Histopathological Relevance of Angiotensin II Type 1 Receptor in Renal Transplant Biopsy

The occurrence of anti-angiotensin II type 1 receptor (AT1R) antibodies is thought to be a risk factor for transplant injury, but the relationship of AT1R to graft loss in renal transplantation has not been assessed. The aim of our study was to evaluate the expression of AT1R and its relationship with graft loss in patients who had a renal transplant biopsy for cause.

METHODS

AT1R immunoreactivity was analyzed in 170 renal transplant biopsies. Immunohistochemical evaluation of AT1R expression was performed on 4 μm-thick paraffin sections mounted on silanized slides. AT1R expression was analyzed in 5 compartments: 1. glomeruli, 2. renal blood vessels (small and intermediate arteries), 3. peritubular capillaries, 4. tubular epithelium, and 5. interstitium based on a 3-step scale.

RESULTS

Initially we checked 170 consecutive samples of biopsies for the immunoreactivity of the AT1R. The study finally included 118 renal transplant patients in 1-year observation after the biopsy. The renal allograft biopsy was performed between 6 days and 24 years after transplantation and the diagnosis was based on Banff criteria. We observed positive immunostaining of AT1R in tubular epithelium in 26.3% (42/118) of patients. A total of 7 patients had staining assessed as 2 and 35 as 1. One year post-biopsy graft loss in the AT1R (+) patients was 35.7 % (15/42) compared to 14.5% (11/76) in the AT1R (-) group (P = .008).

CONCLUSIONS

The expression of AT1R in tubular epithelium of the biopsy for cause was associated with significantly higher graft loss. The relevance of AT1R should be considered for better transplant immunological risk assessment.

Endothelin A Receptors Expressed in Renal Blood Vessels of Renal Transplant Patients Are Connected With Acute Tubular Necrosis or Antibody-Mediated Rejection

BACKGROUND

The role of non-HLA antibodies named antiendothelin A receptor antibodies is potentially significant but not established. The significance of the endothelin A receptor (ETAR) and its expression in renal biopsy has not been defined. We decided to evaluate the presence and relevance of ETARs in renal transplant biopsy for cause. The aim of our study was to evaluate the immunoreactivity of the ETAR and its significance in patients who had a renal transplant biopsy due to deterioration of transplant function (biopsy for cause) with detailed characterization of staining in small and intermediate arteries of renal transplant biopsies.

METHODS

Immunohistochemical expression of ETARs was analyzed in 162 renal transplant biopsies. Microscopic evaluation of ETAR expression (polyclonal antibody) was performed on paraffin sections. ETAR expression was analyzed in renal blood vessels (small and intermediate arteries) based on three-step scale.

RESULTS

We analyzed 154 patients who had renal allograft biopsy between 6 days and 24 years (median 597 days) after transplantation. Positive staining of ETAR in small and intermediate arteries was noticed in 9 patients. Among these patients, 4 had early biopsies (<3 months after transplantation), all developed acute tubular necrosis, and 1 developed additionally acute humoral rejection. Further, 4 patients had late biopsy (1-8 years after transplantation) and all developed characteristics of antibody mediated rejection. Lastly, 1 patient had no characteristic changes in the biopsy 4 months after transplantation. Graft loss 1 year after biopsy was higher in patients who were ETAR-positive but statistical significance was not achieved.

CONCLUSIONS

The expression of endothelin receptors in renal blood vessels (small and intermediate arteries) seems to be important in diagnosis of damage during acute tubular necrosis and antibody-mediated rejection.

The macrostructure and microstructure of the urinary bladder and urethral mucosa in dogs with lower urinary tract diseases

The aim of the study was to assess the macrostructure and the microstructure of the bladder and urethral mucosa in dogs with lower urinary tract disease as well as to evaluate the usefulness of the WHO/ISUP grading of invasive and non-invasive tumours of the bladder and urethral mucosa. The study was carried out on 37 dogs of different breeds and of both sexes, from 9 months to 15 years old. An urethrocystoscopy and a histopathological evaluation of mucosal biopsies were carried out in all the studied dogs. Cystitis was the most common disease noted during urethrocystoscopy. Chronic active inflammation of the bladder was the most common inflammatory lesion diagnosed in the histopathological examination, while the transitional cell carcinoma was the most common tumour of the bladder. Urethrocystoscopy proved to be a very useful tool in the assessment of macroscopic lesions in the bladder and urethral mucosa in dogs. We also evaluated the type and extent of microscopic inflammatory lesions in the bladder and urethral mucosa using the modified Sydney scale. The WHO/ISUP scale is very helpful in the histopathological classification of canine invasive and non-invasive proliferative lesions in the bladder and urethra.

