Myelodysplastic syndromes (MDS) are a group of clonal disorders arising from hematopoietic stem cells generally characterized by inefficient hematopoiesis, dysplasia in one or more myeloid cell lineages, and variable degrees of cytopenias. Most MDS patients are diagnosed in their late 60s to early 70s. The estimated incidence of MDS in the United States and in Europe are 4.3 and 1.8 per 100,000 individuals per year, respectively with lower rates reported in some Asian countries and less well estimated in other parts of the world. Evolution to acute myeloid leukemia can occur in 10-15% of MDS patients. Three drugs are currently approved for the treatment of patients with MDS: immunomodulatory agents (lenalidomide), and hypomethylating therapy [HMT (decitabine and 5-azacytidine)]. All patients will eventually lose their response to therapy, and the survival outcome of MDS patients is poor (median survival of 4.5 months) especially for patients who fail (refractory/relapsed) HMT. The only potential curative treatment for MDS is hematopoietic cell transplantation. Genomic/chromosomal instability and various mechanisms contribute to the pathogenesis and prognosis of the disease. High throughput genetic technologies like single nucleotide polymorphism array analysis and next generation sequencing technologies have uncovered novel genetic alterations and increased our knowledge of MDS pathogenesis. We will review various genetic and non-genetic causes that are involved in the pathogenesis of MDS.
Asian Continental Ancestry Group ; Cell Transplantation ; Europe ; Hematopoiesis ; Hematopoietic Stem Cells ; Humans ; Incidence ; Leukemia, Myeloid, Acute ; Myelodysplastic Syndromes* ; Myeloid Cells ; Polymorphism, Single Nucleotide ; Prognosis ; Transplants ; United States

INTRODUCTION: Noise-induced hearing loss (NIHL) attributed to occupational noise exposure is one of the most common causes of permanent hearing impairment. In the Philippines, road traffic remains the biggest source of noise. The authors aimed to determine the prevalence of NIHL among traffic enforcers in Quezon City and quantify their occupational noise exposure levels. METHODS: Traffic enforcers were recruited via convenience sampling and screened using a questionnaire and otoscopic examination. Participants underwent pure tone audiometry and those found to have hearing loss were classified as “indicative” or “suspected” NIHL. Audiometric measurements of noise levels in areas where the traffic enforcers were assigned were taken using a calibrated smartphone application. RESULTS: “Indicative of NIHL” was highest in the 41 to 50-year age group and “suspected NIHL” was highest in the 31 to 40-year age group. “Indicative of NIHL” was highest among those working for 1 to 5 and 11 to 15 years in the right ear (25%) and 11 to 15 years in the left ear (30%). “Suspected NIHL” was highest among those working for 6 to 10 years. The average noise levels from the different areas measured at different times ranged from 79.0 to 82.5 dB. CONCLUSION “Indicative of NIHL” is more prevalent in the older age group while “suspected NIHL” is more prevalent in the middle age group. The prevalence of “indicative of NIHL” is highest among those in service for 1 to 5 and 11 to 15 years while “suspected NIHL” is highest among those in the service for 6 to 10 years. The average noise level measurements were within the safe values suggested by WHO.
Audiometry, Pure-Tone ; Hearing Loss, Noise-Induced ; Noise, Occupational