TY - JOUR
T1 - Impaired natural immunity, cognitive dysfunction, and physical symptoms in patients with chronic fatigue syndrome
T2 - preliminary evidence for a subgroup?
AU - Siegel, Scott D.
AU - Antoni, Michael H.
AU - Fletcher, Mary Ann
AU - Maher, Kevin
AU - Segota, Mary Catherine
AU - Klimas, Nancy
PY - 2006/6/1
Y1 - 2006/6/1
N2 - Objective: The diagnostic criteria of chronic fatigue syndrome (CFS) define a heterogeneous population composed of several subgroups. Past efforts to identify subgroup markers have met with mixed success. This study was designed to examine natural killer cell activity (NKCA) as a potential subgroup marker by comparing the clinical presentations of CFS patients with and without clinically reduced NKCA. Methods: Forty-one female CFS patients were classified into having either low or normal NKCA levels. These subgroups were then compared on objective measures of cognitive functioning and subjective assessments of fatigue, vigor, cognitive impairment, and daytime dysfunction. Results: Relative to CFS patients in the normal-NKCA subgroup, low-NKCA patients reported less vigor, more daytime dysfunction, and more cognitive impairment. In addition, low-NKCA patients performed less on objective measures of cognitive functioning relative to normal-NKCA patients. Conclusions: The results are offered as preliminary evidence in support of using NKCA as an immunological subgroup marker in CFS. Findings are also discussed in terms of known associations between dysregulated immune functions, somatic symptoms, and psychological stress.
AB - Objective: The diagnostic criteria of chronic fatigue syndrome (CFS) define a heterogeneous population composed of several subgroups. Past efforts to identify subgroup markers have met with mixed success. This study was designed to examine natural killer cell activity (NKCA) as a potential subgroup marker by comparing the clinical presentations of CFS patients with and without clinically reduced NKCA. Methods: Forty-one female CFS patients were classified into having either low or normal NKCA levels. These subgroups were then compared on objective measures of cognitive functioning and subjective assessments of fatigue, vigor, cognitive impairment, and daytime dysfunction. Results: Relative to CFS patients in the normal-NKCA subgroup, low-NKCA patients reported less vigor, more daytime dysfunction, and more cognitive impairment. In addition, low-NKCA patients performed less on objective measures of cognitive functioning relative to normal-NKCA patients. Conclusions: The results are offered as preliminary evidence in support of using NKCA as an immunological subgroup marker in CFS. Findings are also discussed in terms of known associations between dysregulated immune functions, somatic symptoms, and psychological stress.
KW - Chronic fatigue syndrome
KW - Natural killer cell activity
KW - Sickness behavior
KW - Subgroups
UR - http://www.scopus.com/inward/record.url?scp=33646774706&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33646774706&partnerID=8YFLogxK
U2 - 10.1016/j.jpsychores.2006.03.001
DO - 10.1016/j.jpsychores.2006.03.001
M3 - Article
C2 - 16731230
AN - SCOPUS:33646774706
VL - 60
SP - 559
EP - 566
JO - Journal of Psychosomatic Research
JF - Journal of Psychosomatic Research
SN - 0022-3999
IS - 6
ER -