Heart transplantation across preformed donor-specific antibody barriers using a perioperative desensitization protocol.

Heart transplantation across preformed donor-specific HLA-antibody barriers is associated with impaired short- and long-term survival. Therefore, in recipients with preformed anti-HLA antibodies, waiting for crossmatch-negative donors is standard practice. As an alternative strategy, recipients with preformed anti-HLA donor specific antibodies have been managed at our institutions with a perioperative desensitization regimen. A retrospective analysis was performed comparing heart transplant recipients with preformed donor-specific HLA-antibodies to recipients without donor-specific antibodies. Recipients with a positive virtual crossmatch received a perioperative desensitization protocol including tocilizumab intraoperatively, plasma exchange and rituximab followed by a six-month course of IgGAM. Among the 117 heart-transplanted patients, 19 (16%) patients underwent perioperative desensitization, and the remaining 98 (84%) patients did not. Cold ischemic time, posttransplant extracorporeal life support for primary graft dysfunction, and intensive care unit stay time did not differ between groups. At 1-year follow-up, freedom from pulsed steroid therapy for presumed rejection and biopsy-confirmed acute cellular or humoral rejection did not differ between groups. One-year survival amounted to 94.7% in the treated patients and 81.4% in the control group. Therefore, heart transplantation in sensitized recipients undergoing a perioperative desensitization appears safe with comparable postoperative outcomes as patients with a negative crossmatch.

Impact of perioperative blood transfusions on postoperative renal function and survival after resection of colorectal liver metastases.

BACKGROUND AND AIMS: Recent studies focusing on thoracic surgery suggest postoperative kidney injury depending on the amount of perioperative blood transfusions. Data investigating similar effects after resection of colorectal liver metastases (CRLM) are not available. Aim of this study was therefore to evaluate the influence of perioperative blood transfusions on postoperative renal function and survival after resection of CRLM. METHODS: Seven hundred twenty-seven cases of liver resection for CRLM were retrospectively analyzed. Renal function was measured via estimated glomerular filtration rate (eGFR) and a postoperative decline of ≥ 10% was considered substantial. Potential influences on postoperative kidney function were assessed using univariable and multivariable logistic regression analyses. Cox-regression analyses were performed to estimate the impact on overall survival (OS). RESULTS: Preoperative impaired kidney function (p = 0.001, OR 2.477) and transfusion of > 2 units of packed red blood cells (PRBC) (p = 0.046; OR 1.638) were independently associated with an increased risk for ≥ 10% loss of renal function. Neither a pre-existing renal impairment, nor the additional loss of renal function were associated with reduced survival. Chemotherapies in the context of primary colorectal cancer treatment (p = 0.002), age > 70 years at liver resection (p = 0.005), number (p = 0.001), and size of metastases > 50 mm (p = 0.018), duration of resection > 120 min (p = 0.006) and transfusions of > 2 units of PRBC (p = 0.039) showed a negative independent influence on OS. CONCLUSION: The results demonstrate a negative impact of perioperative blood transfusions on the postoperative renal function and OS. Hence, efforts to reduce blood transfusions should be intensified.

B cell depletion impairs vaccination-induced CD8+ T cell responses in a type I interferon-dependent manner.

OBJECTIVES: The monoclonal anti-CD20 antibody rituximab is frequently applied in the treatment of lymphoma as well as autoimmune diseases and confers efficient depletion of recirculating B cells. Correspondingly, B cell-depleted patients barely mount de novo antibody responses during infections or vaccinations. Therefore, efficient immune responses of B cell-depleted patients largely depend on protective T cell responses. METHODS: CD8+ T cell expansion was studied in rituximab-treated rheumatoid arthritis (RA) patients and B cell-deficient mice on vaccination/infection with different vaccines/pathogens. RESULTS: Rituximab-treated RA patients vaccinated with Influvac showed reduced expansion of influenza-specific CD8+ T cells when compared with healthy controls. Moreover, B cell-deficient JHT mice infected with mouse-adapted Influenza or modified vaccinia virus Ankara showed less vigorous expansion of virus-specific CD8+ T cells than wild type mice. Of note, JHT mice do not have an intrinsic impairment of CD8+ T cell expansion, since infection with vaccinia virus induced similar T cell expansion in JHT and wild type mice. Direct type I interferon receptor signalling of B cells was necessary to induce several chemokines in B cells and to support T cell help by enhancing the expression of MHC-I. CONCLUSIONS: Depending on the stimulus, B cells can modulate CD8+ T cell responses. Thus, B cell depletion causes a deficiency of de novo antibody responses and affects the efficacy of cellular response including cytotoxic T cells. The choice of the appropriate vaccine to vaccinate B cell-depleted patients has to be re-evaluated in order to efficiently induce protective CD8+ T cell responses.

