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.

EBV load is associated with cfDNA fragmentation and renal damage in SLE patients.

BACKGROUND: For long Epstein-Barr virus (EBV) has been suspected to be involved in the pathogenesis of systemic lupus erythematosus (SLE). The aim of this study was to verify the association between EBV, cell-free DNA (cfDNA) and kidney disease in SLE. METHODS: Blood samples were obtained from 43 SLE patients and 50 healthy individuals. EBV load was measured via real-time PCR assay. Sizing and quantification of plasma cfDNA was performed on Bioanalyzer. We proposed that the uniformity of cfDNA fragmentation can be described using cfDNA fragmentation index. RESULTS: SLE patients with chronic kidney disease (CKD +) had higher EBV load compared to CKD(-) patients (P = 0.042). Patients with high cfDNA level had higher EBV load (P = 0.041) and higher cfDNA fragmentation index (P < 0.001) compared to patients with low cfDNA level. Among patients with high cfDNA level, EBV load was higher in CKD(+) group compared to CKD(-) group (P = 0.035). EBV load was positively correlated with the fragmentation index in all SLE patients (P = 0.028, R2 = 0.13), and the correlation was even more pronounced in CKD (+) patients (P < 0.001, R2 = 0.20). CONCLUSIONS: We showed that EBV load was associated with non-uniform cfDNA fragmentation, higher cfDNA levels, and kidney disease in SLE patients. Although the causality of this relationship could not be determined with the current study, it brings rationale for further investigations on the role of EBV and cfDNA interplay in SLE pathogenesis.

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.

Cell-free DNA profiling in patients with lupus nephritis.

BACKGROUND: Increased level of cell-free DNA (cf-DNA) is associated with systemic lupus erythematosus (SLE) and might be related to disease activity. The aim of this study was to evaluate whether cfDNA integrity, size distribution and concentration of different cfDNA fractions is associated with lupus activity and kidney involvement. METHODS: Blood samples were collected from 43 SLE patients and 50 healthy controls. Nuclear and mitochondrial fractions of cfDNA and intracellular DNA were quantified by real-time qPCR. Sizing and quantification of total cfDNA level was performed on Bioanalyzer. RESULTS: We determined four parameters that characterized cfDNA profile: fragmentation index, ratio of intra- to extracellular mtDNA copy number, cfDNA concentration, and presence of 54-149 bp and 209-297 bp fragments. Patients with healthy-like cfDNA profile had higher eGFR (P = 0.009) and more often no indications for kidney biopsy or less advanced lupus nephritis (LN) (P = 0.037). In contrary, SLE patients with distinct cfDNA profile (characterized by increased cfDNA concentration and fragmentation, higher discrepancy between intra- to extracellular mtDNA copy number, and the presence of 54-149 bp and 209-297 bp fragments) had lower eGFR (P = 0.005) and more often advanced LN or history of renal transplantation (P = 0.001). CONCLUSIONS: We showed that cfDNA profiling may help to distinguish SLE patients with renal involvement and severe disease course from patients with more favorable outcomes. We suggest cfDNA profile a promising SLE biomarker.

Hybrid procedures in the dialysis fistula aneurysm treatment.

OBJECTIVES: Dialysis fistula aneurysms are common complications which in selective cases require surgical revision. It is recommended to detect and treat outflow stenosis concurrent with a dialysis fistula aneurysm, but usually, the treatment is divided into two stages - the open and endovascular stages are performed separately. We describe the results of hybrid procedures composed of aneurysm resection and endovascular correction for outflow veins performed for a dialysis fistula aneurysm treatment. METHODS: From March 2012, we performed hybrid procedures in 28 patients to correct dialysis fistula aneurysms. Patients, dialysis access, operative data, and the results obtained during a median follow-up of 28.5 months were analyzed. RESULTS: For dialysis fistula aneurysm correction, we performed 27 bypasses and 1 aneurysmorraphy. For outflow vein stenosis correction, we performed standard balloon angioplasty, no stents or stentgraft were used. The average increase in minimal diameter after angioplasty was 135.5% (range 57-275%). The 12- and 24-month primary patency rates of corrected fistulas in the observed group were 92.3% and 80%, respectively. A significant difference in the one-year patency rates between the urgent and planned procedures was observed (81.2% vs. 100%, respectively). No early complications related to endovascular or open procedures were observed. Late complications were observed in seven patients (25%) - mainly thrombosis caused by the recurrence of outflow vein stenosis (six patients, 21.5%), infection, lymphocele, and hematoma (one case of each complication). CONCLUSIONS: A hybrid procedure for the surgical correction of dialysis fistula aneurysms with the simultaneous correction of outflow pathologies enables effective long-term treatment. The obtained data showed the efficiency and good results of this procedure. Procedures performed for urgent indications significantly increase the risk for later complications, especially fistula thrombosis and loss of dialysis access.

