Clinical Allergy, 1979, Volume 9, pages 141-145
Acute asthma compared with exacerbations of chronic bronchitis: changes in complement
R. D. H. MONIE, R. FIFIELD* and B. H. DAVIES Asthma Research Unit, Sully Hospital, Penarth, South Glamorgan, and *Protein Reference Unit, Cardiff Royal Infirmary, Cardiff, South Glamorgan Received 3\ Atigtist 1978.- accepted for publication 15 September 1978)
Summary
Complement levels were measured on admission and at 1 and 7 days following admission in twenty patients with acute severe asthma and ten patients with an acute exacerbation of chronic bronchitis. Although no evidence of hypocomplementaemia was found in any patient, there was a mean fall within the normal range of the individual complement components, C4, C3 and factor B in both groups. The mean fall occurred earlier in the bronchitics than in the asthmatics and this may be related to infection or the administration of corticosteroids. There was a significant fall in C3 {P>0-05) in the bronchitics compared with the asthmatics at 24 hr. From our study, however, we could find no evidence of excessive utilization of complement in acute asthma. Introduction
The aetiology of acute severe asthma remains obscure. Evidence of IgE-mediated asthma is found in only a few patients, and infection remains the commonest precipitating factor. What immunological mechanisms operate in acute asthma is unknown, but recent research suggests that histamine release occurs (Bruce et al., 1976). Whether this is mediated through the vagus (Yu, Galant & Gold, 1972), directly through IgE or through activation of complement with subsequent generation of the anaphylotoxin, C5a, by either classical or alternative pathways is not clear (Grant & Lichtenstein, 1973). Further evidence for complement activation having a role in asthma has come from challenge experiments in patients with stable allergic asthma, complement levels being measured during the immediate and late asthmatic reactions (Arroyave et al., 1977; Hutchcroft & Guz, 1978). This study was designed to investigate whether complement activation occurred in acute severe asthma. Correspondence: Dr B. H. Davies at the above address. 0009-9090/78/0300-0141 $02.00 © 1979 Blackwell Scientific Publications
141
142
R. D. H. Monie, R. Fifleld and B. H. Davies
Materials and methods Patient population All patients were emergency admissions and informed consent was obtained prior to inclusion in the study. The patients had a pulse rate greater than 110 beats per min and PQ^ of less than 60 mmHg on air. Twenty asthmatic patients (seven male and thirteen female, mean age 31, range 15-59 years) and ten chronic bronchitics (five male and five female, mean age, 63, range 52-71 years) were entered into the study. Asthma was defined as paroxysmal attacks of dyspnoea and wheezing with reversible airways obstruction, of greater than 20% change in PEFR with salbutamol, supported by blood or sputum eosinophilia. Skin testing showed that there were seventeen atopic and three idiopathic asthmatics. Patients with chronic bronchitis had cough and sputum for more than 3 months of the year for 2 consecutive years in the absence of focal lung disease and had no evidence of reversible airways obstruction. Complement studies Venous blood was taken on administration, at 1 and 7 days, collected in an EDTA bottle, mixed, centrifuged and plasma stored immediately at — 20°C. C3 and C4 estimations were performed by an automated immunoprecipitation technique (Technicon) (Killingsworth, Savory & Teague, 1971) using antisera from Atlantic Antibodies. Factor B was estimated by electroimmunodiffusion using the rocket technique (Laurell, 1966), using antisera from Atlantic Antibodies. Results Clinieal The twenty asthmatics had on admission a mean pulse of 123 beats per min and aPo^ on air of 53 mmHg compared with a pulse of 116 beats per min and a P^^ on air of 41 mmHg in the ten chronic bronchitics.
10 r-
(b)
(a)
J -iO
(c)
-k
r
-
X N/'-...
-20 -
X
1
\
1 . 1
r'-l
-^ -'-
1 1
X
.
-30 -40
Day I
Day 7
Day I
Day 7
Day I
Day 7
Fig. 1. Percentage falls in levels of complement components compared with the pretreatment level (taken as hase-line). The bars represent the mean + 1 s.e. (a) C4; (b) C3; (c) factor B; ( ) asthmatic; ( ) bronchitis.