Non-invasive screening for subclinical liver graft injury in adults via donor-specific anti-HLA antibodies.

The majority of liver grafts exhibit abnormal histological findings late after transplantation, even when liver enzymes are normal. Such subclinical graft injuries were associated with rejection and fibrosis progression in recent studies. The identification of non-invasive biomarkers for subclinical graft injury might help to individualize immunosuppression. Therefore, graft injury was assessed in 133 liver biopsies with normal/near normal liver enzymes from a prospective liver biopsy program. Cytokeratin-18 cell death marker (M65) and donor specific anti-HLA antibodies (DSA) were measured as non-invasive markers in paired plasma samples in addition to routine parameters. M65 was associated with subclinical graft injury but this association was too weak for reasonable clinical application. DSA positivity was associated with more graft inflammation (OR = 5.4) and more fibrosis (OR = 4.2). Absence of DSA excluded fibrosis in 87-89%, while presence of DSA excluded histological criteria for immunosuppression minimization attempts in 92-97%. While CK18 cell death marker had no diagnostic value for the detection of subclinical liver graft injury, DSA testing can help to preselect patients for immunosuppression reduction in case of DSA negativity, while DSA positivity should prompt elastography or liver biopsy for the assessment of subclinical graft injury.

Variation in the Human Leukocyte Antigen system and risk for endemic Burkitt lymphoma in northern Uganda.

Endemic Burkitt lymphoma (eBL) is an aggressive childhood B-cell lymphoma associated with Plasmodium falciparum (Pf) malaria and Epstein-Barr virus (EBV) infections. Variation in the Human Leukocyte Antigen (HLA) system is suspected to play a role, but assessments using less accurate serology-based HLA typing techniques in small studies yielded conflicting results. We studied 200 eBL cases and 400 controls aged 0-15 years enrolled in northern Uganda and typed by accurate high-resolution HLA sequencing methods. HLA results were analyzed at one- or two-field resolution. Odds ratios and 95% confidence intervals (aOR, 95% CI) for eBL risk associated with common HLA alleles versus alleles that were rare (<1%) or differed by <2% between the cases and controls as the reference category, were estimated using multiple logistic regression adjusting for age, sex, microgeography, region, malaria positivity and treatment history, and genetic variants associated with eBL. Compared to the controls, eBL cases had a lower frequency of HLA-A*02 (aOR = 0·59, 95% CI 0·38-0·91), HLA-B*41 (aOR = 0·36, 95% CI 0·13-1·00), and HLA-B*58 alleles (aOR = 0·59, 95% CI 0·36-0·97). eBL cases had a lower frequency of HLA-DPB1 homozygosity (aOR = 0·57, 95% CI 0·40-0·82) but a higher frequency of HLA-DQA1 homozygosity (aOR = 2·19, 95% CI 1·42-3·37). Our results suggest that variation in HLA may be associated with eBL risk.

DSA Are Associated With More Graft Injury, More Fibrosis, and Upregulation of Rejection-associated Transcripts in Subclinical Rejection.

BACKGROUND: Subclinical T cell-mediated rejection (subTCMR) is commonly found after liver transplantation and has a good short-term prognosis, even when it is left untreated. Donor-specific antibodies (DSA) are putatively associated with a worse prognosis for recipient and graft after liver transplantation. METHODS: To assess the immune regulation in subTCMR grafts, gene expression of 93 transcripts for graft injury, tolerance, and immune regulation was analyzed in 77 biopsies with "no histologic rejection" (NHR; n = 25), "clinical TCMR" (cTMCR; n = 16), and subTCMR (n = 36). In addition, all available subTCMR biopsies (n = 71) were tested for DSA with bead assays. RESULTS: SubTCMR showed heterogeneous and intermediate expression profiles of transcripts that were upregulated in cTCMR. Graft gene expression suggested a lower activation of effector lymphocytes and a higher activation of regulatory T cells in grafts with subTCMR compared to cTCMR. DSA positivity in subTCMR was associated with histological evidence of more severe graft inflammation and fibrosis. This more severe DSA+ associated graft injury in subTCMR was converged with an upregulation of cTCMR-associated transcripts. In nonsupervised analysis, DSA positive subTCMR mostly clustered together with cTCMR, while DSA negative subTCMR clustered together with NHR. CONCLUSIONS: T cell-mediated rejection seems to form a continuum of alloimmune activation. Although subTCMR exhibited less expression of TCMR-associated transcript, DSA positivity in subTCMR was associated with an upregulation of rejection-associated transcripts. The identification of DSA positive subclinical rejection might help to define patients with more inflammation in the graft and development of fibrosis.