IL 6 but not TNF is linked to coronary artery calcification in patients with chronic kidney disease.

INTRODUCTION: Patients with chronic kidney disease (CKD) have a high risk of death mainly due to cardiovascular diseases (CVD). Early risk identification may allow interventions and prevention of fatal events. OBJECTIVES: The study aim was to assess the usefulness of selected CVD biomarkers as predictors of 5-year mortality in patients with different CKD stages. PATIENTS AND METHODS: Study included 57 CKD patients: 38 in stage 5 (ESRD), 19 in stage 3 and 4 (CKD3-4), and 19 healthy controls. Blood samples were obtained once to measure fetuin A, adiponectin, leptin, tumor necrosis factor (TNF), interleukin-6 (IL-6), metalloproteinase-9 (MMP9), intracellular-1 (ICAM1) and vascular-1 (VCAM1) adhesion molecules (ELISA or Luminex platform). Computed tomography was performed to assess the calcium score (CS). Patients were prospectively followed for 5 years to evaluate their all-cause mortality. RESULTS: Serum VCAM1, TNF and IL-6 were significantly higher in more advanced CKD stages. VCAM1 correlated significantly with ICAM1, TNF and IL-6. TNF and IL-6 were also significantly correlated with each other. No significant changes were detected for other markers. IL-6 correlated significantly with CS, age, renal function and CRP. Elevated CS and IL-6 increased over 3 times the 5-year all-cause and cardiovascular mortality risks in patients with CKD or ESRD at baseline. CONCLUSIONS: IL-6 and CS were significantly associated with 5-year risk of all-cause mortality in CKD patients. Our study suggests an involvement of chronic inflammation linked to coronary artery calcification that is likely to contribute to the cardiovascular mortality in patients with impaired renal function.

Effects of liver transplantation on health-related quality of life in patients with primary biliary cholangitis.

BACKGROUND: Patients with primary biliary cholangitis (PBC) have decreased health-related quality of life (HRQoL). Here, we investigate HRQoL in two cohorts of transplanted patients with PBC and compare their results to healthy subjects. PATIENTS AND METHODS: We used generic SF-36 and disease-specific PBC-40 questionnaires to evaluate HRQoL in 26 patients with PBC (23 females, age 59.4 ± 5.7 years) before and after liver transplantation (LT), and in 107 patients with PBC (99 females, age 62.8 ± 6.7 years) who were previously transplanted. The control group was comprised of 60 healthy controls (55 females, age 54.6 ± 8.8 years). RESULTS: Health-related quality of life improved after LT in 85% of PBC patients. The SF-36 measure showed significant (all P < 0.05) improvements in the majority of domains after LT, and in the summary scores both physical and mental. We also documented significant improvements in pruritus and fatigue after LT (all P < 0.01). However, liver graft recipients had significantly worse physical functioning, physical role, and emotional role domains, and physical component score (all P < 0.001), as compared to healthy subjects. No differences in HRQoL were detected between patients evaluated after short and prolonged post-LT periods (P > 0.05). CONCLUSION: Liver transplantation substantially improves most aspects of life quality in PBC patients. Nevertheless, their HRQoL remains worse in comparison to healthy individuals, mainly in physical aspects.

The role and diagnostic value of cell-free DNA in systemic lupus erythematosus.

