Banff schema for grading pancreas allograft rejection: working proposal by a multi-disciplinary international consensus panel

Accurate diagnosis and grading of rejection and other pathological processes are of paramount importance to guide therapeutic interventions in patients with pancreas allograft dysfunction. A multi-disciplinary panel of pathologists, surgeons and nephrologists was convened for the purpose of developing a consensus document delineating the histopathological features for diagnosis and grading of rejection in pancreas transplant biopsies. Based on the available published data and the collective experience, criteria for the diagnosis of acute cell-mediated allograft rejection (ACMR) were established. Three severity grades (I/mild, II/moderate and III/severe) were defined based on lesions known to be more or less responsive to treatment and associated with better- or worse-graft outcomes, respectively. The features of chronic rejection/graft sclerosis were reassessed, and three histological stages were established. Tentative criteria for the diagnosis of antibody-mediated rejection were also characterized, in anticipation of future studies that ought to provide more information on this process. Criteria for needle core biopsy adequacy and guidelines for pathology reporting were also defined. The availability of a simple, reproducible, clinically relevant and internationally accepted schema for grading rejection should improve the level of diagnostic accuracy and facilitate communication between all parties involved in the care of pancreas transplant recipients.

Guidelines for the diagnosis of antibody-mediated rejection in pancreas allografts-updated Banff grading schema

The first Banff proposal for the diagnosis of pancreas rejection (Am J Transplant 2008; 8: 237) dealt primarily with the diagnosis of acute T-cell-mediated rejection (ACMR), while only tentatively addressing issues pertaining to antibody-mediated rejection (AMR). This document presents comprehensive guidelines for the diagnosis of AMR, first proposed at the 10th Banff Conference on Allograft Pathology and refined by a broad-based multidisciplinary panel. Pancreatic AMR is best identified by a combination of serological and immunohistopathological findings consisting of (i) identification of circulating donor-specific antibodies, and histopathological data including (ii) morphological evidence of microvascular tissue injury and (iii) C4d staining in interacinar capillaries. Acute AMR is diagnosed conclusively if these three elements are present, whereas a diagnosis of suspicious for AMR is rendered if only two elements are identified. The identification of only one diagnostic element is not sufficient for the diagnosis of AMR but should prompt heightened clinical vigilance. AMR and ACMR may coexist, and should be recognized and graded independently. This proposal is based on our current knowledge of the pathogenesis of pancreas rejection and currently available tools for diagnosis. A systematized clinicopathological approach to AMR is essential for the development and assessment of much needed therapeutic interventions.

Molecular profiling in IgA nephropathy and focal and segmental glomerulosclerosis

The aim of the study was to characterize by molecular profiling two glomerular diseases: IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS) and to identify potential molecular markers of IgAN and FSGS progression. The expressions of 90 immune-related genes were compared in biopsies of patients with IgAN (n=33), FSGS (n=17) and in controls (n=11) using RT-qPCR. To identify markers of disease progression, gene expression was compared between progressors and non-progressors in 1 year follow-up. The results were verified on validation cohort of patients with IgAN (n=8) and in controls (n=6) using laser-capture microdissection, that enables to analyze gene expression separately for glomeruli and interstitium. In comparison to controls, patients with both IgAN and FSGS, had lower expression of BAX (apoptotic molecule BCL2-associated protein) and HMOX-1 (heme oxygenase 1) and higher expression of SELP (selectin P). Furthermore, in IgAN higher expression of PTPRC (protein-tyrosine phosphatase, receptor-type C) and in FSGS higher expression of BCL2L1 (regulator of apoptosis BCL2-like 1) and IL18 compared to control was observed. Validation of differentially expressed genes between IgAN and controls on another cohort using laser-capture microdissection confirmed higher expression of PTPRC in glomeruli of patients with IgAN. The risk of progression in IgAN was associated with higher expression EDN1 (endothelin 1) (AUC=0.77) and FASLG (Fas ligand) (AUC=0.82) and lower expression of VEGF (vascular endothelial growth factor) (AUC=0.8) and in FSGS with lower expression of CCL19 (chemokine (C-C motif) ligand 19) (AUC=0.86). Higher expression of EDN1 and FASLG along with lower expression of VEGF in IgAN and lower expression of CCL19 in FSGS at the time of biopsy can help to identify patients at risk of future disease progression.

