen is not detectable in the area of FSGS and cellular crescents, suggesting that in these conditions, podocytes undergo irreversible injury even if they are still present on conventional light microscopy.

Podocytes loose their adhesive phenotype in focal segmental glomerulosclerosis.

Podocytes in focal segmental glomerulosclerosis (FSGS) show injury and focal detachment from the glomerular basement membrane (GBM). We studied by immunofluorescence and light microscopy the distribution of components involved in the integrin mediated adhesion of podocytes to the GBM in one case of recurrent idiopathic FSGS which developed in a renal transplant. Two major integrin and actin distribution patterns were observed in podocytes depending on the stage of the disease. Alpha 5 integrin subunit showed a gradual loss in early FSGS and became undetectable in advanced FSGS. Alpha 3 integrin subunit and the beta 3 subunit of the vitronectin receptor lost their polarized expression and could be detected intracellularly in early FSGS, while in advanced stage both integrin subunits were mostly basally polarized. In addition staining for alpha 3 was markedly decreased but enhanced for beta 3. Most of the podocytes in early FSGS showed significant loss of filamentous actin together with a nonpolarized distribution and a transient expression of the HAR/GP90 receptor. An altered matrix composition was also seen corresponding to the newly formed GBM. Based on these results we propose that podocytes loose their adhesive phenotype in early FSGS, which may contribute to the detachment of podocytes from the GBM.

Tissue distribution of antigen(s) defined by monoclonal antibody D8/17 reacting with B lymphocytes of patients with rheumatic heart disease.

Monoclonal antibody D8/17 originally prepared by immunization of mice with B cells from a patient with rheumatic heart disease (RHD) reacts with epitopes expressed on significantly elevated proportions of B cells (10-35%) from all patients with acute rheumatic fever or rheumatic heart disease. This B cell marker does not segregate with any known HLA or DR phenotype. We have examined the reactivity of D8/17 with a broad assortment of human tissues, using indirect immunofluorescence. Strong positive reactivity of D8/17 was observed with cardiac muscle, skeletal muscle, and smooth muscle of blood vessels. Positive fluorescent staining was also noted in cell membranes of hepatocytes and cells lining bile canaliculi as well as in epithelial cells of skin, esophagus, and cervix. D8/17 mAb binding to cardiac muscle was markedly diminished by preincubation of mAb with KH B cell line originally established from an RHD patient. D8/17 mAb binding to human heart was also inhibited by preincubation with myosin and tropomyosin but not by actin. Using the D8/17 mAb in immunoblots, positive binding was noted by the antibody to recombinant type M6 protein, vimentin, and myosin. Our findings indicate that the B cell antigen reacting with mAb D8/17 may be related to contractile proteins present in heart, skeletal and smooth muscle, and may also share epitopes with some components of group A streptococci.

Cyclosporin A nephropathy: standardization of the evaluation of kidney biopsies.

An advisory board of nephropathologists with personal experience in the evaluation of biopsies from patients treated with cyclosporin A (CyA) was set up to address the following problems: 1. Definition of CyA nephropathy as seen in patients with autoimmune diseases; 2. Evaluation of the reliability and reproducibility of the diagnostic criteria for the different morphological lesions seen in CyA nephropathy; 3. Classification of the morphological lesions according to their clinical relevance; 4. Estimation of the possible progression of CyA nephropathy with continuous CyA therapy. The most frequent lesions attributable to CyA therapy in patients with autoimmune diseases are tubular atrophy, interstitial fibrosis, and arteriolar hyalinosis. All other lesions are rare. The reproducibility and diagnostic reliability is high for tubular atrophy and interstitial fibrosis, but low for arteriolar lesions even among experienced nephropathologists. The biopsies may be classified according to the severity of tubular atrophy, interstitial fibrosis and arteriolar hyalinosis with regard to their clinical relevance: In group I (within normal limits), CyA therapy can be continued; in group III (moderate-to-severe CyA-related lesions), CyA should be stopped if possible. Among group II biopsies (slight CyA-related abnormalities), no recommendation can be made in the absence of a second biopsy after a further year of CyA therapy. No clear-cut answer can be given concerning the progression of CyA-induced lesions. However, no significant progression has been found in the cases studied to date.

The localization of thromboxane synthase in normal and pathological human kidney tissue using a monoclonal antibody Tü 300.

Thromboxane, excreted in the urine in increased amounts in glomerular, vascular and tubulo-interstitial diseases, is considered to originate from the kidney. The localization of thromboxane synthase, a key enzyme of arachidonic acid metabolism, was studied in the human kidney by immunohistology using the monoclonal antibody Tü 300. In the interstitial tissue dendritic reticulum cells surrounding the tubules expressed high concentrations of the enzyme. In glomeruli the enzyme was weakly expressed in podocytes. This was confirmed by co-localization with an antiserum directed to podocalyxin, a marker of the visceral epithelial cells. In the study of various kidney diseases, massive accumulation of thromboxane synthase containing cells was observed in interstitial diseases, whereas in glomerular diseases there were no differences from normal kidney; in a case of thrombotic microangiopathy podocytes exhibited an increase in thromboxane-synthase. The thromboxane-synthase positive infiltrating interstitial cells were shown by conventional light microscopy to be mononuclear phagocytic cells. The physiological sources of renal thromboxane are dendritic reticular cells and podocytes. In interstitial renal disease infiltrating cells of the monocyte/macrophage system constitute the major site of thromboxane synthesis. In glomerular disease, a characteristic alteration of thromboxane-synthase was not found.

