Multimodal Imaging Reveals Improvement of Blood Supply to an Artificial Cell Transplant Site Induced by Bioluminescent Mesenchymal Stem Cells

PURPOSE

An artificial site for cell or pancreatic islet transplantation can be created using a polymeric scaffold, even though it suffers subcutaneously from improper vascularisation. A sufficient blood supply is crucial for graft survival and function and can be enhanced by transplantation of mesenchymal stem cells (MSCs). The purpose of this study was to assess the effect of syngeneic MSCs on neoangiogenesis and cell engraftment in an artificial site by multimodal imaging.

PROCEDURES

MSCs expressing a gene for luciferase were injected into the artificial subcutaneous site 7 days after scaffold implantation. MRI experiments (anatomical and dynamic contrast-enhanced images) were performed on a 4.7-T scanner using gradient echo sequences. Bioluminescent images were acquired on an IVIS Lumina optical imager. Longitudinal examination was performed for 2 months, and one animal was monitored for 16 months.

RESULTS

We confirmed the long-term presence (lasting more than 16 months) of viable donor cells inside the scaffolds using bioluminescence imaging with an optical signal peak appearing on day 3 after MSC implantation. When compared to controls, the tissue perfusion and vessel permeability in the scaffolds were significantly improved at the site with MSCs with a maximal peak on day 9 after MSC transplantation.

CONCLUSIONS

Our data suggest that the maximal signal obtained by bioluminescence and magnetic resonance imaging from an artificially created site between 3 and 9 days after MSC transplantation can predict the optimal time range for subsequent cellular or tissue transplantation, including pancreatic islets.

[How to improve the histopathological diagnosis of hepatocellular benign affections (adenoma versus focal nodular hyperplasia) in daily practice?]

Adenomas of the liver and focal nodular hyperplasia (FNH) are benign hepatocellular affection and their distinguishing in a needle biopsy sample and sometimes also in a surgical specimen causes often a problem. Although it might seem that the differentiation of the benign conditions is of a low value for the clinicians and also for the patients, the opposite is true. The risk of life-threatening bleeding and risk of the malignant transformation of adenomas leads to request accurate diagnosis of these conditions. New genetic methods followed by immunohistochemical detection of several antigens enables more accurate distinction not only of the two main groups of FNH and adenomas, but allows also to distinguish subsets of adenomas with varying risk of malignant transformation. Therefore, to determine the subtype of adenoma represents now essential part of a biopsy diagnosis. Identification of the subsets of adenomas allows an individualized treatment with resection in high-risk forms and, on the other hand, allows avoiding liver resection in the case of small liver mass with a low risk of malignant transformation.

Detection of Borrelia burgdorferi sensu lato in endomyocardial biopsy specimens in individuals with recent-onset dilated cardiomyopathy

AIMS

Recent studies in patients with dilated cardiomyopathy (DCM) have detected the genome of Borrelia burgdorferi sensu lato (BBSL) in endomyocardial biopsy (EMB) specimens using a qualitative polymerase chain reaction (PCR), suggesting a causal link between Lyme disease and DCM in areas in which Lyme disease is endemic. We aimed to study this relationship using a comprehensive molecular analysis detecting BBSL in EMB samples.

METHODS AND RESULTS

We performed a comprehensive histopathological, immunohistochemical, ultrastructural, and molecular analysis targeting cardiotropic viruses and BBSL in EMB specimens of 41 individuals with recent-onset DCM and 15 controls with end-stage coronary artery disease. Specifically, quantitative PCR and electron microscopy of EMB specimens were employed. In addition, autoantibodies and manifestation of autoimmune diseases were evaluated in both groups. Individuals with recent-onset DCM presented more frequently with myocardial BBSL persistence as compared with the control group (24% vs. 0%, P = 0.035). In contrast, the prevalence of parvovirus B19 and cytomegalovirus was similar in both groups. Sequence analysis of borrelial DNA revealed the following genospecies: Borrelia burgdorferi sensu stricto in three patients (30%), Borrelia afzelii in two patients (20%), and Borrelia garinii in four patients (40%), the results being inconclusive in one case. BBSL-positive DCM patients had a higher prevalence of organ-specific autoimmune diseases in comparison with the remaining DCM patients (50% vs. 16%, P = 0.030).

