Conversion to Mycophenolate Mofetil Monotherapy in Liver Recipients: Calcineurin Inhibitor Levels are Key

Abstract: The use of calcineurin inhibitors (CNI) after liver transplantation is associated with post-transplant nephrotoxicity. Conversion to mycophenolate mofetil (MMF) monotherapy improves renal function, but is related to graft rejection in some recipients. Our aim was to identify variables associated with rejection after conversion to MMF monotherapy. Conversion was attempted in 40 liver transplant recipients. Clinical variables were determined and peripheral mononuclear blood cells were immunophenotyped during a 12-month follow- up. Conversion was classified as successful (SC) if rejection did not occur during the follow-up. MMF conversion was successful with 28 patients (70%) and was associated with higher glomerular filtration rates at the end of study. It also correlated with increased time elapsed since transplantation, low baseline CNI levels (Tacrolimus ≤ 6.5 ng/mL or Cyclosporine ≤ 635 ng/mL) and lower frequency of tacrolimus use. The only clinical variable independently related to SC in multivariate analysis was low baseline CNI levels (p = 0.02, OR: 6.93, 95%, CI: 1.3-29.7). Mean baseline fluorescent intensity of FOXP3+ T cells was significantly higher among recipients with SC. In conclusion, this study suggests that baseline CNI levels can be used to identify recipients with higher probability of SC to MMF monotherapy. Clinicaltrials.gov identification: NCT01321112.

La infección materna por Helicobacter pylori no aumenta el riesgo de contraer la bacteria en el primer trimestre de vida de sus lactantes / Maternal infection due to Helicobacter pylori does not increase the risk of the infection in the first trimester of the life of their infants

Introducción: La infección por H. pylori se adquiere tempranamente en la infancia. Sin embargo, existe escasa información acerca del rol de la lactancia materna y la adquisición de la bacteria en la etapa neonatal/lactante. Objetivo: Evaluar algunos factores que afectan la adquisición de H. pylori en recién nacidos y lactantes hijos de madres infectadas. Pacientes y método: Reclutamiento consecutivo de binomios madre-hijo en maternidad, inmediatamente posparto. Luego de la firma de consentimiento informado, se obtuvo una muestra de deposición de la madre, previo al alta. Posteriormente se obtuvieron 3 muestras de deposición de los recién nacidos/lactantes a los 15, 60 y 90 días de vida, para la detección de antígeno en deposición de H. pylori (HpSAg monoclonal, sensibilidad 94% y especificidad 97%). Además se registraron variables socio-epidemiológicas y biomédicas. Resultados: Se reclutaron 32 binomios madre-hijo, 64 sujetos. Promedio de edad materna de 30,1 ± 5,1 años, 53% parto eutócico, 85% con lactancia materna exclusiva al final del seguimiento. Se encontró 13 madres (40%) infectadas por H. pylori. No hubo infección por H. pylori en los recién nacidos y lactantes a los 3 meses de seguimiento. No hubo diferencia significativa en el nivel socioeconómico entre madres infectadas versus no infectadas (ambos grupos en nivel socioeconómico muy alto: 28% y 32% respectivamente, p = 0,15), ni en el número de habitantes por domicilio entre madres infectadas y no infectadas (3,8 ± 0,8 vs 4,2 ± 1,8 personas, p = 0,18). Conclusión: A pesar de tener un alto porcentaje de madres infectadas por H. pylori, no hubo recién nacidos/lactantes infectados al tercer mes de vida. El rol protector de la lactancia maternal no se puede descartar.

Introduction: H. pylori infection is acquired early in childhood. However, there is little information available regarding the role of breastfeeding and neonatal acquisition of the infection. Objective: To evaluate factors affecting the acquisition of H. pylori in newborns and infants from infected mothers. Patients and method: Consecutive mothers and their newborns were recruited into the study from the maternity unit, immediately after delivery. After signing informed consent, one stool sample from the mother was obtained before hospital discharge. Three stool samples of the newborns were then collected at home at 15, 60, and 90 days of life, for the detection of H. pylori antigen (Monoclonal HpSAg, sensitivity 94% and specificity 97%). The socio-epidemiological and biomedical variables were also analysed using a questionnaire. Results: A total of 32 mother-child pairs (64 subjects) were enrolled. The mean maternal age was 30.1 ± 5.1 years, with 53% vaginal delivery, and 85% exclusively breastfed. There were 13 (40%) infected mothers. No H. pylori infection was detected in newborns and infants up to 3 months of follow-up. No significant differences were found in socioeconomic level between infected versus non-infected mothers (both groups mostly in the very high socioeconomic category: 28% and 32%, respectively, P = .15) and in the number of family members between infected versus non-infected mothers (3.8 ± 0.8 vs 4.2 ± 1.8 persons, P = .18). Conclusion: Despite having a significant percentage of H. pylori-infected mothers, no newborn was infected at the third month of life. The protective role of breastfeeding cannot be ruled out.

Prevalencia de la infección por Helicobacter pylori en niños: estimando la edad de adquisición / Frequency of Helicobacter pylori infection in 144 school age Chilean children

Background: A 73% prevalence of Helicobacter pylori infection was estimated in adults in the 2003 Chilean National Health Survey. However, this infection is usually acquired during childhood. Aim: To determine the frequency of H. pylori infection in healthy Chilean children from a school in Santiago. Material and Methods: A cross sectional study in a private/ subsidized school in Santiago. Children aged less than 18 years were invited to participate. The parents of those who accepted answered a demographic survey and a stool sample was obtained from participants to detect H. pylori antigen using a monoclonal antibody ELISA kit. Results: We studied 144 students aged 10.6 ± 3.1 years (54% females). Twenty six participants (18.1%, 95% CI: 12.4-24.9%) had a positive test. Children from higher socioeconomic levels had a non-significant lower frequency of infection. No differences in the frequency of infection were observed by age, gender, household type or number of people living in it or history of breastfeeding. Conclusions: In this sample of children, an 18.1% frequency of H. pylori infection was observed.