Molecular diagnosis of ABMR with or without donor-specific antibody in kidney transplant biopsies: Differences in timing and intensity but similar mechanisms and outcomes.

We studied the clinical, histologic, and molecular features distinguishing DSA-negative from DSA-positive molecularly defined antibody-mediated rejection (mABMR). We analyzed mABMR biopsies with available DSA assessments from the INTERCOMEX study: 148 DSA-negative versus 248 DSA-positive, compared with 864 no rejection (excluding TCMR and Mixed). DSA-positivity varied with mABMR stage: early-stage (EABMR) 56%; fully developed (FABMR) 70%; and late-stage (LABMR) 58%. DSA-negative patients with mABMR were usually sensitized, 60% being HLA antibody-positive. Compared with DSA-positive mABMR, DSA-negative mABMR was more often C4d-negative; earlier by 1.5 years (average 2.4 vs. 3.9 years); and had lower ABMR activity and earlier stage in molecular and histology features. However, the top ABMR-associated transcripts were identical in DSA-negative versus DSA-positive mABMR, for example, NK-associated (e.g., KLRD1 and GZMB) and IFNG-inducible (e.g., PLA1A). Genome-wide class comparison between DSA-negative and DSA-positive mABMR showed no significant differences in transcript expression except those related to lower intensity and earlier time of DSA-negative ABMR. Three-year graft loss in DSA-negative mABMR was the same as DSA-positive mABMR, even after adjusting for ABMR stage. Thus, compared with DSA-positive mABMR, DSA-negative mABMR is on average earlier, less active, and more often C4d-negative but has similar graft loss, and genome-wide analysis suggests that it involves the same mechanisms. SUMMARY SENTENCE: In 398 kidney transplant biopsies with molecular antibody-mediated rejection, the 150 DSA-negative cases are earlier, less intense, and mostly C4d-negative, but use identical molecular mechanisms and have the same risk of graft loss as the 248 DSA-positive cases.

The molecular phenotypes of injury, steatohepatitis, and fibrosis in liver transplant biopsies in the INTERLIVER study.

To extend previous molecular analyses of rejection in liver transplant biopsies in the INTERLIVER study (ClinicalTrials.gov #NCT03193151), the present study aimed to define the gene expression selective for parenchymal injury, fibrosis, and steatohepatitis. We analyzed genome-wide microarray measurements from 337 liver transplant biopsies from 13 centers. We examined expression of genes previously annotated as increased in injury and fibrosis using principal component analysis (PCA). PC1 reflected parenchymal injury and related inflammation in the early posttransplant period, slowly regressing over many months. PC2 separated early injury from late fibrosis. Positive PC3 identified a distinct mildly inflamed state correlating with histologic steatohepatitis. Injury PCs correlated with liver function and histologic abnormalities. A classifier trained on histologic steatohepatitis predicted histologic steatohepatitis with cross-validated AUC = 0.83, and was associated with pathways reflecting metabolic abnormalities distinct from fibrosis. PC2 predicted histologic fibrosis (AUC = 0.80), as did a molecular fibrosis classifier (AUC = 0.74). The fibrosis classifier correlated with matrix remodeling pathways with minimal overlap with those selective for steatohepatitis, although some biopsies had both. Genome-wide assessment of liver transplant biopsies can not only detect molecular changes induced by rejection but also those correlating with parenchymal injury, steatohepatitis, and fibrosis, offering potential insights into disease mechanisms for primary diseases.

Donor-Specific Antibody Is Associated with Increased Expression of Rejection Transcripts in Renal Transplant Biopsies Classified as No Rejection.

