Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Sep 8:17:12.
doi: 10.1186/s12878-017-0083-y. eCollection 2017.

Alterations in hematologic indices during long-duration spaceflight

Hawley Kunz  1 , Heather Quiriarte  2 , Richard J Simpson  3 , Robert Ploutz-Snyder  4 , Kathleen McMonigal  5 , Clarence Sams  5 , Brian Crucian  5
Affiliations

Alterations in hematologic indices during long-duration spaceflight

Hawley Kunz et al. BMC Hematol. .

Abstract

Background: Although a state of anemia is perceived to be associated with spaceflight, to date a peripheral blood hematologic assessment of red blood cell (RBC) indices has not been performed during long-duration space missions.

Methods: This investigation collected whole blood samples from astronauts participating in up to 6-months orbital spaceflight, and returned those samples (ambient storage) to Earth for analysis. As samples were always collected near undock of a returning vehicle, the delay from collection to analysis never exceeded 48 h. As a subset of a larger immunologic investigation, a complete blood count was performed. A parallel stability study of the effect of a 48 h delay on these parameters assisted interpretation of the in-flight data.

Results: We report that the RBC and hemoglobin were significantly elevated during flight, both parameters deemed stable through the delay of sample return. Although the stability data showed hematocrit to be mildly elevated at +48 h, there was an in-flight increase in hematocrit that was ~3-fold higher in magnitude than the anticipated increase due to the delay in processing.

Conclusions: While susceptible to the possible influence of dehydration or plasma volume alterations, these results suggest astronauts do not develop persistent anemia during spaceflight.

Keywords: Anemia; Platelets; Red blood cells; Spaceflight.

PubMed Disclaimer

Conflict of interest statement

Ethics approval and consent to participate

Study procedures were reviewed and approved by the NASA Johnson Space Center’s Institutional Review Board. Written informed consent was obtained from all subjects prior to participation. Ethics approval for all subjects participating in the stability study was obtained under a protocol specific for assay development and validation, which was approved by the NASA Johnson Space Center’s Institutional Review Board.

Consent for publication

The astronaut photographed in Fig. 1 reviewed the image and provided written consent to publish.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
Blood collection onboard the ISS. Astronaut Nicole Stott performs phlebotomy on the ISS. Samples were collected ~10 h prior to return vehicle undocking (Space Shuttle or Soyuz). Blood samples were returned to the laboratory for analysis within 48 h of collection
Fig. 2
Fig. 2
Hematologic indices evaluated immediately following blood collection, and 24, 48, and 72 h after collection. All aged samples were compared to the baseline sample analyzed immediately post-collection using two one-sided tests for dependent samples. Data are presented as mean ± standard error. Samples that were not statistically considered equivalent to the baseline sample (p > 0.05) are indicated with *. a Red blood cell concentration (×106 cells/μL); b hemoglobin concentration (g/dL); c mean corpuscular hemoglobin (MCH; pg); d mean corpuscular volume (MCV; fL); e hematocrit (%); and f platelet concentration (×103 cells/μL). All parameters were measured using calibrated automated hematology analyzers
Fig. 3
Fig. 3
Hematologic indices evaluated before, during, and after spaceflight. All samples were compared to the L-180 baseline time point using a linear mixed model with random intercept. Data are presented as mean ± standard error. Significant differences from the L-180 baseline (p < 0.05) are indicated with *. a Red blood cell concentration (×106 cells/μL); b hemoglobin concentration (g/dL); c mean corpuscular hemoglobin (MCH; pg); d mean corpuscular volume (MCV; fL); e hematocrit (%); and f platelet concentration (×103 cells/μL). All parameters were measured using calibrated automated hematology analyzers
See this image and copyright information in PMC

References

    1. Williams D, Kuipers A, Mukai C, Thirsk R. Acclimation during space flight: effects on human physiology. Can Med Assoc J. 2009;180(13):1317–1323. doi: 10.1503/cmaj.090628. - DOI - PMC - PubMed
    1. Alfrey CP, Udden MM, Leach-Huntoon C, Driscoll T, Pickett MH. Control of red blood cell mass in spaceflight. J Appl Physiol. 1996;81(1):98–104. - PubMed
    1. Tavassoli M. Anemia of spaceflight. Blood. 1982;60(5):1059–1067. - PubMed
    1. Udden MM, Driscoll TB, Pickett MH, Leach-Huntoon CS, Alfrey CP. Decreased production of red blood cells in human subjects exposed to microgravity. J Lab Clin Med. 1995;125(4):442–449. - PubMed
    1. Smith SM. Red blood cell and iron metabolism during space flight. Nutrition. 2002;18(10):864–866. doi: 10.1016/S0899-9007(02)00912-7. - DOI - PubMed

LinkOut - more resources