Complement levels in acute asthma
143
Complement levels There was no evidence of hypocomplementaemia in any patient. The levels of the complement components at 24 hr and 7 days are expressed as percentage changes when compared with the pretreatment levels (Fig, 1). There is a 10% laboratory error in each measurement. C4 There was no statistical difference in the fall of C4 between the two groups. The mean percentage fall was greater in the bronchitics at 24 hr (13-2%), and this level did not alter by the seventh day (14-8%); the reverse occurred in asthmatics—virtually no fall at 24 hr (3-2%) but a much greater fall by 7 days (27-7%). 70% of both the asthmatics and the bronchitics had a greater than 20% fall in C4. C2 There was a statistically significant difference {P>005 by Student's t-test) between the percentage fall inC3 at 24 hr (14-7%) in chronic bronchitics compared with asthmatics (0-8%), but at 7 days there was no difference between the two groups. 40% of the asthmatics and the bronchitics had a greater than 20% fall. Factor B There was a similar fall between the two groups although there was a greater initial fall in the bronchitics at 24 hr (9-3%) while the asthmatics had a later fall measured at 7 days (23-6%). 65% of asthmatics and 40% of bronchitics had a greater than 20% fall in factor B. Jn all, seven asthmatics and three bronchitics had a fall of greater than 20% in all the three components measured; one asthmatic had a rise of greater than 20% in all three components. Discussion Complement may contribute to tissue damage in certain hypersensitivity states either by a direct cytotoxic effect or through formation of immune complexes. Thus complement activation has been found in numerous diseases, but only with rapid utilization of components will transient falls in serum levels of the components occur, such as membranoproliferative glomerulonephritis (Peters & Gwyn Williams, 1975). That complement activation may be responsible for some of the pathological changes found in the lungs of patients with status asthmaticus has been suggested previously. Callerame et al. (1971) found immunoglobulin deposition on basement membranes in patients, but rarely C3, and never IgE, while Gerber, Pannetto & Korhua (1971) did find IgE deposition in bronchial glands, on the basement membrane and in the intraluminal mucus. Cochrane (1971) has suggested that antigenic stimulation produces both circulating antigen-antibody complexes and IgE antibodies in rabbits and that vasoactive substances released by platelets allows circulating immune complexes to deposit in the tissues with subsequent production of local infiammatory responses. Evidence for complement activation in asthma is unconfirmed; the late asthmatic response, though thought to be due to formation of immune complexes, has not yet been associated with falls in circulating complement. Using bronchial challenge, no evidence of hypocomplementaemia was found in stable atopic asthmatics during the
144
R. D. H. Monie, R. Fifleld and B. H. Davies
immediate and late asthmatic reactions (Arroyave et al., 1977; Hutchcroft & Guz, 1978). Studies in chronic asthma initially suggested that C4 was higher in atopic than idiopathic asthma (Kay et al., 1974), but this finding has not been confirmed by other workers (Topilsky et al., 1976; Hansson, Kjellman & Leijon, 1975; Godfrey & Hawkesley, 1975). In this study we measured C3, C4 and factor B levels in acute severe asthma: C3 was measured as an indicator ofthe integrity ofthe whole system (Editorial, 1976), C4 as a measure of the classical pathway and factor B of the alternative pathway. No evidence of hypocomplementaemia was found but falls of greater than 20% in concentrations of these components were found in similar numbers of both groups studied. There are, however, differences between the two groups which may be related to the administration of steroids. In germ-free rats, the administration of high doses of methylprednisolone did not lead to any impairment in the synthesis of complement (Baardsen, Midtvedt & Tippested, 1975), but guinea-pigs living in a normal environment did have falls in all components, especially