CONCLUSION

Myocardial persistence of BBSL may be involved in the pathophysiology of DCM in individuals living in areas in which Lyme disease is endemic.

[How to improve the histopathological diagnosis of hepatocellular carcinoma in daily practice?]

Hepatocellular carcinoma (HCC) is one of the most common cancers in the world with an increasing incidence. Recently, an East-West consensus on the histopathologic criteria for the diagnosis of high-grade dysplastic nodules and early hepatocellular carcinoma was published. In addition to classical morphological criteria such as nucleocytoplasmic ratio, thickness of cell plates, mitotic index, and architectural disturbance, a new one--the stromal invasion--was recognized as a crucial criterion for the diagnosis of early HCC. Immunohistochemical detection of glypican--3 was shown as a specific marker for HCC that can be used to distinguish between the benign hepatocellular lesions and HCC.

Glypican-3 immunostaining significantly improves histological diagnosis of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors which occur mainly in patients with chronic liver disease. Early detection of HCC is critically important for treatment of the patients. However, most early HCC cases are asymptomatic clinically with the lack of typical radiological findings. Also histological diagnosis is often very difficult with the lack of agreement even among expert pathologists.

METHODS

We studied the expression of Glypican-3 in 138 liver biopsy samples; 86 HCC, 10 hepatocellular adenomas, 12 focal nodular hyperplasias, 25 samples with liver cirrhosis without tumor, and 5 liver metastases of neuroendocrine carcinomas.

RESULTS

HCC showed positive staining in 80 nodules (93%; all of the 11 needle biopsy samples, 12 out of 15 liver resection specimens, 57 out of 60 nodules in explanted livers). Glypican-3 expression was independent of the differentiation and size of the HCC. Six cases (6.9%), 3 HCC in liver resection specimens and 3 in the explanted liver were negative for Glypican-3. However, all cases with benign nodular lesions and cirrhosis without tumors were negative for Glypican-3.

CONCLUSIONS

Immunohistochemical detection of Glypican-3 significantly improves the complicated routine histological diagnosis of HCC even in early lesions in needle biopsy samples.

[Autoimmune pancreatitis with biliary tree and liver involvement as a part of IgG4-related autoimmune sclerosing disease. Case report]

We report a rare case of autoimmune pancreatitis associated with sclerosing cholangitis, kidney, and salivary glands involvement. Abdominal ultrasound and CT scan showed enlarged pancreas, multiple nodular mass in the liver and kidney. ERCP showed features compatible with primary sclerosing cholangitis. The working clinical diagnosis considered malignant tumor with liver metastases. Histological examination of the liver biopsy sample revealed inflammatory process with numerous IgG4 positive plasma cells. The diagnostic conclusion of IgG4-related autoimmune sclerosing disease was drawn. The serum IgG level was elevated. Treatment with steroids improved the clinical course, all masses in the liver and kidneys disappeared, and laboratory tests were normalized. Now, 4 years after diagnosis the patient is free of all symptoms.

Leflunomide derivate FK 778 in accelerated renal injury in transgenic rat

Renal ischaemia/reperfusion (I/R) injury and hypertension represent major alloantigen-independent risk factors contributing to the development of chronic allograft nephropathy. In a model of accelerated major histocompatibility complex-independent renal injury, we evaluated the effect of leflunomide derivate - FK778 - on the progression of accelerated nephropathy. Thirty-six uninephrectomized hypertensive transgenic (m-REN-2)-27 rats received a clip on renal pedicle for 45 minutes. Animals were treated with FK778 3 mg/kg/day (I/R 3 mg, N = 12), 10 mg/kg/day (I/R 10 mg, N = 12) or placebo (N = 12) via gavage for 16 weeks. Eighteen animals were sham-operated and treated with FK778 3 mg/kg/day (sham 3 mg, N = 6), 10 mg/kg/day (sham 10 mg, N = 6) or were untreated (sham, N = 6). Proteinuria and blood pressure were evaluated throughout and the kidneys were harvested for morphological and immunohistochemical analysis at the end of the experiment. At week 16, rats with I/R injury and FK778 treatment had lower proteinuria compared with placebo-treated rats (I/R 3 mg: 48.42 +/- 26.16, I/R 10 mg 27.28 +/- 21.86 vs. Placebo: 70.13 +/- 50.19 mg/day, P < 0.05). The untreated sham group exhibited lower proteinuria compared with FK778-treated sham groups (Sham 3 mg: 24.23 +/- 10.89; Sham 10 mg: 17.37 +/- 4.13; Sham: 14.23 +/- 1.18) There was no difference in glomerulosclerosis and interstitial fibrosis among the treated groups. In the untreated animals the rate of interstitial fibrosis decline reached statistical significance (Placebo vs. Sham: 1.125 +/- 0.641 % vs. 0.250 +/- 0.500 %, P < 0.05). There was higher CD5+ leukocyte infiltration in the placebotreated group. FK778-treated rats displayed amelioration of some changes induced by the I/R injury. Our observation also suggests potential nephrotoxicity of FK778.

[Experimental small intestine transplantation]

AIM

Transplantation of the small intestine is a standard treatment method in patients with small intestinal failures. The aim of this study was to master the surgical technique, optimalize immunosuppression regimes, diagnose acute cellular graft rejection based on cellular and humoral indicators.

METHODS

The authors performed a total of 43 transplantation procedures in pigs. The first, surgical part of the experiment was aimed at mastering two principal methods of vascular anastomosis- firstly, connecting the graft with mesenteric vessels (Group n1 = 18) and secondly, connecting the graft with the aorta and the inferior vena cava (Group n2 = 25). The second part of the experiment included assessment of rejection changes in various immunosuppression regimes. Only animals who did not die because of a technical failure of the procedure or due to internal reasons (n = 24) were assessed. The study animals were assigned to four groups (A (n = 3)--autotransplantation, without immunosuppresion; B (n = 7) and C (n = 8)--allotransplantation with immunosuppression using tacrolimus, resp. in a combination with sirolimus; D (n = 6)--allotransplantation without immunosuppression. Rejection was diagnosed based on histological examination of the grafts@ biopsy samples. Plasmatic citruline was used as a non-invasive humoral indicator of the graft impairment.

RESULTS

Procedural complications were observed in 12 (67%) study animals from the first group, and in 3 (12%) animals from the second group. In the assessment of rejection changes, the longest survival was observed with autotransplantations, the shortest survival period was shown with allotransplantations without immunosuppression. No significant survival differences were demonstrated between the both treated groups. (p < 0.05). Group C showed lower rates of cellular rejections, compared to Group B and D.

CONCLUSION

During the experiment, the authors managed to master the graft collection, as well as the transplantation technique. Lower rates of surgical complications were observed when the graft was supplied by the central vascular system. No significant differencies were observed between the tacrolimus monoterapy regimen and the combination therapy with sirolimus. Histological examination is the golden standard for the cellular rejection diagnostics. Plasmatic citruline has no signifiance in the rejection assessment.

[Subclinical acute rejections in protocol biopsies at 3 months after kidney transplantation]

AIM

The primary aim of the study was detection of subclinical acute rejection and borderline changes in protocol biopsies at 3 months after transplantation, and assessment of possible clinical and laboratory associations.

METHODS

Biopsy was carried out in 194 patients with stabilized graft function. Patients were treated with immunosuppressive regimen based on cyclosporine A (n = 34), tacrolimus (n = 152), or sirolimus/everolimus (n = 10). Samples were processed by standard paraffine technique, and stained according to laboratory protocol. All samples were tested by immunofluorescence or immunohistochemical procedures for C4d presence as a sign of humoral rejection.

RESULTS

Of 192 representative samples, subclinical acute rejection and borderline changes were found in 24 samples (12.5%). In patients with this finding, the mean serum creatinine was significantly higher (185.2 +/- 2.2 micromol/L), than in patients with normal finding (128.2 +/- 28.3 micromol/L) p < 0.001. Using the ROC curve analysis of serum creatinine, the cut-off point 170 micromol/L was found to discriminate normal findings from subclinical rejection and borderline changes. A significant correlation between acute rejections before protocol biopsy and subclinical acute rejections together with borderline changes in protocol biopsy was found. C4d positivity was found in 6 samples. Immunosuppressive therapy (cyclosporine versus tacrolimus) did not have any impact on subclinical acute rejections and borderline changes prevalence.

CONCLUSIONS

The main conclusion of this study is a finding, that acute rejection early after renal transplantation and serum creatinine > or = 170 micromol/l at three months after transplantation are risks for development of subclinical acute rejection, even of humoral type, or borderline changes.

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.

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.

Soluble CD30 and HLA antibodies as potential risk factors for kidney transplant rejection

Recent literary data suggest that high pre- and post-transplant serum levels of the soluble CD30 (sCD30) molecule may be a risk factor for acute rejection and worse prognosis of the transplanted kidney. The aim of our study was to correlate the concentrations of sCD30 and the presence of HLA antibodies as defined by flow cytometry and ELISA with the clinical course and graft prognosis after transplantation. One hundred and seventeen kidney transplant patients were included into the study. The incidence of rejection episodes, graft function and graft survival for up to 1 year post-transplant were evaluated. Soluble CD30 levels before transplantation were virtually the same in patients who experienced rejection and in non-rejecting patients. In both patient groups, a significant decrease of sCD30 was detected 2 weeks after transplantation (104.4 U/ml before vs. 37.0 U/ml post-transplant, P < 0.001). However, there was a substantial difference in the level of decrease of sCD30 between rejecting and non-rejecting patients. Patients without rejection had lower sCD30 values (31.2 U/ml post-transplant) compared to patients who experienced rejection episodes (62.9 U/ml), P < 0.04. Multifactorial analysis showed that antibodies to HLA class II antigens and elevated concentrations of sCD30 shortly after transplantation were associated with increased risk for acute rejection in the first post-transplant year. Measurement of soluble CD30 after transplantation, taken into consideration with the presence of HLA class II antibodies, might be helpful for evaluating the potential risk for acute rejection.

The effect of different immunosuppressive regimens on TGF-beta1 expression in kidney transplant patients

Transforming growth factor (TGF)-beta1 is a key profibrogenic cytokine associated with the pathogenesis of chronic allograft nephropathy (CAN). The primary aim of this study was to evaluate TGF-beta1 expression in protocol kidney graft biopsy in patients treated with different immunosuppressive regimens. Protocol kidney graft biopsies were carried out in 77 patients with stable graft function at 1 year after kidney transplantation, treated with a triple-drug regimen based on cyclosporin A (CyA; n = 49) or tacrolimus (TAC; n = 28). Morphological findings were assessed using the Banff 97 classification. TGF-beta1 expression was analysed using immunochemistry, and semiquantitatively scored in different renal structures (total score 0-18). Clinical data were analysed at the time of biopsy, and 12 months thereafter. No significant relation was found between the used immunosuppressive regimen and the histomorphological picture in the graft. TGF-beta1 expression within graft tissue was significantly higher in patients treated with CyA when compared with TAC (9.94 +/- 4.2 vs. 5.0 +/- 3.2; P < 0.001). Serum creatinine and glomerular filtration rate (GFR; Cockroft-Gault calculation) were comparable in both groups but, in the course of the next 12 months, GFR significantly decreased only in the CyA-treated group (from 1.03 +/- 0.33 to 0.96 +/- 0.37 ml/s) while not changing in the TAC-treated group. Patients treated with TAC had significantly lower diastolic blood pressure and serum cholesterol. The significantly lower TGF-beta1 expression in 1-year protocol kidney graft biopsy in TAC-treated patients with stable renal function, and the different development of graft function in both groups suggest a possible benefit of TAC for long-term graft acceptance.

Effect of sirolimus on renal ischaemia/reperfusion injury in normotensive and hypertensive rats

BACKGROUND

Renal ischaemia/reperfusion (I/R) injury and hypertension represent major alloantigen-independent factors contributing to the development of chronic allograft nephropathy of renal allografts. In the present study, we investigated the effect of the anti-proliferative immunosuppressant, sirolimus (SIR), in a model of accelerated renal injury in hypertensive transgenic rats (TGRs). Twenty anaesthetized uninephrectomized TGRs with renin overproduction [TGR(mREN2)27] and 20 normotensive Han SD (SD) rats as genetic controls had their renal pedicles clipped for 45 min and were subsequently treated with either SIR (0.5 mg/kg per day, orally) or placebo ( n=10 in each group) for 16 weeks, after which time the kidneys were harvested for morphological and immunohistochemical analysis. High-renin hypertension aggravated the functional and structural changes induced by I/R in SD animals: both SIR-treated and untreated TGRs exhibited significantly greater proteinuria and suffered from more severe glomerulosclerosis ( P<0.01) and vasculopathy ( P<0.01), as well as compensatory renal hypertrophy ( P<0.01) and tissue TGF-beta1 expression, than both normotensive SD groups ( P<0.01). SIR-treated SD rats showed reduced proteinuria ( P<0.01), glomerulosclerosis ( P<0.01), and TGF-beta1 expression in the glomerular epithelium and proximal tubuli ( P<0.05) compared with placebo-treated SD rats. SIR-treated TGRs had significantly lower proteinuria at week 4 after I/R ( P<0.01) than placebo-treated TGRs, but there were no significant differences thereafter. Morphological patterns were similar in treated and untreated TGRs at week 16. High-renin-induced hypertension aggravated the renal injury induced by I/R. Sirolimus treatment ameliorated some late functional and morphological changes induced by I/R injury in hypertensive TGRs but, particularly, in normotensive SD rats.

