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Is Toxemia of Pregnancy an Allergic Reaction?
IS TOXEMIA OF PREGNANCY AN ALLERGIC REACTION? HAZEL
A. C.
I11~,
M.S., l1:.D., NEw YoRK, N.Y.
(llrorn the Reed and CMnriok Institute for Medical Jlesearoh)
HE cause of toxemia of pregnancy presents a great challenge to medical T research. Uremia, bacteria, toxins, faulty metabolism, and e~docrine imbalance have all been blamed. In spite of the tremendous amount of work that has already beert put into it, the real etiology is still unknown. The toxemic manifestations occuP only during pregnancy and often disappear soon after delivery or upon death of the fetus. This sequence suggests that the cause may be connected with the product of conception. The fetus has been eliminated as the cause of the trouble, since these manifestations also occur in molar pregnancy. Therefore, the placenta itself has for a long time been looked upon as the source of all the troubles. The placental aspects have been attacked from all angles. Those workers who advocated hormonal imbalance have reported divergent :findings. Smith and Smith l-s reported high gonadotrophic and low estrogenic levels in toxemic patients. Their theory was substantiated by Anselmino, 4 Rakoff, 5 and White and co-workers/ who discovered excessive gonadotropin in the body fluid of these patients. Taylor and Scadron,7 however, did not find any significant difference in the hormonal values between normal and toxemic patients. Others found acetylcholine in the placenta and identified it as a potent vasodilator. Hofbauer16 then put forth the theory that acetylcholine held the delicate balance between the blood pressure stimulating and depressing principles. Recent interest in antigen-antibody reaction in diseases has been intensified by the work done with anti-kidney serum of ::\1:asugi 8 • 9 and Smade}.1°-12 DobrowlskP 3 reported that placenta antiserum interruped pregnancy in guinea pigs and rabbits. Seegal and I.. oeb 14 also encountered the sanw experience in rats injected with rabbit antiplacenta serum. It is a common finding of the obstetricians that repeated pregnancies intensify all the symptoms and signs of toxemia of pregnancy. The present experiment was undertaken to find out whether toxemia of pregnancy in rats can be produced by antigen-antibody reaction. A group of virgin albino rats were sensitized by frequent intraperitoneal injections of placental suspension. After a sufficient length .of time was allowed for the antibodies to develop, these immunized rats were then allowed to become pregnant. During their periods of gestation, they were tested very carefully for any manifestations of toxemia. Materials and Methods
Preparation of placental suspensions.-Twenty albino female rats were allowed to become pregnant at fixed intervals so that they could furnish the 97
Am.
LIN
98
J.
Ol»t. & Gyner. July, 194i
placentas according to schedule. The date of copulation was timed by daily vaginal smears. Cesarean sections were performed on these rats one day before term. The placentas were removed aseptieally and <·.arefully 'vashed free of blood and ground into small pieces in a glazed porcelain mortar and made up to a 20 per cent suspension with saline solution, Bach suspension was used the day it was prepared, as described in the foJlowing paragraph. Preparation of C:l'peri·mental anirnals.-Ten mature female albino rats weighing 250 to 300 Gm. wer{' kept on Purina dol! chow with weekly supplements of yeast, cod liver oil, and hamburger. These rats were obtained from Rockland Farms. These ten rats were given 2 r.c. of the placental suspension intra· peritoneally twice a week for five weeks. These animals were then allowed to have a rest per·iod of five months. At the end of this time they were mated. From their daily vaginal smears their pregnancies wer(~ also closely dated. Lines of in·uestig(ltions:-Evidenee of abnormal toxemic pregnancies was determined by rareful observation in the urine, blood pressure, and tissue biopsies. One week after copulation each of these animals was put into a metabolism cage where daily 17-hour specimens of urine were collected. Each specimen was diluted to 50 c.c. with distilled water, and filtered. 0.5 c.c. of this was added to 9.5 c.c. of sulfosalicvlic acid. The albumin content was measured bv a Klett • · colorimeter. by Grolltail the from week a twice taken were The blood pressure readings man 's apparatus. The rats were also carefully watched for edema and any other abnormal manifestations during their pregnancies. Biopsies were taken from different organs for microscopic sections. TABLE
1 2
3 4
6
7 8
10
17 25 22 0 39 59 HI 22 22 22 13 22 20 0 49 55
I.
