Changes in the interleukin-6/soluble interleukin-6 receptor axis in meningococcal septic shock.

OBJECTIVE

Interleukin-6 is strongly associated with disease severity and outcome in meningococcal septicemia. It is known that interleukin-6 exerts many of its effects via the soluble interleukin-6 receptor. By facilitating the activity of interleukin-6, it is likely that alterations in the levels of soluble interleukin-6 receptor in septic shock could affect the severity of disease. We aimed to investigate changes in the levels of interleukin-6 and soluble interleukin-6 receptor in acute meningococcal septicemia and the relationship with disease severity.

DESIGN

Laboratory investigation of interleukin-6 and soluble interleukin-6 receptor levels in children with meningococcal disease.

SETTING

University hospital and laboratories.

SUBJECTS

Children with severe meningococcal disease requiring intensive care.

INTERVENTIONS

Blood samples obtained on admission to the intensive care unit were analyzed for interleukin-6 and soluble interleukin-6 receptor levels. Levels were also serially measured for up to 48 hrs in a subset of patients.

MEASUREMENTS AND MAIN RESULTS

Cytokine levels were measured by enzyme-linked immunosorbent assay using mouse monoclonal antihuman antibodies. Acute meningococcemia is associated with a reduction in soluble interleukin-6 receptor levels in proportion to disease severity and is inversely related to interleukin-6 levels. Soluble interleukin-6 receptor returns to levels seen in normal donors following recovery from meningococcal septicemia.

CONCLUSIONS

Changes in the levels of interleukin-6 and soluble interleukin-6 receptor in acute meningococcemia may affect the severity and progression of multiple organ failure. Interventions to modulate this axis may improve outcome from meningococcal septic shock.