An update on chemical pharmacotherapy options for the prevention of kidney transplant rejection with a focus on costimulation blockade

Long Term Outcomes of Transplant Recipients Comparing Belatacept vs. Tacrolimus: A UNOS Database Analysis

Calcineurin inhibitors have been the choice for maintenance immunosuppression (IS) in kidney transplant recipients (KTR), but they are associated with nephrotoxicity and metabolic side effects. We aim to compare the long-term outcomes of KTR on belatacept (bela) versus tacrolimus (tac) IS, in all KTRs and various subgroups. Using the UNOS-STAR files, we identified adult first-KTR from 2010 to 2022. Patients were categorized based on maintenance-IS at index transplant admission by creating a propensity score matched cohort at 1:5 rate using several clinical characteristics. Primary outcomes included patient death, graft failure (GF), and death-censored graft failure (DCGF). Secondary outcomes included delayed graft function (DGF), acute-rejections (AR) within a year, and serum creatinine (Cr) at 1-year. The propensity-matched cohort included KTRs on bela (N = 2612) and tac (N = 12760). There was no significant difference in the hazard ratio of death (1.03 [0.92, 1.14]), GF (1.07 [0.97, 1.17]), or DCGF (1.11 [0.98, 1.25]). A sensitivity analysis comparing a propensity-matched cohort of bela + tac (n = 2033) versus tac (n = 9004); demonstrated significantly reduced risks of death (0.87 [0.76-1.00], p = 0.043) and GF (0.73 [0.64-0.83] p < 0.001) compared to those on Tac alone. In conclusion, bela + tac seems to be a nephron-sparing and rejection-lowering IS regimen with overall improved graft and patient outcomes when compared to the current standard of tacrolimus. Larger Randomized Controlled studies are needed.

Acute diverticulitis in immunocompromised patients: evidence from an international multicenter observational registry (Web-based International Register of Emergency Surgery and Trauma, Wires-T)

BACKGROUND

Immunocompromised patients with acute diverticulitis are at increased risk of morbidity and mortality. The aim of this study was to compare clinical presentations, types of treatment, and outcomes between immunocompromised and immunocompetent patients with acute diverticulitis.

METHODS

We compared the data of patients with acute diverticulitis extracted from the Web-based International Registry of Emergency Surgery and Trauma (WIRES-T) from January 2018 to December 2021. First, two groups were identified: medical therapy (A) and surgical therapy (B). Each group was divided into three subgroups: nonimmunocompromised (grade 0), mildly to moderately (grade 1), and severely immunocompromised (grade 2).

RESULTS

Data from 482 patients were analyzed-229 patients (47.5%) [M:F = 1:1; median age: 60 (24-95) years] in group A and 253 patients (52.5%) [M:F = 1:1; median age: 71 (26-94) years] in group B. There was a significant difference between the two groups in grade distribution: 69.9% versus 38.3% for grade 0, 26.6% versus 51% for grade 1, and 3.5% versus 10.7% for grade 2 (p < 0.00001). In group A, severe sepsis (p = 0.027) was more common in higher grades of immunodeficiency. Patients with grade 2 needed longer hospitalization (p = 0.005). In group B, a similar condition was found in terms of severe sepsis (p = 0.002), quick Sequential Organ Failure Assessment score > 2 (p = 0.0002), and Mannheim Peritonitis Index (p = 0.010). A Hartmann's procedure is mainly performed in grades 1-2 (p < 0.0001). Major complications increased significantly after a Hartmann's procedure (p = 0.047). Mortality was higher in the immunocompromised patients (p = 0.002).

CONCLUSIONS

Immunocompromised patients with acute diverticulitis present with a more severe clinical picture. When surgery is required, immunocompromised patients mainly undergo a Hartmann's procedure. Postoperative morbidity and mortality are, however, higher in immunocompromised patients, who also require a longer hospital stay.

Incidences of infectious events in a renal transplant cohort of the German Center of Infectious Diseases (DZIF)

Background

Infectious complications are a major cause of morbidity and mortality after kidney transplantation.