AJ,BUMINURIA IN MG. PER TWENTY-FOUR HOURS
22 17 25 27 24 32 45 23 40 26 7 10 27 29 72 22 20 20 20 55 26 -:1.1 27 29 59 25 25 19 25 14 24 27 20 25 27 51 27 24 il3 30
95
45 53 50 56 61 51 15
49 49
39 56 45 43 36 21 58 32
il5
50 27
48
40 24 I:U 29 38 27 36 44 20 50
53 42 39 59 52 40 36 40 44 30 39 40
33 37 39 23 32 26
44 47 29 39 r\4 45
55 49 59 52
52 59 72 60 27 59 .36 47 51 59 34 34
7
0
1-:l. 12 0 7 12 0 12 13 9 5 5 5 13 0
0 0 4 0
0 0 5 0
0 0
0 0 0
0 0 0
Results.-A definite albuminuria developed which, though not heavy, was significant. The urine specimens of this group of animals were frequently tested during the five months prior to their pregnancies, and all during that period were protein free. Furthermore, the albuminuria disappeared quite rapidly during postpartum observation. Blood pressw·e stndie8.-'l'o obtain an arcnrate reading the rats were heated in an electric cradle to obtain a general hyperemia. The tail was then inserted into a mercury and water cuff. The hlood was squeezed away from the tail with the mercury manometer pressure, and 1he first return of the pulse was registered by the rise of tlw water manometer as the returning volume of the blood filled the tail. The normal blood pressure of this group of rats was between 110 to 130 mm. of mercury. As can be seen by the ahove chart, their blood pressure was definitely raised.
Volume H Number I
TOXF.MIA OF PREGNANCY
99
Fig. 1.-Kidney tissue obtained by biopsy three days postpartum from rat No. 4. Note the thickening of the walls of tqe two arterioles and the reduction of their lumens. The outer circumference of the larger arteriole measured four microns. Fig. 2.-Kidney tissue obtained by biopsy three days postpartum of a control litter mate of rat No. 4 which had no previous treatment of placental s uspension. Note thil normal thickness of the wall of the arteriole. The outer circumference of this arteriole a lso m easured tour micron s.
.
too
LIN
Am . J. Obst. & Gynec. July, 1947
Fig. 3.-Spleen tissue obta ined by biopsy from rat No. 8. Note the great thickening of the wall of the arteriole. Fig. 4.-Pancreas tissu e obtained by biopsy from rat No. 2. Note the great thickening of the wall of the arteriole.
TOXEMIA OP PREGNANCY
Volume 54 Number I
TABLE II. H.\TS
1 2 3
4 6
7 8
JO
WEEK 145/150 160/160 140/140 110/115 170/Hi5 110/1::10 150/155 135/140
FIRST
101
BLOOD PRESSURE
WEEK 145/145 165/160 145/140 120/125 160/HiO 155/150 160/150 140/140
SECOJ:>,1>
WEEK 170/175 185/180 140/140 125/120 175/160 160/165 150/155 160/165
THIRD
Two rats had ascites which was proved by paracentesis. One rat had convulsions on two occasions while being heated in the electric cradle. No other abnormal symptoms were observed. All rats carried their pregnancies to term. Six of them had their litters born normally, while the other two had stillborn pups. Pathology.-Biopsies were taken from the kidneys, spleen, pancreas and liver of all these rats. Sections showed one striking consistent result, i.e., arteriolosclerosis. Some glomerular tufts were ischemic and the basement membrane.cs thickened. (See Figs. 1, 3, and 4.)
Conclusion A condition closely simulating toxemia of pregnancy with albuminuria, hypertension and edema was produced in rats by sensitizing them against placenta protein before they became pregnant. The most important pathological lesions were found in the arterioleS. The walls became greatly thickened and the vascular lumen correspondingly narrowed. There was in the kidney some thickening of the basement membrane of Bowman's capsules as well as ischemia of the glomerular tufts. This pathology corresponds closely to the early lesions in the human toxemia of pregnancy. Wong and Pillot15 has reported that the earliest sign of' toxemia of pregnancy is spasm of the arteriolar wall and the narrowing of its lumen which can be observed in the eye grounds. The findings in this preliminary experiment suggests that toxemia of pregnancy might be an allergic reaction of the patients to the placental proteins.
