LEP promoter methylation in the initiation and progression of clonal cytopenia of undetermined significance and myelodysplastic syndrome

BACKGROUND

Idiopathic non-clonal cytopenia (ICUS) and clonal cytopenia (CCUS) are common in the elderly population. While these entities have similar clinical presentations with peripheral blood cytopenia and less than 10% bone marrow dysplasia, their malignant potential is different and the biological relationship between these disorders and myeloid neoplasms such as myelodysplastic syndrome (MDS) is not fully understood. Aberrant DNA methylation has previously been described to play a vital role in MDS and acute myeloid leukemia (AML) pathogenesis. In addition, obesity confers a poorer prognosis in MDS with inferior overall survival and a higher rate of AML transformation. In this study, we measured DNA methylation of the promoter for the obesity-regulated gene LEP, encoding leptin, in hematopoietic cells from ICUS, CCUS and MDS patients and healthy controls. We investigated whether LEP promoter methylation is an early event in the development of myeloid neoplasms and whether it is associated with clinical outcome.

RESULTS

We found that blood cells of patients with ICUS, CCUS and MDS all have a significantly hypermethylated LEP promoter compared to healthy controls and that LEP hypermethylation is associated with anemia, increased bone marrow blast percentage, and lower plasma leptin levels. MDS patients with a high LEP promoter methylation have a higher risk of progression, shorter progression-free survival, and inferior overall survival. Furthermore, LEP promoter methylation was an independent risk factor for the progression of MDS in a multivariate Cox regression analysis.

CONCLUSION

In conclusion, hypermethylation of the LEP promoter is an early and frequent event in myeloid neoplasms and is associated with a worse prognosis.

Myeloproliferative and lymphoproliferative malignancies occurring in the same patient: a nationwide discovery cohort

Myeloid and lymphoid malignancies are postulated to have distinct pathogenetic mechanisms. The recent observation that patients with a myeloproliferative neoplasm have an increased risk of developing lymphoproliferative malignancy has challenged this assumption. We collected a nationwide cohort of patients with both malignancies. Patients diagnosed in 1990-2015 were identified through the national Danish Pathology Registry. We identified 599 patients with myeloproliferative neoplasm and a concomitant or subsequent diagnosis of lymphoma. Histopathological review of the diagnostic samples from each patient led to a final cohort of 97 individuals with confirmed dual diagnoses of myeloproliferative neoplasm and lymphoma. The age range at diagnosis was 19-94 years (median: 71 years). To avoid the inclusion of cases of therapy-induced myeloproliferative neoplasm occurring in patients previously treated for lymphoma, only patients with myeloproliferative neoplasm diagnosed unequivocally before the development of lymphoma were included. The average time interval between the diagnoses of the two malignancies was 1.5 years. In the majority of patients (90%) both diagnoses were established within 5 years from each other. Among the lymphoma entities, the frequency of peripheral T-cell lymphomas was markedly increased. Interestingly, all but one of the T-cell lymphomas were of angioimmunoblastic type. These findings suggest that myeloproliferative neoplasm and lymphoproliferative malignancy developing in the same patient may have common pathogenetic events, possibly already at progenitor level. We believe that the molecular characterization of the newly developed biorepository will help to highlight the mechanisms driving the genesis and clonal evolution of these hematopoietic malignancies.

Identification of a novel UTY-encoded minor histocompatibility antigen

Minor histocompatibility antigens (mHags) encoded by the Y-chromosome (H-Y-mHags) are known to play a pivotal role in allogeneic haematopoietic cell transplantation (HCT) involving female donors and male recipients. We present a new H-Y-mHag, YYNAFHWAI (UTY(139-147)), encoded by the UTY gene and presented by HLA-A*24:02. Briefly, short peptide stretches encompassing multiple putative H-Y-mHags were designed using a bioinformatics predictor of peptide-HLA binding, NetMHCpan. These peptides were used to screen for peptide-specific HLA-restricted T cell responses in peripheral blood mononuclear cells obtained post-HCT from male recipients of female donor grafts. In one of these recipients, a CD8+ T cell response was observed against a peptide stretch encoded by the UTY gene. Another bioinformatics tool, HLArestrictor, was used to identify the optimal peptide and HLA-restriction element. Using peptide/HLA tetramers, the specificity of the CD8+ T cell response was successfully validated as being HLA-A*24:02-restricted and directed against the male UTY(139-147) peptide. Functional analysis of these T cells demonstrated male UTY(139-147) peptide-specific cytokine secretion (IFNγ, TNFα and MIP-1β) and cytotoxic degranulation (CD107a). In contrast, no responses were seen when the T cells were stimulated with patient tumour cells alone. CD8+ T cells specific for this new H-Y-mHag were found in three of five HLA-A*24:02-positive male recipients of female donor HCT grafts available for this study.