Mycophenolate Mofetil Ameliorates Accelerated Progressive Nephropathy in Rat

BACKGROUND

Renal ischemia and hypertension have been suggested to be involved in the progression of renal diseases. Recently, we developed a model of accelerated major histocompatibility complex-independent renal injury, where high-renin hypertension aggravates functional and morphological changes induced by ischemia/reperfusion (I/R). In this model, we evaluated the effect of immunosuppressant mycophenolate mofetil (MMF) to test its capability to slow the progression of accelerated nephropathy.

METHODS

34 anesthetized uninephrectomized hypertensive transgenic (mREN2)27 rats (TGR) received a clamp on the renal pedicle for 45 min. Animals were treated with MMF 10 mg/kg/day (n = 10), 20 mg/kg/day (n = 10) or placebo (n = 10) orally via gavage for 12 weeks. Four animals were sham operated and not treated. Proteinuria and blood pressure were evaluated throughout the experiment. At the end of the experiment, kidney function was evaluated and kidneys harvested for morphological analysis and immunohistochemistry (CD4+, CD8+ lymphocytes and specific rat monocyte/macrophage marker ED-1+ cells).

RESULTS

At week 12, both MMF-treated groups had lower proteinuria as compared to the placebo group (MMF 10: 22.4 +/- 9.8, MMF 20: 20.9 +/- 5.6 vs. 126.7 +/- 35.8; p < 0.01; sham 28.1 +/- 1.4 mg/day) and reduced glomerulosclerosis (MMF 10: 11.4 +/- 7.8, MMF 20: 5.2 +/- 2.7 vs. 20.9 +/- 10.9; p < 0.05; sham 15.7 +/- 9.2%). There were no differences in systolic blood pressure among groups. MMF-treated rats had lower CD4+ (MMF 10: 61.2 +/- 46.4, MMF 20: 29.3 +/- 18.2 vs. 125.3 +/- 42.8; p < 0.01, sham 84.9 +/- 6.1 cells/field of view) and CD8+ (MMF 10: 13.7 +/- 10.2, MMF 20: 10.0 +/- 8.1 vs. 37.8 +/- 14.3; p < 0.01; sham: 31.8 +/- 7.6 cells/field of view) lymphocytes infiltration and ED-1 macrophages infiltration (MMF 10: 5.5 +/- 6.4, MMF 20: 2.5 +/- 2.8 vs. 16.7 +/- 4.1; p < 0.01; sham 12.2 +/- 4.6 cells/field of view) than placebo-treated rats.

CONCLUSION

Our results thus support the hypothesis about the key role of immune mechanisms in progression of chronic nephropathies.

Detection of HLA-G on human extravillous cytotrophoblast and skeletal muscle with a new monoclonal antibody MEM-G/1

Using immunohistochemistry with the newly available monoclonal antibody MEM-G/1 the reaction patterns on frozen and formaldehyde-fixed paraffin-embedded sections on human placentas, lymph nodes, skeletal muscles, and kidney and liver allografts were compared. HLA-G (a nonclassical major histocompatibility complex class I molecule that is assumed to influence the immune response during pregnancy and some pathological conditions) was found within human extravillous cytotrophoblast but not within villous cytotrophoblast and placental mesenchymal tissue. No HLA-G expression on human lymph nodes, tonsils, and kidney and liver allografts was demonstrated. However, HLA-G expression was observed in all samples of skeletal muscle. The binding capacity of monoclonal antibody MEM-G/1 provides new possibilities to study physiological and pathophysiological roles of HLA-G in humans.

[Cutaneous sarcoidosis during pegylated interferon alpha and ribavirin treatment of chronic hepatitis C--a case report]

Interferon-induced sarcoidosis is well documented. We report a case of sarcoidosis in a patient with hepatitis C virus infection treated with pegylated interferon alpha and ribavirin. The patient developed cutaneous sarcoidosis about 6 months after beginning of the combination therapy. Spontaneous regression of the lesions was noted after discontinuation of the treatment. Interferon-alpha is known to stimulate T helper cells with a TH-1 profile immune response, which is the key immunologic event of a sarcoid granuloma formation. In addition to its antiviral action, ribavirin also enhanced the TH-1 response. Incidence of drug induced sarcoidosis may be underreported, because many symptoms of sarcoidosis mimic the side-effects of interferon as fever, myalgias, arthralgias, fatigue and symptoms of pulmonary diseases.