BACKGROUND: Donor -specific HLA antibody (DSA) is present in many kidney transplant patients whose biopsies are classified as no rejection (NR). We explored whether in some NR kidneys DSA has subtle effects not currently being recognized. METHODS: We used microarrays to examine the relationship between standard-of-care DSA and rejection-related transcript increases in 1679 kidney transplant indication biopsies in the INTERCOMEX study (ClinicalTrials.gov NCT01299168), focusing on biopsies classified as NR by automatically assigned archetypal clustering. DSA testing results were available for 835 NR biopsies and were positive in 271 (32%). RESULTS: DSA positivity in NR biopsies was associated with mildly increased expression of antibody-mediated rejection (ABMR)-related transcripts, particularly IFNG-inducible and NK cell transcripts. We developed a machine learning DSA probability (DSAProb) classifier based on transcript expression in biopsies from DSA-positive versus DSA-negative patients, assigning scores using 10-fold cross-validation. This DSAProb classifier was very similar to a previously described "ABMR probability" classifier trained on histologic ABMR in transcript associations and prediction of molecular or histologic ABMR. Plotting the biopsies using Uniform Manifold Approximation and Projection revealed a gradient of increasing molecular ABMR-like transcript expression in NR biopsies, associated with increased DSA (P<2 × 10-16). In biopsies with no molecular or histologic rejection, increased DSAProb or ABMR probability scores were associated with increased risk of kidney failure over 3 years. CONCLUSIONS: Many biopsies currently considered to have no molecular or histologic rejection have mild increases in expression of ABMR-related transcripts, associated with increasing frequency of DSA. Thus, mild molecular ABMR-related pathology is more common than previously realized.

The molecular diagnosis of rejection in liver transplant biopsies: First results of the INTERLIVER study.

Molecular diagnosis of rejection is emerging in kidney, heart, and lung transplant biopsies and could offer insights for liver transplant biopsies. We measured gene expression by microarrays in 235 liver transplant biopsies from 10 centers. Unsupervised archetypal analysis based on expression of previously annotated rejection-related transcripts identified 4 groups: normal "R1normal " (N = 129), T cell-mediated rejection (TCMR) "R2TCMR " (N = 37), early injury "R3injury " (N = 61), and fibrosis "R4late " (N = 8). Groups differed in median time posttransplant, for example, R3injury 99 days vs R4late 3117 days. R2TCMR biopsies expressed typical TCMR-related transcripts, for example, intense IFNG-induced effects. R3injury displayed increased expression of parenchymal injury transcripts (eg, hypoxia-inducible factor EGLN1). R4late biopsies showed immunoglobulin transcripts and injury-related transcripts. R2TCMR correlated with histologic rejection although with many discrepancies, and R4late with fibrosis. R2TCMR , R3injury , and R4late correlated with liver function abnormalities. Supervised classifiers trained on histologic rejection showed less agreement with histology than unsupervised R2TCMR scores. No confirmed cases of clinical antibody-mediated rejection (ABMR) were present in the population, and strategies that previously revealed ABMR in kidney and heart transplants failed to reveal a liver ABMR phenotype. In conclusion, molecular analysis of liver transplant biopsies detects rejection, has the potential to resolve ambiguities, and could assist with immunosuppressive management.

Clinicopathologic correlations of renal pathology in the adult population of Poland.

