Granulocyte colony-stimulating factor therapy is associated with a reduced incidence of acute rejection episodes or allograft vasculopathy in heart transplant recipients

Incidence of Acute Cellular Rejection After Granulocyte Colony-Stimulating Factor in Lung Transplant Recipients

BackgroundNeutropenia is a common complication in lung transplant recipients (LTRs). Filgrastim may be used to treat neutropenia in LTRs, but its consequences on acute cellular rejection (ACR) remain controversial. Objective: The purpose was to examine the association between filgrastim and incidence of ACR 6 months after filgrastim administration in LTRs. Secondary outcomes included burden of ACR, infections, chronic lung allograft dysfunction (CLAD), and survival. Methods: This was a matched cohort study of patients transplanted between January 2010 and October 2019. LTRs who received filgrastim for neutropenia were compared to a cohort who did not. LTRs were matched on transplant indication, sex, age, and time post-transplant and multivariable logistic regression models were used to evaluate the likelihood of ACR. Results: 212 patients were included in the analysis (106 in each group). 50 patients (47.2%) in the filgrastim group experienced ACR compared to 37 patients (34.9%) in the no filgrastim group (P = .070). In multivariable analysis, filgrastim use was not associated with ACR at 6 months (OR 1.409, 95% CI 0.772-2.571). Time to first ACR was shorter (P = .049) and 6-month ACR score was higher in the filgrastim group (.49 vs .33, P = .047). LTRs in the filgrastim group had higher incidence of bacterial pneumonia and 1-year mortality. Conclusions: Although not associated with increased likelihood of ACR at 6 months, our study found that filgrastim is associated with increased ACR burden and decreased time to ACR. This study can help inform clinicians of ACR risk after filgrastim use in LTRs.

Unsupervised mRNA-seq classification of heart transplant endomyocardial biopsies

BACKGROUND

Endomyocardial biopsy (EMB) is currently considered the gold standard for diagnosing cardiac allograft rejection. However, significant limitations related to histological interpretation variability are well-recognized. We sought to develop a methodology to evaluate EMB solely based on gene expression, without relying on histology interpretation.

METHODS

Sixty-four EMBs were obtained from 47 post-heart transplant recipients, who were evaluated for allograft rejection. EMBs were subjected to mRNA sequencing, in which an unsupervised classification algorithm was used to identify the molecular signatures that best classified the EMBs. Cytokine and natriuretic peptide peripheral blood profiling was also performed. Subsequently, we performed gene network analysis to identify the gene modules and gene ontology to understand their biological relevance. We correlated our findings with the unsupervised and histological classifications.

RESULTS

Our algorithm classifies EMBs into three categories based solely on clusters of gene expression: unsupervised classes 1, 2, and 3. Unsupervised and histological classifications were closely related, with stronger gene module-phenotype correlations for the unsupervised classes. Gene ontology enrichment analysis revealed processes impacting on the regulation of cardiac and mitochondrial function, immune response, and tissue injury response. Significant levels of cytokines and natriuretic peptides were detected following the unsupervised classification.

CONCLUSION

We have developed an unsupervised algorithm that classifies EMBs into three distinct categories, without relying on histology interpretation. These categories were highly correlated with mitochondrial, immune, and tissue injury response. Significant cytokine and natriuretic peptide levels were detected within the unsupervised classification. If further validated, the unsupervised classification could offer a more objective EMB evaluation.

Outcomes of granulocyte colony-stimulating factor use in pediatric kidney transplant recipients: A Pediatric Nephrology Research Consortium study

BACKGROUND

Neutropenia is common in the first year after pediatric kidney transplant and is associated with an increased risk of infection, allograft loss, and death. Granulocyte colony-stimulating factor (G-CSF) increases neutrophil production, but its use in pediatric solid organ transplant recipients remains largely undescribed.

METHODS

We performed a multicenter retrospective cohort study of children with neutropenia within the first 180 days after kidney transplant. Multivariable linear regression and Poisson regression were used to assess duration of neutropenia and incidence of hospitalization, infection, and rejection.

RESULTS

Of 341 neutropenic patients, 83 received G-CSF during their first episode of neutropenia. Median dose of G-CSF was 5 mcg/kg for 3 (IQR 2-7) doses. G-CSF use was associated with transplant center, induction immunosuppression, steroid-free maintenance immunosuppression, hospitalization, and decreases in mycophenolate mofetil, valganciclovir, and trimethoprim-sulfamethoxazole dosing. Absolute neutrophil count nadir was also significantly lower among those treated with G-CSF. G-CSF use was not associated with a shorter duration of neutropenia (p = .313) and was associated with a higher rate of neutropenia relapse (p = .002) in adjusted analysis. G-CSF use was associated with a decreased risk of hospitalization (aIRR 0.25 (95%CI 0.12-0.53) p < .001) but there was no association with incidence of bacterial infection or rejection within 90 days of neutropenic episode.