[Helicobacter heilmanii, a spiral bacterium, in gastric mucosa biopsies]

Interest in possible microbiological causes of gastritis has increased significantly since the discovery of Helicobacter pylori (Hp). Recently a spiral bacterium named Helicobacter heilmannii (Hh) was described in association with chronic gastritis in adult and pediatric patients. Comparisons between these two organisms, as well as the literature on Hh, have also been reviewed. The incidence of Hh gastritis is far lower than that of Hp gastritis. Concomitant infections by Hh and Hp are very rare. It is very probable that Hh gastritis is transmitted from domestic animals or pets to humans. The frequency of Hh gastritis (11/6059 cases, 0.18%) in authors' material was similar to that reported in Western Europe. The role of touch cytology has been becoming more and more significant recently in the diagnosis of mucosal infections of the GIT.

Correlation of FNAB with histology in human liver allografts. Regional experience

OBJECTIVES

A total of 43 FNABs, corresponding blood specimens and conventional biopsies from 39 adult liver allograft recipients were analysed. The purpose of the present study was to determine whether results obtained by cytological and histological examination were concordant at the monitoring of liver allograft rejection within the first 5 weeks of the posttransplant period.

RESULTS

When histology in 14 cases showed rejection, rejection was diagnosed in 12 out of 14 FNAB specimens. When in other 14 cases the rejection was absent histologically, FNAB was negative in 10 out of those 14 specimens (sensitivity 85.7%, specificity 71.4%). Cholestasis was demonstrated in biopsy and FNAB specimens with sensitivity 83% and specificity 86%.

CONCLUSION

FNAB is a useful method for diagnosis of acute rejection in liver allograft during the early posttransplant period, as well as for evaluation of cholestasis. Results obtained by FNAB correlated well with results obtained by core-needle biopsy.

[Recurrent polyomavirus infections in kidney transplants (BK virus nephropathy)]

BK-virus nephropathy was recently recognised as a new complication that affects renal allografts and causes dysfunction. We report a case of a recipient of simultaneous kidney-pancreas allografts. Fourteen months after the transplant, the renal allograft became dysfunctional with elevation of serum creatinine level. The diagnosis of BK-virus nephropathy was established by needle renal biopsy with immunohistochemical detection of human polyoma virus. Immunosuppressive therapy was reduced but progressive dysfunction developed and the patient had to undergo a renal retransplantation 11 months after the diagnosis of the infection. Due to repeated renal dysfunction, needle biopsy was performed, and the diagnosis of repeated BK-virus nephropathy was established six months after the retransplantation. The pancreas allograft has functioned well for the entire period.

[Biliary (cholestatic) complications in the liver graft biopsy samples early after transplantation]

During the first three months after a liver transplant, cholestasis of various type and degree represents 1 of the most frequent morphological findings in liver graft biopsies. The morphology of cholestasis is typical for all conditions with bile duct impairment but also for other conditions with more severe impairment of hepatocytes, including rejection and recurrence of viral hepatitides. Histological diagnosis represents the gold standard in addressing liver graft dysfunction causes, and in the majority of cases it allows for distinguishing between the main categories of diseases resulting in cholestasis. Usually a combination of various changes can be identified as a cause of the liver graft dysfunction early after transplantation. Therefore, the interpretation of limited morphological characteristics, which usually represent a certain type of tissue reaction, not the cause, is complicated. The close cooperation between the hepatologist and pathologist has become a necessary prerequisite for the best possible interpretation of the morphological conclusion.

[Acute humoral rejection of renal transplant]

Acute humoral rejection (AHR) is a rare complication which often results in the loss of kidney graft. The objective of this retrospective monocentric study was to evaluate two different approaches to AHR. Documentation of 730 patients was analysed, who underwent renal transplantation between 2002 and 2005. From 2002 to 2003, patients with AHR were treated with 5 plasmaphereses (PF group, n = 13), and from 2004 to 2005 with a combination of 5 PF and intravenous immunoglobulins (PF + IVIG, 0.5 g/kg, n = 8). Data for the period of one year post-transplant was analysed. AHR occurred in 21 out of 730 patients (2.9%). Survival of grafts in the 6th month and in the 1st year was significantly higher for the PF + IVIG group than for the PF group only (p < 0.05). Patient survival was similar in both groups. The incidence of infectious complications was similar in both groups. There was a higher incidence of acute cellular rejections in the PF group (46.2 vs. 14.3%) in control rebiopsies (performed due to deteriorated graft function or in order to check the efficiency of the treatment). It can be concluded that acute humoral rejection of transplanted kidney is a rare complication which can be treated by the combination of plasmaphereses and intravenous immunoglobulins.

