Severe neutropenia and thrombocytopenia following cardiac transplantation in a child

Neutropenic Enterocolitis in a Pediatric Heart Transplant Recipient on Multiple Immunosuppressants

Neutropenic enterocolitis (NE) historically primarily affects pediatric patients with leukemia who are undergoing chemotherapy or who have recently received bone marrow transplants. Although a few case reports have shown NE occurring outside of this typical population, to our knowledge, this is the first published case of NE occurring in the setting of pediatric heart transplant. This patient was diagnosed several months after pediatric heart transplant, with radiographs showing evidence of pneumatosis intestinalis. Although NE does not typically affect solid organ transplant patients, this patient had a variety of risk factors that may have predisposed her to development of NE such as severe neutropenia, supratherapeutic tacrolimus level, immunosuppression with cytotoxic agents, and elevated Epstein-Barr viral load. Fortunately, this patient improved with bowel rest, fluids, antibiotics, and alteration of her immunosuppressive regimen. However, NE can be fatal, and thus it is an important condition to consider, even in patients without leukemia or on chemotherapeutic regimens.

Neutropenia in pediatric heart transplant recipients

Neutropenia has been reported in pediatric heart transplant recipients, but its association with infectious morbidity and mortality is unknown. We sought to determine neutropenia's prevalence and impact on infection, rejection, and survival. A retrospective analysis of pediatric heart transplant recipients from March 2005 to August 2015 was performed. Demographics, medications, infection, and rejection data were collected. Of 142 pediatric heart transplant recipients, 77 (54.2%) developed neutropenia within 4.7 months [3.3-12.1 months] of transplant. In all patients, the adjusted 5-year cumulative incidence of neutropenia was 30.2%. Fifty-one patients (66.2%) had recurrent neutropenia. Six of 14 tested had positive antineutrophil antibodies. Medications associated with neutropenia were decreased in 15 (19.5%) and discontinued in 42 (54.4%) patients with no change in 1-year rejection rates compared to published data. Fifteen patients developed infection within 30 days of neutropenia and two from 30 days to 1 year, with an infection rate similar to the non-neutropenic group. There was no significant difference in survival, ANC, rate of rejection or PTLD in neutropenic patients with and without infection at median follow-up (5.5 years). Neutropenia is common in pediatric heart transplant recipients. Neutropenia had <20% risk of associated infection, similar to non-neutropenic patients. Infection in neutropenic patients did not increase mortality.

Specific p38 inhibition in stimulated endothelial cells: a possible new anti-inflammatory strategy after hypothermia and rewarming

To protect immature organ systems during corrective cardiac surgery, patients are cooled to a minimal temperature of 17 degrees C during cardiopulmonary bypass (CPB). However hypothermic CPB triggers the whole body inflammatory response and results in unwanted prolonged inflammation. The present study was designed to clarify the hypothermia and rewarming induced mechanisms and examine interventional pharmacological strategies that could prevent prolonged inflammation. Stimulated primary human umbilical vein endothelial cells (HUVECs) were exposed to a dynamic temperature protocol analogous to clinical settings. Furthermore endothelial cells were pretreated with methylprednisolone and/or tacrolimus as well as with MAPK inhibitors (SB203580, U0126 and SP600125). Cell viability, expression of IL-6 and ERK 1/2, p38 and SAPK/JNK were investigated. Stimulated endothelial cells secreted significantly higher IL-6 protein 2h after rewarming in comparison to normothermic control cells. Moreover, dynamic temperature changes lead to increased MAPK phosphorylation. Only the combined pre-treatment with MP and TAC served to inhibit the IL-6 secretion. As intracellular signalling pathway we could demonstrate that SB203580 as specific p38 inhibitor most effectively down regulated the unwanted IL-6 release after cooling and rewarming. Therefore inhibition of p38 or components of the p38 pathway could be a promising and selective antiinflammatory therapeutic target after hypothermic CPB.