References 1. 2. 3. 4. 5. 6. 7.
8. 9. 10. 11. 12. 13. 14. 15. 16.
Smith, G. V., and Smith, 0. W.: AM. J. OBST. & GYNEO. 38: 618, 1939. Smith, G. V., and Smith, 0. W.: Sur g., Gynec. & Obst. 39: 405, 1940. Smith, G. V., Smith, 0. W., and Schiller, S.: J. Clin. Endocrinol. 1: 461, 470, 1941. An!'lelmino, K. J., and Hoffmann, F.: Ztschr. f. Geburtsch u. Gyniik. 114: 61, 1936. Rflkoff, A. E.: AM. J. OnsT. & GYNEC. 38: 371, 1939. 'V'hite, E. P., Titus, R. S., Joslin, E. P., and Hunt, H.: AM. J. OBST. & GYNEC. 198: 482, 1939. Taylor, H. C., Jr., and Scadron, E. N.: AM. J. OBST. & GYNEC. 37: 963, 1939. Masugi, M.: Japan Path. Soc. 21: 329, 1931. Masugi, M.: Beitr. Path. Anat. u. Allg. Path. 92: 429, 1933-34. Smadel, J. ~.: J. Exper. Med. 64: 921, 1936. Smadel, J. E.: J. Exper. Med. 65: 541, 1()::!7. Smadel, J. E., and Farr, L. E.: J. Exper. Med. 65: 527, 1937. Dobrowlski, M. S.: Bull., Int. Sc. Cra<'ovie 5: 256, Hl03. Seegal, B. C., and Loeb, E. N.: Proc. Soc. Exper. Biol. & Med. 45: 248, 1940. Wong, A., and Pillot: Chinese M. J. 46: 115!1, 1932. Hofbauer, J.: West. J. Surg. 49: 615, 1941.
A. C.
I11~,
M.S., l1:.D., NEw YoRK, N.Y.
(llrorn the Reed and CMnriok Institute for Medical Jlesearoh)
HE cause of toxemia of pregnancy presents a great challenge to medical T research. Uremia, bacteria, toxins, faulty metabolism, and e~docrine imbalance have all been blamed. In spite of the tremendous amount of work that has already beert put into it, the real etiology is still unknown. The toxemic manifestations occuP only during pregnancy and often disappear soon after delivery or upon death of the fetus. This sequence suggests that the cause may be connected with the product of conception. The fetus has been eliminated as the cause of the trouble, since these manifestations also occur in molar pregnancy. Therefore, the placenta itself has for a long time been looked upon as the source of all the troubles. The placental aspects have been attacked from all angles. Those workers who advocated hormonal imbalance have reported divergent :findings. Smith and Smith l-s reported high gonadotrophic and low estrogenic levels in toxemic patients. Their theory was substantiated by Anselmino, 4 Rakoff, 5 and White and co-workers/ who discovered excessive gonadotropin in the body fluid of these patients. Taylor and Scadron,7 however, did not find any significant difference in the hormonal values between normal and toxemic patients. Others found acetylcholine in the placenta and identified it as a potent vasodilator. Hofbauer16 then put forth the theory that acetylcholine held the delicate balance between the blood pressure stimulating and depressing principles. Recent interest in antigen-antibody reaction in diseases has been intensified by the work done with anti-kidney serum of ::\1:asugi 8 • 9 and Smade}.1°-12 DobrowlskP 3 reported that placenta antiserum interruped pregnancy in guinea pigs and rabbits. Seegal and I.. oeb 14 also encountered the sanw experience in rats injected with rabbit antiplacenta serum. It is a common finding of the obstetricians that repeated pregnancies intensify all the symptoms and signs of toxemia of pregnancy. The present experiment was undertaken to find out whether toxemia of pregnancy in rats can be produced by antigen-antibody reaction. A group of virgin albino rats were sensitized by frequent intraperitoneal injections of placental suspension. After a sufficient length .of time was allowed for the antibodies to develop, these immunized rats were then allowed to become pregnant. During their periods of gestation, they were tested very carefully for any manifestations of toxemia. Materials and Methods
Preparation of placental suspensions.-Twenty albino female rats were allowed to become pregnant at fixed intervals so that they could furnish the 97
Am.