Failure to detect unique reactivity to streptococcal streptokinase in either the sera or renal biopsy specimens of patients with acute poststreptococcal glomerulonephritis.

Using purified group A streptokinase (SKA) as the antigen, ELISA assays were carried out on the sera of normal unaffected children, acute poststreptococcal glomerulonephritis patients (APSGN) and acute rheumatic fever patients (ARF). The results demonstrate that antibody titers to SKA increase with age in normal children and by age 8 years the vast majority of children have antibodies to SKA. APSGN patients did not demonstrate unique reactivity to SKA when compared to ARF patients either at time of onset of disease or during convalescence. Polyclonal and monoclonal antibodies to SKA which recognize both group A and C streptokinase failed to detect the presence of streptokinase in the biopsy sections obtained from ten well-documented APSGN patients. We conclude that there is no unique reactivity to group A streptokinase in the sera of APSGN patients. Furthermore, we failed to demonstrate the presence of streptokinase in the biopsy specimens of an early case of APSGN patients.

Adenocarcinoma of ceruminous glands. Ultrastructural, immunohistochemical and lectin histochemical studies.

A case of ceruminous adenocarcinoma is reported. The tumor destroyed the right pyramid, widely invaded the base of the skull and caused death shortly after the diagnosis. Distant metastases were not found by autopsy. The tumour cells reacted with epithelial markers and with the antibody against S-100 protein. Heparan sulphate proteoglycan seemed to be a good marker for detecting basement membrane ruptures and concomitant tumour invasion. Among the lectins BS-I and PNA gave the strongest reactions in the stroma. This is the first immunohistochemical and lectin histochemical report on ceruminous adenocarcinoma.

Comparative distribution of laminin and collagen types I, III and IV in transplant vasculopathy.

Composition of the extracellular matrix (ECM) was studied in transplant vasculopathy occurring in rejected renal allografts using the immunoperoxidase technique with antisera against laminin, and collagen types I, III and IV. In acute transplant vasculopathy the loose ECM network of the intima showed intense immunostaining for laminin and type IV collagen. Type III collagen was detected in the advanced acute cellular intimal proliferations, while early acute lesions did not show immunreactions. Type I collagen was not seen in significant amount. In contrast to these findings in chronic transplant vasculopathy associated with intimal fibrosis the ECM was largely composed of interstitial collagen types III and I, while staining for the basement membrane type ECM components were markedly reduced. Degradation of the matrix components with variable composition was noted in foci of mononuclear infiltrates occurring inside the fibrotic intima. These results indicate that the ECM shows a compositional change in transplant vasculopathy which is associated with the age of the lesion.

Pathogenesis of transplantation arteriopathy. Myointimal cells express HLA-DR antigens during rejection.

Arteries were investigated ultrastructurally in material from 40 needle and wedge biopsies of renal allografts, and immunohistochemically in another 10 cases with signs of chronic obliterative transplantation arteriopathy. In the early biopsies, but even in the control kidneys, thin extensions of the smooth muscle cells of the media were observed, which were in direct contact with the endothelial cells through the lamina elastica interna. These extensions may contain receptors mediating endothelial noxae to the smooth muscle cells thus initiating their proliferation, migration to the intima presumably begins in the early post-transplant period and continues until the lumen is occluded. Concomitantly, inflammatory cells (mainly macrophages, with a smaller number of CD4 and CD8-positive T lymphocytes) invade the intima. The proliferating myointimal cells, possibly having become HLA-DR-positive, may behave as antigen-presenting cells, enhancing the anti-graft immune response further, and aggravating the arterial injury.

[Pathomechanism of the development of chronic obliterative transplantation arteriopathy in human kidney allografts]. / Az idült obliteratív transzplantációs arteriopathia kialakulásának patomechanizmusa humán vese-allotranszplantátumokban.

Authors examined cells participating in intimaproliferation in transplantation arteriopathy ultrastructurally in needle and wedge biopsy material from 40 transplanted kidneys, and immunohistochemically in 10 cases. In early biopsies--even in two control kidneys--it could be observed that the smooth muscle cells of media are in direct contact with endothel cells by their small processes. Processes can fulfil a receptor function and can transmit endothel noxa to smooth muscle cells. Smooth muscle cells of media react to endothel damage caused by rejection with migration to intima and during this period they are transformed to myofibroblasts (myointimal cells). In the mean time inflammatory cells (mainly macrophages, helper and cytotoxic cells in lower number) from the lumen infiltrate the intima, and mediators, enzymes released from them can inspire smooth muscle cells to further proliferation, migration to intima and transformation to myofibroblast. To effect of mediators (gamma interferon) released from inflammatory cells, the myointimal cells during rejection will press out 2nd class transplantation antigens (HLA-DR), and as vicious circle it further aggravates immune reply to graft, causing vascular damage, intimaproliferation.

[A case of ceruminous adenocarcinoma. Ultrastructural and immunohistochemical studies]. / Ceruminális adenocarcinoma esete. Ultrastrukturális és immunhisztokémiai vizsgálatok.

Case of ceruminal adenocarcinoma is reported. Tumor was diagnosed in advance stage, and within a month following diagnosis it caused death. Tumor started from right auditory canal, undermined the pyramidal bone and infiltrated great part of right side of base of skull, narrowing great foramen to a certain extent. Metastasizes were only the right of dura. Besides electron microscopic studies, authors performed the immune-histochemical and lectin-histochemical examination of tumor the first time.