Volume 63 Number 4 part 2
These questions cannot really, be answered without a long and costly period of observation and follow-up of treated and control infants. DR. CLARK D. WEST, The Children's Hospital Research Foundation, Elland and Bethesda Avenues, Cincinnati, Ohio. The effect of exchanges done with 1 unit of fresh blood collected in a plastic bag on tolerance to tissues of the donor of the blood was demonstrated several years ago by Drs. Robert Fowler and William Schubert (Ann. New York Acad. Sc. 87: 403, 1960). They found that skin grafts from the blood donors were accepted for a much longer period by an infant whose blood is exchanged in this way than by control infants with exchanged blood which has been stored for 48 hours or more and kept in glass containers. The tolerance to donor antigen was not complete in that the grafts on the infants with fresh exchanged blood were rejected after periods of 68 to 150 days. These experiments were done not only to determine whether tolerance could be produced in infants, but also to assess the potential hazard of transfusing infants with very fresh blood stored in plastic bags in the production of runt disease as is seen in tolerant mice. In the infants studied, however, there was no sign of a disease resembling runt disease. One of the infants died at the age of 3 months of a typical cot death syndrome but prior to this had been a perfectly normal child.
10. A pair oJ blood chimeric twins with X X / X Y blood mosaicism Bruce C h o w n , M a r i o n Lewis, ~ J. M . Bowman, ~ Hsi-Chang Wang,* and Irene A. Uehida, ~ Rh Laboratory and Department of Paediatrics, U n i v e r s i t y of M a n i t o b a , a n d the D e p a r t m e n t of Medical Genetics, Clinical Investigation a n d Research U n i t , Children's Hospital, Winnipeg, M a n i t o b a , Canada. In the course of a study delineating the frequency of antenatal cross-transfusion in monozygotic twins, with dizygotic twins used as controls, a pair of dizygotic twins were found who were blood group chimeras. Both the boy, genetically group A, and the girl, genetically group O, had 85 per cent O and 15 per cent A erythrocytes in their circulations; 9.7 per cent of the boy's and 7.0 per cent of the girl's neutrophils displayed "female drumsticks." Of leuko-
cytes grown from the peripheral blood, 70 per cent were XX and 30 per cent XY in the boy, 78 per cent XX and 22 per cent XY in the girl. The placentas were fused with a double chorion. Sections were taken through the area of fusion before the chimerlsm was discovered, making it impossible to prove or disprove vascular communications between the placentas. This is the fourth reported instance of blood group "chimeras" in human beings and the first reported in a newborn pair. DISCUSSION DR. RICHARD L. DAY, 125 De Soto Street, Pittsburgh, Pa. I want to describe two patients, two newborn infants, who had double blood groups. The work on these was done by Dr. Marjorie Gray of the Central Blood Bank of Pittsburgh, and what I have to say is entirely based on what she has told me. Neither of these was a twin, though in one there was a strong family history of twinning. One was a Negro and one was white. Both were males. One baby was jaundiced at birth and required an exchange transfusion, and this is how the blood group abnormality was uncovered. This baby had 25 per cent A cells and 75 per cent O ~ o r perhaps better described as "not A" cells. The mother was blood group B, so that a maternal-fetal transfusion was excluded. This baby has not been studied further because the donor cells are still circulating, and obscuring the tests. His chromosome studies are pending. The placenta was examined in the routine manner only and then destroyed, but no evidence of a blightetl twin was noted. In the case of the other patient, also newborn, there was no jaundice, no twinning, and in this instance the placenta was inspected with great care. This baby also had 25 per cent A cells and 75 per cent "not A" cells. He, like the other patient, secreted H substance, and now at 1 month of age the number of "not A" cells has declined from 75 per cent to 10 per cent. The two cell populations in each instance were identical to each other in a number of other blood typing characteristics. In trying to hypothesize as to what might have happened here one comes up against difficulties. It hardly seems likely they were true chimeras. One wonders if there might have been a blighted twin who was reabsorbed.
