Autonomic dysreflexia causes chronic immune suppression after spinal cord injury.
Autonomic dysreflexia (AD), a potentially dangerous complication of high-level spinal cord injury (SCI) characterized by exaggerated activation of spinal autonomic (sympathetic) reflexes, can cause pulmonary embolism, stroke, and, in severe cases, death. People with high-level SCI also are immune compromised, rendering them more susceptible to infectious morbidity and mortality. The mechanisms underlying postinjury immune suppression are not known. Data presented herein indicate that AD causes immune suppression. Using in vivo telemetry, we show that AD develops spontaneously in SCI mice with the frequency of dysreflexic episodes increasing as a function of time postinjury. As the frequency of AD increases, there is a corresponding increase in splenic leucopenia and immune suppression. Experimental activation of spinal sympathetic reflexes in SCI mice (e.g., via colorectal distension) elicits AD and exacerbates immune suppression via a mechanism that involves aberrant accumulation of norepinephrine and glucocorticoids. Reversal of postinjury immune suppression in SCI mice can be achieved by pharmacological inhibition of receptors for norepinephrine and glucocorticoids during the onset and progression of AD. In a human subject with C5 SCI, stimulating the micturition reflex caused AD with exaggerated catecholamine release and impaired immune function, thus confirming the relevance of the mouse data. These data implicate AD as a cause of secondary immune deficiency after SCI and reveal novel therapeutic targets for overcoming infectious complications that arise due to deficits in immune function.
Center for Brain and Spinal Cord Repair, Department of Neuroscience, Division of Oral Biology, College of Dentistry, The Ohio State University, Columbus, Ohio 43210, USA.
Yi
Y
Zhang
Zhen
Z
Guan
Brenda
B
Reader
Todd
T
Shawler
Shweta
S
Mandrekar-Colucci
Kun
K
Huang
Zachary
Z
Weil
Anna
A
Bratasz
Jonathan
J
Wells
Nicole D
ND
Powell
John F
JF
Sheridan
Caroline C
CC
Whitacre
Alexander G
AG
Rabchevsky
Mark S
MS
Nash
Phillip G
PG
Popovich
D058672:Adrenergic beta-2 Receptor Antagonists / Q000494:pharmacology; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D020211:Autonomic Dysreflexia / Q000150:complications / Q000209:etiology / Q000276:immunology; D001794:Blood Pressure / Q000276:immunology; D002078:Butoxamine / Q000494:pharmacology; D003106:Colon / Q000294:innervation; D003345:Corticosterone / Q000097:blood; D004195:Disease Models, Animal; D004837:Epinephrine / Q000097:blood; D005260:Female; D006727:Hormone Antagonists / Q000494:pharmacology; D006801:Humans; D007154:Immune System Diseases / Q000209:etiology*; D007165:Immunosuppression Therapy; D051379:Mice; D015735:Mifepristone / Q000494:pharmacology; D009638:Norepinephrine / Q000097:blood; D010047:Ovalbumin / Q000276:immunology; D010812:Physical Stimulation / Q000009:adverse effects; D013119:Spinal Cord Injuries / Q000150:complications* / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000378:metabolism; D013686:Telemetry
D058672:Adrenergic beta-2 Receptor Antagonists; D015703:Antigens, CD; D006727:Hormone Antagonists; D002078:Butoxamine; D015735:Mifepristone; D010047:Ovalbumin; D003345:Corticosterone; D009638:Norepinephrine; D004837:Epinephrine