Elizabeth W. Ikin

A Study of Two Unusual Blood-group Antigens in West Africans

In 1948 an investigation of the blood groups of Nigerian populations was begun and full ABO, MNS, and Rh genotype studies of some 550 Nigerians have been completed (Chalmers, Ikin, and Mourant, 1953). Early in this work two samples of blood-one from an Efik (Calabar) man and one from a native of the Cameroons -were found to be unusual. Both bloods were agglutinated by all available anti-N sera, but were agglutinated only by one out of several anti-M sera with which they were tested. This finding was briefly described by Ikin and Mourant (1951), who suggested that the antigen concerned might be identical with one described by Landsteiner, Strutton, and Chase (1934) as occurring in some American negroes.

Rare Blood Group Antigen in Negroes

here presented and of the brief follow-up period, which is measured only in months: this must be left for a later occasion. It is, however, permissible to report the immediate post-convalescence progress of these patients. Twelve out of the thirteen are on a full diet; of these, ten will admit to no symptoms, even under pressure of direct questioning; two say that there is an occasional sense of fullness after having eaten a full meal; and the last patient, who has barely finished her convalescence, complains of periodic nausea, but says that this is improving. Freedom from pain is complete and all the patients are enjoying their food. Those who had lost weight before the operation, and who have been followed up for at least three months, have recorded steady gains in weight. No suspicion of a dumping syndrome has been noted, and thf constant presence of bile in the stomach has producedno ill effect. The likelihood of anastomotic ulcer seems remote in this type of operation, where the whole of the alkaline pancreatic and biliary secretions are transferred to the stomach. Post-operative test meals have been carried out, and all show a reduction to normal levels of acidity or to complete achlorhydria. As a routine, samples of gastric juice are now aspirated at hourly intervals over a period of 24 hours while the patient is on a full hospital diet; this would seem to be a better way of getting a true picture of the changing acidity of the stomach. While the operation described is still in the experimental stage, its initial success warrants an extensive trial. No surgeon would wish to remove the stomach in the treatment of peptic ulcer if such a drastic step could be averted. The avoidance of resection may lie along the lines suggested in this preliminary report.

A Rabbit Serum Containing a Specific Agglutinin for the Red Cells of the Newborn

We have for some time, in collaboration with Dr. P. W. Hutton, of Mulago Hospital, Kampala, Uganda, been attempting to repeat the experiments of Schneider and Levin (1950) in which they obtained rabbit antisera giving specific agglutination of the erythrocytes of sicklecell anaemia patients. These particular experiments have, so far, been inconclusive, but in view of the definite results reported below, which we have now obtained by the injection of foetal erythrocytes into rabbits, we hope to continue our investigation of the response to the injection of sickle-cell anaemia erythrocytes. An outstanding finding reported by Schneider and Levin was that their antisera agglutinated the red cells of sickle-cell anaemia patients but not of sickle-cell trait carriers. One of the differences between these two is the presence in the former, but not in the latter, of an alkali-resistant haemoglobin, thought to be foetal haemo-

Second Example of the "Duffy" Antibody.

