Infections and risk factors for infection-related mortality after pediatric allogeneic hematopoietic stem cell transplantation in Mexico: A single center retrospective study.

OBJECTIVE: To identify the type of infections and risk factors for infection-related mortality (IRM) after allogeneic hematopoietic stem cell transplantation (HSCT). METHODS: Retrospective cohort study of patients <16 years of age treated in 2010-2019 was conducted. Unadjusted hazard ratios (HR) and adjusted hazard ratios (aHR) with 95% confidence intervals (95% CIs) were estimated using Cox regression. Cumulative incidence was calculated. RESULTS: Data for 99 pediatric patients were analyzed. The myeloablative conditioning was the most used regimen (78.8%) and the hematopoietic stem cell source was predominantly peripheral blood (80.8%). Primary graft failure occurred in 19.2% of patients. Frequency of acute graft-versus-host disease was 46.5%. Total of 136 infectious events was recorded, the most common of which were bacterial (76.4%) followed by viral infection (15.5%) and then fungal infection (8.1%). The best predictors for infection subtypes where the following: a) for bacterial infection (the age groups of 10.1-15 years: aHR = 3.33; 95% CI: 1.62-6.85 and. >15 years: aHR = 3.34; 95% CI: 1.18-9.45); b) for viral infection (graft versus host disease: aHR = 5.36; 95% CI: 1.62-17.68), however, for fungal infection statistically significant predictors were not identified. Related mortality was 30% (n = 12). Increased risk for infection-related mortality was observed in patients with unrelated donor and umbilical cord stem cells recipients (HR = 3.12; 95% CI: 1.00-9.85). CONCLUSIONS: Frequencies of infections and infection-related mortality appear to be similar to those reported. Unrelated donors and stem cells from umbilical cord recipients were associated with a high risk of mortality.

Prevalence of inhibitors and clinical characteristics in patients with haemophilia in a middle-income Latin American country.

INTRODUCTION: Development of inhibitors is the most serious complication in patients with haemophilia (PWH). The prevalence of inhibitors in patients with severe haemophilia A (HA) is approximately 25%-30%. Inhibitor prevalence differs among populations. Some studies report a prevalence of almost twice in Hispanic as compared to Caucasian patients. Most data available, on the prevalence of inhibitors and their predisposing factors, originate from centres in developed countries. AIM: Establish the prevalence of inhibitors of FVIII and FIX in Mexico. METHODS: This was an observational, cross-sectional and descriptive study. The records of all patients diagnosed with haemophilia A (HA) or B (HB), with and without inhibitors, were included. Clinical and demographical characteristics of patients with inhibitors were assessed. Statistical analysis was performed using IBM SPSS version 22. The Ethics Committees of the various participating institutions approved this study. RESULTS: A total of 1455 patients from the 20 participating centres were recruited, from which 1208 (83.02%) had HA and 247 (16.97%) were diagnosed with HB. The presence of inhibitors in severe HA was reported in 93/777(11.96%), and 10/162 (6.17%) in severe HB. Of them, 91.7% exhibited high titres in HA and 100% in HB. CONCLUSION: In Mexico, the general prevalence of inhibitors varies considerably among centres. This study established a basis of comparison for future development and advances in the treatment and follow-up of patients. These findings also augment our understanding of risk factors related to inhibitor development.

Survival of Mexican Children with Acute Lymphoblastic Leukaemia under Treatment with the Protocol from the Dana-Farber Cancer Institute 00-01.

Our aim in this paper is to describe the results of treatment of acute lymphoblastic leukaemia (ALL) in Mexican children treated from 2006 to 2010 under the protocol from the Dana-Farber Cancer Institute (DFCI) 00-01. The children were younger than 16 years of age and had a diagnosis of ALL de novo. The patients were classified as standard risk if they were 1-9.9 years old and had a leucocyte count <50 × 10(9)/L, precursor B cell immunophenotype, no mediastinal mass, CSF free of blasts, and a good response to prednisone. The rest of the patients were defined as high risk. Of a total of 302 children, 51.7% were at high risk. The global survival rate was 63.9%, and the event-free survival rate was 52.3% after an average follow-up of 3.9 years. The percentages of patients who died were 7% on induction and 14.2% in complete remission; death was associated mainly with infection (21.5%). The relapse rate was 26.2%. The main factor associated with the occurrence of an event was a leucocyte count >100 × 10(9)/L. The poor outcomes were associated with toxic death during induction, complete remission, and relapse. These factors remain the main obstacles to the success of this treatment in our population.

Survival of Mexican children with acute myeloid leukaemia who received early intensification chemotherapy and an autologous transplant.

BACKGROUND: In Mexico and other developing countries, few reports of the survival of children with acute leukaemia exist. Objective. We aimed at comparing the disease-free survival of children with acute myeloid leukaemia who, in addition to being treated with the Latin American protocol of chemotherapy and an autologous transplant, either underwent early intensified chemotherapy or did not undergo such treatment. PROCEDURE: This was a cohort study with a historical control group, forty patients, less than 16 years old. Group A (20 patients), diagnosed in the period 2005-2007, was treated with the Latin American protocol of chemotherapy with an autologous transplant plus early intensified chemotherapy: high doses of cytarabine and mitoxantrone. Group B (20 patients), diagnosed in the period 1999-2004, was treated as Group A, but without the early intensified chemotherapy. RESULTS: Relapse-free survival for Group A was 90% whereas that for Group B it was 60% (P = 0.041). Overall survival for Group A (18, 90%) was higher than that for Group B (60%). Complete remission continued for two years of follow-up. CONCLUSIONS: Relapse-free survival for paediatric patients treated with the Latin American protocol of chemotherapy with an autologous transplant plus early intensified chemotherapy was higher than that for those who did not receive early intensified chemotherapy.