Kidney graft survival of >25 years: a single center report including associated graft biopsy results.

Only few centers have reported their observations on patients with very long-term kidney graft survival of more than 25 years. Eighty-six subjects were identified in our center with graft survival of >25 years. Donor age was 31.3 ± 18.5 years. Mean duration of transplantation was 30.3 ± 3.6 years. At last follow-up, the cystatin C clearance was 47 ± 23 ml/min. Transplant biopsies for cause were performed in 30 subjects at a median of 28.4 years (19.1-40.3) after transplantation. Acute or chronic active T cell-mediated rejection was present in five cases and histological characteristics of acute or chronic active humoral rejection in eight cases. More than 80% of biopsies had inflammatory infiltrates in nonatrophic or atrophic cortical areas. The number of HLA mismatches were higher in biopsied subjects (3.0 ± 1.8 vs. 2.2 ± 1.7 without biopsy). Immunosuppressive therapy was adapted in most biopsied subjects; impaired graft function and proteinuria was unchanged at last follow-up. Sixty percent of all subjects had hyperparathyroidism (iPTH of the whole group: 132 ± 157 pg/ml), which was predominantly secondary, as judged by serum calcium and graft function. Young donor age was certainly a prerequisite of longterm graft survival. Nonetheless, inflammation or rejection in most biopsied patients suggests an important role of alloreactivity even in this late course.

Preemptive treatment of early donor-specific antibodies with IgA- and IgM-enriched intravenous human immunoglobulins in lung transplantation.

This retrospective study presents our 4-year experience of preemptive treatment of early anti-HLA donor specific antibodies with IgA- and IgM-enriched immunoglobulins. We compared outcomes between patients with antibodies and treatment (case patients) and patients without antibodies (control patients). Records of patients transplanted at our institution between March 2013 and November 2017 were reviewed. The treatment protocol included one single 2 g/kg immunoglobulin infusion followed by successive 0.5 g/kg infusions for a maximum of 6 months, usually combined with a single dose of anti-CD20 antibody and, in case of clinical rejection or positive crossmatch, with plasmapheresis or immunoabsorption. Among the 598 transplanted patients, 128 (21%) patients formed the case group and 452 (76%) the control group. In 116 (91%) patients who completed treatment, 106 (91%) showed no antibodies at treatment end. Fourteen (13%) patients showed antibody recurrence thereafter. In case versus control patients and at 4-year follow-up, respectively, graft survival (%) was 79 versus 81 (P = .59), freedom (%) from biopsy-confirmed rejection 57 versus 53 (P = .34), and from chronic lung allograft dysfunction 82 versus 78 (P = .83). After lung transplantation, patients with early donor-specific antibodies and treated with IgA- and IgM-enriched immunoglobulins had 4-year graft survival similar to patients without antibodies and showed high antibody clearance.

Macrophage density in early surveillance biopsies predicts future renal transplant function.

Inflammation impairs renal allograft survival but is difficult to quantify by eye at low densities. Here we measured leukocyte abundance in early surveillance biopsies by digital image analysis to test for a role of chemokine receptor genotypes and analyze the predictive value of leukocyte subsets to allograft function. In six-week surveillance biopsies, T-cell (CD3), B-cell (CD20), macrophage (CD68), and dendritic cell (CD209) densities were assessed in whole slide scans. Renal cortical CD3, CD20, and CD68 were significantly higher in histologic rejection. The CCR2 V64I genotype was associated with lower CD3 and CD209 densities. Above-median CD68 density was significantly associated with lower combined patient and graft survival with a hazard ratio of 3.5 (95% confidence interval 1.1-11.0). Both CD20 and CD68 densities inversely correlated with estimated glomerular filtration rate (eGFR) four years after transplantation. Additionally, CD68 correlated with eGFR loss. Among histological measurements including a complete Banff classification, only CD68 density was a significant predictor of an eGFR under 30ml/min after four years (odds ratio 7.4, 1.8-31.0) and part of the best eGFR prediction set in a multivariable linear regression analysis of multiple clinical and pathologic parameters. In a second independent cohort, the original CD68 median maintained its discriminative power for survival and eGFR. Thus, digital high-resolution assessment of CD68+ leukocyte infiltration significantly improves prognostic value of early renal transplant biopsies.