Methods

In this transplant cohort study at the German Center of Infectious Diseases (DZIF), we evaluated all infections occurring during the first year after renal transplantation. We assessed microbial etiology, incidence rates, and temporal occurrence of these infections.

Results

Of 804 renal transplant recipients (65.2% male, 51 ± 14 years), 439 (54.6%) had 972 infections within the first year after transplantation. Almost half of these infections (47.8%) occurred within the first three months. Bacteria were responsible for 66.4% (645/972) of all infections, followed by viral (28.9%[281/972]) and fungal (4.7%[46/972]) pathogens. The urinary tract was the most common site of infection (42.4%). Enterococcus was most frequently isolated bacteria (20.9%), followed by E.coli (17.6%) and Klebsiella (12.5%). E.coli was the leading pathogen in recipients &lt;50 years of age, whereas Enterococcus predominated in older recipients. Resistant bacteria were responsible for at least one infection in 9.5% (76/804) of all recipients. Viral infections occurred in 201 recipients (25.0%). Of these, herpes viruses predominated (140/281[49.8%]) and cytomegalovirus had the highest incidence rate (12.3%). In the 46 fungal infections, Candida albicans (40.8%) was most commonly isolated. Other fungal opportunistic pathogens, including Aspergillus fumigatus and Pneumocystis, were rare.

Conclusions

Renal allograft recipients in Germany experience a high burden of infectious complications in the first year after transplantation. Bacteria were the predominating pathogen, followed by opportunistic infections such as cytomegalovirus. Microbial etiology varied between age groups and resistant bacteria were identified in 10% of recipients.

Monitoring of gene expression in tacrolimus-treated de novo renal allograft recipients facilitates individualized immunosuppression: Results of the IMAGEN study

AIMS

Calcineurin inhibitors (CNI) have a small therapeutic window, and drug monitoring is required. Pharmacokinetic monitoring does not correlate sufficiently with clinical outcome. Therefore, the expression of nuclear factor of activated T cells (NFAT)-regulated genes in the peripheral blood has been suggested as a potentially useful immune monitoring tool to optimize CNI therapy. NFAT-regulated gene expression (RGE) was evaluated in renal allograft recipients as predictive biomarker to detect patients at risk of acute rejection or infections.

METHODS

NFAT-RGE (interleukin-2, interferon-γ, granular-macrophage colony-stimulating factor) was evaluated by quantitative real-time polymerase chain reaction in whole blood samples at day 7, day 14, month 1, 3, and 6 after transplantation in 64 de novo renal allograft recipients from 3 European centres. Immunosuppression consisted of tacrolimus (Tac), mycophenolic acid, and corticosteroids.

RESULTS

Tac concentrations (C0 and C1.5) correlated inversely with NFAT-RGE (P < .01). NFAT-RGE showed a high interindividual variability (1-61%). Patients with high residual gene expression (NFAT-RGE ≥30%) were at the increased risk of acute rejection in the following months (35 vs. 5%, P = .02), whereas patients with low residual gene expression (NFAT-RGE <30%) showed a higher incidence of viral complications, especially cytomegalovirus and BK virus replication (52.5 vs. 10%, P = .01).

CONCLUSIONS

NFAT-RGE was confirmed as a potential noninvasive early predictive biomarker in the immediate post-transplant period to detect patients at risk of acute rejection and infectious complications in Tac-treated renal allograft recipients. Monitoring of NFAT-RGE may provide additional useful information for physicians to achieve individualized Tac treatment.

Belatacept in Solid Organ Transplant: Review of Current Literature Across Transplant Types

Calcineurin inhibitors (CNIs) have been the backbone immunosuppressant for solid organ transplant recipients for decades. Long-term use of CNIs unfortunately is associated with multiple toxicities, with the biggest concern being CNI-induced nephrotoxicity. Belatacept is a novel agent approved for maintenance immunosuppression in renal transplant recipients. In the kidney transplant literature, it has shown promise as being an alternative agent by preserving renal function and having a minimal adverse effect profile. There are emerging studies of its use in other organ groups, particularly liver transplantation, as well as using with other alternative immunosuppressive strategies. The purpose of this review is to analyze the current literature of belatacept use in solid organ transplantation and discuss its use in current practice.