- Email: [email protected]
SMOKING AND CORONARY HEART-DISEASE
1211 factor in serum, since all sera were pre-treated with an IgG immunoabsorbent, which removes such activity. Immune complexes differ widely in antibody class and subclass, in size, and complement-binding characteristics as well as in the antigen. Gleicher et al. assume that a complementbased immune-complex assay always measures the same population of complexes as an Fc-determined assay. Yet there is strong evidence that this is not true, for in the steroid-responsive nephrotic syndrome of childhood, the IgG complexes do not bind Clq.9 Gleicher’s negative findings in pregnancy and pre-eclampsia only provide information about the assay system they used and do not prove whether immune complexes are present or absent in these conditions. We conclude that raised levels of IgG-containing immune complexes may be found in both normal and pre-eclamptic pregnancies. We do not know vhat role they play or whether they are of primary or secondary importance in the pathogenesis of pre-eclampsia. Department of Immunology, Institute of Child Health, London WC1N 1EH
R.
John Radcliffe Hospital,
G. M. STIRRAT C. W. G. REDMAN
Oxford
J. LEVINSKY
SMOKING AND CORONARY HEART-DISEASE
SIR,-Bain et al.l report a significant increase in coronary heart-disease (C.H.D.) deaths above a threshold dose of one pack of cigarettes per day. This observation adds a new interpretation to the "controlled" clinical trial comparing the effects of substituting vegetable fats for dietary fats of animal origin. Dayton et a1.2 observed 424 subjects for eight years. They ate skim milk, imitation ice cream, and margarine. They avoided butterfat. They had a lower incidence of C.H.D. deaths than the controls who used butter and eggs. These results are often cited as supporting the use of margarine over butter. However, when the "heavy" smokers are identified, the protective effect of margarine is open to question. Although the total number of smokers in each group was similar (subjects 283, controls 279), there was a striking similarity between the numbers of heavy smokers (over a pack a day) and the numbers of C. H.D. deaths in each group. The butter-eaters included 70 heavy smokers: there were 70 C.H.D. deaths. The margarine-users included only 45 heavy smokers, and they had only 48 C.H.D. deaths. The total deaths were essentially the same in each group (subjects 174, controls 178) and meticulous necropsy studies showed no difference in the degree of atherosclerosis in each group. It is unfortunate that the "threshold effect of one pack of cigarettes per day" was not known two decades ago. A more meaningful distribution of the heavy smokers may have shown
CREATINE KINASE ISOENZYMES IN HEART DISEASE
SIR,-Dr Marmor and colleagues (Oct. 14, p. 812) suggest that certain patients with angina may have significant increases in the MB isoenzyme of creatinine kinase (C.K.-M.B.) with normal total C.K. activity. Two issues deserve consideration. First, one would expect significant increases in total C.K. activity based on Roberts’ evidence that 85% of myocardial C.K. were activity is C.K.-M.M.2 Perhaps significant increases in total C.K. were obscured by the unusually broad "normal" range encountered in the laboratory. High normal values tend to run five to ten times greater than the low normal. Analysis of changes in baseline C.K. activity in Marmor’s study might provide an answer. The problem is compounded by the use of the same normal range for both males and females even though the upper limit for normal males is twice as high as the upper limit for females, presumably due to quantitative differences in the source of creatinine phosphokinase in normal individuals. In this regard, evaluation of total C.K. activity on the basis of muscle mass, perhaps c.K./creatinine ratios, is a logical first attempt to define a more meaningful normal range. The second consideration relates to the significance of the C.K.-M.B. which appeared in certain individuals after stress testing. A previous study failed to detect raised levels of C.K.-M.B. in patients with angina even though an extremely sensitive radioimmunoassay was used.3 This suggests that uncomplicated angina is unaccompanied by rises in C.K.-M.B. and that stress testing per se may cause this enzyme to appear in the blood of patients with angina. Long-distance running provoked the appearance of C.K.-M.B. in 25% of a group of marathon runners.4 Clearly, interpretation of rises in C.K.-M.B. after exertion must be made cautiously. Department of Pathology, Malden Hospital, Malden, Massachussetts 02148, U.S.A. 9.
