Autoimmune Neutropenia After Kidney Transplantation: A Disregarded Entity of Posttransplant Neutropenia

An adult case of refractory autoimmune neutropenia after liver transplantation

Autoimmune neutropenia (AIN) is an exceptionally rare condition that occurs after liver transplantation. Here, we report an adult case of refractory AIN 3.5 years after liver transplantation. A 59-year-old man who underwent brain-dead donor liver transplantation in August 2018 developed rapid neutropenia (0.07 × 10⁹/L) in December 2021. The patient was diagnosed with AIN based on positivity for anti-human neutrophil antigen-1a antibody. There was no response to granulocyte colony-stimulating factor (G-CSF), prednisolone, or rituximab, and intravenous immunoglobulin (IVIg) therapy induced only a temporary recovery in neutrophil count. The patient continued to have a low neutrophil count for several months. However, the response to IVIg and G-CSF improved after the post-transplant immunosuppressant was changed from tacrolimus to cyclosporine. Post-transplant AIN has many unknown aspects. Tacrolimus-induced immunomodulation and graft-associated alloimmunity may be involved in its pathogenesis. Further studies are needed to elucidate the underlying mechanisms and explore new treatment options.

Granulocyte colony-stimulating factor with or without immunosuppression reduction in neutropenic kidney transplant recipients

Neutropenia post-kidney transplantation is associated with adverse graft and patient outcomes. We aimed to analyze the effect of granulocyte colony-stimulating factor (G-CSF) use with and without immunosuppression reduction on graft outcomes in neutropenic recipients. In this retrospective cohort study, we identified 120 recipients with neutropenia, within the first-year post-transplant. Of these, 45.0% underwent no intervention, 17.5% had immunosuppression reduced, 18.3% were only given G-CSF, and 19.2% had both interventions. Overall, 61 patients experienced the composite outcome of de-novo DSA, biopsy-proven acute rejection, and all-cause graft failure and the cumulative incidence of this outcome did not vary by any of the four interventions (p = 0.93). When stratifying the cohort by G-CSF use alone, those who received G-CSF were more likely to have had severe neutropenia (<500/mm³ :51.1%vs.12.0%, p<0.001), and immunosuppression reduction (51.1%vs.28.0%, p = 0.003). However, the composite outcome was not different in the G-CSF and no G-CSF cohort (53.3%vs.49.3%, p = 0.67), and in a multivariate model, G-CSF use was not associated with this outcome (aHR = 1.18, 95%CI:0.61-2.30). However, a trend towards higher DSA production was noted in the G-CSF cohort (87.5%vs.62.2%) and this observation warrants prospective evaluation. Overall, we conclude that G-CSF use with or without immunosuppression reduction was not associated with graft outcomes. This article is protected by copyright. All rights reserved.

Severe neutropenia in children after renal transplantation: incidence, course, and treatment with granulocyte colony-stimulating factor

BACKGROUND

Infections are an important cause of morbidity and mortality in solid organ transplant recipients. Neutrophils play a crucial role in the initial host defense against bacterial pathogens. Neutropenia is not uncommon after renal transplantation in adults; however, there are scarce published data in children. We conducted a historical cohort study to evaluate the incidence, clinical course, and management of severe neutropenia after renal transplantation in children.

METHODS

In a single-center study, we collected clinical and laboratory data on all children (<20 years) who underwent renal transplantation from January 2005 to March 2014. All post-transplantation blood counts were reviewed; the lowest absolute neutrophil count was recorded and correlated with clinical information and other laboratory findings.

RESULTS

Of the 72 patients studied, 46 (64%) had at least one episode of neutropenia [absolute neutrophil count (ANC) <1500/μl] during the study period, 16 of whom (22%) had severe neutropenia (ANC < 500/μl), 2-11 months (median, 3.5) after renal transplantation. Work-up for viral infection or malignancy was performed. Initial management included dose decrease and subsequent discontinuation of antimetabolite, stopping co-trimoxazole and valganciclovir. Bone marrow aspiration in four children revealed normal marrow cellularity in all cases, with myelocyte maturational arrest in two. Eight children (11%) were treated with granulocyte colony-stimulating factor (G-CSF) (5 mcg/kg/day) 1-4 doses (median, 2), with excellent response in all and no adverse effects. Eight children presented with fever during severe neutropenia, and were treated with empiric antibiotics. Mycophenolate/azathioprine were resumed in all patients unless contraindicated (pre-existing BK viremia -1, PTLD -1). Recurrence of neutropenia was seen in five patients, only one of whom required further treatment with G-CSF. Graft function was preserved during and after resolution of neutropenia. Post-transplant neutropenia in children is common, and mostly occurs in the first few months. Its etiology is probably primarily a result of the combination of immunosuppressive agents and prophylactic treatment of infections in the early post-transplant period.

CONCLUSIONS

Decreasing immunosuppressive or antimicrobial medications carries the risk of acute rejection or infection. Off-label treatment with G-CSF may present a safe and effective alternative.