BACKGROUND: This is the first report on the epidemiology of biopsy-proven kidney diseases in Poland. METHODS: The Polish Registry of Renal Biopsies has collected information on all (n = 9394) native renal biopsies performed in Poland from 2009 to 2014. Patients' clinical data collected at the time of biopsy, and histopathological diagnoses were used for epidemiological and clinicopathologic analysis. RESULTS: There was a gradual increase in the number of native renal biopsies performed per million people (PMP) per year in Poland in 2009-14, starting from 36 PMP in 2009 to 44 PMP in 2014. A considerable variability between provinces in the mean number of biopsies performed in the period covered was found, ranging from 5 to 77 PMP/year. The most common renal biopsy diagnoses in adults were immunoglobulin A nephropathy (IgAN) (20%), focal segmental glomerulosclerosis (FSGS) (15%) and membranous glomerulonephritis (MGN) (11%), whereas in children, minimal change disease (22%), IgAN (20%) and FSGS (10%) were dominant. Due to insufficient data on the paediatric population, the clinicopathologic analysis was limited to patients ≥18 years of age. At the time of renal biopsy, the majority of adult patients presented nephrotic-range proteinuria (45.2%), followed by urinary abnormalities (38.3%), nephritic syndrome (13.8%) and isolated haematuria (1.7%). Among nephrotic patients, primary glomerulopathies dominated (67.6% in those 18-64 years of age and 62.4% in elderly patients) with leading diagnoses being MGN (17.1%), FSGS (16.2%) and IgAN (13.0%) in the younger cohort and MGN (23.5%), amyloidosis (18.8%) and FSGS (16.8%) in the elderly cohort. Among nephritic patients 18-64 years of age, the majority (55.9%) suffered from primary glomerulopathies, with a predominance of IgAN (31.3%), FSGS (12.7%) and crescentic GN (CGN) (11.1%). Among elderly nephritic patients, primary and secondary glomerulopathies were equally common (41.9% each) and pauci-immune GN (24.7%), CGN (20.4%) and IgAN (14.0%) were predominant. In both adult cohorts, urinary abnormalities were mostly related to primary glomerulopathies (66.8% in younger and 50% in elderly patients) and the leading diagnoses were IgAN (31.4%), FSGS (15.9%), lupus nephritis (10.7%) and FSGS (19.2%), MGN (15.1%) and pauci-immune GN (12.3%), respectively. There were significant differences in clinical characteristics and renal biopsy findings between male and female adult patients. CONCLUSIONS: The registry data focused new light on the epidemiology of kidney diseases in Poland. These data should be used in future follow-up and prospective studies.

Epidemiology of infections in kidney transplant recipients - data miner's approach.

Infections remain a frequent complication following organ transplantation. Agents present within the general population remain common in recurrent infections among renal transplant recipients. Data mining methodology has become a promising source of information about patterns in the organ transplant recipient population. The aim of the study was to use data mining to describe the factors influencing single and recurrent infections in kidney transplant recipients. A group of 159 recipients who underwent kidney transplantation between 2005 and 2008 was analysed. RapidMiner and Statistica softwares were used to create decision tree models based on CART Quinlan and C&RT algorithms. There were 171 microbiologically confirmed episodes among 67 recipients (41%), and 191 separate species isolations were performed. Over 50% of the infected patients underwent two or more infectious episodes. Two classification decision tree models were created. The following features were enabled to differentiate the groups with single or recurrent infections: the duration of cold ischaemia, the post-transplant hospitalization period, the cause of chronic kidney disease and pathogens. The post-transplant hospitalization period and the length of cold ischaemia appear to be the principal parameters differentiating the subpopulations analysed. These coexisting factors, connected with recurrent infections in kidney transplant recipients, resemble a network which requires an advanced analysis to support the traditional statistics.

Prooxidative-antioxidative balance of cells in different types of renal replacement therapy.

BACKGROUND: Patients suffering from chronic kidney disease (CKD) are exposed to increased oxidative stress and disturbances manifesting in the enzymatic and non-enzymatic antioxidative defence system. The object of the research was to assess the differences between conservative treatment, peritoneal dialysis and haemodialysis in moderating cellular antioxidative agents. METHODS: The group examined comprised 145 patients. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase were obtained using kinetic methods. The spectrophotometric method established the concentrations of reduced glutathione, albumin, uric acid, glucose, total protein and lipids. RESULTS: The type of treatment determined significant changes in antioxidative enzyme activities and concentrations of non-enzymatic antioxidative compounds. CONCLUSIONS: Peritoneal dialysis provides better antioxidant protection than other types of therapy in CKD and should be considered as first-choice treatment despite more metabolic disorders.

Immunosuppressant Adherence Factors Differentiating Compliant and Non-Compliant Kidney Transplant Recipients.

