TO THE EDITOR:

Erythrocytosis is an increase in the number of circulating red blood cells especially resulting from a known stimulus (such as hypoxia). Chronic mountain sickness (CMS) is defined as “a clinical syndrome that occurs to natives or life-long residents above 2500 m. It is characterized by excessive erythrocytosis (females hemoglobin concentration ([Hb]) ≥ 19 g·dL−1; males [Hb] ≥ 21 g·dL−1), severe hypoxemia, and in some cases moderate or severe pulmonary hypertension.2(p149) This syndrome is most prevalent among Andean high-altitude residents and is, presumably, the consequence of a loss of ventilatory acclimatization to altitude promoting hypoxemia and the excessive erythropoietic response leading to high [Hb], hematocrit, and blood viscosity.3,4  CMS is diagnosed on the basis of a score that includes 7 clinical symptoms and 1 clinical sign, [Hb]. Measuring erythrocytosis...

REFERENCES

REFERENCES
1.
Merriam-Webster.com Medical Dictionary. “Erythrocytosis”. https://www.merriam-webster.com/medical/erythrocytosis. Accessed 15 May 2020.
2.
León-Velarde
F
,
Maggiorini
M
,
Reeves
JT
, et al
.
Consensus statement on chronic and subacute high altitude diseases
.
High Alt Med Biol
.
2005
;
6
(
2
):
147
-
157
.
3.
Monge
C
.
High altitude disease
.
Arch Intern Med (Chic)
.
1937
;
59
(
1
):
32
-
40
.
4.
Villafuerte
FC
,
Corante
N
.
Chronic mountain sickness: clinical aspects, etiology, management, and treatment
.
High Alt Med Biol
.
2016
;
17
(
2
):
61
-
69
.
5.
Hurtado
A
.
Some clinical aspects of life at high altitudes
.
Ann Intern Med
.
1960
;
53
(
2
):
247
-
258
.
6.
Claydon
VE
,
Norcliffe
LJ
,
Moore
JP
, et al
.
Orthostatic tolerance and blood volumes in Andean high altitude dwellers
.
Exp Physiol
.
2004
;
89
(
5
):
565
-
571
.
7.
Lawrence
JH
,
Huff
RL
,
Siri
W
,
Wasserman
LR
,
Hennessy
TG
.
A physiological study in the Peruvian Andes
.
Acta Med Scand
.
1952
;
142
(
2
):
117
-
131
.
8.
Wachsmuth
N
,
Soria
R
,
Jimenez
J
,
Schmidt
W
.
Modification of the CO-rebreathing method to determine haemoglobin mass and blood volume in patients suffering from chronic mountain sickness
.
Exp Physiol
.
2019
;
104
(
12
):
1819
-
1828
.
9.
West
JB
.
Physiological effects of chronic hypoxia
.
N Engl J Med
.
2017
;
376
(
20
):
1965
-
1971
.
10.
Enserink
M
.
Hypoxia city
.
Science
.
2019
;
365
(
6458
):
1098
-
1103
.
11.
Jefferson
JA
,
Escudero
E
,
Hurtado
M-E
, et al
.
Excessive erythrocytosis, chronic mountain sickness, and serum cobalt levels
.
Lancet
.
2002
;
359
(
9304
):
407
-
408
.
12.
Richalet
J-P
,
Rivera-Ch
M
,
Maignan
M
, et al
.
Acetazolamide for Monge’s disease: efficiency and tolerance of 6-month treatment
.
Am J Respir Crit Care Med
.
2008
;
177
(
12
):
1370
-
1376
.
13.
Richalet
J-P
,
Rivera
M
,
Bouchet
P
, et al
.
Acetazolamide: a treatment for chronic mountain sickness
.
Am J Respir Crit Care Med
.
2005
;
172
(
11
):
1427
-
1433
.
14.
Siebenmann
C
,
Keiser
S
,
Robach
P
,
Lundby
C
.
CORP: the assessment of total hemoglobin mass by carbon monoxide rebreathing
.
J Appl Physiol (1985)
.
2017
;
123
(
3
):
645
-
654
.
15.
Whittembury
J
,
Monge
CC
.
High altitude, haematocrit and age
.
Nature
.
1972
;
238
(
5362
):
278
-
279
.
16.
Monge
C
,
León-Velarde
F
,
Arregui
A
.
Increasing prevalence of excessive erythrocytosis with age among healthy high-altitude miners
.
N Engl J Med
.
1989
;
321
(
18
):
1271
.
17.
Stembridge
M
,
Williams
AM
,
Gasho
C
, et al
.
The overlooked significance of plasma volume for successful adaptation to high altitude in Sherpa and Andean natives
.
Proc Natl Acad Sci USA
.
2019
;
116
(
33
):
16177
-
16179
.
18.
Tremblay
JC
,
Hoiland
RL
,
Howe
CA
, et al
.
Global REACH 2018: high blood viscosity and hemoglobin concentration contribute to reduced flow-mediated dilation in high-altitude excessive erythrocytosis
.
Hypertension
.
2019
;
73
(
6
):
1327
-
1335
.
19.
Stauffer
E
,
Loyrion
E
,
Hancco
I
, et al
.
Blood viscosity and its determinants in the highest city in the world [published online ahead of print 22 May 2020]
.
J Physiol
.
doi: 10.1113/JP279694
.
20.
Prchal
JT
.
Clinical manifestations and classification of erythrocyte disorders
. In:
Kaushansky
K
,
Lichtman
M
,
Prchal
JT
, et al
, eds.
Williams Hematology, 9th ed
.
New York
:
McGraw-Hill Education
;
2015
:
503
-
512
21.
Gordeuk
VR
,
Key
NS
,
Prchal
JT
.
Re-evaluation of hematocrit as a determinant of thrombotic risk in erythrocytosis
.
Haematologica
.
2019
;
104
(
4
):
653
-
658
.
22.
Gordeuk
VR
,
Miasnikova
GY
,
Sergueeva
AI
, et al
.
Thrombotic risk in congenital erythrocytosis due to up-regulated hypoxia sensing is not associated with elevated hematocrit
.
Haematologica
.
2020
;
105
(
3
):
e87
-
e90
.
23.
Greksa
LP
.
Growth and development of Andean high altitude residents
.
High Alt Med Biol
.
2006
;
7
(
2
):
116
-
124
.
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