CHARLES
J. PRZYJEMSKI
Levinsky, R. J., Masseson, P., Barratt, T. M., Soothill, J. F. New Engl. J. Med. 1978, 298, 126. 1. Marmor, A., Alpan, G., Keidar, S., Grenadier, E., Palant, A. Lancet, 1978, ii, 812. 2. Roberts, R., Gowda, K. S., Ludbrook, P. A., Sobel, B. E. Am. J. Cardiol. 1975, 36, 433. 3. Roberts, R., Parker, C. W., Sobel, B. E. Lancet, 1977, ii, 319. 4. Oliver, L. R., and others, S. Afr. med. J. 1978, 53, 83
protection from the margarine diet, and saved us a decade of unwarranted concern over the hazards of dairy fats. Recent animal studies have suggested that margarine may be even more atherogenic than butter because of the presence of trans no
fat.3 Centinela
Hospital, Inglewood, California, 90307,
THOMAS
U.S.A.
J. BASSLER
CIMETIDINE AND PSORIASIS
SIR,-18 months ago
started treating with cimetidine a duodenal ulcer. This patient had of 9, and for a long time she had been treated with steroids and even methotrexate. The duodenal ulcer was diagnosed by radiology and confirmed at endoscopy. An acid-secretion test revealed hyperchlorhydria, both in the basal state (4-2 mmol/h) and after maximal stimulation with pentagastrin (31.7 mmol/h). When we first saw her the ulcer symptoms of epigastric pain and vomiting were accompanied by psoriasis, in a typical nummular form with discs and plaques of varying sizes. Short-term cimetidine therapy (28 days) was started, at a dose of 1 g/day. All other treatments-systemic and topicalwere stopped. Her ulcer symptoms responded to cimetidine, and at endoscopy the duodenal lesion had gone; the skin lesions also disappeared. 5 months after the cimetidine course ended, the patient returned to us with an ulcer relapse; her psoriasis had started to reappear in the previous 2 months. A second 28-day course of cimetidine was followed by endoscopic evidence of ulcer healing and by total remission of the psoriatic manifestations. Long-term cimetidine at 400 mg/day has so far prevented relapses of both the ulcer and the psoriasis. We subsequently gave cimetidine (1 g/day) to two patients with psoriasis but no lesions of the upper gastrointestinal tract. One patient had the suberythrodermic type of psoriasis with diffuse skin involvement and inflammation. After 7 days there was a striking decrease in the inflammatory component and in we
43-year-old woman with a had psoriasis since the age
1. Bain, C., Hennekens, C. H., Rosner, B.,
Speizer,
F. E.,
Jesse, M. J. Lancet,
1978, i, 1007. 2.
3.
Dayton, S., Pearce, M. L., Hashimoto, S., Dixon, culation, 1969, 40, suppl. 2, p. 1. Kummerow, F. A.J. Food Sci. 1975, 40, 12.
W.
J., Tomiyasu, U. Cir-
R.
John Radcliffe Hospital,
G. M. STIRRAT C. W. G. REDMAN
Oxford
J. LEVINSKY
SMOKING AND CORONARY HEART-DISEASE
SIR,-Bain et al.l report a significant increase in coronary heart-disease (C.H.D.) deaths above a threshold dose of one pack of cigarettes per day. This observation adds a new interpretation to the "controlled" clinical trial comparing the effects of substituting vegetable fats for dietary fats of animal origin. Dayton et a1.2 observed 424 subjects for eight years. They ate skim milk, imitation ice cream, and margarine. They avoided butterfat. They had a lower incidence of C.H.D. deaths than the controls who used butter and eggs. These results are often cited as supporting the use of margarine over butter. However, when the "heavy" smokers are identified, the protective effect of margarine is open to question. Although the total number of smokers in each group was similar (subjects 283, controls 279), there was a striking similarity between the numbers of heavy smokers (over a pack a day) and the numbers of C. H.D. deaths in each group. The butter-eaters included 70 heavy smokers: there were 70 C.H.D. deaths. The margarine-users included only 45 heavy smokers, and they had only 48 C.H.D. deaths. The total deaths were essentially the same in each group (subjects 174, controls 178) and meticulous necropsy studies showed no difference in the degree of atherosclerosis in each group. It is unfortunate that the "threshold effect of one pack of cigarettes per day" was not known two decades ago. A more meaningful distribution of the heavy smokers may have shown
CREATINE KINASE ISOENZYMES IN HEART DISEASE