The purpose of this study is to find out the psychological factor characteristic of non-adherence patients. The study population comprised kidney transplant recipients aged between 18 and 82 years at least 3 months post-transplant who voluntarily agreed to answer a couple of fully anonymous questionnaires that questions pertaining to basic data, type of immunosuppressive drugs taken, and standardized questionnaires. Participants were recruited using direct routine, free-of-charge visits to specialist doctors in transplant clinics. There was no significant difference in the percentage of men and women in both adherence and non-adherence groups. Non-adherence patients were significantly younger compared to adherence patients. There was also a significant difference in the patient's level of education. Adherence patients were better educated. No significant differences in criteria such as place of residence, having children or a partner, or way of living were observed. However, the emotion scale correlated negatively with the level of life orientation in both groups, but the level of the emotions scale and distractions subscale was negatively correlated with the level of self-esteem only for the adherence group. In future research, it would be worthwhile to focus on lifestyle and health-promoting behaviors in juxtaposition with the propensity for adherence.

Relating Molecular T Cell-mediated Rejection Activity in Kidney Transplant Biopsies to Time and to Histologic Tubulitis and Atrophy-fibrosis.

BACKGROUND: We studied the variation in molecular T cell-mediated rejection (TCMR) activity in kidney transplant indication biopsies and its relationship with histologic lesions (particularly tubulitis and atrophy-fibrosis) and time posttransplant. METHODS: We examined 175 kidney transplant biopsies with molecular TCMR as defined by archetypal analysis in the INTERCOMEX study ( ClinicalTrials.gov #NCT01299168). TCMR activity was defined by a molecular classifier. RESULTS: Archetypal analysis identified 2 TCMR classes, TCMR1 and TCMR2: TCMR1 had higher TCMR activity and more antibody-mediated rejection ("mixed") activity and arteritis but little hyalinosis, whereas TCMR2 had less TCMR activity but more atrophy-fibrosis. TCMR1 and TCMR2 had similar levels of molecular injury and tubulitis. Both TCMR1 and TCMR2 biopsies were uncommon after 2 y posttransplant and were rare after 10 y, particularly TCMR1. Within late TCMR biopsies, TCMR classifier activity and activity molecules such as IFNG fell progressively with time, but tubulitis and molecular injury were sustained. Atrophy-fibrosis was increased in TCMR biopsies, even in the first year posttransplant, and rose with time posttransplant. TCMR1 and TCMR2 both reduced graft survival, but in random forests, the strongest determinant of survival after biopsies with TCMR was molecular injury, not TCMR activity. CONCLUSIONS: TCMR varies in intensity but is always strongly related to molecular injury and atrophy-fibrosis, which ultimately explains its effect on survival. We hypothesize, based on the reciprocal relationship with hyalinosis, that the TCMR1-TCMR2 gradient reflects calcineurin inhibitor drug underexposure, whereas the time-dependent decline in TCMR activity and frequency after the first year reflects T-cell exhaustion.

"A Comparative Analysis of the Number of Organ Retrievals in Relation to Potential Donation Qualifications in Populations of Patients From a Single Anesthesiology and Intensive Care Unit in 2017-2018".

The population of patients declared as brain dead and qualified for organ donation is relatively low in Poland. The main causes of brain death include cerebral vascular diseases and brain trauma (54 and 34%, respectively, according to Poltransplant registry data). The number of organ procurements in Poland is constantly recorded on average at 14 donations per 1 million citizens (14/mln) in 2017 and 12 donations per one million in 2018. It is difficult to precisely define the number of patients who meet the criteria for brain death certification. The authors have retrospectively analyzed the medical data of 229 patients from 2017 and 2018 records with the aim of identifying potential organ donors among patients of the Intensive Care Unit (ICU) in the University Hospital in Western Poland. Brain death was suspected in 53 patients (23.14%). Brain imaging to confirm no cerebral flow (which is consistent with brain death) was performed in 17 patients (7.45%) and this, as a result, led to organ donation in 9 cases (3.93%). The factors identified as having a positive influence on organ donation included: daily thorough physical examination, (Glasgow Coma Scale) GCS assessment, depth and duration of sedation, ICU length of stay and early performance of a CT-angiogram.

