Kidney Allograft Rejection and Coronavirus Disease 2019 Infection: A Narrative Review

Inappropriate Prescribing of Nirmatrelvir/Ritonavir in Solid Organ Transplantation With COVID-19 Infection: A Multicenter Retrospective Study

BACKGROUND

Nirmatrelvir-ritonavir (NR) has demonstrated effectiveness in halting the progression to severe coronavirus disease 2019 (COVID-19) among solid organ transplant recipients (SOTRs) infected with Severe Acute Respiratory Syndrome Coronavirus 2. However, it has a wide range of interactions, especially with immunosuppressants. The study aimed to comprehensively evaluate the Inappropriate prescribing of NR and immunosuppressants in SOTRs with COVID-19, while also highlighting the essential aspects.

METHODS

We included hospitalized SOTRs who received NR at five tertiary hospitals between December 2022 and June 2023, and evaluated their prescription.

RESULTS

A total of 211 patients were enrolled, of which 205 did not meet all criteria for appropriate prescribing (97.16%). Inappropriateness primarily stemmed from starting treatment more than 5 days after symptom onset (87.68%), followed by application in severe-to-critical cases of COVID-19 (52.13%), the inappropriate dosages based on renal function (47.87%). Contraindications encompassed 17.06% of patients with severe renal impairment and 5.69% with contraindicated drug interactions. Inappropriate resumption of immunosuppressants accounted for a larger proportion than inappropriate discontinuation or dose adjustment (30.16% vs 8.99%). More than one-third of patients neglected to monitor concentrations. About 8% experienced abnormal high concentrations.

CONCLUSION

Inappropriate prescribing of NR is widespread among hospitalized SOTRs. Adjusting doses based on patients' renal function and paying attention to concurrent use of immunosuppressive drugs are crucial, and therapeutic drug monitoring is necessary. Clinical practitioners should enhance their vigilance and attention.

A Case of Autoimmune Hemolytic Anemia Following COVID-19 Infection Accompanied by Acute Tubulointerstitial Nephritis in a Kidney Transplant Recipient

BACKGROUND

Acute tubular injury is one of the main causes of acute tubular injury (acute kidney injury ) in patients with COVID-19 infection. Autoimmune hemolytic anemia (AIHA) is also one of the autoimmune complications of COVID-19. However, AIHA accompanied by acute tubulointerstitial nephritis (ATIN) caused by SARS-CoV-2 is rarely reported. Here, we report a kidney transplant recipient who underwent graftectomy owing to ATIN accompanied by AIHA, possibly exacerbated by COVID-19 infection.

CASE PRESENTATION

A 32-year-old male renal allograft recipient owing to immunoglobulin A nephropathy visited the emergency department owing to dyspnea and general weakness. Three weeks earlier, the patient had been transplanted with deceased-donor kidney with full HLA-A, -B, -DR match, and had been on tacrolimus, prednisolone, and mycophenolate since then. At the time of the visit, laboratory findings revealed hemoglobin of 2.4 g/dL, reticulocyte of 21.7%, total bilirubin of 1.9 mg/dL, direct bilirubin of 0.3 mg/dL, lactate dehydrogenase of 946 U/L, haptoglobin of <10 mg/dL, and severe red cell agglutination on peripheral blood smear, which suggested AIHA. In addition, his SARS-CoV-2 real-time polymerase chain reaction test was positive. During steroid treatment for AIHA, a sudden decrease in urine volume, estimated glomerular filtration rate (from 64.9 to 35.1 mL/min/1.73 m2) and increase of creatinine (from 1.42 to 2.36 mg/dL) indicated renal function deterioration, so steroid was increased to 500 mg. On the third day of renal function deterioration, dialysis was started owing to anuria and fluid retention. On renal biopsy, C4d was absent; however, ATIN with eosinophilic infiltration was observed. On renal ultrasound examination, a severely enlarged kidney with edema was observed. At the same time, the patient had a high fever with increased C-reactive protein and procalcitonin. Graftectomy was performed to prevent secondary infection. The postgraftectomy renal biopsy showed renal parenchymal and hilar inflammatory change, endotheliitis, and lymphocytic infiltration of peripheral nerve fibers. After graftectomy, dialysis was maintained and AIHA had ameliorated.

CONCLUSION

The patient had to have his allografted kidney removed owing to ATIN possibly caused by COVID-19 infection. Acute kidney injury caused by SARS-CoV-2 can be either by direct viral infection or as consequence of immunological response. The exact immunological mechanism of AIHA secondary to COVID-19 infection remains to be elucidated.

Unmasking the Silent Threat: COVID-19's Pervasive Impact on Renal Allografts

OBJECTIVES

Growing evidence has highlighted the substantial effects of COVID-19 on kidneys, ranging from mild proteinuria to severe acute kidney injury. However, comprehensive assessments of histopathological features in renal allograft biopsies are lacking.

MATERIALS AND METHODS

Seventeen kidney transplant recipients with COVID-19 between March 2020 and November 2022 were evaluated. Clinical characteristics, pathological findings, and outcomes were studied.

