Leukocyte oxygen radical production determines disease severity in the recurrent Guillain-Barré syndrome.

BACKGROUND: The recurrent Guillain-Barré syndrome (RGBS) is characterized by at least two GBS episodes with intervening remission. In a previous study of monophasic GBS, we reported that the magnitude of oxygen radical production ("respiratory burst") in peripheral blood leukocytes was inversely correlated to disease severity. The present study sought to establish a similar correlation in patients with RGBS. METHODS: Oxygen radical production in leukocytes was induced by formyl-Met-Leu-Phe (fMLF), Trp-Lys-Tyr-Met-Val-Met-NH2 (WKYMVM), or phorbol myristate acetate (PMA) and assessed by quantifying superoxide anion formed by the leukocyte NADPH oxidase. RESULTS: Disease severity, assessed using the MRC score, was negatively correlated to superoxide anion production triggered by fMLF or WKYMVM (p = 0.001 and 0.002, respectively; n = 10). Superoxide anion production also was significantly lower in RGBS patients with incomplete recovery after stimulation with fMLF (p = 0.004) or WKYMVM (p = 0.003). CONCLUSION: We conclude that a lower respiratory burst in leukocytes is strongly associated with a severe course of RGBS.

Oxygen radical production and severity of the Guillain--Barré syndrome.

The NADPH oxidase-dependent formation of reactive oxygen species ("oxygen radicals") by phagocytic cells constitutes an important part of the innate immune defence against microorganisms. Recent studies in animal models imply that a deficient function of the NADPH oxidase may be linked to the development of autoimmunity, but a link between oxygen radical production and severity of autoimmune disease in humans has not been established. We have examined the oxygen radical production in peripheral blood leukocytes from patients with the Guillain-Barré syndrome (GBS). Leukocytes from GBS patients in a stationary phase 1-5 years after their acute episode were activated by the formyl peptide receptor (FPR) ligand formyl-Met-Leu-Phe (fMLF) or the closely related formyl peptide like receptor 1 (FPRL1) ligand Trp-Lys-Tyr-Met-Val-Met-NH2 (WKYMVM). The patients were dichotomized according to severity by 1) the requirement of intensive care unit treatment and 2) the ability to walk independently after 3 months. Our data show that the amount of superoxide release following challenge with either of the two agonists fMLF and WKYMVM was significantly lower in patients requiring intensive care unit treatment or unable to walk after 3 months. Results obtained with the global activator phorbol myristate acetate, as well as with fMLF in TNF alpha-primed leukocytes, suggested that the deficiency of oxygen radical production in patients with severe GBS was the result of a specific deficiency of radical production in response to FPR/FPRL1 ligands rather than an inherent deficiency of NADPH oxidase function.

Urinary tract infection caused by Haemophilus influenzae and Haemophilus parainfluenzae in children.

There are few reports on urinary tract infections caused by Haemophilus influenzae or Haemophilus parainfluenzae in children. The true incidence is not known, since bacteria of Haemophilus species do not grow in standard urine culture media. With the objective of investigating the occurrence and character of urinary tract infections (UTIs) caused by Haemophilus bacteria in children, we searched the files of our UTI clinic. Over a 24-year period 36 children with Haemophilus spp. bacteriuria were identified out of a total of more than 5,000 UTI episodes. There was a significant gender difference in that Haemophilus influenzae dominated in girls and Haemophilus parainfluenzae in boys. With one exception, all children had important urinary tract abnormalities, such as malformation, gross reflux or bladder dysfunction. Permanent renal damage was seen in 25. We conclude that growth of Haemophilus bacteria in urine is associated with serious urinary tract abnormalities. The inability of bacteria of the Haemophilus species to grow in standard media commonly used for culture of uropathogens suggests that the true frequency of these strains as a cause of urinary tract infections is underestimated.