Archetypal Analysis of Injury in Kidney Transplant Biopsies Identifies Two Classes of Early AKI.

All transplanted kidneys are subjected to some degree of injury as a result of the donation-implantation process and various post-transplant stresses such as rejection. Because transplants are frequently biopsied, they present an opportunity to explore the full spectrum of kidney response-to-wounding from all causes. Defining parenchymal damage in transplanted organs is important for clinical management because it determines function and survival. In this study, we classified the scenarios associated with parenchymal injury in genome-wide microarray results from 1,526 kidney transplant indication biopsies collected during the INTERCOMEX study. We defined injury groups by using archetypal analysis (AA) of scores for gene sets and classifiers previously identified in various injury states. Six groups and their characteristics were defined in this population: No injury, minor injury, two classes of acute kidney injury ("AKI," AKI1, and AKI2), chronic kidney disease (CKD), and CKD combined with AKI. We compared the two classes of AKI, namely, AKI1 and AKI2. AKI1 had a poor function and increased parenchymal dedifferentiation but minimal response-to-injury and inflammation, instead having increased expression of PARD3, a gene previously characterized as being related to epithelial polarity and adherens junctions. In contrast, AKI2 had a poor function and increased response-to-injury, significant inflammation, and increased macrophage activity. In random forest analysis, the most important predictors of function (estimated glomerular filtration rate) and graft loss were injury-based molecular scores, not rejection scores. AKI1 and AKI2 differed in 3-year graft survival, with better survival in the AKI2 group. Thus, injury archetype analysis of injury-induced gene expression shows new heterogeneity in kidney response-to-wounding, revealing AKI1, a class of early transplants with a poor function but minimal inflammation or response to injury, a deviant response characterized as PC3, and an increased risk of failure. Given the relationship between parenchymal injury and kidney survival, further characterization of the injury phenotypes in kidney transplants will be important for an improved understanding that could have implications for understanding native kidney diseases (ClinicalTrials.gov #NCT01299168).

SARS-CoV-2 mRNA Vaccine-Induced Cellular and Humoral Immunity in Hemodialysis Patients.

BACKGROUND/AIMS: Chronic kidney disease CKD patients on intermittent hemodialysis IHD are exposed to SARS-CoV-2 infection and carry a risk of developing severe symptoms. The aim of this study was to evaluate the humoral and cellular immunity induced by two doses of mRNA vaccines, the Pfizer-BioNTech (Comirnaty) COVID-19 Vaccine and the Moderna (mRNA-1273) COVID-19 vaccine. PATIENTS AND METHODS: The study included 281 patients from five dialysis centers in northern Poland. Within 2 weeks prior to the first dose of the vaccine, a blood sample was collected for an evaluation of SARS-CoV-2 antibodies. Thirty to forty-five days after the second dose of the vaccine, a blood sample was taken to evaluate humoral and cellular response. RESULTS: Patients with stage 5 CKD on IHD were characterized by a considerable SARS-CoV-2 vaccine-induced seroconversion rate. The strongest factors influencing the antibodies AB level after vaccination were a pre-vaccination history of SARS-CoV-2 infection, age, the neutrophil-to-lymphocyte ratio NLR, neutrophil absolute count, and the hemoglobin level. Cellular immunity was higher in patients with a pre-vaccination history of SARS-CoV-2 infection. Cellular immunity depended on the albumin level. Positive cellular response to vaccination was a positive factor reducing all-cause mortality, except for COVID-19 mortality (no such deaths were reported during our follow-up). Cellular immunity and humoral immunity were positively mutually dependent. High levels of albumin and hemoglobin, low neutrophil count, and a reduced NLR, translated into better response to vaccination. CONCLUSIONS: Patients with stage 5 CKD on IHD were characterized by a considerable SARS-CoV-2 vaccine-induced seroconversion rate and a good rate of cellular immunity. The factors that change with exacerbating inflammation and malnutrition (albumin, hemoglobin, neutrophil count, the NLR) affected the efficacy of the vaccination.