in C4 and C8 (Atkinson & Frank, 1973). The fall in complement was concluded to be due to increased susceptibility to infection while on steroids and therefore greater utilitation of complement. In our study steroids were administered to all the asthmatics, but to only three out ofthe ten bronchitics. The greater fall in complement at 24 hr in the bronchitics is probably explained by the exacerbation of their symptoms being due to infection and this quickly resolved following treatment with physiotherapy and antibiotics. In the asthmatics, where infection is not the only factor producing symptoms, there is little fall in complement at 24 hr, but because steroids lead to a diminished inflammatory response, there will be greater susceptibility to subclinical infection and therefore greater utilization of complement which is reflected in the figures at 7 days. This would explain the statistically significant fall in the bronchitics of C3 at 24 hr. Thus from our results there is no rapid utilization of complement in acute severe asthma, which confirms the results of the previous studies using bronchial challenge techniques, although we cannot exclude activation of the complement system leading to fall ofthe complement components but still within the normal range. References ARROYAVE, CM., STEVENSON, D.D., VAUGHAN, J.H. & TAN, E.M. (1977) Plasma complement
changes during bronchospasm provoked in asthmatic patients. Clinical Allergy, 7, 173. ATKINSON, J.P. & FRANK, M.M. (1973) Effect of cortisone on serum complement components. Journal of of Immunology, l i t , 1061. BAARDSEN, A., MIDTVEDT, T. & TIPPESTAD, A. (1975) Influence of methylprednisolone on complement
activity in germ-free rats, and antibody activity to E. coli in monocontaminated rats. Acta pathologica microbiologica scandinavica, 83, 37. BRUCE, C, WEATHERSTONE, R., SEATON, A. & TAYLOR, W.H. (1976) Histamine levels in plasma, blood
and urine in severe asthma and the effect of corticosteroid therapy. Thorax, 31, 724. CALLERAME, M.L., CONDEMI, J.J., ISHIZOKOA, K . , JOHANSSON, S.G.O. & VAUGHAN, J.H. (1971)
Immunoglobulins in bronchial tissues from patients with asthma with special reference to TgE. Journal of Allergy and Clinical Immunology, 47, 187. CocHRANE, C.G. (1971) Mechanisms involved in the deposition of immune complexes in tissues. Journal of Experimental Medicine, 134, 75s. EDITORIAL (1976) Complement Activation and Disease. British Medical Journal, 1, 416. GERBER, M.A., PANNETTO, F . & KORHUA, A. (1971) Immunochemical localisation of IgE in asthmatic
lungs. American Journal of Pathology, 62, 339.
Complement levels in acute asthma
145
GODFREY, R,C, & HAWKESLEY, M,R, (1975) C4 levels and classification of bronchial asthma. X,a/ice/, i, 464, GRANT, J,A, & LICHTENSTEIN, L,M, (1973) The role of complement in human immediate hypersensitivity evidence against involvement of the alternative pathway of complement activation. Journal of Immunology, 111, 733, HANSSON, L,O,, KJELLMAN, N , - J , M , & LEIJON, I, (1975) Complement in bronchial asthma. Lancet,
ii, 874, HUTCHCROFT, B.J, & Guz, A, (1978) Levels of complement components during allergen induced asthma. Clinical Allergy, 8, 59. LAURELL, C,G, (1966) Quantitative estimation of protein by electrophoresis in agarose gel containing antibodies. Annals of Biochemistry, 15, 45, KAY, A.B,, BACON, G , D , , MERCER, B , A , , SIMPSON, H , & CROFTON, J , W . (1974) Complement
components and IgE in bronchial asthma. Lancet, ii, 916, KILLINGSWORTH, L , M , , SAVORY, J, & TEAGUE, P,O, (1971) Automated immunoprecipitation
technique for analysis of the third component of complement (C3) in human serum. Clinical Chemistry, 17, 374, PETERS, D , K , & GWYN WILLIAMS, D , (1975) Pathogenetic mechanisms in glomerulonephritis. Recent Advances in Renal Medicine (ed, N, F, Jones), Churchill Livingstone, Edinburgh. ToPiLSKY, M,, SPITZER, S,, PICK, A,I, & WEISS, H , (1976) Complement in asthma. Lancet, i, 813, Yu, D,Y,, GALANT, S,P, & GOLD, W , M , (1972) Inhibition of antigen induced bronchoconstriction by atropine in asthmatic patients. Journal of Applied Physiology, 32, 823,
D
Acute asthma compared with exacerbations of chronic bronchitis: changes in complement
