Clin. exp. Immunol. (1976) 24, 287-291.
Smooth muscle antibodies in Mycoplasma pneumoniae infection GUNNEL B IBERFELD & G. STERNER Central Microbiological Laboratory, Stockholm County Council, Department of Immunology, National Bacteriological Laboratory, Stockholm, and Department of Infectious Diseases, Danderyd Hospital, Danderyd, Sweden (Received 15 August 1975)
SUMMARY
Paired sera from forty-five cases of Mycoplasma pneumoniae (MP) infection associated with acute lower respiratory tract illness were examined by immunofluorescence for antibodies to smooth muscle. Twenty-five (56%) of these cases had smooth muscle antibodies (SMA) of IgM class. A significant ( >4-fold) increase in titre of these antibodies was demonstrated in fifteen of thirtyfive patients with a significant rise in titre of MP antibodies. SMA of IgG class occurred in eleven of forty-five cases (24%)0 but a 4-fold rise in antibody titre was found only in two cases. Three of forty-five sera (70%) from healthy donors contained SMA of IgM class and eight sera (18%) SMA of IgG class. MP antigen did not absorb SMA. Liver tests were performed in twenty-nine patients. In eighteen patients SGPT values were moderately or slightly elevated. There was no correlation between the occurrence of increased levels of transaminases and the presence of SMA in serum. In a patient with active chronic hepatitis, who had had a high titre of SMA exclusively of IgG class for 2 years, SMA of IgM class appeared transiently in association with an acute respiratory illness due to MP.
INTRODUCTION Smooth muscle antibodies (SMA), predominantly of IgG class commonly occur in patients with active chronic hepatitis (ACH) (Johnson, Holborow & Glynn, 1965; Whittingham, Mackay & Irwin, 1966). The demonstration of these antibodies is a useful aid in the differential diagnosis of cases of liver diseases. SMA, mainly of IgM class, also appear transiently in viral infections associated with liver manifestations (Farrow et al., 1970; Holborow, Hemstad & Mead, 1973; Ajdukiewicz et al., 1972). However, the occurrence of SMA is not associated exclusively with liver disease. In cases with malignant tumours a high incidence of SMA (at low titres) has been found (Whitehouse & Holborow, 1971; Wasserman, Glas & Blomgren, 1975). The present paper describes the appearance of SMA, predominantly of IgM class, in patients with MP infection and acute respiratory illness. MATERIALS AND METHODS Two or more sera from each of forty-five cases of MP infection associated with lower respiratory tract illness were examined for SMA. Thirty-five of these patients had a 4-fold or greater rise in titre of complement fixing (CF) antibodies to MP. The other ten patients had high titres (.> 128) of CF antibodies to MP together with a positive test for cold agglutinins. Sera from forty-five age and sex matched healthy donors were examined as controls. Liver tests, including SGPT, SGOT, serum alkaline phosphatase and bilirubin, were performed in twenty-nine patients. Immunofluorescence (IFL). Sera were examined for SMA by IFL as described previously (Biberfeld, Fagraeus & Lenkei,
Correspondence: Dr G. Biberfeld, Central Microbiological Laboratory, Stockholm County Council, Box 177, 101 22 Stockholm 1, Sweden.
287
G. Biberfeld L G. Sterner
288
1974). The following fluorescein-isothiocyanate conjugates were employed: (1) sheep anti-IgM (Wellcome Laboratories) with a molar fluorescein:protein (F:P) ratio of 2:9, used in dilution 1/6. (2) sheep anti-IgG (Wellcome) with a F:P ratio 3:5; used in dilution 1/12. The preparations were examined with a Leitz orthoplan microscope using a HBO 200 mercury lamp, incident illumination, excitation filter BG 38/BG12, interference filter KP 490 and barrier filters K495 and K 510. Absorption with MP antigen. A concentrate of whole MP organisms was used for absorption of convalescent phase sera from two cases of MP infection (Biberfeld, 1971a). Two additional MP sera were absorbed with a sonicated MP antigen (a concentrate of MP organisms sonicated for 30 min).