Therapeutic dilemmas in dialysis patients hospitalized for COVID-19: balancing between nihilism, off-label treatment and side effects.

Avoiding the use of drugs in patients with a glomerular filtration rate (GFR) <30 mL/min/1.73 m2 is due to the exclusion of this group of patients from many clinical trials. However, in view of the widespread COVID-19 pandemic and the need to treat all patients, including those with renal failure, the World Health Organization points out in the Solidarity trial the need for the inclusion some patients with kidney failure and recognizes the urgent need for trials/studies in patients with coronavirus disease 2019 (COVID-19) with lower GFR. It is well known that the therapeutic goal to treat patients with renal failure, acute kidney injury or on maintenance dialysis is complicated by pharmacokinetics, drug interactions and extracorporeal therapies. In patients with COVID-19 and impaired kidney function, the role of nephrologists is crucial in order to draw a balance between nihilism and benefits or potentially harmful effects of current available treatments. The potential use of European Medicines Agency recommended remdesivir and dexamethasone for COVID-19 among dialysis patients are discussed.

A 2-fold Approach to Polyoma Virus (BK) Nephropathy in Kidney Transplants: Distinguishing Direct Virus Effects From Cognate T Cell-mediated Inflammation.

BACKGROUND: BK nephropathy (BKN) in kidney transplants diagnosed by histology is challenging because it involves damage from both virus activity and cognate T cell-mediated inflammation, directed against alloantigens (rejection) or viral antigens. The present study of indication biopsies from the Integrated Diagnostic System in the International Collaborative Microarray Study Extension study measured major capsid viral protein 2 (VP2) mRNA to assess virus activity and a T cell-mediated rejection (TCMR) classifier to assess cognate T cell-mediated inflammation. METHODS: Biopsies were assessed by local standard-of-care histology and by genome-wide microarrays and Molecular Microscope Diagnostic System (MMDx) algorithms to detect rejection and injury. In a subset of 102 biopsies (50 BKN and 52 BKN-negative biopsies with various abnormalities), we measured VP2 transcripts by real-time polymerase chain reaction. RESULTS: BKN was diagnosed in 55 of 1679 biopsies; 30 had cognate T cell-mediated activity assessed by by MMDx and TCMR lesions, but only 3 of 30 were histologically diagnosed as TCMR. We developed a BKN probability classifier that predicted histologic BKN (area under the curve = 0.82). Virus activity (VP2 expression) was highly selective for BKN (area under the curve = 0.94) and correlated with acute injury, atrophy-fibrosis, macrophage activation, and the BKN classifier, but not with the TCMR classifier. BKN with molecular TCMR had more tubulitis and inflammation than BKN without molecular TCMR. In 5 BKN cases with second biopsies, VP2 mRNA decreased in second biopsies, whereas in 4 of 5 TCMR classifiers, scores increased. Genes and pathways associated with BKN and VP2 mRNA were similar, reflecting injury, inflammation, and macrophage activation but none was selective for BKN. CONCLUSIONS: Risk-benefit decisions in BKN may be assisted by quantitative assessment of the 2 major pathologic processes, virus activity and cognate T cell-mediated inflammation.

Still diagnosed too late and under-recognized? The first comprehensive report on primary hyperoxaluria in Poland.

