In vivo assay of crevicular leukocyte migration. Its development and potential applications

Defects in neutrophil or polymorphonuclear leukocyte (PMNL) chemotaxis have been observed in a number of clinical conditions, including Down's syndrome and insulin-dependent diabetes mellitus (IDDM), which tend to be associated with severe forms of periodontal disease. In addition, impaired PMNL chemotaxis is frequently detected in individuals with localized juvenile periodontitis (LJP). The ability to monitor PMNL function in vivo at the gingival sulcus should therefore be useful as a diagnostic test. In this regard, we developed a technique which measures the response of PMNLs to a chemotactic agent, e.g., casein and N-formylmethionylleucylphenylalanine (N-FMLP) placed directly into gingival crevices. The development of the technique and its relationship to in vitro assays of chemotaxis are discussed, and data obtained from tests of the assay on control and streptozotocin-induced diabetic rats and human subjects with various periodontal diseases and IDDM are presented. As compared with healthy subjects and control animals, atypical (double peak) and reduced crevicular PMNL response patterns were observed during oral and systemic diseases. This suggests that the in vivo assay with appropriate modifications can be used diagnostically to assess PMNL migratory dysfunction and to identify individuals who may be susceptible to severe forms of periodontal disease.