Haematological modifications after acute exposure to high altitude: possible implications for detection of recombinant erythropoietin misuse

We have evaluated changes in haematological parameters
in 24 healthy Western subjects, normally living at
sea level, exposed to high altitude during a scientific
expedition to the `Pyramid', Italy's National Research
Committee (CNR) laboratory located in the Kumbu Valley
(Nepal) at 5050 m. Blood samples were collected as follows:
(A) at standard conditions (Kathmandu, 1200 m); (B) upon
arrival at the Pyramid, after 6 d walking from 2800 m up to
5050 m; and (C) after an 8-d stay at the Pyramid.
Haemoglobin concentration (Hb), haematocrit (Hct), red
blood cell count (RBC), white blood cell count (WBC) and
platelet number (Plt) were measured on the spot, using a
portable automatic counter (Coulter ACT8). In addition, sera
were cryopreserved in liquid nitrogen for later measurement,
in our laboratory in Pavia, of erythropoietin (Epo) and soluble
transferrin receptor (sTfr) concentrations (Quantikine ELISARD
System), ferritin (ftr) concentrations (electrochemiluminescence
immunoassay `ECLIA'; Boehringer Mannheim) and
serum iron concentration (BM/Hitachi 717).
Changes in Hb, Plt, sTfr, ferritin and sTfr/ftr concentrations
between times A and B and between times B and C were
statistically significant (Table I). Moreover, we observed a
significant increase in Epo levels between times A and B and
between times A and C, but not between times B and C.
Haematocrits were significantly higher at time C with respect
to time A and B. Finally, the sTfr/ftr ratio increased threefold
between standard conditions (A) and the departure from the
Pyramid (C).