INTRODUCTION: Primary hyperoxalurias (PHs) are rare disorders leading to overproduction and increased urinary excretion of oxalate. Three monogenic forms (PH1-PH3) were classified. PHs lead to urolithiasis and chronic kidney disease. There are only sparse data on patients with PH from Eastern European countries including Poland. OBJECTIVES: The aim of the study was to evaluate the prevalence, genetic background, and clinical course of PH in the Polish population. PATIENTS AND METHODS: This was a retrospective multicenter study including data of all identified and genetically confirmed Polish patients with PH. RESULTS: Between 1998 and 2019, 21 patients with PH were identified, including 13 patients with PH1 (62%), 2 with PH2 (9%), and 6 with PH3 (29%). In those with PH1, the most common mutation was c.508G>A in AGXT and in PH3, c.700+5G>T in HOGA1. Nine patients (69%) developed end­stage renal disease at a median age of 13 years and 2 died. In 6 (46%) PH1 cases, the diagnosis was made only after patients had progressed to end­stage renal disease and received isolated kidney transplantation, followed by graft failure. Combined liver­kidney transplantation was performed in 6 patients with PH1. Two siblings with PH2 showed a milder course with slightly decreased renal function in one, at age of 11 years. Despite infantile onset of urolithiasis, all patients with PH3 at a median age of 10 years maintained normal renal function. CONCLUSIONS: The prevalence of PH1 and PH2 in Poland seems to be much lower than in Western countries with PH3 constituting about 30% of all cases. The molecular findings and clinical course are typical, but the underdiagnosis is of concern.

The association between cytokine gene polymorphisms and kidney allograft survival.

BACKGROUND: Cytokines regulate cellular and humoral immune responses. One determinant of the variable cytokine production observed among individuals is genetic polymorphism in cytokine genes. These polymorphisms represent normal allelic variations in the cytokine genes; usually single base changes. Homozygous genotypes for high producer alleles are generally associated with high cytokine production, heterozygotes with intermediate production, and homozygotes for the low producer alleles with low cytokine production. Cytokines have been implicated in the regulation of acute and chronic rejection of allografts. The aim of the study was to evaluate the promoter polymorphism of TNF-alpha gene (-308 promoter polymorphism), IL-2 gene (-330 promoter polymorphism), IL-4 gene (-590 promoter polymorphism), and IL-6 gene (-174 promoter polymorphism) in renal transplant recipients with allograft duration under and over 10 years to establish whether aforementioned polymorphism are involved in kidney allograft survival. MATERIAL/METHODS: The study included 197 renal transplant recipients with well-functioning grafts for 2 to 18 years. The patients were divided into two subgroups: recipients with allograft duration under 10 years and recipients with allograft duration over 10 years. RESULTS: Among renal transplant recipients with allograft duration over 10 years we observed the prevalence of subjects with the T1T1 genotype of TNF alpha (low expression of TNF alpha) and GG of IL-6 (high expression of IL-6). There was no difference in relation to IL-2 and IL-4 promoter polymorphism. CONCLUSIONS: The results of present study suggest that the TNF-alpha -308 and the IL-6 -174 promoter polymorphisms may be the genetic factors influencing the renal allograft survival.

DNA microsatellite analysis in families with autosomal dominant polycystic kidney disease (ADPKD): the first Polish study.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common inherited renal disorders with genetic heterogeneity. Mutations of two known genes are responsible for this disease: PKD1 at 16p13.3 and PKD2 at 4q21-23. A majority of cases (85%) are caused by mutations in PKD1. Because direct mutation screening remains complex, we describe here the application of an efficient approach to studies based on highly informative dinucleotide and tetranucleotide repeats flanking genes PKD1 and PKD2. METHODS: For this study a series of microsatellites closely linked to locus PKD1 (D16S291, D16S663, D16S665, D16S283, D16S407, D16S475) and to locus PKD2 (D4S1563, D4S2929, D4S414, D4S1534, D4S423) were selected. Short (81-242 bp) DNA fragments containing the tandem repeats were amplified by polymerase chain reaction (PCR). The number of repeat units of microsatelite markers was determined by fluorescent capillary electrophoresis. RESULTS: DNA microsatellite analysis was performed in 25 Polish ADPKD families and established the type of disease (21 families PKD1-type, 1 family PKD2-type). CONCLUSIONS: While a disease-causing mutation in the PKD1 and PKD2 genes cannot be identified, DNA microsatellite analysis provided an early diagnosis and may be considered in ADPKD families.

Plasma prekallikrein as a risk factor for diabetic retinopathy.