American Pediatric Society
Another possibility is that the acquisition of the A characteristic does not always occur in all clones of cells, and perhaps the population of cells at birth represented some old cells which were O and some more recently made cells which were A. This hypothesis would fit with the fact that parallel with the decline in the proportion of cells which were of the O type the baby became anemic to the extent of a fall in hemoglobin of from 18 to 9 Gm. I simply present these two cases as representing an interesting additional variant not as yet understood and by no means as yet completely studied. DR. BOWMAN.~* Thank you, Dr. Day. I think those are interesting comments, but certainly if there were no other blood group differences one would wonder if this finding was not due to an incomplete expression of A in what are genetically A cells where actually the babies are entirely Group A. DR. HULDA 1~. TI-IELANDER, 3641 California Street, San Francisco, Calif. In our Child Development Center we have some 30 sets of dizygotic twins with one twin of each set retarded or defective. This aroused our interest in the possibility of chimerism playing a role in the development of twins. So far we have tested six of the sets but have not found any case of chimerism. I still think this should be pursued further as a possible cause for the retardation of certain twins. DR. BOWMAN. I cannot very well answer that, but of course there are extensive studies being carried out. We are studying all dizygotic twins we see, including more prompt and more complete examination of their placentas. T w o studies have been reported, one of 100 sets of dizygotic twins, and another of 70 sets, where no blood chimerism could be discovered. There may be a tremendous discrepancy in the red cell ratios, and certainly in some bovine chimeras one red cell population may be very difficult or impossible to discover by routine methods. We have one other set of twins in whom we thought there might be chimerism. We sent blood off to some colleagues in the East, who by the use of fluorescent antibody felt that roughly one red cell in a thousand was Group B. Since the mother was not Group B and they are dizygotic twins, we are not sure just what to make of this at the present time.
~*Rh Laboratory and Department of Paediatrlcs, University of Manitoba, Winnipeg, Manitoba, Canada.
One means of possibly narrowing the search, of course, is the fact that, if you have a chimera of a group O - G r o u p A setup, whether or not the baby appears to be Group O entirely, if there are any Group A or B cells, the individual will be missing the corresponding isohemagglutinin. DR. FREDERICKHECHT, Department of Medical Genetics, University of Washington Medical Center, Seattle, Wash. Is not this the first direct demonstration of exchange of leukocytes between chimeric twins? DR. BOWMAN. No, that is not entirely true. The second set of blood-chimeric twins, which was described in 1957, on whom reciprocal skin grafts were done by Woodruff, also had their leukocytes searched for drumsticks. They had the typical X X - X Y mixture. So this is the second set on w h o m cultures were carried out. DR. HECHT. My second thought is about freemartins. When cattle twins are of unlike sex, the male is born a normal bull, but the female is born a sterile freemartin. The placentas of cattle twins have vascular anastomoses which permit the twins to exchange blood cells. Owens (Owens, R. D.: Immunogenetic consequences of vascular anastomoses between bovine twins, Science 102: 400, 1945) demonstrated their red cell chimerism. W a x m a n and Gartler thought that perhaps the freemartin's sterility was due to gonadal mosaicism. They biopsied the freemartin's and the male twin's gonads and in cell culture found only normal X X 'cells in the female and normal X Y cells in the male. They found no evidence for gonadal mosaicism in the freemartin. Third, what would your ideas be as to why the female leukocytes seem to have won out here over the male? I notice that both of the twins you have studied seem to have come up with around 80 per cent female cells and only about 20 per cent male cells. DR. BOWMAN. They both also have 80 per cent of the female red cells; I guess it is just another example of the relative strength of the weaker sex. I have no other explanation. DR. MELVIN M. GRUMBACIG Babies Hospital, 3975 Broadway, New York, N. Y. I have been fascinated by Dr. Bowman's very fine study, and in addition to hematopoietic transplants which were exhibited here I would like to ask the question that Dr. Hecht raised about the possibility of implantation of primordial germ cells in the opposite sex's gonads.
