Clinical characteristics and management of paroxysmal nocturnal haemoglobinuria in Latin America: a narrative review.

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare, complement-associated, haematological disorder. The level of knowledge about the disease and its management varies around the world. This narrative review provides an overview of available clinical data on PNH in Latin America (LATAM). A search of the PubMed, EMBASE and LILACS/IBECS databases to February 2023, and addition of author-known articles, yielded 24 relevant published articles, the majority (n = 15) from Brazil. Fourteen articles were full papers; 10 were conference abstracts. The prevalence of PNH in Brazil is estimated at 1:237,000 inhabitants. Among blood samples sent for flow cytometry screening for suspected PNH in Brazil and Colombia, 14 - 30% were positive. There is suggestion that disease subtypes may differ among LATAM populations, with classical PNH more common in Brazilian patients and PNH with aplastic anaemia more common in Mexican patients. Median age at diagnosis of PNH ranged from 24 to 41 years. Common symptoms included fatigue, haemoglobinuria, and abdominal pain, although the symptom profile varied by subtype. Three available studies indicated that eculizumab was effective at reducing haemolysis, improving anaemia, and reducing the risk of thrombosis in patients with PNH with intravascular haemolysis. A consensus document from the Brazilian Association of Hematology, Hemotherapy and Cell Therapy RBC and Iron Committee provides guidance on identifying and managing PNH patients, including appropriate selection of patients for eculizumab. Additional data on the epidemiology, natural history and outcomes of patients with PNH in LATAM countries are needed to better understand the disease and its management throughout the region.

A modified CALGB 10403 in adolescents and young adults with acute lymphoblastic leukemia in Central America.

Mexico and Central America have a high incidence of acute lymphoblastic leukemia (ALL) in adolescents and young adults. Historically, this patient group has been treated using adult-based regimens, which entails a high rate of treatment-related mortality and a poor overall survival (OS). The use of the CALGB 10403, a pediatric-inspired regimen, has been proven effective in this patient subgroup. Nonetheless, low- and middle-income countries (LMICs) may present limited access to standard care treatments implemented elsewhere, warranting the need for further research to improve outcomes among vulnerable populations. In this study, we present the outcomes in terms of safety and effectiveness of using a modified CALGB 10403 regimen to reflect drug and resource availability in LMICs. Modifications included the use of Escherichia coli asparaginase,6-mercaptopurine instead of thioguanine and the use of rituximab among patients with CD20+. A total of 95 patients with a median age of 23 (range, 14-49) years treated with this modified scheme were prospectively assessed at 5 centers in Mexico and 1 in Guatemala. Among these, 87.8% achieved a complete response after induction. During follow-up, 28.3% of patients relapsed. Two-year OS rate was 72.1%. Factors associated with worse OS included hyperleukocytosis (hazard ratio [HR], 4.28; 95% confidence interval [CI], 1.81-10.10) and postinduction minimal residual disease (HR, 4.67; 95% CI, 1.75-12.44). Most patients presented hepatotoxicity (51.6% and 53.7% during induction and consolidation, respectively), and the treatment-related mortality was 9.5%. Overall, results highlight that implementing a modified CALGB 10403 regimen in Central America is feasible, and it is associated with improvements in clinical outcomes and a manageable safety profile.

Manejo de pacientes con síndrome mielodisplásico en época COVID-19 / Management of patients with Myelodysplastic Syndrome in the COVID-19 era

Resumen La infección por coronavirus 2 del síndrome respiratorio agudo grave ha provocado un cambio en la forma de atender a los pacientes con enfermedades hematológicas en todo el mundo. Los pacientes con síndrome mielodisplásico (SMD) se han visto afectados por la ausencia de conocimiento del comportamiento de la enfermedad por coronavirus 2019 (COVID-19) en este tipo de padecimiento. Se han establecido lineamientos internacionales que han permitido continuar con la atención de dichos pacientes. El principal objetivo de esta revisión es definir las medidas preventivas y las estrategias de tratamiento que se deben de tomar al momento de evaluar a un paciente con SMD en la época COVID-19.

Abstract SARS-CoV-2 infection has caused a change in the way we care for patients with hematological diseases around the world. Patients with myelodysplastic syndrome (MDS) have been affected by the lack of knowledge of the behavior of COVID-19 in this type of condition. International guidelines have been established that have made it possible to continue caring for these patients. The main objective of this review is to define the preventive measures and treatment strategies that should be taken when evaluating a patient with myelodysplastic syndrome in the COVID-19 era.

Acute Myeloid Leukemia in Mexico: The Specific Challenges of a Developing Country. Results From a Multicenter National Registry.

