Cryopreservation of human pulmonary alveolar macrophages.

Human pulmonary alveolar macrophages (PAM) from 30 patients with a variety of pulmonary diseases were tested for their ability to undergo cryopreservation. The cells were cryopreserved and stored under liquid nitrogen for intervals of 2, 4, 6, 8, or 12 wk, then assayed for viability (using the trypan dye exclusion method as well as the NADH-dependent cytochrome c reductase (cytochrome c) assay) and cellular function (as documented by the measurement of in vitro aryl hydrocarbon hydroxylase (AHH) induction by benzanthracene (BA) and by quantitation of PAM particulate phagocytosis). These results demonstrated no decrease in PAM viability after 2 wk of cryopreservation compared with that of the control cells (p greater than 0.30, paired, 2-tailed t test). However, PAM viability decreased slightly compared with the 0-time (p less than 0.003 in all instances) when cells were stored for intervals of 4, 6, 8, or 12 wk. In addition, cells demonstrated no further decrease in viability after being cryopreserved for as long as 12 wk, thawed, and cultured for as long as 48 h compared with the 0-time control cells (p greater than 0.10 in all instances). Similarly, when AHH induction was fluorometrically quantitated in PAM cultured for 24 h, there was no decrease in BA-induced AHH levels after a 2-wk cryopreservation period. However, AHH levels decreased slightly compared with those in the 0-time control cells (p less than 0.004), when PAM were stored for longer intervals of 4, 6, or 8 wk. The phagocytic activity of cryopreserved PAM was also quantitated using amorphous silica as a substrate.(ABSTRACT TRUNCATED AT 250 WORDS)