[A first pilot study on the neonatal screening of primary immunodeficiencies in Spain: TRECS and KRECS identify severe T- and B-cell lymphopenia]. / Primer estudio piloto en España sobre el cribado neonatal de las inmunodeficiencias primarias: TRECS y KRECS identifican linfopenias T y B graves.

INTRODUCTION: Early diagnosis of primary immunodeficiency such as severe combined immunodeficiency (SCID) and X-linked agammaglobulinemia (XLA) improves outcome of affected infants/children. The measurement of T-cell receptor excision circles (TRECS) and kappa-deleting recombination excision circles (KRECS) can identify neonates with severe T or B-cell lymphopenia. OBJECTIVES: To determine TRECS and KRECS levels from prospectively collected dried blood spot samples (DBS) and to correctly identify severe T and B-cell lymphopenia. MATERIAL AND METHODS: Determination of TRECS and KRECS by multiplex PCR from neonates born in two tertiary hospitals in Seville between February 2014 and May 2014. PCR cut-off levels: TRECS<15 copies/µl, KRECS<10 copies/µl, ACTB (ß-actin)>1000 copies/µl. Internal (XLA, ataxia telangiectasia) and external (SCID) controls were included. RESULTS: A total of 1068 out of 1088 neonates (mean GA 39 weeks (38-40) and BW 3238g (2930-3520) were enrolled in the study. Mean (median, min/max) copies/µl, were as follows: TRECS 145 (132, 8/503), KRECS 82 (71, 7/381), and ACTB 2838 (2763, 284/7710). Twenty samples (1.87%) were insufficient. Resampling was needed in one neonate (0.09%), subsequently giving a normal result. When using lower cut-offs (TRECS<8 and KRECS<4 copies/µl), all the samples tested were normal and the internal and external controls were correctly identified. CONCLUSION: This is the first prospective pilot study in Spain using TRECS/KRECS/ACTB-assay, describing the experience and applicability of this method to identify severe lymphopenias. The ideal cut-off remains to be established in our population. Quality of sampling, storage and preparation need to be further improved.

[Anhydrotic ectodermal dysplasia associated to mannose-binding lectin deficiency]. / Displasia ectodérmica anhidrótica asociada a déficit de lectina de unión a manosa.

Mannose-binding lectin (MBL) is a serum protein of the innate immune system. MBL enhances opsonophagocytosis by binding to carbohydrates expressed by multiple pathogens. MBL deficiency is due to polymorphisms in the structural and promoter sequences of the MBL2 gene and is associated with variety of recurrent infections, including respiratory tract infections. We present a case of anhidrotic ectodermal dysplasia associated with severe mannose-binding lectin deficiency, never described in patients with anhidrotic ectodermal dysplasia.

[Peritoneal equilibrium test using icodextrin and glucose at different concentrations]. / Test de equilibrio peritoneal con icodextrina y glucosa a distintas concentraciones.

UNLABELLED: The aim of this study was to compare, under standard conditions (Peritoneal Equilibrium Test, "PET"), the peritoneal permeability to water and several solutes using icodextrin and glucose (3.86% and 1.36%) dialysates. The study includes 14 patients (3 women and 11 men), mean age 64 +/- 13 years, average time on peritoneal dialysis 23.5 +/- 17 months. PETs with icodextrin were performed in all of them (n = 14); PETs with 3.86% glucose were carried out in 7, and PETs with all the three solutions were performed in 5 patients. Samples were taken at 0, 30, 60, 120, 240 minutes, and after the rinsing procedure using 1.36% glucose in order to calculate the residual volume. RESULTS: Sodium concentration in the effluent and D/P sodium did not change significantly from minute 0 to 240 with icodextrin and 1.36% glucose; but with 3.86% glucose both sodium and D/P sodium decreased at thirty minutes, remained at the same levels till the 120 minutes and then had a tendency to increase. Glucose concentration and osmolarity in the effluent did not vary throughout the time with icodextrin, but progressively decreased during the 4-hour period with 3.86% and 1.36% glucose solutions. The drainage after the 4-hour period was higher for the 3.86% glucose (2,608 +/- 388 ml, p = 0.03) than for the 1.36% glucose (2,070 +/- 120 ml) or the icodextrin (2,212 +/- 213 ml). Low molecular weight permeability: D/P creatinine after the 4-hour dwell was significantly lower for the icodextrin (0.66 +/- 0.1, p = 0.05) than for the 3.86% glucose (0.71 +/- 0.1) or the 1.36% glucose (0.72 +/- 0.1). The creatinine clearance for 3.86% glucose (7.4 +/- 0.4 ml/min p = 0.007) was higher than for icodextrin (5.6 +/- 0.5 ml/min) or for 1.36% glucose (5.8 +/- 0.6 ml/min). The clearances for total protein, albumin and beta 2-microglobulin did not show significant differences between the solutions. CONCLUSIONS: Our study confirms that the icodextrin solution remains iso-osmolar with plasma during the 4-hour dwell. The sodium profile suggests that the ultrafiltration induced by icodextrin and 1.36% glucose depends on small pore-mediated sodium and water transport; on the other hand, 3.86% glucose also induces transport of water without solutes throughout the ultra-small aquaporin-mediated, pores, producing sodium dilution in the effluent. Ultrafiltration and solute clearances for icodextrin are lower than for 3.86 glucose during a 4-hour dwell.