Katacalcin and calcitonin immunoreactivity in different types of leukocytes indicate intracellular procalcitonin content.
OBJECTIVE
Procalcitonin is a new marker of severity of nonviral, in particular, bacterial infections. In respect of sepsis its site of production remains unknown. This study was carried out to determine whether subsets of human leukocytes contain procalcitonin.


METHODS
Blood samples of 17 patients who had demonstrated various degrees of serum procalcitonin levels on the day before evaluation were analyzed for serum procalcitonin by immunoluminometry and for intracellular reaction of monocytes, granulocytes, B-, and T-lymphocytes against katacalcin- or calcitonin-sensitive antibodies. Katacalcin and calcitonin are part of the procalcitonin molecule. Associations of these reactions with serum procalcitonin levels as well as differences between groups with a normal or elevated serum level were analyzed.


RESULTS
Intracellular antibody reaction against katacalcin was demonstrated in all cell types. We also found a lower rate of intracellular antibody reaction against calcitonin. Associations of serum procalcitonin with the two antibody reactions were demonstrated. Differences in intracellular reactions in the group with elevated serum procalcitonin were seen with both antibodies compared with a normal control.


CONCLUSIONS
Intracellular antibody reaction against katacalcin supports the notion that various types of leukocytes contain procalcitonin.
Oberhoffer
M
M
Department of Anaesthesiology and Intensive Care, Friedrich Schiller University, Jena, Germany.
Vogelsang
H
H
Jäger
L
L
Reinhart
K
K
D000917:Antibody Formation; D001424:Bacterial Infections / Q000175:diagnosis*; D015415:Biomarkers; D002116:Calcitonin / Q000097:blood* / Q000276:immunology; D015740:Calcitonin Gene-Related Peptide; D006801:Humans; D007150:Immunohistochemistry; D007962:Leukocytes / Q000378:metabolism*; D010446:Peptide Fragments / Q000097:blood* / Q000276:immunology; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood*; D012720:Severity of Illness Index
D015415:Biomarkers; C000606589:CALCA protein, human; D010446:Peptide Fragments; D011498:Protein Precursors; C037553:katacalcin; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide