Dominika Konecka-Mrówka

Advanced glycation end product accumulation in the cardiomyocytes of heart failure patients with and without diabetes.

BACKGROUND Non-enzymatic coupling of protein and lipid cellular structures with glucose leading to the formation of advanced glycation end products (AGE) plays a role in aging and the development of diabetic complications, but its contribution to myocardial pathology is unclear. We aimed to assess the role of heart failure on AGE formation in patients with or without diabetes mellitus type 2 (DM2). MATERIAL/METHODS Heart tissue specimens from 136 patients undergoing transplantation were grouped as follows: 14 cases of ischemic cardiomyopathy (ICM) and DM2, 8 cases of dilated cardiomyopathy (DCM) and DM2, 67 cases of ICM without DM2, and 47 cases of DCM without DM2. Fourteen heart samples were from the autopsies of patients with DM2 without heart disease, and 20 heart samples were from organ donors in whom the heart was wasted. AGE deposits were localized immunohistochemically counted using a semiquantitative scale and characterized by their staining pattern. RESULTS Positive staining was present in all samples from both cardiomyopathy groups with DM2, in 71% of healthy hearts from the DM2 subjects, in 51% of ICM non-diabetic hearts, and in 38% of DCM non-diabetic hearts, and in only 15% of the organ donors. Mixed-diffuse and granular AGE patterns were characteristic for DM2, while a diffuse pattern was more frequently observed in heart failure patients without diabetes. The semiquantitative results supported increased AGE accumulation in patients with DM2 and/or cardiomyopathy. CONCLUSIONS The amount of AGE in cardiomyocytes increases significantly in both diabetes and heart failure, with a staining pattern typical for each condition.

Quilty effect correlates with biopsy-proven acute cellular rejection but does not predict transplanted heart coronary artery vasculopathy.

BACKGROUND The appropriate therapy after orthotopic heart transplantation (OHT) is determined by the results of endomyocardial biopsies (EMBs). The Quilty effect (QE) is a recognized cause of discrepancies in EMB grading, but its clinical implications remain unclear. In this study we assess the correlation of the QE with biopsy-proven acute cellular rejection (AR) and coronary artery vasculopathy (CAV). METHODS We reassessed 5,361 EMB samples, obtained from 429 patients, based on QE occurrence and its impact on EMB score. Next, we divided all patients with at least 1 year of follow-up into two groups: a QE(+) group (n = 202, 58.7% of sample, 172 males/30 females, 44.8 +/- 12 years of age) and a QE(-) group (n = 142, 41.3% of sample, 124 males/18 females, 45.4 +/- 12 years of age), and compared AR and CAV occurrences. RESULTS The QE was observed in 669 EMBs (12.5%), and at least 1 EMB with QE was found among the 231 patients (53.8%). The initial QE occurrence took place during the first 3 months after OHT in 68% of QE(+) patients, and >1 year post-OHT in 13% of patients. The average EMB score was significantly higher in QE(+) biopsies. A comparison of the two groups revealed a significantly higher number of AR episodes and number of patients with at least one episode of AR in QE(+) patients. There was no significant difference in number of CAV occurrences between groups. CONCLUSIONS The QE seems to be a marker of the same increased immune system activity that can lead to AR. A relationship between QE and CAV was not supported by the present results.

Advanced glycation end products and lipofuscin deposits share the same location in cardiocytes of the failing heart.

BACKGROUND Disturbed glucose metabolism, particularly in diabetes type 2 (DM2), may result in advanced glycation end product (AGE) formation. One of the possible targets for this reaction is lipofuscin (LF), an intracytoplasmic garbage presumed to be a marker of physiologic and preterm aging of cells. The study was performed to seek for a relationship between AGE and LF in cardiocytes of the failing hearts. MATERIAL AND METHODS Archived tissue samples from 136 hearts explanted before transplantation (in 14 pts. with ischemic cardiomyopathy (CM) and DM2; 8 pts. with dilated CM and DM2; 67 non-diabetic pts. with ischemic CM; 47 non-diabetic pts. with dilated CM), 14 autopsy cases with DM2, and 20 heart donors (control group) were involved in the study. Immunohistochemical localization of AGE was applied. The coexistence of lipofuscin and AGE was studied by LF autofluorescence in AGE-positive slides. RESULTS LF granules inside AGE deposits were present in all studied groups with varying frequencies, but the differences were non-significant. LF granules joined significantly with dispersed patterns of AGE i.e. diffuse and mixed, whereas coincidence of LF and AGE forming granular pattern was rare. CONCLUSIONS We demonstrate that LF may belong to the components of the AGE deposits. The frequency of this phenomenon is dependent on the AGE dispersion grade, but neither on diabetes nor cardiomyopathy presence.

Advanced glycation end-products in myocardium-supported vessels: Effects of heart failure and diabetes mellitus

BACKGROUND Disturbed glucose metabolism, particularly in diabetes, is an important but not the sole factor leading to advanced glycation end-product (AGE) formation. The AGE amount and its distribution in cardiopathic myocardial tissues in the presence or absence of diabetes are not well documented. The aim of this study was to assess AGE deposition in unaffected myocardial vessels in heart failure patients with and without diabetes mellitus type 2 (DM2) undergoing transplantation. METHODS The following groups were established: 14 hearts harvested from subjects with ischemic cardiopathy and DM2; 8 hearts from subjects with dilated cardiopathy with DM2; 67 hearts from subjects with ischemic cardiopathy; 47 hearts from subjects with dilated cardiopathy; and 14 hearts from autopsy cases with diagnosed DM2. A control group consisted of 20 heart donors. AGE localization was determined immunohistochemically in tissue sections. A semi-quantitative scale was used to assess reaction intensity in arteries, arterioles, capillaries, venules and veins. RESULTS Both types of cardiomyopathy increased AGE accumulation in intramyocardial veins more than in arteries. The presence of DM2 significantly increased AGE in arterioles and capillaries, especially when coexisting with cardiomyopathy. The type of cardiopathy did not influence the pattern of AGE accumulation in myocardial vessels. CONCLUSION Both chronic heart failure and DM2 intensified AGE pathology and changed the susceptibility of myocardial vasculature to glycation. However, chronic heart failure increases AGE deposition mostly in veins, whereas DM2 predisposes arterioles to AGE accumulation.

Advanced Glycation End Products in the Development of Ischemic and Dilated Cardiomyopathy in Patients With Diabetes Mellitus Type 2

INTRODUCTION Hyperglycemia intensifies nonenzymatic glucose coupling to tissues, resulting in myocardial stiffness and formation of advanced glycation end products (AGE). The aim of this study was to assess seeking AGE in the myocardium from patients with type 2 diabetes (DM2) subjected to orthotopic heart transplantation (OHT), seeking to establish whether AGE play a role in the development of cardiomyopathies leading to OHT. MATERIAL The 2 studied groups consisted of 11 hearts explanted from patients with ischemic cardiomyopathy+DM2 (ICM+DM2, 55 +/- 6.5 years) and 8 from dilated cardiomyopathy+DM2 (DCM+DM2, 49.6 +/- 4.5 years). Comparative subgroups were composed of nondiabetic explanted hearts, 41 with ICM (52.8 +/- 5.8 years) and 41 with DCM (52.7 +/- 4.2 years). All patients were males. METHODS We examined immunohistochemical localization of AGE using a semiquantitative scale of reaction intensity in cardiomyocytes, fibroblasts, capillaries, arterioles, and arteries. Additionally, we calculated the scores for cardiocytes (AGE(Cardiocyte)) and all left ventricular components (AGE(LV)). RESULTS The cytoplasmic AGE deposits in cardiomyocytes were predominantly diffuse-granular in DM2 groups, whereas nondiabetic groups showed a lack of a reaction or a diffuse pattern. There were no differences in the reaction intensity between the 2 studied groups, or 2 comparative groups. All myocardial constituents showed higher AGE intensity in DM2 than nondiabetic groups. Only in the ICM+DM2 group did the DM2 duration correlate with AGE staining in selected myocardial layers and with AGE(Cardiocyte) and AGE(LV). CONCLUSIONS The presence of AGE in the hearts of patients requiring transplantation was related to the duration of DM2. The deposition of AGE in left ventricular myocardium was enhanced by DM2 particularly in patients with ICM.

Cytomegalovirus Infection Does Not Accelerate Microvasculopathy Development in Heart Transplant Recipients

BACKGROUND Clinical studies with intravascular ultrasound have suggested that even subclinical cytomegalovirus (CMV) infections increase intimal hyperplasia in transplanted heart coronary arteries after 1 year. The potential influence of CMV on microvasculopathy development is not known. The Aim of our study was to compare the occurrence of microvasulopathy in endomyocardial biopsies (EMBs) of heart transplant recipients with versus without CMV infection. MATERIALS AND METHODS We performed a case-controlled, retrospective study of 58 subjects diagnosed with CMV infection by the presence of pp65 antigen. The 49 men and 91 women of overall age 49 +/- 8 years showed ischemic cardiomyopathy in 52%. We matched a control cohort of 58 subjects without CMV disease. Microvasculopathy was assessed using 4-degree grading system developed by Hiemann et al for elective EMBs performed at 1 and 12 months after transplantation. RESULTS Significant acute rejection episodes were observed among 22% versus 21% of 1-month EMBs, and 3% versus 5% of 12-month EMBs for CMV(+) versus control group subjects respectively. The commonest microvasculopathy was nonstenotic thickening (grade B) 60% versus 59% (35 versus 34 patients) among 1-month EMBs; and 50% versus 60% (29 vs 35 patients) among 12-month EMBs, respectively. Progression of microvasculopathy score between 1- and 12-month EMB was observed in 40% versus 41% of subjects, and regression occurred in 22% versus 21%, respectively. None of differences was significant. CONCLUSION Our data do not support the thesis that CMV infection promotes microvasculopathy development among heart transplant recipients.

Microvasculopathy Observed in Early or Late Endomyocardial Biopsies Is Not Related to Angiographically Confirmed Transplanted Heart Coronary Vasculopathy

INTRODUCTION The aim of the study was to examine the potential relation between microvasculopathy observed in endomyocardial biopsies (EMBs) and clinical coronary vasculopathy (CAV) after orthotopic heart transplantation (OHT). MATERIALS AND METHODS We preformed a retrospective analysis involving 68 OHT patients in whom the procedure was performed before 1999. The CAV(+) group consisted of 37 subjects (35 males/2 females) of overall mean age of 45 +/- 11 years. Ischemic cardiomyopathy was the diagnosis in 57% of the cohort that displayed CAV established by angioplasty, myocardial infarction, or CAV-related death. The control group contained 31 subjects (24 male/7 female) of overall mean age of 43 +/- 16 years. The pretransplant diagnosis was ischemic c-pathy in 39%. These subjects displayed negative coronary angiography at 10 years after OHT. Based upon studies early after OHT 55 subjects were divided based on the myocardial blush grade (MBG) upon coronary angiography performed between 4th and 6th week after surgery: one cohort of six individuals showed decreased MBG (6 males) of mean age 52 +/- 7 years. There was prior ischemic c-pathy in 50%. In contrast, 49 subjects showed a normal MBG (43 males/67 females) of overall mean age of 45 +/- 12 years. Ischemic c-pathy had been present in 39%. Microvasculopathy was defined as the presence of prominent endothelial cells, vacuolation of the endothelium, thickening of the basal membrane and/or muscle layer, the presence of lymphocytes in the arteriolar wall, periarteriolar fibrosis, or stenotic arteriolar lumenia in the 12- and 36 month EMB (CAV groups) or the 4-week EMB (MBG groups). RESULTS Rejection grades were comparable in CAV(+) and CAV(-) groups, but decreased in normal MBG group. The only significant difference was observed in the occurrence of basal membrane thickening, which was present in 22% of subjects from the CAV(+) group and 3% of individuals from the CAV(-) group in the 12-month EMB. CONCLUSION Microvasculopathy observed early or late after OHT was not related to angiographically confirmed CAV.

Vascular abnormalities and cardiomyocyte lipofuscin deposits in endomyocardial biopsy specimens of heart transplant recipients: are they related to the development of cardiac allograft vasculopathy?

OBJECTIVE The aim of this study was to assess the predictive value of microvascular abnormalities and lipofuscin observed in endomyocardial biopsy samples for the development of cardiac allograft vasculopathy. METHODS The study group consisted of 68 cardiac allograft recipients (63 men and 5 women, 43 +/- 12 years old). We performed a re-evaluation of 1071 endomyocardial biopsy specimens to search for microvascular diseases and lipofuscin in cardiocytes. Endomyocardial biopsy specimens with an International Society for Heart and Lung Transplantation rejection grade of 2 or more and those without arterioles were excluded. Abnormalities found in the remaining 517 specimens were correlated with the grade of rejection. Biopsy specimens obtained 2 weeks, 12 months, and 36 months after transplantation were compared with coronary angiography results, clinical events of cardiac allograft vasculopathies, and survivals. Kaplan-Meier curves were constructed to compare the time to the development of cardiac allograft vasculopathy or death. RESULTS Enlarged endothelial cells, lymphocytes inside the arteriolar wall, occluded arteriolar lumen, endothelial vacuolization, and hypertrophy of the vascular muscle were significantly correlated with rejection grade. Although none of the vascular abnormalities predicted cardiac allograft vasculopathy, patients with lipofuscin deposits at the 12-month biopsy specimens were characterized by the rapid development of angiography-confirmed cardiac allograft vasculopathy (P < .08) and events related to cardiac allograft vasculopathy (P < .03, log-rank test). CONCLUSION Microvascular abnormalities correlate with mild cellular rejection, but they do not seem to be predictive for development of cardiac allograft vasculopathy detected by angiography. The presence of lipofuscin in 12-month endomyocardial biopsy specimens may be predictive of development of angiographically confirmed cardiac allograft vasculopathy.

Coincidence of cellular and antibody mediated rejection in heart transplant recipients – preliminary report

Antibody mediated rejection (AMR) can significantly influence the results of orthotopic heart transplantation (OHT). However, AMR and cellular rejection (CR) coexistence is poorly described. Therefore we performed a prospective pilot study to assess AMR/CR concomitance in endomyocardial biopsies (EMBs) obtained electively in 27 OHT recipients (21 M/6 F, 45.4 ± 14.4 y/o). Biopsy samples were paraffin embedded and processed typically with hematoxylin/eosin staining to assess CR, and, if a sufficient amount of material remained, treated with immunohistochemical methods to localize particles C3d and C4d as markers of antibody dependent complement activation. With this approach 80 EMBs, including 41 (51%) harvested within the first month after OHT, were qualified for the study. Among them 14 (18%) were C3d+, 37 (46%) were C4d+, and 12 (15%) were both C3d and C4d positive. At least one C3d+, C4d+, and C3d/C4d+ EMB was found in 10 (37%), 17 (63%), and 8 (30%) patients, respectively. Among 37 CR0 EMBs C3d was observed in 4 (11%), C4d in 17 (46%), and both C3d/C4d in 3 (8%) cases. Among 28 CR1 EMBs C3d was observed in 3 (11%), C4d in 11 (39%), and C3d/C4d in 3 (11%) cases. Among 15 CR2 EMBs C3d was observed in 7 (47%), C4d in 9 (60%), and C3d/C4d in 6 (40%) cases. Differences in C3d and C3d/C4d occurrence between grouped CR0-1 EMBs and CR2 EMBs (7/65 – 11% vs. 7/15 – 47%; 6/65 – 9% vs. 6/15 – 40%) were significant (p = 0.0035 and p = 0.0091, respectively, χ2 test). In conclusion, apparently frequent CR and AMR coexistence demonstrated in this preliminary study warrants further investigation in this field.

Paradox of advanced glycation end-products in late cardiac biopsies of heart transplant recipients.

BACKGROUND A pilot study of orthotopic heart transplant (OHT) recipients showed that advanced glycation end-product (AGE) deposits were related to acute rejection episodes among subjects with diabetes mellitus (DM); in contrast, among non-DM patients it was associated with prolonged freedom from coronary artery vasculopathy (CAV). However the number of observations in non-diabetic subjects was low. The aim of the current study was to establish the role of AGEs in late endomyocardial biopsies (EMBs) among a larger group of non-diabetic patients. MATERIAL AND METHODS Elective EMBs were performed at 3 years post OHT in 62 subjects with DM, namely, 57 males and 5 females of overall mean age of 50±8 years versus 92 free of DM, including 79 males and 13 females of mean age 51±13 years. We localized AGEs in myocardial paraffin sections using monoclonal mouse anti-AGE antibodies. The presence of AGEs in cardiomyocytes, stromal cells, capillaries, and arterioles was described with a semiquantitative scale. RESULTS All-cause deaths, CAV, and CAV-related events were observed in 28% versus 23%, 27% versus 29%, and 15% versus 19% of non-DM versus DM patients (P=NS). The occurrence of AGEs was significantly more frequent among non-DM than DM subjects: cardiocytes, 100% versus 69% (P<.0001); stroma, 54% versus 31% (P=.0037); capillaries, 67% versus 31% (P<.0001); and arterioles, 26% versus 3% (P=.0002; chi-square). Among the DM group, mean EMB score correlated with AGE presence in cardiomyocytes (n=0.29; P<.05, Spearman test) AGE presence had no impact on survival or CAV development. CONCLUSION AGE presence was more common in late EMB from non-diabetic than diabetic OHT recipients; they had no impact on survival or CAV in non-diabetic patients.