Long term outcomes of 176 patients with X-linked hyper IgM syndrome treated with or without hematopoietic cell transplantation

BACKGROUND: X-linked hyper IgM syndrome (XHIGM) is a primary immunodeficiency with high morbidity and mortality compared to normal individuals. Hematopoietic cell transplant (HCT) has been considered a curative therapy, but the procedure has inherent complications, and may not be available for all patients. OBJECTIVES: We sought to collect data on the clinical presentation, treatment, and follow-up of a large sample of patients with XHIGM in order to (1) compare long-term overall survival and general well-being of patients treated with or without HCT along with clinical factors associated with mortality, and (2) summarize clinical practice and risk factors in the subgroup of patients treated with HCT. METHODS: Physicians caring for patients with primary immunodeficiency diseases were identified through the Jeffrey Modell Foundation, United States Immunodeficiency Network, Latin American Society for Immunodeficiency, and the Primary Immune Deficiency Treatment Consortium. Data was collected using a REDCap web application. Survival from time of diagnosis or transplant was estimated using the Kaplan-Meier method, compared using log-rank tests, and modeled using proportional hazards regression. RESULTS: Twenty-eight clinical sites provided data on 189 patients diagnosed with XHIGM between 1964 and 2013; 176 had valid follow-up and vital status information. Sixty-seven patients (38%) received HCT. The average follow-up time was 8.5 ± 7.2 years (range: 0.1-36.2 years). No difference in overall survival was observed between patients treated with or without HCT (p=0.671). However, risk associated with HCT decreased for diagnosis years 1987-1995; the hazard ratio was significantly < 1 for diagnosis years 1995-1999. Liver disease was a significant predictor of overall survival [HR (95% CL): 4.9 (2.2, 10.8), p<0.001]. Among survivors, those treated with HCT had higher median Lansky and Karnofsky scores than those treated without HCT (p<0.001). Among patients receiving HCT, 27 (40%) developed graft versus host disease, and most deaths occurred within 1 year of transplant. CONCLUSION: No difference in survival was observed between patients treated with or without HCT across all diagnosis years 1964-2013. However, survivors treated with HCT experienced somewhat greater well-being and hazards associated with HCT decreased, reaching levels of significantly less risk, in the late 1990s. Among patients treated with HCT, treatment at an early age is associated with improved survival Optimism remains guarded as additional evidence accumulates

Dissipative Particle Dynamics Simulations for Phospholipid Membranes Based on a Four-To-One Coarse-Grained Mapping Scheme

In this article, a new set of parameters compatible with the dissipative particle dynamics (DPD) force field is developed for phospholipids. The coarse-grained (CG) models of these molecules are constructed by mapping four heavy atoms and their attached hydrogen atoms to one bead. The beads are divided into types distinguished by charge type, polarizability, and hydrogen-bonding capacity. First, we derive the relationship between the DPD repulsive force and Flory-Huggins χ-parameters based on this four-to-one CG mapping scheme. Then, we optimize the DPD force parameters for phospholipids. The feasibility of this model is demonstrated by simulating the structural and thermodynamic properties of lipid bilayer membranes, including the membrane thickness, the area per lipid, the lipid tail orientation, the bending rigidity, the rupture behavior, and the potential of mean force for lipid flip-flop

Hypothermia and Amiloride Preserve Energetics in a Neonatal Brain Slice Model

A period of secondary energy failure consisting of a decline in phosphocreatine/inorganic phosphate (PCr/Pi), a rise in brain lactate, and alkaline intracellular pH (pH(i)) has been described in infants with neonatal encephalopathy. Strategies that ameliorate this energy failure may be neuroprotective. We hypothesized that a neonatal rat brain slice model undergoes a progressive decline in energetics, which can be ameliorated with hypothermia or amiloride. Interleaved phosphorus ((31)P) and proton ((1)H) magnetic resonance (MR) spectra were obtained from 350 microm neonatal rat brain slices over 8 h in a bicarbonate buffer at 37 degrees C and at 32 degrees C in 7- and 14-d models. (31)P MR spectra were obtained with amiloride in a bicarbonate-free buffer at 37 degrees C in the 14-d model. Findings were similar in 7- and 14-d models. In the 14-d model, there was a Pi doublet structure corresponding to alkaline pH(i) values of 7.50 +/- 0.02 and 7.21 +/- 0.04. Compared with the stabilized baseline of 100, at 5 h PCr/Pi was 65 +/- 6.3 and lactate/NAA was 187 +/- 3 at 37 degrees C, but PCr/Pi and lactate/NAA were not significantly different from baseline at 32 degrees C. Nucleotide triphosphate (NTP)/phosphomonoester (PME) was 0.93 +/- 0.23 at 37 degrees C and 1.81 +/- 0.21 at 32 degrees C at 5 h. With amiloride exposure in the 14-d model, baseline pH(i) values were 7.25 +/- 0.09 and 6.98 +/- 0.02 and NTP/PME was 1.81 +/- 0.05; these parameters were not significantly different at 5 h. Our interpretation of these findings is that the brain slice model underwent secondary energy failure, which was delayed with hypothermia or amiloride