Hematopoyesis Clonal de Potencial Indeterminado (HCPI): más allá de un modelo de campo de cancerización / Clonal hematopoiesis of indeterminate potential (CHIP): Beyond a model of field cancerization

Resumen La Hematopoyesis Clonal de Potencial Indeterminado (HCPI), más conocida como CHIP por sus siglas en inglés, se define como la expansión clonal de Células Madre Hematopoyéticas (CMHs) que albergan una o más mutaciones somáticas (en la mayoría de los casos una sola mutación) sin un cáncer hematológico subyacente ni evidencia morfológica definitiva de displasia, con una frecuencia alélica mayor al 2%. Los individuos con HCPI progresan a malignidad a una tasa de cerca del 0.5% a 1% por año, convirtiéndose así en un modelo de campo de cancerización. Sin embargo, sus implicaciones van más allá debido a que se ha encontrado asociación con enfermedades inflamatorias crónicas, como enfermedad cardiovascular ateroesclerótica, diabetes y enfermedades autoinmunes. Además, es considerado un factor predictivo en pacientes con cáncer hematolológico y no hematológico que reciben quimioterapia y radioterapia.

Abstract Clonal hematopoiesis of indeterminate potential (CHIP) is the expansion of hematopoietic stem cells harboring one or more somatic mutations. These patients do not have underlying hematologic neoplasia, myelodysplasia, or dysplasia, but can progress to a malignant state at a rate of 0.5 to 1% per year. CHIP could be used as a model of field cancerization, since it has been associated with chronic inflammatory diseases, arteriosclerosis, diabetes, and autoimmune conditions. CHIP is also considered a predictive factor in hematological and non-hematological cancer patients receiving chemotherapy and radiotherapy.

Late-Onset Hematological Toxicity (LOHT) in Patients with B-Cell Lymphomas: A Survey in 758 Cases

ABSTRACT Background: The increasing survival of patients with non-Hodgkin lymphoma has allowed the diagnosis of long-term complications, including late-onset hematological toxicity (LOHT), transitory cytopenias, or therapy-related myeloid neoplasm (t-MDS/t-AML). Objective: The objective of the study was to determine the frequency and clinical evolution of LOHT in patients with lymphoproliferative malignancies. Materials and Methods: Two cohorts of patients B-cell lymphomas were reviewed. Patients who achieved full hematologic recovery at the end of treatment, and thereafter developed any degree of cytopenia were included in the study. Clinical and biochemical parameters were compared between patients with and without cytopenias with X2 test. Bi- and multivariate analyses were performed to evaluate factors associated with the development of late-onset cytopenias. Results: Of 758 patients enrolled, 19 developed cytopenias (2.5%). Transitory cytopenia was documented in 6 cases, 3 developed ICUS, 8 t-MDS, and 2 t-AML. In patients with FL, only hemoglobin < 12 g/dL (p = 0.032) and >6 nodal areas (p = 0.037) at diagnosis were factors statistically significant for the development of cytopenia. During cytopenias, 55% of patients died. Conclusions: LOHT constitutes a cause of morbidity and mortality in 2.5% of lymphoma patients treated with different therapy regimens.

A Case of Therapy-related Myeloid Neoplasm after Successful Treatment of Acute Promyelocytic Leukemia

Acute promyelocytic leukemia (APL) is considered as a curative disease after combined chemotherapy based on all-trans retinoic acid (ATRA) and anthracycline. However, as long-term survivors continue to increase, reports on sporadic cases of therapy-related myeloid neoplasm (t-MN) after successful APL treatment are also increasing. Recently, we have experienced one patient who developed t-MN 7 yr after APL diagnosis. Even though he had not been exposed to alkylating agents at all, he showed alkylating agents-associated features such as long latency period (>5 yr), first presentation as myelodysplatic phase (multilineage dysplasia with increased blasts), and complex karyotype including monosomy 5 and 7. He received only supportive care and expired 3 months after the diagnosis of t-MN (6 months of survival after the onset of cytopenias). t-MN after complete remission of APL is a rare but fatal complication, and patients with complex karyotypes show ominous prognosis in particular. For the early diagnosis of t-MN, long-term and close monitoring of the patient is needed. One should suspect this late complication whenever any unknown cytopenia develops, and should perform bone marrow biopsy and cytogenetic analysis.