Long-term outcome of patients with idiopathic membranous nephropathy

Although idiopathic membranous nephropathy (iMN) is a common glomerular disease, its therapy still remains controversial. The aim of our study was to analyse the outcome of patients with iMN diagnosed and treated in our center. We retrospectively studied 82 patients with iMN that were diagnosed between January 1991 and June 2002. The group consisted of 57 males (69.5%) and 25 females (30.5%) with a mean age of 53 years. The mean follow-up was 56 +/- 38 months. Remission was achieved in 59.2% of patients treated with chlorambucil, 71.4% treated with cyclophosphamide, 85.7% treated with cyclosporine and in 71.4% of those who were left untreated intentionally. However, the proportion of patients in the different treatment subgroups differed significantly (60% vs. 8.5% vs. 8.5% vs. 23%, respectively). The relapse rate was 31.3%. The second-line treatment was effective in a majority of the patients. At the end of follow-up, almost 70% of the patients were in remission with the parameters of nephrotic syndrome significantly improved and renal function unchanged. The renal survival was 100%. Immunosuppressive therapy is effective in iMN, but spontaneous remissions occur as well. Although relapses are frequent, almost 70% of the patients were in remission at the end of follow-up. The renal survival in our group of iMN patients was very good, probably due to preserved renal function at diagnosis.

[The Churg-Strauss syndrome with rapidly progressive glomerulonephritis positive for antineutrophil cytoplasmic antibodies]

Renal failure developed in a patient treated for worsening spastic dyspnoea, high erythrocyte sedimentation rate and enlarged peribronchial lymph nodes by the antituberculotic regimen. Renal biopsy disclosed rapidly progressive glomerulonephritis with 95% crescents, granulomatous periglomerulonephritis vasculitis and eosinophilic interstitial infiltrates. On the basis of the positivity of antineutrophil cytoplasmic antibodies (ANCA), eosinophilia and profound ventilatory impairment the diagnosis of Churg-Strauss syndrome was established. The patient was treated by plasma exchanges and combined immunosuppression with the profound effect on erythrocyte sedimentation rate, eosinophilia a negativization of ANCA and preservation of at least minimal renal function. Further therapy was complicated by steroid diabetes, repeated leucopenia and exacerbation of spastic bronchitis and eventually by the massive gastrointestinal haemorrhage from asymptomatic gastric ulcer. There were no signs of inflammation in renal autopsy specimens with prevailing glomerulosclerosis a periglomerular fibrosis. Renal impairment is rare in Churg-Strauss syndrome and it is only exceptionally the cause of renal failure.

BK-virus nephropathy and simultaneous C4d positive staining in renal allografts

The role of antibodies in rejection of transplanted kidneys was the subject of debate at the last two Banff meetings and in medical journals. Diffuse C4d positive staining of peritubular capillaries (PTCs) was recognized as a marker of antibody-mediated rejection and this morphological feature was included in the updated Banff schema. At the same time polyomavirus infection of the renal allografts has been reported more frequently and is emerging as an important cause of renal allograft dysfunction and graft loss. At the present time, BK-virus nephropathy (BKN) represents the most common viral disease affecting renal allografts. BKN was identified in 6 patients in 12 biopsies and 2 graft nephrectomy specimens of 1115 biopsies between September 2000 and December 2003. Definite virus identification was done by immunohistochemistry. The reason for graft nephrectomies was graft failure due to BKN in a recipient after kidney-pancreas transplantation with good function of his pancreas graft and the necessity of continuing immunosuppression. Detection of C4d deposits was performed by immunofluorescence or by immunohistochemistry. In graftectomy samples C4d detection was performed by immunohistochemistry and retrospectively in all cases of BKN. Focal C4d positive PTCs and BKN were found simultaneously in 9 of 12 needle biopsies and in both graft nephrectomy samples. Detection of C4d by immunohistochemistry disclosed focal C4d positive staining in kidney tissue but diffuse in the sites where BK-virus inclusions in tubular epithelial cells were found. The complement system is part of the host defense response and is crucial to our natural ability to ward off infection. In cases of BKN, virus likely gains access to the bloodstream through injured tubular walls and via PTCs. Vascular endothelium in the PTCs represents a potential target antigen for alloresponse, and simultaneously possibly represents an imprint of complement activation or complement production in the places with BK-virus infection.

[The risk of malignancy after organ transplantation]

Improvements in immunosuppressive therapy during the past decade brought about improvements of the long term tolerance of organ allografts. However, the long-term immunosuppressive therapy has an important limitation, because it can increase the risk of cardivascular diseases, infections and tumors. As compared with age-matched healthy population, organ-transplant recipients have an increased incidence of tumors.