R. D. H. MONIE, R. FIFIELD* and B. H. DAVIES Asthma Research Unit, Sully Hospital, Penarth, South Glamorgan, and *Protein Reference Unit, Cardiff Royal Infirmary, Cardiff, South Glamorgan Received 3\ Atigtist 1978.- accepted for publication 15 September 1978)
Summary
Complement levels were measured on admission and at 1 and 7 days following admission in twenty patients with acute severe asthma and ten patients with an acute exacerbation of chronic bronchitis. Although no evidence of hypocomplementaemia was found in any patient, there was a mean fall within the normal range of the individual complement components, C4, C3 and factor B in both groups. The mean fall occurred earlier in the bronchitics than in the asthmatics and this may be related to infection or the administration of corticosteroids. There was a significant fall in C3 {P>0-05) in the bronchitics compared with the asthmatics at 24 hr. From our study, however, we could find no evidence of excessive utilization of complement in acute asthma. Introduction
The aetiology of acute severe asthma remains obscure. Evidence of IgE-mediated asthma is found in only a few patients, and infection remains the commonest precipitating factor. What immunological mechanisms operate in acute asthma is unknown, but recent research suggests that histamine release occurs (Bruce et al., 1976). Whether this is mediated through the vagus (Yu, Galant & Gold, 1972), directly through IgE or through activation of complement with subsequent generation of the anaphylotoxin, C5a, by either classical or alternative pathways is not clear (Grant & Lichtenstein, 1973). Further evidence for complement activation having a role in asthma has come from challenge experiments in patients with stable allergic asthma, complement levels being measured during the immediate and late asthmatic reactions (Arroyave et al., 1977; Hutchcroft & Guz, 1978). This study was designed to investigate whether complement activation occurred in acute severe asthma. Correspondence: Dr B. H. Davies at the above address. 0009-9090/78/0300-0141 $02.00 © 1979 Blackwell Scientific Publications
141
142
R. D. H. Monie, R. Fifleld and B. H. Davies
Materials and methods Patient population All patients were emergency admissions and informed consent was obtained prior to inclusion in the study. The patients had a pulse rate greater than 110 beats per min and PQ^ of less than 60 mmHg on air. Twenty asthmatic patients (seven male and thirteen female, mean age 31, range 15-59 years) and ten chronic bronchitics (five male and five female, mean age, 63, range 52-71 years) were entered into the study. Asthma was defined as paroxysmal attacks of dyspnoea and wheezing with reversible airways obstruction, of greater than 20% change in PEFR with salbutamol, supported by blood or sputum eosinophilia. Skin testing showed that there were seventeen atopic and three idiopathic asthmatics. Patients with chronic bronchitis had cough and sputum for more than 3 months of the year for 2 consecutive years in the absence of focal lung disease and had no evidence of reversible airways obstruction. Complement studies Venous blood was taken on administration, at 1 and 7 days, collected in an EDTA bottle, mixed, centrifuged and plasma stored immediately at — 20°C. C3 and C4 estimations were performed by an automated immunoprecipitation technique (Technicon) (Killingsworth, Savory & Teague, 1971) using antisera from Atlantic Antibodies. Factor B was estimated by electroimmunodiffusion using the rocket technique (Laurell, 1966), using antisera from Atlantic Antibodies. Results Clinieal The twenty asthmatics had on admission a mean pulse of 123 beats per min and aPo^ on air of 53 mmHg compared with a pulse of 116 beats per min and a P^^ on air of 41 mmHg in the ten chronic bronchitics.
10 r-
(b)
(a)
J -iO
(c)
-k
r
-
X N/'-...
-20 -
X
1
\
1 . 1
r'-l
-^ -'-
1 1
X
.
-30 -40
Day I
Day 7
Day I
Day 7
Day I
Day 7
Fig. 1. Percentage falls in levels of complement components compared with the pretreatment level (taken as hase-line). The bars represent the mean + 1 s.e. (a) C4; (b) C3; (c) factor B; ( ) asthmatic; ( ) bronchitis.