Repeated human leukocyte antigen mismatches in lung re-transplantation.

BACKGROUND: The role of HLA-sensitization in the absence of detectable DSA in lung re-transplantation is unclear. Antigens of the second donor matching the HLA typing of the first donor are considered 'unacceptable', by some tissue typing laboratories, especially in kidney re-transplantation. METHODS: Thus, we performed a retrospective analysis of all lung re-transplantations focussing on the impact of HLA-homologies between the first and the second donor ('unacceptable' antigens; repeated HLA mismatch) on patient and graft survival. RESULTS: A total of 132 lung re-transplantations were performed at our centre between 1985 and 2014, of which 120 with complete HLA data were analysed. 55.8% of the recipients received re-transplants with repeated HLA mismatched antigens whereas 43.2% of the re-transplants were transplanted without repeated HLA mismatched antigens. Postoperative survival showed no difference between re-transplant procedures with or without repeated HLA mismatches (p=0.99). While neither homologies on the HLA-A, -B, -C, or -DR locus, nor the addition of several locus homologies (p=0.72) had an impact on survival, unexpectedly, repeated HLA mismatching on the HLA-DQ locus was correlated with better survival. Re-transplantations with repeated HLA mismatches did not result in more development of CLAD as compared to recipients without repeated HLA mismatches (p=0.99). Neither the number of repeated HLA mismatched antigens (p=0.52) nor the HLA locus (HLA-A(p=0.34), HLA-B(p=0.97), HLA-C (p=0.80), HLA-DR(p=0.49) and HLA-DQ(p=0.07)) had an impact on the development of CLAD after re-transplantation. CONCLUSION: Transplantation with repeated HLA mismatches due to sensitization by a previous transplantation in the absence of detectable HLA-antibodies does not have a negative impact on patient or graft survival.

Human leucocyte antigens and pediatric autoimmune liver disease: diagnosis and prognosis.

UNLABELLED: An association of human leukocyte antigen (HLA) class II alleles with autoimmune conditions is increasingly being used for diagnostic purposes. The aim of our study was to examine whether HLA class II alleles in pediatric-onset autoimmune liver disease (pAILD) may serve as diagnostic markers and if they correlate with clinical outcome parameters. HLA-DRB1 alleles of 76 children with pAILD (autoimmune hepatitis [AIH], autoimmune sclerosing cholangitis [AISC], primary sclerosing cholangitis [PSC]) and of 50 healthy blood donors as control group were analyzed retrospectively. Diagnosis of these patients was confirmed by the autoimmune hepatitis score including liver histology, which has been re-evaluated by a blinded liver pathologist, and by bile duct imaging, as appropriate. Our results showed significant association of HLA-DRB1*03 with AIH1 and AISC with 82 % specificity for AIH. For pAILD (excluding AIH2), HLA-DRB1*03 homozygosity had specificity of 98 %, whereas sensitivity is low. Remission in HLA-DRB1*03-positive patients appears to be less likely. HLA-DRB1*13 is significantly associated with PSC and also with AIH1. CONCLUSION: HLA-DRB1 alleles provide supportive information for diagnostic workup in patients with liver disease, but they were not suitable for differentiation within pAILD. Their prognostic value could be helpful but needs to be evaluated further. WHAT IS KNOWN: • HLA-DRB1*03 is NOT associated with pediatric AIH in a previous national study. • In other studies, HLA-DRB1*03 is associated with AIH1. • HLA-DRB1*13 is associated with PSC. • HLA-DRB1*04 is described as protective for AILD. What is New: • HLA-DRB1 four-digit typing for all alleles and for all subgroups of pAILD combined with re-assessment of liver histology • HLA-DRB1*03:01 is associated with pediatric AIH1 and AISC. • HLA-DRB1*03:01 appears to be a prognostic marker. • HLA-DRB1*13:01 is associated with pediatric AIH1 in mixed ethnicity cohort. • HLA-DRB1*04 does not show any protective effect for pAILD.

IgM-Enriched Human Intravenous Immunoglobulin-Based Treatment of Patients With Early Donor Specific Anti-HLA Antibodies After Lung Transplantation.