Discussion These cases present interesting features both clinically and pathologically. Laparotomy was essential in order to make a diagnosis, and easily removable tumours were found, but in both cases blood pressure fell sharply afterwards, suggestive of suprarenal shock, and it seems probable that this feature was in part, if not entirely, the cause of death. It is therefore important to consider the possibility of a cortical suprarenal neoplasm when a very large encapsulated retroperitoneal tumour is found which is causing no symptoms referable to the organ of origin; for it seems likely that if the diagnosis were made early enough hormonal replacement therapy might prevent post-operative collapse. It is therefore particularly valuable to note that the naked-eye appearances in my two cases and in the case described by Anderson et al. (1943) were exactly similar. Walters and Kepler (1938) pointed out that probably the most important single feature in the surgical treatment of cortical adrenal tumours was the control of post-operative shock. Cecil (1933) stated that 39% of patients operated on died of shock. It may be added in this connexion that Cahill et al. considered that post-operative shock occurred only in those cases in which, as a result of the tumour, a syndrome of Cushings type was present and hormonal excess was affecting metabolic functions such as salt-and-water balance and capillary permeability. They further state that, in their series, cases without clinical hormonal upsets were never associated with post-operative collapse. This view cannot be confirmed from the present cases. From the pathological point of view the gross and the microscopical structure of these tumours provokes discussion whether they are benign or malignant. Features in favour of their benignity are the presence of the wellformed capsule and the absence of evidence of metastases, although it must be admitted that it was not possible to perform necropsies. The absence of demonstrable mitoses and the close resemblance of the tumour cells to those of the normal adrenal seem to point to a non-malignant origin, although it may be repeated that numbers of metastasizing tumours with complete differentiation of cell type have been described. It is somehow difficult to reconcile such very large masses showing so much necrosis and haemorrhage with benign growths. Another feature suggestive of malignancy is the association of tumour cells with the vessel walls, and in many cases the presence of strands of cells lying free in blood spaces. The marked tendency towards thrombosis in the vessels is more commonly seen in malignant than in benign tumours. Examples in the literature of large cortical adrenal tumours are rare. Among the largest is the case recorded by Holmes (1925) in which a tumour weighing 1,025 g. (2 lb. 4 oz.) and measuring 17 by 14 by 9.5 cm. was found to be of benign type, and that of Anderson et al. (1943), who described a malignant cortical tumour weighing 1,780 g. (3 lb. 14 oz.) in which a solitary metastasis was found in the liver. The latter case is of interest, as the appearance of the tumour was identical with those described above, although a relatively anaplastic histological nattern was recorded. It may again be stressed that histologically benign tumours merge imperceptibly into the malignant varieties, and in the absence of demonstrable metastases opinions might well differ about their correct interpretation. It might be argued that haemorrhage into a simple adenoma is the more correct view in the above cases, but it is my opinion, based on the reasons already given, that these are examples of slowly advancing malignant tumours.

Agglutinin Anti-S in Human Serum

The antibody anti-S was first discovered by Walsh and Montgomery (1947) in the serum of a puerperal patient whose fifth pregnancy had resulted in the birth of a macerated and oedematous foetus. Her second child had died of haemolytic disease of the newborn; the third and fourth pregnancies had ended in early miscarriages. Her serum was found to contain anti-D together with an unidentified antibody which agglutinated the red cells of 48.6% out of a total of 253 Australian individuals chosen at random. The agglutinin reacted most strongly at 370 C., but was also active at lower temperatures. It did not sensitize cells to the Coombs test. The corresponding antigen S was shown by Sanger and Race (1947) to be very closely related to the MN blood group system, in a manner similar to the relation between the C, D, and E antigens of the Rh system. The simplest explanation of the experimental results is that two genes, S and s, exist and that either one or the other is always very closely linked to each M and N gene, thus giving rise to four possible chromosome arrangements-MS, Ms, NS, or Ns. Each individual has, of course, two such chromosomes, and these would therefore give rise to 10 possible genotypes or combinations of two chromosomes as shown in the accompanying Table. The red blood cells of any person possessing

Blood Groups and Enzymes of Human Red Cells after Two Years' Storage in Liquid Nitrogen

Bader, S. (1959) J. blophys. biochem. Cytol.. 5, 217. Joneja, M. G., aqd Stich, H. F. (1963). Exp. Cell Res., 31, 220. Mendelsohn, M. L. (1958). J. Biophys. biochem. Cytol., 4, 415. Patau, K. (1952). Chromosoma (Berl.), 5, 341. Richards, B. M., and Atkin, N. B. (1959). Brit. J. Cancer, 13, 788. Stich, H. F. (1960). J. nat. Cancer Inst., 24, 1283. (1962). Fourth Canadian Cancer Conference, 4, 99. Florian, S. F., and Emson, H. E. (1960). J. nat. Cancer Inst., 24, 471. and Steele, H. D. (1962). Ibid., 28, 1207.