Neutropenia in pediatric heart transplant recipients

Neutropenia in pediatric solid organ transplant

Neutropenia is generally defined as an absolute neutrophil count in the circulation of less than 1500/mm³ and occurs in up to 25%-30% of pediatric solid organ transplant recipients (SOT) within the first year after transplantation. In the SOT population, neutropenia is most often a result of drug-induced bone marrow suppression but can also be secondary to viral infection, nutritional deficiencies, lymphoproliferative infiltrate, and inherited causes. Outcomes for patients with neutropenia vary by degree of neutropenia and type of solid organ transplant. Management of neutropenia should begin by addressing the underlying cause, including reducing or removing medications when appropriate, treating infections, and addressing nutrient deficiencies; however, consultation with an experienced pediatric hematologist and use of granulocyte colony-stimulating factor (G-CSF) may be helpful in some cases. Overall, data on clinical outcomes for G-CSF use remain limited, but observational studies may support its use in patients with infections or severe neutropenia.

Characteristics, risk factors, and outcomes of neutropenia after liver or kidney transplantation in children

BACKGROUND

While prior adult studies have shown that approximately 20%-38% of subjects undergoing solid-organ transplant develop neutropenia, similar analyses in pediatric subjects are scarce.

METHODS

We conducted a retrospective chart review of liver transplant (LT) and kidney transplant (KT) recipients at our center during the period 2008-2018. All of the KT and none of the LT subjects during this time period had induction with either anti-thymocyte globulin (ATG) or basiliximab at time of transplant. Neutropenia was defined as absolute neutrophil count (ANC) value ≤1000/mm3 .

RESULTS

One hundred subjects with LT and 82 subjects with KT were included. The incidence of neutropenia within the first year of transplant in KT was higher compared to LT (54.8% vs 39%, p = .01). The median number of hospitalizations (p = .001) and infectious complications (p = .04) was significantly higher only in the KT subjects who developed neutropenia (compared to those who did not). Multivariate analysis identified factors associated with severity of liver disease at transplant, namely h/o upper gastrointestinal bleeding (p = .02), weight deficit (p = .01), and pre-LT ANC (p = .01), along with high or moderate risk cytomegalovirus status (p = .05) as predictors of neutropenia in LT subjects. Female gender (p = .03) predicted neutropenia, while BK virus infection was protective for neutropenia (p = .04) in KT subjects.

CONCLUSIONS

The incidence of and morbidity associated with neutropenia within 1 year post-transplant is higher in KT subjects compared to LT subjects. The likely reason for this is the use of induction therapy (ATG, basiliximab) at the time of transplant in KT subjects.

Persistent Neutropenia after ABOi Kidney Transplantation: A Case Report

Post-transplant neutropenia (PTN) is frequently reported in the first-year after transplantation. Although prevalence and clinical consequences are widely described, there are no guidelines to manage diagnosis and treatment. We report here a case of persistent PTN occurred in a patient undergoing a kidney transplant from an AB0-incompatible living donor. The desensitization protocol consisted of Rituximab administration and immunoadsorption while the pre-transplant protocol, which was initiated 14 days before the transplant, included Tacrolimus, Mofetil Mycophenolate (MMF), antimicrobial and antiviral prophylaxis. Induction therapy consisted of anti-thymocyte globulins and steroids, while maintenance after transplantation consisted of steroid, tacrolimus and MMF. When the first occurrence of leukopenia was observed six weeks after the transplant, firstly antimicrobial/antiviral prophylaxis was stopped and later also MMF treatment was interrupted but severe neutropenia relapsed after MMF resuming treatment. Immunological and virological causes were excluded. The patient was treated with Filgrastim. Bone marrow biopsy, which was performed to exclude a hematological cause of severe persistent neutropenia, revealed a bone marrow hypoplasia with neutrophils maturation interrupted at the early stages. This case highlights the need to establish diagnostic and therapeutic guidelines for PTN which take in consideration all the therapeutic steps including the pre-transplant phase in particular in the context of AB0i where immunosuppression is more consistent.

Factors associated with neutropenia post heart transplantation

BACKGROUND

Neutropenia is a serious complication following heart transplantation (OHT); however, risk factors for its development and its association with outcomes is not well described. We sought to study the prevalence of neutropenia, risk factors associated with its development, and its impact on infection, rejection, and survival.

METHODS

A retrospective single-center analysis of adult OHT recipients from July 2004 to December 2017 was performed. Demographic, laboratory, medication, infection, rejection, and survival data were collected for 1 year post-OHT. Baseline laboratory measurements were collected within the 24 hours before OHT. Neutropenia was defined as absolute neutrophil count ≤1000 cells/mm3. Cox proportional hazards models explored associations with time to first neutropenia. Associations between neutropenia, analyzed as a time-dependent covariate, with secondary outcomes of time to infection, rejection, or death were also examined.

RESULTS

Of 278 OHT recipients, 84 (30%) developed neutropenia at a median of 142 days (range 81-228) after transplant. Factors independently associated with increased risk of neutropenia included lower baseline WBC (HR 1.12; 95% CI 1.11-1.24), pre-OHT ventricular assist device (1.63; 1.00-2.66), high-risk CMV serostatus [donor positive, recipient negative] (1.86; 1.19-2.88), and having a previous CMV infection (4.07; 3.92-13.7).

CONCLUSIONS

Neutropenia is a fairly common occurrence after adult OHT. CMV infection was associated with subsequent neutropenia, however, no statistically significant differences in outcomes were found between neutropenic and non-neutropenic patients in this small study. It remains to be determined in future studies if medication changes in response to neutropenia would impact patient outcomes.

Hospital readmission following pediatric heart transplantation

The frequency, indications, and outcomes for readmission following pediatric heart transplantation are poorly characterized. A better understanding of this phenomenon will help guide strategies to address the causes of readmission. Data from the Clinical Trials in Organ Transplantation for Children (CTOTC-04) multi-institutional collaborative study were utilized to determine incidence of, and risk factors for, hospital readmission within 30 days and 1 year from initial hospital discharge. Among 240 transplants at 8 centers, 227 subjects were discharged and had follow-up. 129 subjects (56.8%) were readmitted within one year; 71 had two or more readmissions. The 30-day and 1-year freedom from readmission were 70.5% (CI: 64.1%, 76.0%) and 42.2% (CI: 35.7%, 48.7%), respectively. The most common indications for readmissions were infection followed by rejection and fever without confirmed infection, accounting for 25.0%, 10.6%, and 6.2% of readmissions, respectively. Factors independently associated with increased risk of first readmission within 1 year (Cox proportional hazard model) were as follows: transplant in infancy (P = .05), longer transplant hospitalization (P = .04), lower UNOS urgency status (2/IB vs 1A) at transplant (P = .04), and Hispanic ethnicity (P = .05). Hospital readmission occurs frequently in the first year following discharge after heart transplantation with highest risk in the first 30 days. Infection is more common than rejection as cause for readmission, with death during readmission being rare. A number of patient factors are associated with higher risk of readmission. A fuller understanding of these risk factors may help tailor strategies to reduce unnecessary hospital readmission.