BACKGROUND: The aim of the study was to verify the hypothesis that in diabetes there is an increased activation of coagulation system leading in consequence to diabetic retinopathy. METHODS: Thirty three healthy subjects (controls, 16 males and 17 females) and 35 patients with diabetes type 1 (15 males and 20 females) were examined. We monitored plasma prekallikrein (PPK), glycemia, fructosamine, glycosylated hemoglobin, activated partial thromboplastin time (PTT), INR, fibrinolysis in euglobulins time (FET), level of antithrombin III (AT III), fibrinogen (Fb) and fibrinogen degradation products (FDP). RESULTS: In diabetic patients without retinopathy, PKK concentration was 16% higher (p <0.005), in patients with background retinopathy 33% higher (p <0.001), and in patients with proliferative retinopathy PKK concentration was 50% higher (p <0.001) than in controls. In the subgroup of patients with proliferative retinopathy PTT was significantly shorter (p <0.001), and FET was significantly longer (p <0.001) than in control. In patients with diabetes higher FDP concentrations were found than in controls (p <0.05). Significant correlations were found between PPK and fructosamine levels in all diabetic patients (R(S)=+0.57 p <0.001), in diabetic patients without retinopathy (R(S)=+0.61, p <0.05), and in diabetic patients with retinopathy (R(S)=+0.62, p <0.005). We found negative correlation between PPK concentration and PTT (R(S)=-0.43, p <0.001) and positive correlation between PPK concentration and FET (R(S)=+0.59, p <0.00001) in the entire study group. CONCLUSIONS: The occurrence of diabetic retinopathy is connected with higher levels of plasma prekallikrein.

Impaired synthesis is not the reason for decreased activity of extracellular superoxide dismutase in patients with diabetes.

BACKGROUND: The aim of the study was to find the cause of decreased activity of extracellular superoxide dismutase (EC SOD) in patients with diabetes-is it the decreased synthesis or increased glycation? METHODS: Total EC SOD activity, the activity of its fractions (A, B, and C) and its glycated form were determined in basal state and 30 min after intravenous (i.v.) administration of 50 mg of heparin. Patients were given i.v. heparin at a dose of 10,000 IU (100 mg) each 6 h for at least 3 days, and the activity of EC SOD was determined before the first heparin administration, just before each subsequent administration, and 30 min after heparin administration. RESULTS: Pre- and postheparinic activities of EC SOD and its fraction C in the group of patients with diabetes were significantly lower (p <0.001) than in control group. Preheparinic activities of EC SOD did not differ between the examined groups of patients. The postheparinic activities were different during the first 18 h of treatment. They were significantly lower in the group of patients with diabetes. During the following hours, after subsequently administered doses, there were no differences in the activity of EC SOD between the examined groups. Decline of EC SOD activity was observed after administration of repeated doses of heparin both in the examined and in the control groups. CONCLUSIONS: The decrease of extracellular superoxide dismutase activity in diabetes develops due to excessive glycation but not due to impaired synthesis. Therefore, appropriate glycemic control can lead to normalization of EC SOD activity.

Oral iron absorption test: should it be performed before starting treatment with ferrous preparations?

The oral iron absorption test is sometimes used in the assessment of ferrous preparation efficacy before therapeutic use in the treatment of patients with anemia. Overdoses of Fe can cause the production of free radicals that are dangerous because of chemical modifications and damage of proteins, lipids, carbohydrates, and nucleotides. We suggest that this test should not be performed with the recommended dose of iron because of the potential threat to the patients. We assessed the serum concentration of iron and total iron-binding capacity during the test. Before and after the test, the concentration of malonyldialdehyde, an end product of lipid peroxidation, was determined in serum. In most patients, we found an increase in malonyldialdehyde concentration, suggesting the enhanced production of free radicals. This increase was particularly marked in patients with an overabsorption of iron. The administration of iron in the dose recommended for the oral iron absorption test causes increase in serum malonyldialdehyde concentration, proving an overproduction of free radicals. This test should not be performed because of the evidence proving detrimental effects of free-radical overproduction on the human body.