Cell-free DNA (cfDNA) represents a small fraction of total DNA pool that circulates freely in the blood both in normal and pathological conditions. Data indicate that cfDNA plays an important role in the pathogenesis of systemic lupus erythematosus (SLE) and hypomethylation may be crucial for its immunogenic properties. Although differences in quantification methodology hinder the comparison of results between the studies, it appears that levels of cfDNA are abnormally elevated in SLE patients and correlate with various antibody titers, but not with disease activity. Increased cfDNA concentration, however, may be associated with active lupus nephritis. Most of the studies confirmed apoptosis as the major cfDNA release mechanism in various conditions, but formation of neutrophil extracellular traps may significantly contribute to the cfDNA generation in SLE patients. In this review, we summarise current knowledge about the role and possible origin of cfDNA in SLE patients, and discuss why cfDNA testing for diagnostic and prognosis of SLE remains questionable.

The use of nonsteroidal anti-inflammatory drugs and analgesics by liver transplant recipients.

AIMS AND OBJECTIVES: This study aimed to assess the reasons and the frequency of the use of over-the-counter (OTC) nonsteroidal anti-inflammatory drugs (NSAIDs) or analgesics by liver transplant recipients (LTR). Patient awareness of possible drug-related side-effects was also assessed. BACKGROUND: NSAIDs and analgesics available without prescription belong to the most commonly used class of drugs. However, use of these drugs might be complicated by toxic adverse effects (AEs). Patients at risk for AEs include the transplant recipients. DESIGN/METHODS: This was a descriptive study. An anonymous survey was carried out in 73 randomly selected LTR, who represented 10% of all LTR at our centre. RESULTS: There were 64% of the patients who confirmed taking NSAIDs or analgesics; 16% of these patients took these drugs at least several times a week and 10% took them daily. For 39% of patients, the only way to manage their pain were OTC NSAIDs or analgesics. As many as 36% of patients were unaware of the risks associated with the use of these drugs. Ninety per cent of LTR consider physicians the most trusted source of drugs information. CONCLUSIONS: Our study shows that two-thirds of LTR take OTC NSAIDs or analgesics and one-third are unaware of the AEs associated with these drugs. Therefore, both transplant nurses and doctors should educate their patients about the use and possible AE of these drugs. RELEVANCE TO CLINICAL PRACTICE: Considering the high NSAIDs consumption rates, the side effects of these drugs should always be suspected. Especially in patients taking these drugs and referring to medical advisors with specific symptoms, such as: abdominal pain, anaemia, elevated serum creatinine concentration or liver enzymes activity. Awareness of the scale of the problem enables health professionals to cooperate in educating patients. Such practices may reduce uncontrolled abuse of these drugs and related health care costs.

Uterine Artery Pulsatility Index in Pregnant Kidney or Liver Recipients and Its Impact on Perinatal Outcome.

BACKGROUND: The uterine artery pulsatility index (UtA PI) is associated with blood flow to the placenta. Its increased values imply impaired placentation. This study aimed to evaluate UtA PI measurements in first-trimester ultrasound in pregnancies after kidney (KTx) or liver transplantation (LTx) and its relationship with perinatal outcome. MATERIALS AND METHODS: A retrospective analysis of 72 pregnancies in female kidney (35) or liver (37) transplant recipients between 2017 and 2023 was performed. Data concerning UtA PI were available for 17 kidney and 19 liver recipients. Statistical analysis of variables between KTx and LTx groups and the correlation with perinatal outcomes was performed using Student's t test and Pearson's correlation with P < .05 considered statistically significant. RESULTS: The mean UtA PI results were similar, and there were no statistical differences between the group of pregnant kidney and liver recipients with mean values of 1.46 (SD 0.44] and 1.73 (SD 0.51] respectively (P = .10). The mean neonate birth weight was lower in KTx group (2158 g ([SD 723 g]) compared with the LTx group (2780 g [SD 754g]; P =.02). In the KTx and LTx groups, mean UtA PI was in negative correlation with Apgar score in the first minute (P = .04, P = .01 respectively). CONCLUSIONS: Uterine artery Doppler is useful in predicting perinatal outcomes in the general population and organ recipient pregnancies, even in the early stages of pregnancy, as we observed the correlation between UtA PI and Apgar score. Pregnant kidney recipients remain at higher risk for complications and more unpredictable outcomes than liver recipients.

Anti-HLA and anti-MICA antibodies in liver transplant recipients: effect on long-term graft survival.

