CORRELATION OF LACTOFERRIN WITH NEUTROPHILIC INFLAMMATION IN BODY-FLUIDS

We have reported that lactoferrin, a 77-kDa iron-binding glycoprotein found in secondary neutrophil granules, provides a useful marker of fe cal leukocytes in fecal specimens from patients with inflammatory diar rhea (R. L. Guerrant, V. Araujo, E. Soares, K. Kotloff, A. A. M. Lima, W. H. Cooper, and A. G. Lee, J. Clin. Microbiol. 30:1238-1242, 1992). In order to determine the usefulness of this marker of neutrophilic i nflammation in different body fluids, we examined blood, gingival swab s, sputum, and saliva using antilactoferrin antibodies (lactoferrin la tex agglutination [LFLA]). LFLA titers in whole blood samples were les s than or equal to 1:4 in all eight samples from patients with neutrop enia (absolute neutrophil count [ANC] = <150 polymorphonuclear cells [ PMNs] per mu l), less than or equal to 1:8 in samples from 13 individu als with moderate leukocyte counts (ANC = 150 to 8,000), and 1:8 to 1: 32 in samples from six patients with neutrophilia (ANC > 8,000), While the overlap precludes a useful role in the identification of neutrope nia, these data confirm that lactoferrin titers of >1:100 indeed indic ate inflammation in fluid specimens. On quantitative elution of lactof errin from gingival swabs, all 7 patients with dental plaque had titer s of 1:200 to 1:400; 9 of 12 patients with clinical gingivitis had LFL A titers of 1:200 to 1:1,600, while all 7 individuals with healthy gum s and teeth and 4 edentulous patients had LFLA titers of less than or equal to 1:100. Eight purulent sputum samples had titers of greater th an or equal to 1:400 (7 were 1:1,600) while 11 normal saliva samples s howed titers of less than or equal to 1:100. Lactoferrin titers in spu tum, gingival swabs, and whole blood correlate with the presence of ne utrophils or inflammation in these specimens and may offer a convenien t rapid test for inflammatory processes.