Complement levels in acute asthma
143
Complement levels There was no evidence of hypocomplementaemia in any patient. The levels of the complement components at 24 hr and 7 days are expressed as percentage changes when compared with the pretreatment levels (Fig, 1). There is a 10% laboratory error in each measurement. C4 There was no statistical difference in the fall of C4 between the two groups. The mean percentage fall was greater in the bronchitics at 24 hr (13-2%), and this level did not alter by the seventh day (14-8%); the reverse occurred in asthmatics—virtually no fall at 24 hr (3-2%) but a much greater fall by 7 days (27-7%). 70% of both the asthmatics and the bronchitics had a greater than 20% fall in C4. C2 There was a statistically significant difference {P>005 by Student's t-test) between the percentage fall inC3 at 24 hr (14-7%) in chronic bronchitics compared with asthmatics (0-8%), but at 7 days there was no difference between the two groups. 40% of the asthmatics and the bronchitics had a greater than 20% fall. Factor B There was a similar fall between the two groups although there was a greater initial fall in the bronchitics at 24 hr (9-3%) while the asthmatics had a later fall measured at 7 days (23-6%). 65% of asthmatics and 40% of bronchitics had a greater than 20% fall in factor B. Jn all, seven asthmatics and three bronchitics had a fall of greater than 20% in all the three components measured; one asthmatic had a rise of greater than 20% in all three components. Discussion Complement may contribute to tissue damage in certain hypersensitivity states either by a direct cytotoxic effect or through formation of immune complexes. Thus complement activation has been found in numerous diseases, but only with rapid utilization of components will transient falls in serum levels of the components occur, such as membranoproliferative glomerulonephritis (Peters & Gwyn Williams, 1975). That complement activation may be responsible for some of the pathological changes found in the lungs of patients with status asthmaticus has been suggested previously. Callerame et al. (1971) found immunoglobulin deposition on basement membranes in patients, but rarely C3, and never IgE, while Gerber, Pannetto & Korhua (1971) did find IgE deposition in bronchial glands, on the basement membrane and in the intraluminal mucus. Cochrane (1971) has suggested that antigenic stimulation produces both circulating antigen-antibody complexes and IgE antibodies in rabbits and that vasoactive substances released by platelets allows circulating immune complexes to deposit in the tissues with subsequent production of local infiammatory responses. Evidence for complement activation in asthma is unconfirmed; the late asthmatic response, though thought to be due to formation of immune complexes, has not yet been associated with falls in circulating complement. Using bronchial challenge, no evidence of hypocomplementaemia was found in stable atopic asthmatics during the
144
R. D. H. Monie, R. Fifleld and B. H. Davies
immediate and late asthmatic reactions (Arroyave et al., 1977; Hutchcroft & Guz, 1978). Studies in chronic asthma initially suggested that C4 was higher in atopic than idiopathic asthma (Kay et al., 1974), but this finding has not been confirmed by other workers (Topilsky et al., 1976; Hansson, Kjellman & Leijon, 1975; Godfrey & Hawkesley, 1975). In this study we measured C3, C4 and factor B levels in acute severe asthma: C3 was measured as an indicator ofthe integrity ofthe whole system (Editorial, 1976), C4 as a measure of the classical pathway and factor B of the alternative pathway. No evidence of hypocomplementaemia was found but falls of greater than 20% in concentrations of these components were found in similar numbers of both groups studied. There are, however, differences between the two groups which may be related to the administration of steroids. In germ-free rats, the administration of high doses of methylprednisolone did not lead to any impairment in the synthesis of complement (Baardsen, Midtvedt & Tippested, 1975), but guinea-pigs living in a normal environment did have falls in