Serum amyloid A (SAA) in viral infection: rubella, measles and subacute sclerosing panencephalitis (SSPE).

Serum amyloid A (SAA) levels were determined in the serial serum samples of eight rubella, 10 measles and seven subacute sclerosing panencephalitis (SSPE) patients. An early rise in SAA levels was detected in the acute phase in rubella and measles, followed by a prompt decrease in the convalescent phase. In a number of measles and rubella patients from whom early serum samples were available, the rise of SAA levels could be demonstrated before specific viral antibodies could be detected by complement fixation (CF) (measles) and haemagglutination inhibition (HI) (rubella). In only one rubella and one measles patient was no rise of SAA level detected. In SSPE only a moderate increase in SAA levels was noted except in one patient during a temporary deterioration, at which time the SAA level was very high; it returned to close to normal shortly thereafter. The possibility that SAA levels might be of value in monitoring the severity of infections, the recovery process and effects of anti-viral agents is discussed.