BACKGROUND: At our institution, until April 2013, patients who showed early donor specific anti-HLA antibodies (DSA) after lung transplantation were preemptively treated with therapeutic plasma exchange (tPE) and a single dose of Rituximab. In April 2013, we moved to a therapy based on IgM-enriched human immunoglobulins (IVIG), repeated every 4 weeks, and a single dose of Rituximab. METHODS: This observational study was designed to evaluate the short-term patient and graft survival in patients who underwent IVIG-based DSA treatment (group A, n = 57) versus contemporary patients transplanted between April 2013 and January 2015 without DSA (group C, n = 180), as well as to evaluate DSA clearance in IVIG-treated patients versus historic patients who had undergone tPE-based treatment (group B, n = 56). Patient records were retrospectively reviewed. Follow-up ended on April 1, 2015. RESULTS: At 6 months and 1 year of follow-up, group A had a survival similar to group C (P = 0.81) but better than group B (P = 0.008). Group A showed statistically nonsignificant trends toward improved freedom from pulsed-steroid therapy and biopsy-confirmed rejection over groups B and C. The DSA clearance was better in group A than group B at treatment end (92% vs 64%; P = 0.002) and last DSA control (90% vs 75%; P = 0.04). CONCLUSIONS: Patients with new early DSA but without graft dysfunction that are treated with IVIG and Rituximab have similarly good early survival as contemporary lung transplant recipients without early DSA. The IVIG yielded increased DSA clearance compared with historic tPE-based treatment, yet spontaneous clearance of new DSA also remains common.

Long-term kidney allograft survival in patients with transplant glomerulitis.

BACKGROUND: Renal transplant glomerulitis (G) is associated with acute antibody-mediated rejection (ABMR) in the presence of donor-specific antibodies. However, the long-term prognosis of isolated G (isG) in the absence of donor-specific antibodies or G in combination with T cell-mediated rejection (TCMR) remains unexplored. METHODS: Seventy recipients with G were included in this retrospective study and subdivided into 3 groups: isG, G with TCMR (G+TCMR), and G with acute ABMR. The control groups were: patients with TCMR Banff type I or II without G (TCMR) and patients without rejection (NR). Kaplan-Meier death-censored survival plots and Cox regression were used to analyze graft survival. The combined graft survival endpoint was defined as a return to dialysis or estimated glomerular filtration rate less than 15 mL/min/1.73 m. The median follow-up was 37 (14; 77) months from biopsy. RESULTS: Graft survival was significantly lower in patients with G than in the NR and TCMR groups. No significant differences were observed among the isG, G+TCMR, and ABMR groups. Graft survival was lower in the G+TCMR group than in the TCMR group. Glomerulitis was independently associated with the risk of adverse graft outcome in a multivariate Cox regression model adjusted for other confounders (hazard ratio, 4.52 [95% confidence interval, 2.37-8.68] vs controls; P<0.001). CONCLUSIONS: Glomerulitis is strongly associated with increased risk of graft failure. Graft survival in patients with isG that do not meet the Banff criteria for acute/active ABMR and in patients with G accompanying TCMR is comparable to the ABMR group.

Preemptive treatment with therapeutic plasma exchange and rituximab for early donor-specific antibodies after lung transplantation.

OBJECTIVE: De novo donor-specific anti-human leukocyte antigen antibodies develop in a high proportion of lung transplant recipients early after lung transplantation. We recently showed that de novo donor-specific antibodies (DSA) occurrence is associated with significantly increased mortality. Here, we studied the efficacy of a preemptive treatment protocol. METHODS: A retrospective observational study was conducted on all lung transplantations at Hanover Medical School between January 2009 and May 2013. RESULTS: Among the 500 transplant recipients, early DSA developed in 86 (17%). Of these, 56 patients (65%; Group A) received therapeutic plasma exchange, and 30 patients (35%; Group B) did not. Among Group A patients, 51 also received rituximab. Between groups, there was no statistically significant difference in mortality, incidence of pulsed steroid therapies, rejections diagnosed by biopsy specimen, incidence of bronchitis obliterans syndrome (BOS), or infections requiring hospitalization at 1 year and 3 years. Also, there were no statistically significant differences after matching 21 Group A with 21 Group B patients through propensity score analysis. Significantly more Group A patients (65%) than Group B patients (34%) cleared DSA at hospital discharge (p = 0.01). At the last control after transplantation (median, 14 months; interquartile range, 5-24 months), 11 Group A (22%) and 9 Group B patients (33%) still showed DSA (p = 0.28). CONCLUSIONS: Preemptive treatment with therapeutic plasma exchange and rituximab led to improved elimination of DSA early after lung transplantation (p = 0.01). However, spontaneous elimination in untreated Group B patients also occurred frequently. This treatment protocol was not associated with significantly improved outcome.