Monocyte (A) and PMN (B) internalization of erythrocytes coupled with specific human IgG myeloma proteins (E-hIgG₁and E-hIgG₂), murine IgG₁ myeloma protein (E-mIgG₁), or anti-FcγRII MoAb IV.3 (E-IV.3). The phagocytic index shown for each erythrocyte probe reflects simultaneous experiments with phagocytes from individuals of each of three FcγRIIA genotypes: Q/Q¹²⁷, H/H¹³¹; Q/Q¹²⁷, R/R¹³¹; and K/Q¹²⁷, R/R¹³¹. The % Phagocytic Index = (PI_donor/ PI_Q/Q¹²⁷_{, R/R}¹³¹) × 100. Values represent the mean ± SD of two to five experiments comparing the K¹²⁷ variant with different H/H¹³¹ and R/R¹³¹ homozygotes. % PI were compared using the paired Student's t-test. *P< .05, K/Q¹²⁷, R/R¹³¹vQ/Q¹²⁷, R/R¹³¹; **P < .01, K/Q¹²⁷, R/R¹³¹v Q/Q¹²⁷, H/H¹³¹; ***P = .051, K/Q¹²⁷, R/R¹³¹v Q/Q¹²⁷, H/H¹³¹.