Bolivian Aymara Natives with Chronic Mountain Sickness Have Autonomous BFU-E Growth
Bibliographic record
Abstract
Abstract Background Erythrocytosis / polycythemia is divided into primary and secondary. Primary polycythemia can be either acquired; i.e. polycythemia vera (PV) due to somatic JAK2 mutation, or congenital due to germ-line DNA changes (erythropoietin (EPO) receptor and VHL mutations in Chuvash polycythemia). These mutations are expressed within erythroid progenitors, drive increased erythropoiesis and are detected by hypersensitive or autonomous EPO BFU-E responses. In contrast, secondary erythrocytosis (SE), such as seen with cardiopulmonary pathologies, is driven by the circulating EPO. Chronic mountain sickness (CMS) is characterized by high altitude pathological erythrocytosis and by cognitive and neurological impairments. CMS is found in subjects living in high altitude (2500 meters and higher). In La Paz, Bolivia, (3600m) there is 7% incidence of CMS erythrocytosis. Some human populations (Tibetans, Andean Quechuas and Aymaras, and Ethiopians) are adapted to very high altitudes and their adapted phenotypes and, in some instances, evolutionarily selected haplotypes, have been reported. Whole genome was evaluated in Andeans and two genes, SENP1 and ANP32D were found to be evolutionarily selected and correlated with presence or absence of erythrocytosis. The genes down-regulation in hypoxia had survival benefit in Drosophila ortholog (1).SENP1 desumoylate GATA-1 and other regulatory proteins and is critical for definitive erythropoiesis (2,3). Here we evaluated native Aymara La Paz dwellers with three types of polycythemia: CMS, SE secondary to cardiopulmonary disease, and PV, by clinical studies and by in vitro evaluation of erythroid progenitors, and compared them to non-polycythemic subjects. Patients and Methods Complete blood count was performed by automatic hematologic counter (Micro 60, USA). Serum EPO was measured by Elisa (R&D System, USA) and JAK2V617F mutation analysis by PCR assay. Erythroid progenitors were isolated by density gradient centrifugation and cultured in methylcellulose medium with and without EPO (Stem Cell technologies, Canada) at 370 C and 5 % CO2. BFU-E colonies reading was carried out according to standardized criteria at 7 and 14 days. Results Table. Normal Control(n=10) CMS (n=15) Secondary Erythrocytosis(n=10) PolycythemiaVera (n=5) 1.Gender M/F 10/0 15/0 10/0 3/2 Age (range) 42 (40-47) 48 (29-58) 53 (34-72) 67 (42-74) Hb g/dl (SD) 16.2 (+ 0.9) 20.3 (+ 0.9) 22.8 (+ 1.4) 20.0 (+ 2.5) Ret % (SD) 1.3 (+ 0.1) 2.9 (+ 1.3) 3.6 (+ 1.2) 2.1 (+ 0.3) WBC /ul (SD) 6300 (+ 1600) 7200 (+ 1900) 6600 (+ 1700) 16600 (+ 4800) PLT 103 ul (SD) 273 (+ 80) 229 (+ 58) 193 (+ 54) 604 (+ 177) sEPO mUI/ml (SD) 10.0 (+ 3.9) 10.5 (+ 2.2) 82.9 (+ 30.4) 3.0 (+ 1.2) JAK2 V617F, No. (%) 0 (0) 0 (0) 0 (0) 100 Apoptosis Normal Delayed Normal Delayed BFU-E: EEC 0 (0-0) 10 (2-25) 0 (0-0) 45 (25-70) References: 1. Yu L et al. J Exp Med., 2010, 207:1183. 2. Sharma D et al. Cell Report, 2013, 3:1640. 3. Zhou D et al. Am J Hum Genet. 2013, 93:452. 4. Kapralova K et al. Blood. 2014,123:391 Conclusions a) Endogenous erythroid colony (EEC) are present in Aymaras with CMS, indicating primary polycythemia. b) Endogenous EECs are higher in PV than in CMS. c) CMS subjects have normal serum EPO levels. d) The role of SENP1, and hypoxia-regulated RUNX1 and NF-E2 (4) that promote erythropoiesis, is being interrogated in native erythroid cells. e) It remains to be determined if the autonomous BFU-E growth is specific for Aymara's CMS or present in CMS individuals of other ethnicities. Disclosures No relevant conflicts of interest to declare.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".