Detection by 4-parameter microscopic imaging and increase of rare mononuclear blood leukocyte types expressing the Fc gamma RIII receptor (CD16) for immunoglobulin G in human sporadic amyotrophic lateral sclerosis (ALS).

By using quantitative multiparameter microscopic imaging we demonstrate concentration of two peripheral mononuclear blood leukocyte types expressing the Fc gamma RIII receptor for immunoglobulin G in a clinical subgroup of amyotrophic lateral sclerosis (ALS, n = 9) showing bulbar palsy (ALSBP) and/or predominant involvement of the upper motor neuron (ALSC). Triple fluorescence staining and overlay with phase contrast images (4 parameters) reveals that cell type 1 co-expresses Fc gamma RIII (CD16), CD8 and CD57 surface antigens (ALSC 50 +/- 33.6 cells/microliters, P = 0.0012; ALSBP 16.5 +/- 32.4, P = 0.029). This cell type is not observed in healthy individuals (n = 8) and is only insignificantly increased (P > 0.05) in neurological disease controls (stroke, n = 3, 2.1 +/- 3.7; polymyositis, n = 6, 1.5 +/- 4.0 cells/microliters) and in ALS cases with peripheral symptoms (ALSP n = 12: 7.6 +/- 8.7). Cell type 2 co-expresses Fc gamma RIII (CD16) and CD8, but is negative for CD57 (ALSC 60.1 +/- 19.3; ALSBP 24.2 +/- 28.0 cells/microliters). These findings are consistent with previous reports on IgG isotype changes and immune-cell invasion of the motor system in ALS.