LIN
98
J.
Ol»t. & Gyner. July, 194i
placentas according to schedule. The date of copulation was timed by daily vaginal smears. Cesarean sections were performed on these rats one day before term. The placentas were removed aseptieally and <·.arefully 'vashed free of blood and ground into small pieces in a glazed porcelain mortar and made up to a 20 per cent suspension with saline solution, Bach suspension was used the day it was prepared, as described in the foJlowing paragraph. Preparation of C:l'peri·mental anirnals.-Ten mature female albino rats weighing 250 to 300 Gm. wer{' kept on Purina dol! chow with weekly supplements of yeast, cod liver oil, and hamburger. These rats were obtained from Rockland Farms. These ten rats were given 2 r.c. of the placental suspension intra· peritoneally twice a week for five weeks. These animals were then allowed to have a rest per·iod of five months. At the end of this time they were mated. From their daily vaginal smears their pregnancies wer(~ also closely dated. Lines of in·uestig(ltions:-Evidenee of abnormal toxemic pregnancies was determined by rareful observation in the urine, blood pressure, and tissue biopsies. One week after copulation each of these animals was put into a metabolism cage where daily 17-hour specimens of urine were collected. Each specimen was diluted to 50 c.c. with distilled water, and filtered. 0.5 c.c. of this was added to 9.5 c.c. of sulfosalicvlic acid. The albumin content was measured bv a Klett • · colorimeter. by Grolltail the from week a twice taken were The blood pressure readings man 's apparatus. The rats were also carefully watched for edema and any other abnormal manifestations during their pregnancies. Biopsies were taken from different organs for microscopic sections. TABLE
1 2
3 4
6
7 8
10
17 25 22 0 39 59 HI 22 22 22 13 22 20 0 49 55
I.
AJ,BUMINURIA IN MG. PER TWENTY-FOUR HOURS
22 17 25 27 24 32 45 23 40 26 7 10 27 29 72 22 20 20 20 55 26 -:1.1 27 29 59 25 25 19 25 14 24 27 20 25 27 51 27 24 il3 30
95
45 53 50 56 61 51 15
49 49
39 56 45 43 36 21 58 32
il5
50 27
48
40 24 I:U 29 38 27 36 44 20 50
53 42 39 59 52 40 36 40 44 30 39 40
33 37 39 23 32 26
44 47 29 39 r\4 45
55 49 59 52
52 59 72 60 27 59 .36 47 51 59 34 34
7
0
1-:l. 12 0 7 12 0 12 13 9 5 5 5 13 0
0 0 4 0
0 0 5 0
0 0
0 0 0
0 0 0
Results.-A definite albuminuria developed which, though not heavy, was significant. The urine specimens of this group of animals were frequently tested during the five months prior to their pregnancies, and all during that period were protein free. Furthermore, the albuminuria disappeared quite rapidly during postpartum observation. Blood pressw·e stndie8.-'l'o obtain an arcnrate reading the rats were heated in an electric cradle to obtain a general hyperemia. The tail was then inserted into a mercury and water cuff. The hlood was squeezed away from the tail with the mercury manometer pressure, and 1he first return of the pulse was registered by the rise of tlw water manometer as the returning volume of the blood filled the tail. The normal blood pressure of this group of rats was between 110 to 130 mm. of mercury. As can be seen by the ahove chart, their blood pressure was definitely raised.
Volume H Number I
TOXF.MIA OF PREGNANCY
99
Fig. 1.-Kidney tissue obtained by biopsy three days postpartum from rat No. 4. Note the thickening of the walls of tqe two arterioles and the reduction of their lumens. The outer circumference of the larger arteriole measured four microns. Fig. 2.-Kidney tissue obtained by biopsy three days postpartum of a control litter mate of rat No. 4 which had no previous treatment of placental s uspension. Note thil normal thickness of the wall of the arteriole. The outer circumference of this arteriole a lso m easured tour micron s.