Pathogenic role of antibodies against monomeric C-reactive protein in tubulointerstitial nephritis and uveitis syndrome

Antibodies against monomeric C-reactive protein, which is a target antigen expressed both in kidney tubules and uveal cells, have been recently detected in patients with active tubulointerstitial nephritis and uveitis syndrome. We report the case of an 65-year-old woman with acute renal failure caused by biopsy-proven tubulointerstitial nephritis and the onset of uveitis 21 months later. The expression of monomeric C-reactive protein in kidney oligobiopsy was confirmed by immunohistochemical staining using mouse monoclonal antibody against human monomeric C-reactive protein. The levels of antibodies against monomeric C-reactive protein were 117% of the reference during the flare and 22% during the remission of the disease. The difference in the levels of antibodies against monomeric C-reactive protein during flare and remission, and above all positive biopsy staining, supports their pathogenic role in this disease.

Pseudomyxoma peritonei originating from urachus-case report and review of the literature

Pseudomyxoma peritonei (pmp) is a rare clinical condition defined as extensive intraperitoneal spread of mucus associated with a variety of mucinous tumours of varying biologic behavior. Although appendix or ovaries have usually been implicated as the primary site, cases have been reported in association with neoplastic lesions of other sites. Pseudomyxoma peritonei originating from urachal remnants is a unique entity, reported only 18 times in the English literature thus far. Considering the rarity of the lesion, we report the case of a 50-year-old man surgically treated for pmp associated with a low-grade mucinous urachal neoplasm. Unique aspects of case are the low histologic aggressiveness of the causative lesion (reported only twice worldwide) and the early stage of the disease, with a relatively small amount of intraperitoneal free mucin. Review of the literature about pmp in general and a collation of previously reported cases of pmp originating from the urachus are presented and discussed.

Kidney ischemic injury genes expressed after donor brain death are predictive for the outcome of kidney transplantation

The results of deceased donor kidney transplantation largely depend on the extent of organ injury induced by brain death and the transplantation procedure. In this study, we analyzed the preprocurement intragraft expression of 29 genes involved in apoptosis, tissue injury, immune cell migration, and activation. We also assessed their influence on allograft function. Before flushing with cold solution we obtained 50 kidney core biopsies of deceased donor kidneys immediately after organ retrieval. The control group included 18 biopsies obtained from living donors. Gene expression was analyzed with low-density arrays (Taqman). LCN2/lipocalin-2 is considered a biomarker of kidney epithelial ischemic injury with a renoprotective function. HAVCR1/KIM-1 is associated with acute tubular injury. Comparison of deceased donor kidneys to control organs revealed a significantly higher expression of LCN2 (8.0-fold P=.0006) and HAVCR1 (4.7-fold, P<.0001). Their expressions positively correlated with serum creatinine concentrations after 6 months after transplantation: LCN2 (r=.65, P<.0001), HAVCR1 (r=.44, P=.006). Kidneys displaying delayed graft function and/or an acute rejection episode in the first 6 months after showed higher LCN2 expression compared to event-free ones (1.7-fold, P=.027). A significantly higher increase in expression of TLR2 (5.2-fold), Interleukin (IL) 18 (4.6-fold), HMGB1 (4.1-fold), GUSB (2.4-fold), CASP3 (2.0-fold) FAS (1.8-fold), and TP53 (1.6-fold) was observed among deceased donor kidneys compared with the control group. Their expression levels were not related to clinical outcomes: however, they showed significant correlations with one another (r>.6, P<.0001). We also observed a slightly reduced expression of IL10 (0.6-fold, P=.004). Our data suggested that increased LCN2 and HAVCR1 expression observed in the kidneys after donor brain death were hallmarks of the organ injury process. LCN2 expression level in retrieved kidneys can predict kidney transplantation outcomes.

Kidney donation from a patient with cardiac myxoma: a case report

INTRODUCTION

Renal transplantation has still become the preferred method to treat end-stage renal failure. The majority of organs are obtained from individuals with irreversible central nervous system injury. This group is nowadays unsatisfactory and small relative to the needs. A significant percentage of donors may be found among patients primarily suffering from benign neoplasms whose nature does not show malignant potential and do not metastasize. To date, there have been no reports about successful organ transplantation from an organ donor with cardiac myxoma.

AIM

The aim of this report was to present a successful transplantation of cadaveric kidney grafts from a 61-year-old female donor with a left atrial cardiac myxoma, which initially appeared as an embolic cerebral infarct. The kidney graft recipients were a 51-year-old woman and a 57-year-old man with long-lasting histories of chronic renal failure under treatment by hemodialysis. The transplant function of both kidneys has been satisfactory with a 5-year follow-up. For the present, apart from single event of acute rejection in a male recipient, the patients have maintained stable renal function. Routine accessory examinations did not reveal any changes within the kidney or other organs. To date, a renal biopsy has not been taken. Both recipients are undergoing special follow-up.

CONCLUSION

Patients with myxoma should be accepted as donors, since the risk of dying on the waiting list is greater than the tumor transfer risk. Exclusion of these potential donors decreases the donor pool and unnecessarily wastes valuable organs.

Hepatic Steatosis in Liver Transplant Donors: Rare Phenomenon or Common Feature of Donor Population?

AIM

The aim of this research was a histopathological assessment of cadaveric donor liver steatosis including: the degree (percent of involved hepatocytes) and type size of vacuoles showing fatty change by various histologic techniques.