CONCLUSION

G-CSF use for neutropenia in pediatric kidney transplant recipients did not shorten the overall duration of neutropenia but was associated with lower risk of hospitalization. Prospective studies are needed to determine which patients may benefit from G-CSF treatment.

The pharmaceutical management of cardiac allograft vasculopathy after heart transplantation

INTRODUCTION

Cardiac allograft vasculopathy (CAV) is a major limitation to long-term survival after heart transplantation. Its peculiar pathophysiology involves multifactorial pathways including immune-mediated and metabolic risk factors, which are associated with the development of specific pathological lesions. The often diffuse and chronic nature of the disease reduces the effectiveness of revascularization procedures, and pharmacological prevention of the disease is the sole therapeutic approach with some proven efficacy.

AREAS COVERED

In this article, after briefly outlining the risk factors for CAV, the authors revise the potential pharmacological approaches that may reduce the burden of CAV. While several therapies have shown convincing efficacy in terms of CAV prevention diagnosed by coronary imaging, very few have been reported to improve prognosis with any meaningful level of evidence.

EXPERT OPINION

The authors believe that a customizable approach is necessary for clinical practice given the currently available evidence. Furthermore, it is important, in the future, to address the glaring therapeutic gap of an effective treatment against donor-specific antibodies, whose effect on endothelial injury is currently one of the major mechanisms of CAV development and for which no pharmacological treatment is currently available.

Lung transplant outcomes are influenced by severity of neutropenia and granulocyte colony-stimulating factor treatment

Although neutropenia is a common complication after lung transplant, its relationship with recipient outcomes remains understudied. We evaluated a retrospective cohort of 228 adult lung transplant recipients between 2008 and 2013 to assess the association of neutropenia and granulocyte colony-stimulating factor (GCSF) treatment with outcomes. Neutropenia was categorized as mild (absolute neutrophil count 1000-1499), moderate (500-999), or severe (<500) and as a time-varying continuous variable. Associations with survival, acute rejection, and chronic lung allograft dysfunction (CLAD) were assessed with the use of Cox proportional hazards regression. GCSF therapy impact on survival, CLAD, and acute rejection development was analyzed by propensity score matching. Of 228 patients, 101 (42.1%) developed neutropenia. Recipients with severe neutropenia had higher mortality rates than those of recipients with no (adjusted hazard ratio [aHR] 2.97, 95% confidence interval [CI] 1.05-8.41, P = .040), mild (aHR 14.508, 95% CI 1.58-13.34, P = .018), or moderate (aHR 3.27, 95% CI 0.89-12.01, P = .074) neutropenia. Surprisingly, GCSF treatment was associated with a higher risk for CLAD in mildly neutropenic patients (aHR 3.49, 95% CI 0.93-13.04, P = .063), although it did decrease death risk in severely neutropenic patients (aHR 0.24, 95% CI 0.07-0.88, P = .031). Taken together, our data point to an important relationship between neutropenia severity and GCSF treatment in lung transplant outcomes.

Drug-Induced Hematological Cytopenia in Kidney Transplantation and the Challenges It Poses for Kidney Transplant Physicians

Drug-induced hematological cytopenia is common in kidney transplantation. Various cytopenia including leucopenia (neutropenia), thrombocytopenia, and anemia can occur in kidney transplant recipients. Persistent severe leucopenia or neutropenia can lead to opportunistic infections of various etiologies. On the contrary, reducing or stopping immunosuppressive medications in these events can provoke a rejection. Transplant clinicians are often faced with the delicate dilemma of balancing cytopenia and rejection from adjustments of immunosuppressive regimen. Differentials of drug-induced cytopenia are wide. Identification of culprit medication and subsequent modification is also challenging. In this review, we will discuss individual drug implicated in causing cytopenia and correlate it with corresponding literature evidence.

Increase in short-term risk of rejection in heart transplant patients receiving granulocyte colony-stimulating factor

BACKGROUND

Neutropenia is a significant adverse event after heart transplantation (HT) and increases infection risk. Granulocyte colony-stimulating factor (G-CSF) is commonly used in patients with neutropenia. In this work, we assessed the adverse effects of G-CSF treatment in the setting of a university hospital.

METHODS

Data on HT patients from January 2008 to July 2016 were reviewed. Patients who received G-CSF were identified and compared with patients without a history of therapy. Baseline characteristics, rejection episodes, and outcomes were collected. Data were analyzed by incidence rates, time to rejection and survival were analyzed using Kaplan-Meier curves, and odds ratios were generated using logistic regression analysis.

