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 denovo. The patients were classified as standard risk if they were 1–9.9 years old and had a leucocyte count 100 × 10⁹/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.

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.

We present a study performed on 54 unrelated subjects, with and without thalassemic features. Two primer pairs were proposed to perform Sanger sequencing of the complete HBB gene. The bioinformatic analysis was performed taking advantage of the availability of free online tools. In the sample, we found 11 variants, 10 reported, and one novel. Among the variants found, six are clinically important: three encode a premature stop codon [codon 39 (C>T) (HBB: c.118C>T); IVS-II-1 (G>A) (HBB: c.315+1G>A), and one not reported], a double substitution within the same allele [Hb Borås (HBB: c.266T>G) and Hb Santa Giusta Sardegna (HBB: c.282T>C)], and one whose pathogenicity is not yet defined [Hb Fannin-Lubbock I (HBB: c.359G>A)]. Even though the variants Hb Borås and Hb Santa Giusta Sardegna have been described, there is no report of their combined occurrence on the same allele, which could cause hemolytic anemia. Although the p.Leu88Arg and p.Cys93Trp variants do not alter the final length of the protein, the bioinformatic results suggest that there are differences in the tertiary structure of β-globin genes, mainly affecting helices E and F, being the motifs of interaction with the heme group. The novel variant is a 4 bp insertion that modifies the open reading frame, changing the last amino acid residue and causing a premature stop codon (HBB: c.291-294insGCAC). The variant was associated with β-thalassemia (β-thal). Bioinformatic analysis made it possible to predict the consequences that the new variant of the HBB gene caused on the β-globin tertiary structure.

NOTCH1 and PAX5 participate in the proliferation and differentiation of B and T lymphocytes. Their expression can be modified by activation of NOTCH1, induced by the Epstein–Barr (EBV) viral proteins identified as LMP1 and LMP2. To identify whether PAX5, NOTCH1, and EBV latency genes participate in the oncogenic process of pediatric patients with classical Hodgkin lymphoma (cHL), the present study aimed to identify the variable expression of NOTCH1 among disease subtypes and to assess its effect on PAX5 expression. A total of 41 paraffin-embedded tissues from Mexican pediatric patients with cHL were analyzed. The expression of CD30, CD20, NOTCH1, PAX5, and LMP1 was evaluated by immunohistochemistry and immunofluorescence. EBV detection was performed by in situ hybridization. Out of all cases, 78% (32/41) of the cHL cases were EBV positive. NOTCH1 expression was detected in 78.1% (25/32) of EBV-positive cases, nodular sclerosis being the most frequent subtype (11/25, 44%). In cases where the expression of both genes was identified, double immunofluorescence assays were conducted, finding no colocalization. We found that Reed–Sternberg cells had aberrant expression compared to their cells of origin (B lymphocytes) due to the molecular mechanisms involved in the loss of expression of PAX5 and that the identification of NOTCH1 could be considered as a candidate diagnostic/prognostic marker and a therapeutic target in pediatric cHL.

Hemophagocytic syndrome, macrophage activation syndrome, reactive histiocytosis or hemophagocytic lymphohistiocytosis (HLH) represent a group of diseases whose common thread is reactive or neoplastic mononuclear phagocytic system cells and dendritic cell proliferation. We present a case of an HLH probably associated with Epstein-Barr virus (EBV) in a 4-year-old male patient treated with HLH-04 protocol. Viral etiology in HLH is well accepted. In this case, clinical picture of HLH was assumed secondary to EBV infection because IgM serology at the time of clinical presentation was the only positive factor in the viral panel. Diagnosis of HLH is the critical first step to successful treatment. The earlier it is identified, the less the tissue damage and reduced risk of multiple organ failure, which favors treatment response.