Multiple listing for pediatric heart transplantation in the U.S.A.: analysis of OPTN registry data from 1995 through 2009.

Multiple listing is associated with shorter waitlist durations and increased likelihood of transplantation for renal candidates. Little is known about multiple listing in pediatric heart transplantation. We examined the prevalence and outcomes of multiple listing using OPTN data from 1995 through 2009. Characteristics and waitlist outcomes of propensity-score-matched single- and multiple-listed patients were compared. Multiple listing occurred in 23 of 6290 listings (0.4%). Median days between listings was 35 (0-1015) and median duration of multiple listings was 32 days (3-363). Among multiple-listed patients, there were trends toward less ECMO use (0% vs. 11%, p = 0.1) and more frequent requirement for a prospective cross-match (17% vs. 8%, p = 0.08). Multiple-listed patients more commonly had private insurance (78% vs. 56%; p = 0.03). Urgency status at listing was similar between groups (1/1A: 61% vs. 64%, 1B/2: 39 vs. 36%; p = 0.45) as were weight, age, diagnosis, ventilator/inotrope use, and median income (each p ≥ 0.17). There was a trend toward increased incidence of heart transplantation for multiple-listed patients at three, six, and 24 months (50%, 65%, 80%) vs. single-listed patients (40%, 54%, 64%; p = 0.11). Multiple listing for pediatric heart transplantation in the USA occurs infrequently and is more common in patients with private insurance.

Trophoblasts regulate natural killer cells via control of interleukin-15 receptor signaling.

PROBLEM: Trophoblasts are known to decrease natural killer (NK) cell cytotoxicity. However, little is known about the interaction between trophoblasts and NK cells during pregnancy. Interleukin-15 (IL-15) is essential for priming NK cells and maximizing their effector functions. We investigated whether trophoblasts regulate NK cell activation via IL-15/IL-2 receptor and its signaling pathways. METHOD OF STUDY: Natural killer-92 cells were primed with human first-trimester trophoblast cells (Sw.71) conditioned medium (CM) and co-cultured with K562 cells. Flow cytometry, Western blot analysis, and real-time PCR were performed to assess NK cell cytotoxicity, IL-15/IL-2 receptor expression, phosphorylation of STAT5 and MAPKs, and mRNA expression of IL-15-related genes. RESULTS: Natural killer-92 cells incubated with Sw.71 CM showed reduced cytotoxicity and IL-15-mediated proliferation, and expression of IL-15/IL-2 receptor subunits. STAT5 phosphorylation, EOMES and T-bet mRNA expressions, and ERK/JNK pathways of NK 92 cells were suppressed by Sw.71 CM. Productions of perforin, granzyme B, and IFN-γ were also downregulated. CONCLUSION: Trophoblasts regulate human NK cell functions via suppression of IL-15/IL-2 receptor expression, transcription factors, and ERK/JNK pathways.