MATERIALS AND METHODS

The study included 70 donor livers. Hematoxylin-eosin and Sudan III staining methods were used for the examination. The degree of steatosis was assessed according to the Dixon scale with the type of fatty degeneration classified into three steatotic patterns.

RESULTS

Steatosis was observed in 36/70 donor livers (51.4%) including those from 23 male (64%) and 13 female (36%) patients. The mean age of the steatotic donors was 53.7 years in contrast to the nonsteatotic donors of 45.3 years. Mild steatosis was identified in five of all sections (7.1%); mild focal and moderate zonal steatosis in 10 (14.3%), and severe, panlobular steatosis in 11 (15.3%). Fatty liver was observed as the only microscopic feature in nine cases (13%), in combination with cholestasis in 2 (2.8%); with inflammation in 5 (7%); and together with inflammation, fibrosis, and cholestasis in 20 (29%). Three types of steatotic pattern were shown: (1) small-droplet lipid vacuolization (microsteatosis) in 7/36 cases (19%); (2) large and small fat drops (macromicrosteatosis) in 8/36 (22%); and (3) typical macrosteatosis in 21/36 (59%) cases.

CONCLUSIONS

Moderate to severe steatosis is a quite frequent finding in donor livers. Donor livers with 1(0) or 2(0) steatosis as the only pathological feature can be successfully used in orthotopic liver transplantation.

Contribution of flow cytometric immunophenotyping and bone marrow trephine biopsy in the detection of lymphoid bone marrow infiltration in non-Hodgkin's lymphomas

The bone marrow (BM) is a frequent site of involvement in non-Hodgkińs lymphomas (NHL) and evidence of an infiltrated BM may implicate different therapeutical regimens. Flow cytometric immunophenotyping of bone marrow aspirates now is included in the assessment of patients with NHL and used as an adjunct to morphologic evaluation in the staging of lymphoma. The aim of the study was to compare flow cytometric immunophenotyping of BM and paraffin section staining of BM biopsies in the marrow involvement of NHL. Cytometric immunophenotyping of bone marrow and immunohistochemical paraffin section staining of bone marrow biopsies in 53 B- and T-cell lymphoma patients were performed. We used the following fluorochrom conjugated monoclonal antibodies specific for: CD3, CD4, CD5, CD7, CD8, CD10, CD19, CD20, CD22, CD23, CD79B, FMC7 and Ig kappagamma light chain. Unilateral BM trephine biopsies were obtained in all cases, fixed, decalcified and paraffin-embedded. Morphologic marrow involvement by lymphoma was found in 24 cases; flow immunophenotyping identified 26 cases with NHL: morphology-positive/flow-positive (n=21), morphology positive/flow-negative (n=3), morphology-negative/flow-positive (n=4), and morphology-negative/flow-negative (n=23). The concurrence rate of BM trephine biopsy and flow cytometric immunophenotyping in evaluation of NHL bone marrow infiltration was 88.7%. Immunophenotyping of the bone marrow of NHL patients by flow cytometry is helpful for assessment of bone marrow infiltration, especially in B-cell disorders. Both trephine biopsies and flow cytometry are better than single investigation for detection of infiltration in NHL.

Biopsy eosinophilia as a predictor of renal graft dysfunction

AIM

The aim of this research was to assess the impact of eosinophilia in renal biopsy specimens obtained during an acute rejection (AR) episode on the severity and reversibility of rejection and on long-term graft function.

MATERIAL

Among 165 renal graft recipients who underwent transplantation (Tx) in 2001 and 2002 whose biopsy specimens revealed AR, 49 with tissue eosinophilia were compared with control group of 48 without this feature. The average biopsy time was 60.6 and 95.8 days, respectively. Biopsies during delayed graft function were performed in 46.9% of patients with eosinophilia and 29% in the control group. The immunosuppressive regimen was based on tacrolimus or cyclosporine.

RESULTS

Tissue eosinophilia was observed in 49 of 165 patients (29.6%): 5 patients had eosinophilia <10/mm(2), 31 patients 10-100/mm(2), 13 patients >100mm(2) (3 patients >300/mm(2)). Severity of AR according to Banff score was statistically lower in the control group (P <.002). Patients with tissue eosinophilia who initially received steroid-free treatment presented with significantly higher (P =.02) biopsy/patients index (2.3 vs 1.81) than the total eosinophilic group. Serum creatinine values at 6 and 12 months after transplantation (Tx) were higher among eosinophilic when compared with the control group (2.41 vs 1.82 mg/dL, P <.002; 2.10 vs 1.98 mg/dL, P =.006, respectively). Chronic rejection within the first year occurred in 25% of patients with tissue eosinophilia, and 8.3% of patients in the control group. One-year graft survival rate among patients with tissue eosinophilia was lower compared with the control group (89.8% and 93.7%, respectively).

CONCLUSIONS

Biopsy eosinophilia is a negative predictor that indicates a more severe course of AR and a worse response to treatment with the threat of chronic graft dysfunction.