RESULTS Twenty-five of forty-five patients (56%) had IgM antibodies to SM at a titre of 10 or higher. A significant (>4-fold) increase in titre of these antibodies was demonstrated in fifteen of the thirty-five cases (43°/%) which had a significant rise in CF antibody titre to MP and in one case without a demonstrable rise in CF antibody titre. In four of the patients with a titre rise of SMA, from whom sera had been collected also late (6-12 weeks) after onset of illness, a fall in titre of SMA antibody of IgM class was demonstrated. The change in antibody titre in relation to the time after onset of illness is shown in Table 1. TABLE 1. Titre of SMA of IgM class in relation to time after onset of illness in three cases of MP infection
Case number 1800
1535
1779
Days after onset of illness
Titre of CF antibody to MP
Titre of SMA of IgM class
9 32 86 7 22 45 87 10 18 28 39
256 2048 2048 4 128 64 32 32 256 512 256
Smooth muscle antibodies in Mycoplasma pneumoniae infection GUNNEL B IBERFELD & G. STERNER Central Microbiological Laboratory, Stockholm County Council, Department of Immunology, National Bacteriological Laboratory, Stockholm, and Department of Infectious Diseases, Danderyd Hospital, Danderyd, Sweden (Received 15 August 1975)
SUMMARY
Paired sera from forty-five cases of Mycoplasma pneumoniae (MP) infection associated with acute lower respiratory tract illness were examined by immunofluorescence for antibodies to smooth muscle. Twenty-five (56%) of these cases had smooth muscle antibodies (SMA) of IgM class. A significant ( >4-fold) increase in titre of these antibodies was demonstrated in fifteen of thirtyfive patients with a significant rise in titre of MP antibodies. SMA of IgG class occurred in eleven of forty-five cases (24%)0 but a 4-fold rise in antibody titre was found only in two cases. Three of forty-five sera (70%) from healthy donors contained SMA of IgM class and eight sera (18%) SMA of IgG class. MP antigen did not absorb SMA. Liver tests were performed in twenty-nine patients. In eighteen patients SGPT values were moderately or slightly elevated. There was no correlation between the occurrence of increased levels of transaminases and the presence of SMA in serum. In a patient with active chronic hepatitis, who had had a high titre of SMA exclusively of IgG class for 2 years, SMA of IgM class appeared transiently in association with an acute respiratory illness due to MP.
INTRODUCTION Smooth muscle antibodies (SMA), predominantly of IgG class commonly occur in patients with active chronic hepatitis (ACH) (Johnson, Holborow & Glynn, 1965; Whittingham, Mackay & Irwin, 1966). The demonstration of these antibodies is a useful aid in the differential diagnosis of cases of liver diseases. SMA, mainly of IgM class, also appear transiently in viral infections associated with liver manifestations (Farrow et al., 1970; Holborow, Hemstad & Mead, 1973; Ajdukiewicz et al., 1972). However, the occurrence of SMA is not associated exclusively with liver disease. In cases with malignant tumours a high incidence of SMA (at low titres) has been found (Whitehouse & Holborow, 1971; Wasserman, Glas & Blomgren, 1975). The present paper describes the appearance of SMA, predominantly of IgM class, in patients with MP infection and acute respiratory illness. MATERIALS AND METHODS Two or more sera from each of forty-five cases of MP infection associated with lower respiratory tract illness were examined for SMA. Thirty-five of these patients had a 4-fold or greater rise in titre of complement fixing (CF) antibodies to MP. The other ten patients had high titres (.> 128) of CF antibodies to MP together with a positive test for cold agglutinins. Sera from forty-five age and sex matched healthy donors were examined as controls. Liver tests, including SGPT, SGOT, serum alkaline phosphatase and bilirubin, were performed in twenty-nine patients. Immunofluorescence (IFL). Sera were examined for SMA by IFL as described previously (Biberfeld, Fagraeus & Lenkei,
Correspondence: Dr G. Biberfeld, Central Microbiological Laboratory, Stockholm County Council, Box 177, 101 22 Stockholm 1, Sweden.
287
G. Biberfeld L G. Sterner
288
1974). The following fluorescein-isothiocyanate conjugates were employed: (1) sheep anti-IgM (Wellcome Laboratories) with a molar fluorescein:protein (F:P) ratio of 2:9, used in dilution 1/6. (2) sheep anti-IgG (Wellcome) with a F:P ratio 3:5; used in dilution 1/12. The preparations were examined with a Leitz orthoplan microscope using a HBO 200 mercury lamp, incident illumination, excitation filter BG 38/BG12, interference filter KP 490 and barrier filters K495 and K 510. Absorption with MP antigen. A concentrate of whole MP organisms was used for absorption of convalescent phase sera from two cases of MP infection (Biberfeld, 1971a). Two additional MP sera were absorbed with a sonicated MP antigen (a concentrate of MP organisms sonicated for 30 min).
RESULTS Twenty-five of forty-five patients (56%) had IgM antibodies to SM at a titre of 10 or higher. A significant (>4-fold) increase in titre of these antibodies was demonstrated in fifteen of the thirty-five cases (43°/%) which had a significant rise in CF antibody titre to MP and in one case without a demonstrable rise in CF antibody titre. In four of the patients with a titre rise of SMA, from whom sera had been collected also late (6-12 weeks) after onset of illness, a fall in titre of SMA antibody of IgM class was demonstrated. The change in antibody titre in relation to the time after onset of illness is shown in Table 1. TABLE 1. Titre of SMA of IgM class in relation to time after onset of illness in three cases of MP infection
Case number 1800
1535
1779
Days after onset of illness
Titre of CF antibody to MP
Titre of SMA of IgM class
9 32 86 7 22 45 87 10 18 28 39
256 2048 2048 4 128 64 32 32 256 512 256