TGF-beta1 expression and chronic allograft nephropathy in protocol kidney graft biopsy

Chronic allograft nephropathy (CAN) represents a frequent and irreversible cause of long-term renal graft loss. TGF-beta1 is a key profibrogenic cytokine associated with CAN pathogenesis. Because of clinical diagnostic inaccuracy, protocol biopsy has been suggested to be a beneficial method for early CAN detection. Protocol core biopsy was carried out in 67 consecutive cyclosporine-based immunosuppression-treated kidney transplant recipients with stable renal function 12 months after renal transplantation. Biopsy specimens were analyzed morphologically according to Banff-97' criteria and immunohistologically for TGF-beta1 staining. The data obtained were correlated with plasma TGF-beta1 levels and clinical data. CAN (grade I-III) was found in 51 patients (76 %). CAN grade I was found to be the most frequent one (44 %). A normal finding within the graft was made in only 12 patients (18 %). Clinically silent acute rejection Banff IA was present in 4 patients (6 %). In 8 patients (12 %) with CAN, borderline changes were present. We found a significant correlation between CAN grade and creatinine clearance, as measured by the Cockroft-Gault formula (p<0.01) as well as body mass index (p<0.01). There was a significant correlation between chronic vasculopathy (Banff cv) and creatinine clearance, and between the degree of TGF-beta1 staining and chronic vasculopathy (p<0.01). There were no relations between morphological findings and TGF-beta1 plasma levels, cyclosporine levels, plasma lipids, HLA-mismatches, panel reactive antibodies (PRA), proteinuria, and the donor's age. In conclusion, CAN is a frequent finding in protocol kidney graft biopsies 12 months after transplantation. TGF-beta1 tissue expression is linked with chronic vasculopathy.

[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.

Clinical relevance of antibodies to HLA antigens undetectable by the standard complement-dependent cytotoxicity test

Recent literary data suggest that antibodies to HLA antigens undetectable by the standard complement-dependent cytotoxicity test may cause not only chronic, but also acute immunological complications after kidney transplantation. The aim of this study was to investigate the significance of non-cytotoxic antibodies to HLA antigens for the development of immunological complications and a worse graft prognosis after first kidney transplantation. Sera before and early after transplantation from 120 first kidney recipients were analyzed by flow cytometry (FCXM), ELISA and the standard complement-dependent cytotoxicity (CDC) test. Pre-transplant FCXM negativity was related to a lower incidence of rejection episodes in the first post-transplant year ( P<0.01). A significant association between acute rejection and the presence of antibodies to HLA class II antigens before and after transplantation was also found ( P<0.05). Our study supports the findings of other centers of the detrimental role to the kidney graft played by anti-HLA antibodies undetectable by the classical CDC test.

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.

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.

Effect of daclizumab on inflammatory infiltrate in fine needle aspiration biopsy in patients after liver transplantation

OBJECTIVES

FNAB is a cytological procedure enabling the monitoring of inflammatory cells in the graft, morphological modification of parenchymal cells, and expression of antigens on aspirated cells. The aim of the study was to evaluate whether Daclizumab influences the composition of inflammatory infiltrate and expression of HLA-DR antigens and intercellular adhesive molecule ICAM-1 on parenchymal cells.

METHODS

Two groups of liver allograft recipients were included and they were treated with two different immunosuppressive protocols. The first group with quadruple immunosuppression therapy (Cyclosporine A, Mycophenolate mofetil, steroids, and Daclizumab). The second group with quadruple combination immunosuppression (Cyclosporine A, Azathioprine, steroids and ATG-Fresenius). FNAB and blood samples were collected simultaneously. Corrected increments of inflammatory cells were statistically evaluated as well as expression of HLA-DR antigens and ICAM-1 on parenchymal cells.

