Validation of Procedures for Monitoring Crewmember Immune Function - Short Duration Biological Investigation (Integrated Immune-SDBI) - 09.17.14
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Validation of Procedures for Monitoring Crew Member Immune Function - Short Duration Biological Investigation (Integrated Immune-SDBI) will assess the clinical risks resulting from the adverse effects of space flight on the human immune system and will validate a flight-compatible immune monitoring strategy. Immune system changes will be monitored by collecting and analyzing blood, urine and saliva samples from crewmembers before, during and after space flight.
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Nine Shuttle crew members gave their blood, sweat, and tears – make that blood, spit, and urine – for this study of immune system changes in space. Samples analyses, done at the Johnson Space Center laboratory, indicate that immune function becomes more compromised as mission workloads grow greater and more complex, which creates more stress. Mission planners need to understand how mission variables and stress levels affect immune responses so they can keep crew members healthy and still meet long-duration mission requirements. Immune system function is particularly a concern for missions exploring the Moon or Mars.
Johnson Space Center, Human Research Program, Houston, TX, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
October 2007 - September 2011
Previous ISS Missions
This is a continuing investigation which began on STS-120/10A.
- There is ample postflight evidence to suggest that space flight has a negative effect on the immune system however; little inflight data has been collected. The inflight data that exists suggests immune dysregulation occurs during flight. There are several possible causes ranging from microgravity to stress to radiation. Complications arising from an immune system dysregulation have the potential to pose a clinical risk for exploration-class space missions.
- In order to develop countermeasures to reduce inflight immune dysfunction, a monitoring strategy must be developed.
- The objective of this study is to validate a monitoring strategy that will allow future countermeasures to be developed.
The Validation of Procedures for Monitoring Crewmember Immune Function - Short Duration Biological Investigation (Integrated Immune-SDBI) is to develop and validate an immune monitoring strategy consistent with operational flight requirements and constraints. There are no procedures currently in place to monitor immune function or its influence on crew health. Immune dysregulation has been demonstrated to occur during spaceflight, yet precious little inflight immune data has been generated to assess this clinical problem. Integrated Immune-SDBI assesses the clinical risks resulting from the adverse effects of space flight on the human immune system and will validate a flight-compatible immune monitoring strategy. Characterization of the clinical risk and the development of a monitoring strategy are necessary prerequisite activities prior to validating countermeasures.
Preflight, inflight and postflight assessments will be performed. The inflight samples will allow a distinction between legitimate inflight alterations and the physiological stresses of landing which are believed to alter landing day assessments. The overall status of the immune system during flight (activation, deficiency, dysregulation) and the response of the immune system to specific latent virus reactivation (known to occur during space flight) will be thoroughly assessed.
Following completion of the investigation, the data will be evaluated to determine the optimal set of assays for routine monitoring of crewmember immune system function. It is intended that the determined set of relevant assays will be incorporated into the Clinical Status Evaluation (CSE) and utilized to monitor the effectiveness of human medical countermeasures related to immune function (exercise, medication, diet regulation-supplementation, immune modulators, etc.). In addition, the assays validated here will have significant benefit for the routine monitoring of crewmember's immune system status with regard to diagnosis and prognosis of immune-related disease states.
The study will result in the validation of a monitoring strategy that will allow the development of effective countermeasures, which, when implemented, will safeguard the health of the crew during long-duration space missions.
The data collected during this investigation may lead a greater understanding of how the immune system is affected by different factors from stress to the environment. This data could potentially be used to help develop new treatments and preventative measures for immune dysfunctions.
Preflight, each subject performs two sessions: one at L-180 (launch minus 180) days and another at L-10 days. Each session consists of four liquid saliva collections (performed every other day), with the blood draw, 24-hour urine and dry book saliva sample collection occurring on the day between the second and third liquid saliva collection.
Postflight, a liquid saliva sample is collected every other day from R+0 (Return plus 0) to R+14 days along with blood and 24-hour urine samples collected on R+0 and R+14 days. Dry book saliva samples are collected on R+1 and R+14 days.