An epidemiologic investigation of a rubella outbreak among the Amish of northeastern Ohio

From April 1990 to April 1991, 278 cases of rubella were reported to the Ohio Department of Health. Of these, 276 (99 percent) were among the Amish of northeastern Ohio. The outbreak involved eight counties in an area that contains large settlements of Old Order Amish. Members of this community of Amish frequently take religious exemption from recommended immunization practices and are believed to represent a high proportion of Ohio's rubella-susceptible persons. Vaccination history was known only for 146 of the Amish people. Of those, only four had a positive history of rubella vaccination. Of the 276 Amish with cases of rubella, 65 (24 percent) were younger than age 5 years, 104 (38 percent) were ages 5-14, 46 (17 percent) were ages 15-19, 32 (12 percent) were ages 20-29, 6 (2 percent) were ages 30 or older, and age was not reported for 23 (8 percent). The ratio of males to females with rubella was 1:1. Five women of the Amish community were pregnant; four had been ill with symptoms consistent with rubella. Three were in their first trimester. Congenital rubella syndrome did not occur in any of the four live births. Serology was available for only the two non-Amish people, and both were acute phase serum-positive for Immunoglobulin M.

Determination of Mirex in human blood serum containing polychlorinated biphenyls by using packed column gas chromatography

An analytical method has been developed that uses electron capture/gas-liquid chromatography to determine Mirex in serum containing polychlorinated biphenyls (PCBs) (Aroclor 1260). With this method, 0.2 ppb Mirex can be determined in 4 mL serum that also contains 10 ppb PCBs. The method provides approximately 70% recovery of Mirex at 1.0 and 3.5 ppb. The coefficients of variation are 4.5 and 4.6% at 1.0 and 3.5 ppb, respectively. In a cooperative study with the Ohio Department of Health, the Centers for Disease Control used this method to determine the extent of exposure of Salem, OH, residents to Mirex. Confirmation of Mirex was obtained by using high resolution gas chromatography and high resolution mass spectrometry.

Childhood injury mortality in Ohio, 1979 to 1986. Setting priorities for prevention

Injury deaths in Ohio children aged 1 to 16 years account for less than 0.5% of all deaths in the state but 6% of all years of life lost before age 65 years. In this study, injury mortality rates were calculated by sex for three age groups (1 to 5, 6 to 11, and 12 to 16 years) and three population groups (metropolitan white, metropolitan nonwhite, and nonmetropolitan). The 15 metropolitan counties were those with a central city of at least a population of 50,000, containing 60% of the state's population. Fire is the leading cause of injury mortality for metropolitan children aged 1 to 5 years, while motor vehicle injuries and drowning are the leading causes for nonmetropolitan children in this age group. Fire is also the leading cause for metropolitan nonwhite children aged 6 to 11 years, while motor vehicle injuries are the leading cause for nonmetropolitan children, and pedestrian injuries are the leading cause for metropolitan white children. For nonmetropolitan and metropolitan white children aged 12 to 16 years, motor vehicle injuries are the leading cause, while for metropolitan nonwhite children homicide is the leading cause. Excess deaths for each cause were estimated by calculating the number of deaths expected for each age group if the rate experienced by the second-lowest population race group had applied to the whole population in that age group, and comparing this with the observed number. Using this approach, highest priority would be placed on prevention of motor vehicle deaths in 12- to 16-year-old nonmetropolitan and metropolitan white children, of fire deaths in metropolitan nonwhite children aged 1 to 11 years, and of drowning deaths in boys aged 12 to 16 years in all three population groups.