OBJECTIVE: Presence of anti-HLA antibodies has a well-known impact on kidney grafts survival; however their role in liver transplantation has not been fully elucidated. We conducted a 7-year prospective study to show correlation between presence of anti-HLA and anti-MICA antibodies and liver graft survival. METHODS: Blood samples from 123 liver transplant recipients were collected during patients routine visits. Time from transplantation to blood sample collection was different for each patient. Blood samples were tested for anti-HLA (separately class I and II) and MICA antibodies using Luminex assays. RESULTS: There were 32 (26%) patients with positive anti-HLA and 37 (30%) with positive anti-MICA antibodies. Graft loss occurred in 7 cases (23%) in anti-HLA positive group compared to 20 (22%) in anti-HLA negative group (P = ns) and in 8 cases (22%) in anti-MICA positive group but 19 (23%) in anti-MICA negative group (P = ns). No correlations were detected between presence of antibodies and acute graft rejection (AGR). Presence of any antibodies (anti-HLA or anti-MICA antibodies) correlated with late graft rejection (P = 0.04). CONCLUSION: Presence of anti-HLA or anti-MICA had no impact on long-term liver graft survival; however, detection of any antibodies was correlated with episodes of late graft rejection.

Results of liver transplantation in the Department of General, Transplant and Liver Surgery at the Medical University of Warsaw in patients with chronic hepatitis B and C viruses infection.

INTRODUCTION: Cirrhosis related to hepatitis C virus (HCV) and hepatitis B virus (HBV) infection is the most frequent indication for liver transplantation worldwide. Progress in prophylaxis of posttransplant HBV recurrence has led to major improvements in long-term outcomes of patients after liver transplantation. Conversely, impaired posttransplant survival of patients with HCV infection was reported in several studies, mainly due to recurrence of viral infection. The purpose of this study was to compare long-term results of liver transplantation between patients with HBV monoinfection, HCV monoinfection and HBV/HCV coinfection. MATERIAL AND METHODS: A total of 1090 liver transplantations were performed in the Department of General, Transplant and Liver Surgery in cooperation with the Department of Immunology, Internal Medicine, and Transplantology at the Transplantation Institute Medical University of Warsaw between December 1994 and May 2012. After exclusion of patients with cirrhosis of non-viral etiology, patients with malignant tumors, and patients with acute liver failure, the final study cohort comprised 209 patients with HBV (HBV+/HCV- subgroup; n = 56) or HCV (HBV-/HCV+ subgroup; n = 119) monoinfection or HBV/HCV coinfection (HBV+/HCV+; n = 34). These subgroups of patients were compared in terms of long-term results of transplantations, defined by 5-year patient and 5-year graft survival estimates. RESULTS: Overall and graft survival rates after 5-years for the whole study cohort were 74.5% and 72.6%, respectively. Five-year overall survival was 70.4% for patients within the HBV+/HCV- subgroup, 77.8% for patients within the HBV-/HCV+ subgroup, and 68.5% for patients within the HBV+/HCV+ subgroup. The corresponding rates of graft survival were 67.0%, 76.3%, and 68.5% for patients within the HBV+/HCV-, HBV-/ HCV+, and HBV+/HCV+ subgroups, respectively. Observed differences were non-significant, both in terms of overall (p = 0.472) and graft (p = 0.461) survival rates. CONCLUSIONS: Both overall and graft survival rates after liver transplantations performed in the Department of General, Transplant and Liver Surgery in cooperation with the Department of Immunology, Internal Medicine, and Transplantology at the Transplantation Institute Medical University of Warsaw in patients with HBV and HCV infection are comparable to those reported by other European and American centers. In contrast to other studies, obtained results do not confirm the negative impact of HCV infection on long-term outcomes of patients.

Lupus Nephritis and Dysbiosis.

Lupus nephritis (LN) is one of the most common and serious complications of systemic lupus erythematosus (SLE). The risk factors for developing LN by SLE patients are not fully understood. They are considered to be a mix of genetic and environmental variables, one of them being dysbiosis, proposed recently to interfere with autoimmunity. As of yet, the relations between the human microbiome, its genetic determinants, individual variability and clinical consequences remain to be established. One of the major obstacles in studying them is the magnitude of confounders, such as diet, drugs, infections or antibiotics use. They also make comparison between the studies extremely complicated. We reviewed the available evidence for the interplay between microbiome, dysbiosis and mechanisms triggering the autoimmune responses and potentially contributing to LN development. One such mechanism is the stimulation of autoimmune responses by bacterial metabolites that can mimic autoantigens and cause antibody production. These mimicking microbial antigens seem to be a promising target for future interventions.

