Are lymphocyte β-adrenoceptors altered in patients with cystic fibrosis?

Beta-adrenergic responsiveness may be decreased in cystic fibrosis. In order to determine whether this reflects an alteration in the human lymphocyte beta-receptor complex, we studied 12 subjects with cystic fibrosis (six were stable and ambulatory and six were decompensated, hospitalized) as compared with 12 normal controls. 2. Lymphocyte beta-receptor mediated adenylate cyclase activity (EC 4.6.1.1) was not decreased in the ambulatory cystic fibrosis patients as compared with controls. In contrast, decompensated hospitalized cystic fibrosis patients demonstrated a significant reduction in beta-receptor mediated lymphocyte adenylate cyclase activity expressed as the relative increase over basal levels stimulated by the beta-agonist isoprenaline compared with both normal controls and stable ambulatory cystic fibrosis patients (control 58 +/- 4%; ambulatory cystic fibrosis patients 51 +/- 7%; decompensated hospitalized cystic fibrosis patients 28 +/- 5%; P less than 0.05). 3. Our data suggest that defects in lymphocyte beta-receptor properties in cystic fibrosis patients may be better correlated with clinical status than with presence or absence of the disease state.