• We determined cytosol aminopeptidase (c-AP; EC 184.108.40.206) and lactate dehydrogenase (LDH) levels in serum; these enzymes are known to originate from lymphocytes in patients with measles and rubella. In patients with measles (n=19), both enzyme levels increased markedly with the onset of rash: mean (±SD) c-AP was 269.7± 103.5 U/L and LDH was 1149.5±255.2 U/L. In patients with rubella, activities of both enzymes increased mildly: c-AP (n=18) was 81.6 ± 24.4 U/L and LDH (n = 13) was 674.0±168.8 U/L. Increased c-AP and LDH levels in patients with measles and rubella presumably originate from the destruction of infected, activated lymphocytes, especially T lymphocytes.
Sugaya N, Nirasawa M, Mitamura K, Takeuchi Y, Osano M, Kanno T. Increased Cytosol Aminopeptidase and Lactate Dehydrogenase in Serum Originating From Lymphocytes in Measles and Rubella Infection. Am J Dis Child. 1988;142(12):1352-1355. doi:10.1001/archpedi.1988.02150120106051