RESULTS

FNAB specimens from the Daclizumab group demonstrated significantly lower values of the total corrected increment, the corrected increment of monocytes, number of blast cells per slide, and a lower number of ICAM-1 expressing parenchymal cells.

CONCLUSION

We summarise that Daclizumab significantly reduces inflammatory cells in liver graft, as well as expression of ICAM-1 on parenchymal cells.

LF 08-0299 in the prophylaxis and treatment of chronic rejection in a rat aortic allograft model

Chronic rejection is the major cause of late kidney allograft failure. We evaluated the efficacy of LF 08-299 (LF), an analogue of 15-deoxyspergualin, in a rat aortic allograft model of chronic rejection. BN aortic allografts were transplanted to Lew recipients. LF was administered at a dose of 6 mg/kg and 2.5 mg/kg on days 0-20 and 6 mg/kg on days 60-90. CyA was used at a dose of 5 mg/kg on days 0-20. Untreated isografts and allografts were used as controls. Histological changes and immunohistochemistry were monitored sequentially at 8, 12, 16 and 20 weeks. There were no differences in intimal proliferation between LF-treated allografts and untreated or CyA-treated controls. Only a tendency in adventitial infiltration reduction was seen in LF-treated animals. We found a significantly less pronounced reduction in media diameter in LF-treated animals. We concluded that LF 08-0299 is only able to reverse reduction in media thickness in aortic allografts, but not intimal proliferation in this model of chronic rejection.

Withdrawal of steroids from triple-drug therapy in kidney transplant patients

BACKGROUND

In renal transplant patients with stable graft function, triple-drug immunosuppression may not be necessary, while withdrawal of steroids may eliminate side effects. The primary aim of this study was to assess the risk of rejection after steroid withdrawal.

METHODS

A total of 88 patients with stable graft function and serum creatinine <160 micromol/l, treated with cyclosporin A, azathioprine and prednisone were randomized into group A (n=46) with a gradual prednisone reduction to zero in the course of 6 months, and group B (n=42) on triple-drug therapy without change. At the time of randomization, fine-needle aspiration biopsy (FNAB) was carried out in all of the patients. After stopping steroids, the patients were followed up for a period of 12 months.

RESULTS

Four patients failed to complete steroid withdrawal, three due to rejection, and one due to leukopenia. The proportion of rejection in three patients in group A (6.6%) was not significantly different from rejection in two patients in group B (4.8%). The mean value of serum creatinine was not significantly different in both groups in the course of follow-up. A finding of some degree of immunological activity in FNAB was made in four patients in each group, but none of these patients developed rejection. Compared with group B, significant decreases in serum cholesterol and blood leukocytes were observed in group A. Prednisone withdrawal did not have any influence on hypertension and serum triglycerides.

CONCLUSIONS

Gradual withdrawal of steroids is not associated with a higher risk for rejection and has a beneficial effect on serum total cholesterol levels. FNAB was not a useful tool for predicting rejection.

[Withdrawal of prednisone from a triple combination of immunosuppressive agents after kidney transplantation]

BACKGROUND

Triple-drug immunosuppression may not be necessary in a majority of stabilized patients over 1 year after kidney transplantation. In contrary steroid withdrawal may be beneficial for the patient by elimination of side-effects. The primary aim of this study was assessment of the risk of rejection after the prednisone withdrawal.

METHODS AND RESULTS

88 patients 1 year after the first renal transplantation with stable graft function and serum creatinine < 160 mumol/l treated with cyclosporine-A, azathioprine and prednisone were randomized into group A (n = 46) with a prednisone withdrawal and group B (n = 42) on triple-drug therapy without change. At the time of randomization, fine-needle biopsy was carried out in all of the patients. In group A, the dose of prednisone was gradually reduced to zero in the course of six months and the patients were followed up for the next 12 months. In the group B, patients on triple-drug therapy were followed for the corresponding period of time. 3 patients (6.6%) in group A, and 2 (4.8%) in group B experienced rejection (NS). Mean values of serum creatinine were in the course of follow-up in both groups without any statistical difference. Suspect immunological activity or proved immunological activity in aspiration biopsy was present in 4 patients in each group, but one of them rejected the graft. In comparison with group B, a significant decrease of cholesterol and leukocytes was observed in group A. Prednisone withdrawal had no influence on hypertension and triglyceride.