SIR,-Dr Marmor and colleagues (Oct. 14, p. 812) suggest that certain patients with angina may have significant increases in the MB isoenzyme of creatinine kinase (C.K.-M.B.) with normal total C.K. activity. Two issues deserve consideration. First, one would expect significant increases in total C.K. activity based on Roberts’ evidence that 85% of myocardial C.K. were activity is C.K.-M.M.2 Perhaps significant increases in total C.K. were obscured by the unusually broad "normal" range encountered in the laboratory. High normal values tend to run five to ten times greater than the low normal. Analysis of changes in baseline C.K. activity in Marmor’s study might provide an answer. The problem is compounded by the use of the same normal range for both males and females even though the upper limit for normal males is twice as high as the upper limit for females, presumably due to quantitative differences in the source of creatinine phosphokinase in normal individuals. In this regard, evaluation of total C.K. activity on the basis of muscle mass, perhaps c.K./creatinine ratios, is a logical first attempt to define a more meaningful normal range. The second consideration relates to the significance of the C.K.-M.B. which appeared in certain individuals after stress testing. A previous study failed to detect raised levels of C.K.-M.B. in patients with angina even though an extremely sensitive radioimmunoassay was used.3 This suggests that uncomplicated angina is unaccompanied by rises in C.K.-M.B. and that stress testing per se may cause this enzyme to appear in the blood of patients with angina. Long-distance running provoked the appearance of C.K.-M.B. in 25% of a group of marathon runners.4 Clearly, interpretation of rises in C.K.-M.B. after exertion must be made cautiously. Department of Pathology, Malden Hospital, Malden, Massachussetts 02148, U.S.A. 9.
CHARLES
J. PRZYJEMSKI
Levinsky, R. J., Masseson, P., Barratt, T. M., Soothill, J. F. New Engl. J. Med. 1978, 298, 126. 1. Marmor, A., Alpan, G., Keidar, S., Grenadier, E., Palant, A. Lancet, 1978, ii, 812. 2. Roberts, R., Gowda, K. S., Ludbrook, P. A., Sobel, B. E. Am. J. Cardiol. 1975, 36, 433. 3. Roberts, R., Parker, C. W., Sobel, B. E. Lancet, 1977, ii, 319. 4. Oliver, L. R., and others, S. Afr. med. J. 1978, 53, 83
protection from the margarine diet, and saved us a decade of unwarranted concern over the hazards of dairy fats. Recent animal studies have suggested that margarine may be even more atherogenic than butter because of the presence of trans no
fat.3 Centinela
Hospital, Inglewood, California, 90307,
THOMAS
U.S.A.
J. BASSLER
CIMETIDINE AND PSORIASIS
SIR,-18 months ago
started treating with cimetidine a duodenal ulcer. This patient had of 9, and for a long time she had been treated with steroids and even methotrexate. The duodenal ulcer was diagnosed by radiology and confirmed at endoscopy. An acid-secretion test revealed hyperchlorhydria, both in the basal state (4-2 mmol/h) and after maximal stimulation with pentagastrin (31.7 mmol/h). When we first saw her the ulcer symptoms of epigastric pain and vomiting were accompanied by psoriasis, in a typical nummular form with discs and plaques of varying sizes. Short-term cimetidine therapy (28 days) was started, at a dose of 1 g/day. All other treatments-systemic and topicalwere stopped. Her ulcer symptoms responded to cimetidine, and at endoscopy the duodenal lesion had gone; the skin lesions also disappeared. 5 months after the cimetidine course ended, the patient returned to us with an ulcer relapse; her psoriasis had started to reappear in the previous 2 months. A second 28-day course of cimetidine was followed by endoscopic evidence of ulcer healing and by total remission of the psoriatic manifestations. Long-term cimetidine at 400 mg/day has so far prevented relapses of both the ulcer and the psoriasis. We subsequently gave cimetidine (1 g/day) to two patients with psoriasis but no lesions of the upper gastrointestinal tract. One patient had the suberythrodermic type of psoriasis with diffuse skin involvement and inflammation. After 7 days there was a striking decrease in the inflammatory component and in we
43-year-old woman with a had psoriasis since the age
1. Bain, C., Hennekens, C. H., Rosner, B.,
Speizer,
F. E.,
Jesse, M. J. Lancet,
1978, i, 1007. 2.
3.
Dayton, S., Pearce, M. L., Hashimoto, S., Dixon, culation, 1969, 40, suppl. 2, p. 1. Kummerow, F. A.J. Food Sci. 1975, 40, 12.
W.
J., Tomiyasu, U. Cir-