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.

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.

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.

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.

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.

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.

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.

Renal amyloidosis. Histological differentiation based on chemical types compared to Reimann's classification.

13 cases of renal amyloidosis were reclassified on the basis of the chemical types of the major amyloid fibril proteins. The classification (primary, secondary) depending on the absence or presence of a coexisting disease was found not to correlate with the classification based on the chemical types (AL, AA). It is concluded that in association with a disease capable of inducing amyloidosis amyloid of type AA does not necessarily appear. The deposited amyloid may be of AL type. No difference of decisive importance between the AL and the AA type was observed concerning the tissue distribution of the amyloid within the kidney. With respect to the cause of death, however, a significant difference was found between the chemical types. In amyloidosis of AA type, the cause of death was always renal insufficiency, whereas in the cases of AL type cardiac or hepatic insufficiency led to death. Differentiation of the types of amyloid proteins has gained practical importance, as it offers the possibility of selective therapeutic approaches. Their routine differentiation is possible with the potassium permanganate method.

Application of the immunoperoxidase technique to formalin fixed, paraffin embedded kidney biopsies.

Different immunohistological methods were compared in 30 renal biopsy cases. The direct immunoperoxidase method gave identical results with immunofluorescence in 88% concerning IgG and C3, while IgA, IgM and fibrinogen have been identically detected by the PAP method in 82%. The non-identical results of the direct method consisted, with one exception, of negative readings, while the non-identical PAP readings were positive with two exceptions. Thus the trypsin-immunoperoxidase method proved to be well applicable on paraffin embedded formalin fixed material. In 10 cases the HRP-labelled direct method was applied also to fresh, frozen sections. It gave almost entirely identical results to immunofluorescence.

[Heparan sulfate proteoglycan distribution in the glomerular basal membrane in human glomerulonephritis]. / Heparánszulfát-proteoglikán eloszlása a glomerulus basal membranjában emberi glomerulonephritisben.

Authors studied the dispersion of immunoreactive HSPG with monoclonal antibody specific to protein nucleus of HSPG in renal diseases associated with nephrosis syndrome. Their results showed that the dispersion of HSPG in GBM does not fully agree with dispersion of anion linkage places known in literature. In membrane and diffuse proliferative lupus glomerulonephritis immunoreactive HSPG cannot be demonstrated in the place of immune deposits, concurrent with dispersion of anion places, while it appears in GBM newly developed round the deposits. Inconsistent with this, in glomerulonephritis having minimal changes, the anion loss of GBM is not associated with absence of nuclear protein, the immunoreactive HSPG remains intact. These observations reflected in literature indicate that--similarly to proteinuria--presumably, deficiency of anion linkage places of GBM is caused by different pathomechanisms.

[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.