Inflight, only blood and saliva samples are collected for subjects. There is no urine sample requirement for inflight operations. Subjects provide a liquid saliva sample every other day for the duration of the mission such that the final sample is collected on R-1. Also dry book saliva samples are collected on Flight Day 2 and on R-1. One blood sample is collected on R-1 in conjunction with the final liquid saliva sample and second dry book saliva sample.
Operations for this experiment consist of three types of sample collections: blood, urine and saliva. There are two types of saliva samples collected. Liquid saliva samples require the subject to soak a piece of cotton with saliva and place the cotton in a salivette bag. Dry book saliva samples are collected on filter paper bound in a small, specialized book at certain time intervals throughout the collection day. For preflight and postflight BDC only, 24-hour urine collections require the subject to collect all urine starting with the first void of the day and continuing for a full 24-hour period.
Nine short-duration (13 to 16 days) Space Shuttle crewmembers participated in this study (eight men, one woman). The astronauts flew on Shuttle missions STS-124, STS-125, or STS-126. Samples of saliva, blood, and urine (not required during flight) were collected preflight, inflight , and postflight from each subject and analyzed at NASA Johnson Space Center’s laboratory to assess the immune response state of crewmembers.
In addition to factors common to all space flights such as microgravity, stress, disrupted sleep, reduced oxygen, etc., varying mission objectives and requirements, or unexpected scenarios, often impose different stress levels on crewmembers, and research results show that particular stress conditions on short-duration space flights appear to affect the immune system in distinct ways. This study focused on a type of white blood cells called monocytes which play multiple roles within the immune system. Evidently, the more complex and greater the workloads and associated stress crewmembers experienced, the more their immune function, in this case monocyte parameters, appeared to be compromised, mainly in the reduction of the body’s defense signaling capability and pronounced suppression of the immune system’s ability to identify and neutralize potential pathogens. A related study also found increases in the stress hormone cortisol in Shuttle crewmembers which were accompanied by significant changes in white blood cells even days prior to launch, presumably due to the rigors of preflight training (Stowe et al. 2011). It is important to note, however, that for short-duration crewmembers, these immune system changes do not appear to linger beyond a few days after mission completion.
Further understanding that unique mission variables and stress levels can elicit specific immune responses in space flight crewmembers is crucial for mission planners as they strive to maintain a balance between optimum crew health, mission requirements, and stress inducing factors especially on prolonged missions. And although it is not likely to be a serious concern for short-duration orbital space flight, immune system impairment could pose potentially serious clinical risk for exploration-class lunar or Mars missions (Crucian et al. 2011).
Crucian BE, Stowe RP, Quiriarte HD, Quiriarte HD, Pierson DL, Sams CF. Monocyte Phenotype and Cytokine Production Profiles Are Dysregulated by Short-Duration Spaceflight. Aviation, Space, and Environmental Medicine. 2011; 82(9): 857-862.
Crucian BE, Stowe RP, Mehta SK, Uchakin P, Quiriarte HD, Quiriarte HD, Pierson DL, Sams CF. Immune System Dysregulation Occurs During Short Duration Spaceflight On Board the Space Shuttle . Journal of Clinical Immunology. 2012; epub. DOI: 10.1007/s10875-012-9824-7.
Mehta SK, Laudenslager ML, Stowe RP, Crucian BE, Sams CF, Pierson DL. Multiple latent viruses reactivate in astronauts during Space Shuttle missions. Brain, Behavior, and Immunity. 2014 June 1; epub. DOI: 10.1016/j.bbi.2014.05.014. PMID: 24886968.
Ground Based Results Publications
Stowe RP, Sams CF, Mehta SK, Kaur I, Jones ML, Feeback DL, Pierson DL. Leukocyte subsets and neutrophil function after short-term spaceflight. Journal of Leukocyte Biology. 1999 February; 65(2): 179-186. PMID: 10088600.
International Space Station Medical Project (ISSMP)
The image above is the kit that contains all the items the crew will need for taking blood samples. Image courtesy of NASA, Johnson Space Center.
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Pictured here is the kit that will be used to collect the saliva samples. In the upper left of the image the rolled gaze is seen; this will be place into the mouth to absorb saliva. Image courtesy of NASA, Johnson Space Center.
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