Volume 63 Number 4 part 2
The explanation of the freemartin has been that the male morphogenetic substance is transmitted to modify the female gonad. However, Dr. Ohno has obtained some evidence, which appears to be contrary to that of the Seattle group, that in the bovine freemartin gonad there can be two populations of cells, XX and XY. Now, the XX cells were found in primordia that appeared to resemble testicular tissue. Some day, perhaps fifteen years from now, I hope that you will be able to come back and report on these twins and to tell us from studying testicular squash preparations whether in the germ cells of the male twin there are any XX cells. This is quite possible, because current thinking suggests that the primordial germ cells themselves do not determine whether they are going to turn into oogonia or spermatogonia. DR. BOWMAN. I think those are very interesting comments. Was this from the freemartin, that is, from the female twin, that these studies were done? DR. GRUMBACIt.Yes, this was from the female, but you have an opportunity here to study the male. I think studying the germ cells of the female is a bit more difficult. The thought is that these cells migrate through the dorsal mesentery, but in the freemartin they apparently can get into the blood stream, so that in the trip from the yolk sac endoderm through the dorsal mesentery some of them may also find their way into the blood vessels. DR. BOWMAN. We would be loath to do testicular biopsies in a clinically normal male. I wonder if Dr. Grumbach would be able to wait until these youngsters are about 20 years old, so that we might have rather indirect evidence that they are normal? DR. NEMAT HESiIEM, 5-E1-Goum Nourry A Street, Cairo, Egypt. Currently we are engaged in some in vitro culture studies involving the mixing of different proportions of human leukocytes from males and females. Astonishingly enough, we find that when we start with equal numbers of male and female leukocytes, we usually end with an overwhelming preponderance of the XX pattern over the XY pattern, when we examine the metaphases after culture. I wonder how this would apply to the chimeras which have been described, which occur in the developing organism? DR. BOWMAN. I haven't any comments except that again there must be something in the female that overpowers the male!
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11. Pancreatic insui~ciency and bone marrow dys[unction: A new clinical
entity H a r r y S h w a c h m a n , M.D., Louis K. Diam o n d , M.D., F r a n k A. Oski, M.D.,* a n d K o n - T a i k K h a w , M.D.,* D e p a r t m e n t of Pediatrics, H a r v a r d Medical School, a n d Children's Hospital Medical Center, Boston, Mass. A previously unreported syndrome consisting of pancreatic insufficiency, failure to thrive, neutr0penia, and galactosuria has been observed in 5 children, 2 of whom were siblings. These children, except in the last case, were at first suspected of cystic fibrosis, but the lack of pulmonary involvement and repeated normal sweat tests excluded this disease. I n addition, the parents as well as all siblings were found to have normal sweat electrolytes. Pancreatic insufficiency was demonstrated in each patient. The duodenal fluid showed no activity for trypsin, lipase, or amylase, but the viscosity of the duodenal fluid was normal. The patients, 2 females and 3 males, at present range in age from 7 mo.nths to 9 years. The disease first manifested itself between 2 and 10 months of life by diarrhea and failure to gain weight. Pancreatic achylia was demonstrated as early as 3 months and has persisted to the age of 9 years in the oldest patient. Leukopenia has been a constant hematologic manifestation and was noted to be present on the first day of life in one patient. Bone marrow examinations reveal hypoplasia of all elements in varying degrees, with the oldest children showing the most marked changes. Two of the 5 patients have thrombocytopenia and one patient has mild anemia. Fetal hemoglobin elevations have been found in all 4 patients tested. Serum iron, folic acid, and BI2 levels are normal. Galactose has been present in the urine in trace amounts. Erythrocyte uridine diphosphate galactose transferase levels are normal. Galactose tolerance tests on 2 patients also were normal. All 5 patients have been shown to have normal intestinal absorption of glucose and none demonstrates steatorrhea despite the absence of pancreatic lipase. Duodenal mucosal biopsies have revealed normal histologic patterns in the 3 patients examined.