.
too
LIN
Am . J. Obst. & Gynec. July, 1947
Fig. 3.-Spleen tissue obta ined by biopsy from rat No. 8. Note the great thickening of the wall of the arteriole. Fig. 4.-Pancreas tissu e obtained by biopsy from rat No. 2. Note the great thickening of the wall of the arteriole.
TOXEMIA OP PREGNANCY
Volume 54 Number I
TABLE II. H.\TS
1 2 3
4 6
7 8
JO
WEEK 145/150 160/160 140/140 110/115 170/Hi5 110/1::10 150/155 135/140
FIRST
101
BLOOD PRESSURE
WEEK 145/145 165/160 145/140 120/125 160/HiO 155/150 160/150 140/140
SECOJ:>,1>
WEEK 170/175 185/180 140/140 125/120 175/160 160/165 150/155 160/165
THIRD
Two rats had ascites which was proved by paracentesis. One rat had convulsions on two occasions while being heated in the electric cradle. No other abnormal symptoms were observed. All rats carried their pregnancies to term. Six of them had their litters born normally, while the other two had stillborn pups. Pathology.-Biopsies were taken from the kidneys, spleen, pancreas and liver of all these rats. Sections showed one striking consistent result, i.e., arteriolosclerosis. Some glomerular tufts were ischemic and the basement membrane.cs thickened. (See Figs. 1, 3, and 4.)
Conclusion A condition closely simulating toxemia of pregnancy with albuminuria, hypertension and edema was produced in rats by sensitizing them against placenta protein before they became pregnant. The most important pathological lesions were found in the arterioleS. The walls became greatly thickened and the vascular lumen correspondingly narrowed. There was in the kidney some thickening of the basement membrane of Bowman's capsules as well as ischemia of the glomerular tufts. This pathology corresponds closely to the early lesions in the human toxemia of pregnancy. Wong and Pillot15 has reported that the earliest sign of' toxemia of pregnancy is spasm of the arteriolar wall and the narrowing of its lumen which can be observed in the eye grounds. The findings in this preliminary experiment suggests that toxemia of pregnancy might be an allergic reaction of the patients to the placental proteins.
References 1. 2. 3. 4. 5. 6. 7.
8. 9. 10. 11. 12. 13. 14. 15. 16.
Smith, G. V., and Smith, 0. W.: AM. J. OBST. & GYNEO. 38: 618, 1939. Smith, G. V., and Smith, 0. W.: Sur g., Gynec. & Obst. 39: 405, 1940. Smith, G. V., Smith, 0. W., and Schiller, S.: J. Clin. Endocrinol. 1: 461, 470, 1941. An!'lelmino, K. J., and Hoffmann, F.: Ztschr. f. Geburtsch u. Gyniik. 114: 61, 1936. Rflkoff, A. E.: AM. J. OnsT. & GYNEC. 38: 371, 1939. 'V'hite, E. P., Titus, R. S., Joslin, E. P., and Hunt, H.: AM. J. OBST. & GYNEC. 198: 482, 1939. Taylor, H. C., Jr., and Scadron, E. N.: AM. J. OBST. & GYNEC. 37: 963, 1939. Masugi, M.: Japan Path. Soc. 21: 329, 1931. Masugi, M.: Beitr. Path. Anat. u. Allg. Path. 92: 429, 1933-34. Smadel, J. ~.: J. Exper. Med. 64: 921, 1936. Smadel, J. E.: J. Exper. Med. 65: 541, 1()::!7. Smadel, J. E., and Farr, L. E.: J. Exper. Med. 65: 527, 1937. Dobrowlski, M. S.: Bull., Int. Sc. Cra<'ovie 5: 256, Hl03. Seegal, B. C., and Loeb, E. N.: Proc. Soc. Exper. Biol. & Med. 45: 248, 1940. Wong, A., and Pillot: Chinese M. J. 46: 115!1, 1932. Hofbauer, J.: West. J. Surg. 49: 615, 1941.