[Transarterial chemoembolization in hepatocellular carcinoma]

INTRODUCTION

Hepatocelullar carcinoma (HCC) is the fifth most common cancer in the world. It mostly occurs in patients with cirrhosis. In the Czech Republic, about 250 new cases are reported per year. Surgery, i.e. liver resection or transplantation, as the only potentially curable method is possible in 15-20% of them. For the rest, palliative treatment is indicated. This includes ablative methods (radiofrequency ablation, alcoholization), transarterial chemoembolization (TACE), systemic chemotherapy or biological treatment by sorafenib. TACE is method of choice in patients unsuitable for surgery and ablative treatment. Another indication is embolization of HCC before liver transplantation to prevent tumour progression. In combination with other methods, down staging of the tumour and curable treatment afterward is possible.

AIMS

To assess the outcome of transarterial chemoembolisation in patients with hepatocellular carcinoma.

METHODS

Between 2004-2008 we performed 30 TACE. Of that number, 28 TACE were performed in 20 patients with HCC. We super selectively catheterized the tumour via arteria femoralis and used Doxorubicin with Lipiodol as embolic material. In follow up, we carried out laboratory studies and CT.

RESULTS

We have not noticed any major complications. Post-embolization syndrome with fever, nausea and right upper quadrant pain occurred after 10 TACE (33%). One-, two- and three years survival of the patients was 53%, 40% a 20%.

CONCLUSION

TACE is safe method prolonging patients' survival with unresectable HCC. For the correct treatment of HCC, its concentration to cancer centres and the cooperation between multiple specialists is necessary.

[Systemic amyloidoses in renal biopsy samples]

The kidneys are one of the most frequent sites of amyloid deposition during systemic AL, AA, and several hereditary amyloidoses. Distinguishing between different forms of amyloids is clinically important because of their different treatment.

MATERIAL AND METHODS

We present a 5-year retrospective study of amyloidoses diagnosed in renal biopsy samples. The classification of amyloidosis was made by immunofluorescence and immunohistochemical staining with antibodies to kappa and lambda immunoglobulin light chains, and for serum amyloid A protein.

RESULTS

From January 2003 to December 2007, 996 renal biopsy samples from one centre were evaluated. Amyloidosis was diagnosed in 62 samples (6.2%); 33 (53.2%) were classified as AL and 25 (40.3%) as AA amyloidosis. Four cases have remained unclassified. We did not identify any difference in the distribution of deposits among cases with AL and AA amyloidosis, respectively. The majority of patients underwent the renal biopsy due to severe proteinuria or nephrotic syndrome. Three patients had very low proteinuria, less than 0.5 g/day. Diagnosis of amyloidosis was suspected by nephrologists in 48 patients (77.4%).

CONCLUSION

Diagnosis of amyloidosis involves detection of amyloid deposits and classification of the amyloid form, which represent the basic step for appropriate therapy. Altogether it is not an easy task for pathologists, and with the emergence of markedly different treatments depending on the specific type of amyloid, the precise typing is of increasing clinical importance and should be performed with great care. Immunofluorescence can be very useful in daily practice for classification of the type of amyloidosis.

Effect of diets on lipoprotein concentrations in heterozygous apolipoprotein E-deficient mice

Loss of apolipoprotein E synthesis causes increased serum cholesterol concentrations and the sensitivity to high-fat diet in mice. We analyzed the changes in lipoprotein and hepatic structures in apolipoprotein E-deficient mice kept on control diet and cholesterol diets. Basal cholesterolemia of heterozygous (+/-) mice (2.2+/-0.28 mmol/l) was the same compared to wild-type (+/+) mice (2.3+/-0.15 mmol/l), but was lower compared to homozygous (-/-) mice (10.3+/-1.40 mmol/l). In +/- mice, cholesterolemia rose to 3.2 mmol/l on cholesterol diet and to 9 mmol/l on cholate diet, to 3 mmol/l and 3.6 mmol/l in +/+ mice, and to 23.4 mmol/l and 70.5 mmol/l in -/- mice, respectively. While the ratio of cholesterol/triglyceride concentrations in VLDL, IDL and LDL fractions was not increased in +/- mice and +/+ mice, it was increased in -/- mice on control diet. On the cholesterol diet, this ratio rose and was dramatically increased by cholate diet in all groups of mice. Even though cholate supplementation increased cholesterol concentration, it led to substantial toxic changes in hepatic morphology of all animals. In conclusion, one functional apo E allele in +/- mice is effective in keeping serum cholesterol concentrations in normal range on a control diet, but not on the cholesterol and cholate diets.