Am. J. Respir. Crit. Care Med., Vol 150, No. 1, 07 1994, 131-134.
Buccal cell carbohydrates are altered during critical illness
KD Weinmeister and AR Dal Nogare
Pulmonary and Critical Care Division, University of Texas Southwestern Medical Center, Dallas 75235-9034.
Cell-surface carbohydrates mediate the adherence of many pathogenic
bacteria to epithelial cells. Because gram-negative bacteria adhere
especially well to respiratory epithelial cells obtained from severely ill
patients, we compared respiratory epithelial cell-surface carbohydrate
levels of normal subjects with those of critically ill patients. Lectins
were used to quantitate the amount of mannose, galactose, fucose, and
sialic acid on buccal and tracheal cells. Fifteen critically ill patients,
20 normal subjects, and 10 minimally ill hospitalized patients were
studied. The severely ill patients' buccal cells had decreased amounts of
sialic acid and galactose. No differences were found between the normal and
critically ill patients' tracheal-cell carbohydrates. The results obtained
with a sialic acid- specific lectin were confirmed by direct measurement of
buccal-cell sialic acid. We conclude that severely ill patients have
decreased amounts of galactose and sialic acid on their upper-airway
epithelial cells, and that loss of these two monosaccharides may explain
the high prevalence of gram-negative bacterial colonization and pneumonia
in the critically ill.