CONCLUSIONS

Gradual withdrawal of steroids is not associated with higher risks of rejection and has a beneficial effect on cholesterol levels. Aspiration biopsy was of no use for the prediction of rejection.

Morphology and immunohistochemistry of rat aortic grafts

Allotransplantation (TPL) of the abdominal aortic segments of BN donors was performed in 32 Lewis recipients with or without cyclosporin A (CyA) immunosuppression, and the vascular changes were compared to those of 10 syngeneic grafts (Lewis-->Lewis) and to the autologous rat aortae. The vessels were examined 2, 3, 4 and 5 months post TPL by light microscopy, the thickness of intima and media was measured morphometrically and the cell infiltration of adventitia and intima was assessed semiquantitatively. Thirty-six aortae were examined by three-step enzyme immunohistochemistry (proof of selected differentiation, proliferation, cytoskeletal and connective tissue matrix antigens). The adventitia displayed an intense focal and scattered mononuclear cell infiltration; it was more discrete and focal in the intima. This cellularity persisted in the allografts but disappeared from the intima and was reduced in the adventitia of the isografts after four and five months. Disseminated ED1+ activated macrophages were the most prominent population of infiltrates whereas modest numbers of adventitial ED2+ tissue macrophages remained constant throughout the intervals examined. CD4+ cells (focal and scattered) outnumbered (roughly twice) the scattered CD8+ lymphocytes; both these types were rare in the intima. Leukocyte invasion of the media was lacking (except for scarce isolated CD8+ cells in some allografts). In syngeneic grafts the smooth muscle cells (SMC) of media remained intact and the intimal thickening was slight to absent (about 5 microns) four and five months post TPL. On the other hand, the allograft media underwent severe destructive changes (karyolysis, depletion of alpha-SMC actin, focal calcification and general thinning without rupture or aneurysm). The prominent allograft intimal thickening (70-80 microns) was due to the proliferation of longitudinally oriented myointimal cells (alpha-SMC actin, FD2, PCNA and Ki67+) and an increase in matrix substance (strong metachromasia and positivity of chondroitin-sulfate proteoglycan). The deposition of lipids remained discrete, without atheromatous plaques and mural thrombosis. All changes were comparable in CyA-treated and untreated animals. Thus the main lesions of the allografts were (i) persistent mononuclear infiltration chiefly in adventitia, (ii) destruction of medial SMC, and (iii) intimal thickening by proliferation of myointimal cells. At the postTPL intervals examined the proliferation and intimal migration of medial SMC were not apparent and a morphological correlate of significant anti-medial-SMC cytotoxic attack was lacking.

[Conversion of cyclosporin A therapy to conventional treatment with diagnostic use of aspiration biopsy in kidney transplantation]

BACKGROUND

Withdrawal of cyclosporin-A from maintenance immunosuppressive therapy involves risk of rejection. The aim of the study was to reduce the risk of rejection and to evaluate the fine-needle aspiration biopsy in predicting rejection.

METHODS AND RESULTS

In 41 patients 14.4 +/- 2.6 months after the first transplantation of a cadaveric graft with good and stabilized function, cyclosporine was withdrawn from triple-drug therapy while the doses of azathioprine and prednisone were increased. Prior to the change fine-needle aspiration biopsy (FNAB) was performed and methylprednisolone 500-250-250 mg administered in 3 days. FNAB was repeated after 2 weeks. 39 patients fulfilling inclusion criteria but ineligible for the switch for different reasons served as a control group. Both groups were comparable in demographic and immunological parameters. Within 3 months after conversion, rejection was observed in 3 patients (7%) vs 2 patients (5%) of the control group over a comparable period of time: and within 6 months in 6 patients (15%) and 3 patients (8%) respectively (NS). No relationship between rejections before and after conversion was found. FNAB appeared to have some predictive value for rejection. In all of the 3 patients experiencing rejection, a rejection pattern was present in the 2nd biopsy.

CONCLUSIONS

Incorporation of methylprednisolone into conversion therapeutic regime decreased the risk of rejection to 7%. The rejection pattern in the second FNAB after methylprednisolone administration may be predictive for further rejection development.