BACKGROUND: In the past decades, long-term survival outcomes for younger patients with acute myeloid leukemia (AML) have improved. Nonetheless, developing nations might be lagging behind, highlighting the need to assess real-world outcomes in such regions. METHODS: We performed a multicenter retrospective study, which included patients with AML diagnosed between January 2013 and December 2017 from 13 centers in Mexico. RESULTS: A total of 525 patients with AML met the inclusion criteria and were included in the study. Median age for the entire cohort was 47 years. The patients were classified according to cytogenetic risk: favorable 16.0%, intermediate 55.6%, and unfavorable 28.4%. Most patients received intensive chemotherapy (80.2%), and among these 74.1% underwent a 7 + 3 induction regimen. A complete remission was achieved in 71.3% of patients. Induction-related mortality occurred in 17.8% and we identify the following as independent risk factors: >60 years (odds ratio [OR] 2.09 [1.09-4.02]), Eastern Cooperative Oncology Group >2 (OR 4.82 [2.46-9.43]), prior solid tumor (OR 3.8 [1.24-11.59]) and active infection (OR 1.82 [1.06-3.12]). Further, allogeneic hematopoietic stem-cell transplantation (AlloHSCT) was performed in 8.2% in CR1. The 3-year overall survival (OS) was 34.8%. In a multivariate analysis, several factors were independently associated with a worse OS, including secondary AML (hazard ratio [HR] 2.14 [1.15-4.01]) and unfavorable cytogenetic risk (HR 1.81 [1.16-2.82]), whereas maintenance therapy (HR 0.53 [0.32-0.86]) and AlloHSCT (HR 0.40 [0.17-0.94]) were associated with better OS. CONCLUSIONS: This is the first multicenter report analyzing AML survival in Mexico. Challenges in this setting include a high induction-related mortality and low AlloHSCT rate, which should be addressed to improve outcomes.

Prognostic Factors and Outcomes in Adults With Secondary Hemophagocytic Lymphohistiocytosis: A Single-center Experience.

INTRODUCTION: Hemophagocytic lymphohistiocytosis (HLH) is a disorder caused by severe immune activation. There are no specific criteria to establish the diagnosis in adults; however, the HLH-04 criteria are among the most commonly used. The HScore is a non-validated tool that can also be useful for HLH diagnosis. PATIENTS AND METHODS: We describe the prognostic factors and outcomes of 64 adults diagnosed with HLH in a reference medical center in Mexico City. We included patients ≥ 18 years with HLH, diagnosed and treated at our institution from 1998 to 2016. RESULTS: The median age was 35 years (range, 18-77 years). The underlying cause of HLH was lymphoma in 33 (51.56%) patients (MA-HLH). Cutaneous involvement was more frequent in MA-HLH (33.33%), when compared with patients with non-malignancy associated HLH (NM-HLH) (9.68%) (P = .022). Neurologic symptoms were more frequent in NM-HLH (25.81%) versus MA-HLH (6.06%) (P = .032). After a median follow-up of 14 months (range, 0-216 months), 30-day mortality was 26.56%. Three-year overall survival (OS) was higher for patients with MA-HLH compared with patients with NM-HLH (41% vs. 22.5%; P = .046). Multivariate analysis showed that the presence of nosocomial infection and neurologic symptoms were statistically significant predictors of inferior OS (P = .034 and P = .033, respectively). CONCLUSION: In this series of adults with HLH, patients with nosocomial infections and neurologic symptoms had a statistically significant worse OS. In the largest series in Latin America, the most common cause of HLH was T-cell lymphoma. In our population, NM-HLH presented a higher mortality.

Clinical outcomes and risk factors for posterior reversible encephalopathy syndrome in systemic lupus erythematosus: a multicentric case-control study.

BACKGROUND: Posterior reversible encephalopathy syndrome (PRES) is a well-known but rare complication in patients (<1%) with systemic lupus erythematosus (SLE). However, current epidemiological data are quite scant. The aim of the present study was to describe potentially unrecognised risk factors. PATIENTS AND METHODS: We performed a multicentre, retrospective case-control study in Mexico between 1999 and 2014. We included a total of 168 patients who accounted for 77 episodes of PRES, as follows: SLE/PRES, 43 patients with 48 episodes; SLE without PRES, 96 patients; and PRES without SLE, 29 patients. SLE diagnosis was considered when patients fulfilled ≥4 American College of Rheumatology criteria. PRES was defined by reversible neurological manifestations and MRI changes. RESULTS: Patients with SLE/PRES were younger, presented with seizures as the most common manifestation (81%) and 18% had the typical occipital MRI finding. Hypertension (OR=16.3, 95% CI 4.03 to 65.8), renal dysfunction (OR=6.65, 95% CI 1.24 to 35.6), lymphopenia (OR=5.76, 95% CI 1.36 to 24.4), Systemic Lupus Erythematosus Activity Index ≥ 6 points (OR=1.11, 95% CI 1.01 to 1.22) and younger age (OR=0.86, 95% CI 0.81 to 0.91, p<0.001) were independent risk factors for development of PRES in SLE. Furthermore, dyslipidemia also characterised the association between PRES and SLE (OR=10.6, 95% CI 1.17 to 96.4). CONCLUSIONS: This is the largest reported series of patients with SLE and PRES. We were able to corroborate the known risk factors for of PRES, and found two previously undescribed factors (lymphopenia and dyslipidemia), which suggests that endothelial dysfunction is a key element in PRES pathogenesis in lupus patients.