all components, especially in C4 and C8 (Atkinson & Frank, 1973). The fall in complement was concluded to be due to increased susceptibility to infection while on steroids and therefore greater utilitation of complement. In our study steroids were administered to all the asthmatics, but to only three out ofthe ten bronchitics. The greater fall in complement at 24 hr in the bronchitics is probably explained by the exacerbation of their symptoms being due to infection and this quickly resolved following treatment with physiotherapy and antibiotics. In the asthmatics, where infection is not the only factor producing symptoms, there is little fall in complement at 24 hr, but because steroids lead to a diminished inflammatory response, there will be greater susceptibility to subclinical infection and therefore greater utilization of complement which is reflected in the figures at 7 days. This would explain the statistically significant fall in the bronchitics of C3 at 24 hr. Thus from our results there is no rapid utilization of complement in acute severe asthma, which confirms the results of the previous studies using bronchial challenge techniques, although we cannot exclude activation of the complement system leading to fall ofthe complement components but still within the normal range. References ARROYAVE, CM., STEVENSON, D.D., VAUGHAN, J.H. & TAN, E.M. (1977) Plasma complement
changes during bronchospasm provoked in asthmatic patients. Clinical Allergy, 7, 173. ATKINSON, J.P. & FRANK, M.M. (1973) Effect of cortisone on serum complement components. Journal of of Immunology, l i t , 1061. BAARDSEN, A., MIDTVEDT, T. & TIPPESTAD, A. (1975) Influence of methylprednisolone on complement
activity in germ-free rats, and antibody activity to E. coli in monocontaminated rats. Acta pathologica microbiologica scandinavica, 83, 37. BRUCE, C, WEATHERSTONE, R., SEATON, A. & TAYLOR, W.H. (1976) Histamine levels in plasma, blood
and urine in severe asthma and the effect of corticosteroid therapy. Thorax, 31, 724. CALLERAME, M.L., CONDEMI, J.J., ISHIZOKOA, K . , JOHANSSON, S.G.O. & VAUGHAN, J.H. (1971)
Immunoglobulins in bronchial tissues from patients with asthma with special reference to TgE. Journal of Allergy and Clinical Immunology, 47, 187. CocHRANE, C.G. (1971) Mechanisms involved in the deposition of immune complexes in tissues. Journal of Experimental Medicine, 134, 75s. EDITORIAL (1976) Complement Activation and Disease. British Medical Journal, 1, 416. GERBER, M.A., PANNETTO, F . & KORHUA, A. (1971) Immunochemical localisation of IgE in asthmatic
lungs. American Journal of Pathology, 62, 339.
Complement levels in acute asthma
145
GODFREY, R,C, & HAWKESLEY, M,R, (1975) C4 levels and classification of bronchial asthma. X,a/ice/, i, 464, GRANT, J,A, & LICHTENSTEIN, L,M, (1973) The role of complement in human immediate hypersensitivity evidence against involvement of the alternative pathway of complement activation. Journal of Immunology, 111, 733, HANSSON, L,O,, KJELLMAN, N , - J , M , & LEIJON, I, (1975) Complement in bronchial asthma. Lancet,
ii, 874, HUTCHCROFT, B.J, & Guz, A, (1978) Levels of complement components during allergen induced asthma. Clinical Allergy, 8, 59. LAURELL, C,G, (1966) Quantitative estimation of protein by electrophoresis in agarose gel containing antibodies. Annals of Biochemistry, 15, 45, KAY, A.B,, BACON, G , D , , MERCER, B , A , , SIMPSON, H , & CROFTON, J , W . (1974) Complement
components and IgE in bronchial asthma. Lancet, ii, 916, KILLINGSWORTH, L , M , , SAVORY, J, & TEAGUE, P,O, (1971) Automated immunoprecipitation
technique for analysis of the third component of complement (C3) in human serum. Clinical Chemistry, 17, 374, PETERS, D , K , & GWYN WILLIAMS, D , (1975) Pathogenetic mechanisms in glomerulonephritis. Recent Advances in Renal Medicine (ed, N, F, Jones), Churchill Livingstone, Edinburgh. ToPiLSKY, M,, SPITZER, S,, PICK, A,I, & WEISS, H , (1976) Complement in asthma. Lancet, i, 813, Yu, D,Y,, GALANT, S,P, & GOLD, W , M , (1972) Inhibition of antigen induced bronchoconstriction by atropine in asthmatic patients. Journal of Applied Physiology, 32, 823,
D