Hybrid Immunity Provides the Best COVID-19 Humoral Response in Immunocompromised Patients with or without SARS-CoV-2 Infection History.

Immunization against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has significantly limited the spread of coronavirus disease 2019 (COVID-19) and reduced the associated complications, especially mortality. To prolong immunity, an immune booster was implemented. We evaluated the role of SARS-CoV-2 infection history in the vaccination schedules of kidney and liver transplant recipients and patients with chronic kidney disease (CKD). To this end, we retrospectively analyzed the data of 78 solid organ transplantation (SOT) recipients and 40 patients with immunoglobulin A (IgA) nephropathy as representatives of the CKD group. Patients received two or three doses of the BNT162b2 vaccine. At the follow-up, antibody (Ab) titer, graft function, COVID-19 history, and patients' clinical condition were assessed. Ab level was higher after two doses in patients with a COVID-19 history over three doses in patients with no COVID-19 history. Compared to three doses, subjects who were administered two doses had a longer median time to infection. Positive antibodies, in response to the third dose, were not observed in up to 8.4% of SOT patients. The results show that the vaccination schedule should take into account the vaccine response rate and COVID-19 history. So-called hybrid immunity appears to be most efficient at providing humoral responses against SARS-CoV-2 infection in immunocompromised patients.

Nephro-oncology: clinical and biochemical aspects of kidney disease and cancer.

Onco-nephrology is a new field of medicine which combines many aspects of kidney injury in cancer patients and cancers in patients with kidney disease. This connection takes many forms and includes drug-induced nephrotoxicity, electrolyte disorders, numerous paraneoplastic syndromes and an increased rate cancers in dialysis and transplanted patients. The appropriate laboratory assessment of the kidney function allows to optimize chemotherapy and thus minimizes the risk of complications. This article focuses on acute kidney injury (AKI), chronic kidney disease (CKD), various electrolyte and acid-base disorders, the most common cancers after kidney transplantation and the kidney disorders associated with HSCT (hematopoietic stem cell transplantation). The possibility of the application of novel cancer therapy, such as cancer immunotherapy and proton therapy in transplant recipients was also discussed.

The Different Patterns of Over-the-Counter Nonsteroidal Anti-Inflammatory Drugs or Analgesics Use in Patients with Chronic Kidney Disease and the General Population.

Nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics are the most commonly used drugs worldwide and their availability over-the-counter is increasing. The aim of this study was to examine the frequency of their use as well as the awareness of the associated risk of side effects in patients with chronic kidney disease (CKD) compared to the patients at general practice (GP) offices. We found that 88.5% of the CKD and 97.1% of the GP group used NSAIDs and/or analgesics (p < 0.0001). Paracetamol was chosen the most often by both study groups, but the proportion of patients taking paracetamol was significantly higher in the CKD group (p < 0.006). On the contrary, the proportion of patients taking ibuprofen was significantly higher in GP group (p < 0.0001). Furthermore, almost 37% of CKD and 60% of GP patients never consult with their doctor before taking NSAIDs or analgesics. The influence of advertisements on the decision to take these drugs was found to be marginal in both groups. In conclusion, the NSAIDs and/or analgesics use is very common. The differences between the studied cohorts in self-decision making and the type of drugs used between the studied cohorts warrant tailored educational approaches.

Osteopontin-A Potential Biomarker for IgA Nephropathy: Machine Learning Application.