RESULTS

Six kidney transplant recipients (35.3%) developed acute kidney injury, leading to the requirement for hemodialysis. COVID-19 severity, as indicated by pneumonia (P = .028) and hospitalization (P = .002), was significantly associated with development of acute kidney injury. Most patients with COVID-19 (82.4%) showed considerably increased proteinuria levels (82.4%), along with presence of new-onset microscopic hematuria (35.3%) and nephrotic syndrome (58.8%). Tubular viral inclusionlike changes were detected in 47.1% of cases and were associated with a higher risk of graft loss (75%). Thrombotic microangiopathy and endothelial cell swelling in glomeruli were prevalent, highlighting extensive endothelial cell injury. Most recipients (88.2%) experienced rejection after COVID-19, with graft loss occurring in 46.7% of these cases. Biopsies revealed collapsing (n = 5), noncollapsing (n = 3), and recurrent (n = 2) focal segmental glomerulosclerosis, as well as acute tubulointerstitial nephritis (n = 3), crescentic glomerulonephritis with immunoglobulin A nephropathy (n = 1), and membranoproliferative glomerulonephritis (n = 1), in 129.7 ± 33 days. Eight patients experienced graft loss (8.2 ± 2 mo posttransplant). Hospitalization (P = .044) and viralinclusion-like nuclear changes in tubules (P = .044) significantly influenced graft survival. Collapsing (60%) and noncollapsing (66.7%) focal segmental glomerulosclerosis increased the risk of graft loss.

CONCLUSIONS

COVID-19 has had a multifaceted and enduring effect on renal allografts, urging the need for meticulous monitoring and tailored management strategies to mitigate the risk of severe kidney-related complications and graft loss in this vulnerable population.

Adequacy to immunosuppression management guidelines in kidney transplant recipients with severe COVID-19 pneumonia: a practice survey

Introduction

Coronavirus disease 2019 (COVID-19) poses an important risk of morbidity and of mortality, in patients after solid organ transplantation. Recommendations have been issued by various transplantation societies at the national and European level to manage the immunosuppressive (IS) regimen upon admission to intensive care unit (ICU).

Method

The aim of this study was to evaluate the adequacy of IS regimen minimization strategy in kidney transplant recipients hospitalized in an ICU for severe COVID-19, in relation to the issued recommendations.

Results

The immunosuppressive therapy was minimized in all patients, with respectively 63% and 59% of the patients meeting the local and european recommendations upon admission. During ICU stay, IS was further tapered leading to 85% (local) and 78% (european) adequacy, relative to the guidelines. The most frequent deviation was the lack of complete withdrawal of mycophenolic acid (22%). Nevertheless, the adequacy/inadequacy status was not associated to the ICU- or one-year-mortality.

Discussion

In this single-center cohort, the only variable associated with a reduction in mortality was vaccination, emphasizing that the key issue is immunization prior to infection, not restoration of immunity during ICU stay.

Prior viral infection primes cross-reactive CD8+ T cells that respond to mouse heart allografts

Introduction

Significant evidence suggests a connection between transplant rejection and the presence of high levels of pre-existing memory T cells. Viral infection can elicit viral-specific memory T cells that cross-react with allo-MHC capable of driving allograft rejection in mice. Despite these advances, and despite their critical role in transplant rejection, a systematic study of allo-reactive memory T cells, their specificities, and the role of cross-reactivity with viral antigens has not been performed.

Methods

Here, we established a model to identify, isolate, and characterize cross-reactive T cells using Nur77 reporter mice (C57BL/6 background), which transiently express GFP exclusively upon TCR engagement. We infected Nur77 mice with lymphocytic choriomeningitis virus (LCMV-Armstrong) to generate a robust memory compartment, where quiescent LCMV-specific memory CD8+ T cells could be readily tracked with MHC tetramer staining. Then, we transplanted LCMV immune mice with allogeneic hearts and monitored expression of GFP within MHC-tetramer defined viral-specific T cells as an indicator of their ability to cross-react with alloantigens.

Results

Strikingly, prior LCMV infection significantly increased the kinetics and magnitude of rejection as well as CD8+ T cell recruitment into allogeneic, but not syngeneic, transplanted hearts, relative to non-infected controls. Interestingly, as early as day 1 after allogeneic heart transplant an average of ~8% of MHC-tetramer+ CD8+ T cells expressed GFP, in contrast to syngeneic heart transplants, where the frequency of viral-specific CD8+ T cells that were GFP+ was <1%. These data show that a significant percentage of viral-specific memory CD8+ T cells expressed T cell receptors that also recognized alloantigens in vivo. Notably, the frequency of cross-reactive CD8+ T cells differed depending upon the viral epitope. Further, TCR sequences derived from cross-reactive T cells harbored distinctive motifs that may provide insight into cross-reactivity and allo-specificity.

Discussion

In sum, we have established a mouse model to track viral-specific, allo-specific, and cross-reactive T cells; revealing that prior infection elicits substantial numbers of viral-specific T cells that cross-react to alloantigen, respond very early after transplant, and may promote rapid rejection.