RESULTS

Two hundred twenty-two HT patients were studied and 40 (18%) received G-CSF for a total of 85 total neutropenic events (0.79 event/patient year). There were no differences in baseline characteristics between the groups. In the 3 months after G-CSF, the incidence rate of rejection was 0.067 event/month. In all other time periods considered free of G-CSF effect, the incidence rate was 0.011 event/month. This rate was similar to the overall incidence rate in the non-GCSF group, which was 0.010 event/month. There was a significant difference between the incidence rates in the G-CSF group at 0 to 3 months after G-CSF administration and the non-GCSF group (p = 0.04), but not for the other time periods (p = 0.5). Freedom from rejection in the 3 months after G-CSF administration was 87.5% compared with 97.5% in the non-GCSF group (p = 0.006).

CONCLUSIONS

G-CSF administration was found to be associated with significant short-term risk of rejection. This suggests the need for increased surveillance during this time period.

Evaluation of Filgrastim Therapy in Kidney Transplant Recipients

CONTEXT

Neutropenia is associated with a high risk of serious infections in kidney transplant recipients. There are no sufficient studies of using granulocyte colony-stimulating factors, such as filgrastim, in renal transplant recipients to establish a clear, specified role of this off-label indication. Using filgrastim in these patients may increase the risk of rejection by overstimulating the immune system.

OBJECTIVE

To evaluate the use of filgrastim in adult kidney transplant recipients presenting with neutropenia.

PATIENTS AND DESIGN

Data were obtained from a medication utilization report of filgrastim in kidney transplant recipients at our center from September 2012 to August 2015. Main Outcome Measure(s) and Results: There were 28 cases of neutropenia that were treated with a range of 1 to 5 doses of filgrastim 300 or 480 μg, with a mean of 1.79 doses. The mean total dose of filgrastim administered per episode of neutropenia was 632 μg (8.6 μg/kg). Overall, 87.5% of the cases achieved a white blood cell count of at least 3 × 10⁹ cells/L within 7 days of hospital discharge. There were no cases of infection or acute rejection following treatment.

CONCLUSIONS

The use of filgrastim in kidney transplant recipients demonstrated success in reversing neutropenia. Short courses of therapy were required with minimal adverse events. Patients who required readmission were successfully re-treated. Additional studies are required to determine the most effective dose and duration of treatment.

Risk factors, survival, and impact of prophylaxis length in cytomegalovirus-seropositive lung transplant recipients: A prospective, observational, multicenter study

BACKGROUND

The optimal length of cytomegalovirus (CMV) prophylaxis in lung transplantation according to CMV serostatus is not well established.

METHODS

We have performed a prospective, observational, multicenter study to determine the incidence of CMV infection and disease in 92 CMV-seropositive lung transplant recipients (LTR), their related outcomes and risk factors, and the impact of prophylaxis length.

RESULTS

At 18 months post transplantation, 37 patients (40%) developed CMV infection (23 [25%]) or disease (14 [15.2%]). Overall mortality was higher in patients with CMV disease (64.3% vs 10.2%; P<.001), but only one patient died from CMV disease. In the multivariate analysis, CMV disease was an independent death risk factor (odds ratio [OR] 18.214, 95% confidence interval [CI] 4.120-80.527; P<.001). CMV disease incidence was higher in patients with 90-day prophylaxis than in those with 180-day prophylaxis (31.3% vs 11.8%; P=.049). Prophylaxis length was an independent risk factor for CMV disease (OR 4.974, 95% CI 1.231-20.094; P=.024). Sixteen patients withdrew from prophylaxis because of adverse events.

CONCLUSION

CMV infection and disease in CMV-seropositive LTR remain frequent despite current prophylaxis. CMV disease increases mortality, whereas 180-day prophylaxis reduces the incidence of CMV disease.

Incidence of acute cellular rejection following granulocyte colony-stimulating factor administration in lung transplantation: A retrospective case-cohort analysis

Granulocyte colony-stimulating factor (GCSF) is an option to treat leukopenia in lung transplant recipients. Conflicting evidence exists regarding its effects on acute cellular rejection (ACR). A retrospective, case-cohort study was conducted to assess whether the use of GCSF in lung transplant recipients is associated with an increased incidence of ACR. Patients had to have received at least one dose of GCSF but were excluded if they received GCSF within 30 days prior to transplant or received a lymphocyte-depleting agent within 14 days of GCSF administration. Thirty-five patients who received GCSF within 3 months of transplant met inclusion criteria and 105 patients were identified as controls based on a 1:3 allocation scheme. Incidence of ACR was 57.1% in the GCSF group versus 50.5% in the control group (relative risk (RR)=1.13; 95% CI, 0.80 to 1.59; P=.48). At 3 months post-transplant, 74.3% of the GCSF group had a dose reduction or discontinuation of their antiproliferative agent versus 17.1% of the control group (RR=4.33; 95% CI, 2.73 to 6.89; P<.0001). Rejection severity and incidence of infections was similar among groups. These findings show that GCSF administration within 3 months following lung transplantation was not associated with a higher incidence or severity of ACR.