Many potential biomarkers in nephrology have been studied, but few are currently used in clinical practice. One is osteopontin (OPN). We compared urinary OPN concentrations in 80 participants: 67 patients with various biopsy-proven glomerulopathies (GNs)-immunoglobulin A nephropathy (IgAN, 29), membranous nephropathy (MN, 20) and lupus nephritis (LN, 18) and 13 with no GN. Follow-up included 48 participants. Machine learning was used to correlate OPN with other factors to classify patients by GN type. The resulting algorithm had an accuracy of 87% in differentiating IgAN from other GNs using urinary OPN levels only. A lesser effect for discriminating MN and LN was observed. However, the lower number of patients and the phenotypic heterogeneity of MN and LN might have affected those results. OPN was significantly higher in IgAN at baseline than in other GNs and therefore might be useful for identifying patients with IgAN. That observation did not apply to either patients with IgAN at follow-up or to patients with other GNs. OPN seems to be a valuable biomarker and should be validated in future studies. Machine learning is a powerful tool that, compared with traditional statistical methods, can be also applied to smaller datasets.

Organization of Post-Transplant Care and the 5-Year Outcomes of Kidney Transplantation.

The outcomes of kidney transplantation depend on numerous factors and vary between transplant centers. The aim of this study is to assess the relationship between selected organizational factors, comorbidities, and patient and graft survival. This is a retrospective analysis of 438 renal transplant recipients (RTR) followed for 5 years. Patient and graft survival were evaluated in relation to hospitalization length, distance from the patient's residence to the transplant center, the frequency of outpatient transplant visits, and the number and type of comorbidities. Five-year patient and graft survival rates were 93% and 90%, respectively. We found significant associations of patient survival with the prevalence of pre-transplant diabetes, cardiovascular diseases, malignancies, the number of comorbidities, and the first post-transplant hospitalization length. The incidence of infections, cardiovascular diseases, and transplanted kidney diseases was 60%, 40%, and 33%, respectively. As many as 41% of RTR had unknown etiology of primary kidney disease. In conclusion, the organization of post-transplant care needs to be adapted to the multi-morbidity of contemporary RTR and include multi-specialist care, especially in the context of current problems related to the COVID-19pandemic. The high proportion of patients with undetermined etiology of their primary renal disease carry the risk for additional complications during their long-term follow-up.

Comparison of Post-Transplantation Lymphoproliferative Disorder Risk and Prognostic Factors between Kidney and Liver Transplant Recipients.

Post-transplantation lymphoproliferative disorder (PTLD) is a life-threatening complication of solid organ transplantation (SOT). Its development risk varies among organ graft recipients. In this study, retrospective data were analyzed to compare PTLD's risk and prognostic factors between adult kidney and liver transplant recipients (KTRs and LTRs, respectively). Over 15 years, 2598 KTRs and 1378 LTRs were under observation at our center. Sixteen KTRs (0.62%) and twenty-three LTRs (1.67%) were diagnosed with PTLD. PTLD developed earlier in LTRs (p < 0.001), SOT patients > 45 years old (p = 0.002), and patients receiving tacrolimus (p < 0.001) or not receiving cyclosporin (p = 0.03) at diagnosis. Tacrolimus use, male sex, and age > 45 years old significantly affected the time of PTLD onset in KTRs (hazard ratio (HR) = 18.6, 7.9 and 5.2, respectively). Survival was longer in LTRs < 45 years old (p < 0.009). LTRs were more likely than KTRs to achieve complete remission (p = 0.039). Factors affecting PTLD development and outcome differ between KTRs and LTRs; thus, these populations should be separately evaluated in future studies.

Immunology and Donor-Specific Antibodies in Corneal Transplantation.

The first human corneal transplantation was performed in 1905 by Eduard Zirm in the Olomouc Eye Clinic, now Czech Republic. However, despite great advancements in microsurgical eye procedures, penetrating keratoplasty in high-risk patients (e.g., vascularized or inflamed corneal tissue, consecutive transplants) remains a challenge. The difficulty is mainly due to the risk of irreversible allograft rejection, as an ocular immune privilege in these patients is abolished and graft rejection is the main cause of corneal graft failure. Therefore, tailored immunosuppressive treatment based on immunological monitoring [e.g., donor-specific antibodies (DSA)] is considered one of the best strategies to prevent rejection in transplant recipients. Although there is indirect evidence on the mechanisms underlying antibody-mediated rejection, the impact of DSA on cornea transplantation remains unknown. Determining the role of pre-existing and/or de novo DSA could advance our understanding of corneal graft rejection mechanisms. This may help stratify the immunological risk of rejection, ultimately leading to personalized treatment for this group of transplant recipients.