Antibody formation after murine injury

Myelin basic protein autoantibodies, white matter disease and stroke outcome

Antibodies to brain antigens are present in stroke survivors. In this study, we assessed autoantibody responses to white matter antigens, their correlation to white matter disease and stroke outcome. Antibody titers (immunoglobulin G [igG]) to myelin basic protein (MBP), proteolipid protein (PLP) and tetanus toxoid (TT) were available at one or more time points for 112 subjects with ischemic stroke. In comparison to the control subjects (N=40), there was a global decrease in IgG titers to TT early after stroke. Patients with white matter disease on magnetic resonance imaging had elevated titers of antibodies to both MBP and PLP at 30days after stroke, and anti-MBP antibodies were associated with worse outcome. The potential pathologic consequences of antibodies to white matter, especially MBP, is deserving of further investigation.

The immunological consequences of injury

Immediate and early trauma death rates are determined by "first hits" such as hypoxia, hypotension and organ injury, while late mortality correlates closely with "second hits" such as infection. An imbalance between the early systemic inflammatory response (SIRS), and the later compensatory counter-inflammatory response (CARS), is considered to be responsible for much post-traumatic morbidity and mortality. From a clinical perspective, this remains a significant healthcare problem, which has stimulated decades of experimental and clinical research aimed at understanding the functional effects of injury on the immune system. This review describes the impact of injury on the innate and adaptive immune systems. Though it is worth noting that the features of the immune response to injury overlap in many areas with immune dysregulation in sepsis, we attempt here to elucidate the mechanism by which injury predisposes to infection rather than to describe the alterations in host immunity consequent to established sepsis.

Effect of cyclo-oxygenase inhibition on in vitro B-cell function after burn injury

The role of PGE2 in suppression of B-cell function after burn injury was investigated. Splenocytes from burned or sham-burned mice were isolated 8 days after burn injury and cultured with lipopolysaccharide with or without the addition of prostaglandin E2 (PGE2) or indomethacin (Indo). Anti-peptidoglycan polysaccharide immunoglobulin (Ig)M (specific antibody to a bacterial antigen), total IgM, and total IgG levels in culture supernatant and lymphocyte proliferation were measured. All B-cell functions were significantly suppressed by burn injury. PGE2 suppressed all B-cell functions except for IgG synthesis. Indo restored anti-peptidoglycan polysaccharide IgM to normal levels, but did not have a significant effect on suppressed proliferation and total IgM synthesis. IgG synthesis was increased by PGE2 and inhibited by Indo. Although not all B-cell suppression was accounted for by PGE2, this prostaglandin appeared to be a mechanism responsible for impaired antigen specific antibody response and isotype switching. Successful restoration of specific antibody synthesis to bacterial antigen suggests a potential therapeutic role for a cyclo-oxygenase blocking agent after burn injury.