Smooth Muscle Autoantibodies in Infectious Mononucleosis

Abstract

SummarySmooth muscle antibodies (S.M.A.) were found in the sera of 81% of 126 patients over 10 years old with seropositive infectious mononucleosis tested within one month of onset. In 27 patients presenting clinically with infectious mononucleosis but having negative Paul-Bunneil tests the incidence of S.M.A. was 44%. In children 10 years of age or less in these two categories S.M.A. were present in 75% and 25% respectively, while in children of similar age not suspected of having infectious mononucleosis the incidence of S.M.A. was 10%. Among 45 adults with past histories of seropositive infectious mononucleosis more than one year before the incidence of S.M.A. was 33%, in contrast to 14% in 98 subjects with a negative history for infectious mononucleosis.

Mechanisms of smooth muscle antibody production: a clinical study in children with infections, haemolytic syndromes, and idiopathic thrombocytopenic purpura.

“…The lack of correlation between the presence of SMA and the clinical and laboratory findings, either during the course of the disease or after recovery, suggests that SMA do not participate in immunopathogenic processes. In the small proportion of patients in whom SMA persisted for up to 1 years there was also no association with the course of the disease, in agreement with previous observations in viral hepatitis (Ajdukiewicz et al, 1972) and infectious mononucleosis (Holborow et al, 1973) patients.…”

“…In chickenpox, although SMA was found in about half of the patients (9/19), the incidence was not significantly raised, but this may be due to the smaller number examined. These prevalence findings for SMA in viral hepatitis and infectious mononucleosis in children are similar to those reported for adults, viz, up to 81 % in viral hepatitis (Farrow et al, 1970;Ajdukiewicz et al, 1972;Vittal et al, 1974) and up to 75 % in infectious mononucleosis (Holborow et al, 1973;Sutton et al, 1974b). The incidence of SMA in healthy adults, ranging from 12 % to 20% (Whitehouse and Holborow, 1971;Holborow et al, 1973;Sutton et al, 1974a;Shu etal., 1975), is similar to that in a random population sample in Greece (19 4%).…”

“…In the present study SMA was present in 20% of control children at titres of > 1:40 and in 25 % at lower titres ( < 1/20). Holborow et al (1973), however, found SMA in 10% of healthy children aged 10 years and under. The relatively higher incidence in the present study may be due to the wider age spectrum (infancy, pre-school age, school age, and puberty) and to the susceptibility of young infants to asymptomatic viral infections such as CMV and EBV.…”

“…Smooth muscle autoantibodies (SMA) are present in the sera of some patients with chronic active hepatitis (CAH) (Doniach et al, 1966;Johnson et al, 1965), acute viral hepatitis (Farrow et al, 1970;Ajdukiewicz et al, 1972;Vittal et al, 1974;Kanakoudi et al, 1975), infectious mononucleosis (Holborow et al, 1973;Sutton et al, 1974a), cytomegalovirus (Andersen and Andersen, 1975), Mycoplasma pneumoniae infections (Biberfeld and Sterner, 1976), and malignant disease (Whitehouse and Holborow, 1971). It has been suggested that high SMA titres (> 1/100) of the IgG class are of value in the diagnosis of CAH (Lidman et al, 1976).…”

Actin filaments of hepatocytes in experimental rat cholestasis - Observations using a fluorescent staining method by DACM labeled heavy meromyosin.

“…SMA-positive sera confirmed the "polygonal" pattern of SMA binding to hepatocytes (14,15,16). Anti-actin sera, prepared against human uterus actin, stained liver cells in the region of their cell membrane, in polygonal pattern (8).…”