Large numbers of papers have been published on the relationship of different diseases and human blood-groups. Comparing blood-group distribution of a great number of patients suffering from acute leukaemia (AL) to that of control persons, no significant differences could be detected (Shirley & Desai, 1965; Vogel & Helmbold, 1972; Harris et al, 1977).We found blood-group 0 frequency surprisingly high among female patients with AL treated in our clinic between 1974 and 1980. Therefore blood-group distribution of patients related to sex was studied. Data of 45 female and 69 male patients are summarized in Table 1. Women suffering from AL have significantly more blood-group 0 than men (51 % and 22%, respectively; x2 = 11.1 1, significant difference). Blood-group A occurred more often (46%) in men with AL than in women (33%). When comparing different types of AL-though our case-number is rather limited-it could be pointed out that blood-group 0 was in highest frequency in women with acute lymphoid leukaemia (62%), while it was less often present in men with acute myeloid leukaemia (21%).These results were compared to blood-group frequency in Hungary. Blood-group 0 occurs in 30-32% of the whole Hungarian population without considerable differences among the different regions (Rex-Kiss & Szabit, 1979). There was no difference when a comparison was made between blood-group distribution of patients with AL and that of a healthy population. However, in group 0 a sex-linked difference was evident. A similar difference in blood-group frequency of a healthy population seems to be rather improbable and no data supporting it are available in the literature.The probable importance of sex differences in blood-group distribution of patients with AL has not been emphasized yet. However, studying retrospectively Mustacchi's earlier report (1960) on 570 patients with AL a similar distribution could be detected. 41 % ofpatients Changes in blood-group characteristics of patients with AL in the course ofdisease are well known but it cannot be used for explaining sex differences in blood-group distribution.

The case of a 52-year-old woman with congenital cyclo-oxygenase deficiency, signs of generalized atherosclerosis and a moderate bleeding tendency is reported. Secondary platelet aggregation was absent. Platelet aggregation induced by arachidonic acid failed totally while that induced by calcium ionophore was normal. No malondialdehyde formation could be detected in her platelet-rich-plasma. The life-long deficiency of cyclo-oxygenase had not protected her from progressive vascular disease. This case suggests that the chronic intake of large doses of aspirin cannot prevent arterial disorders.

A 52-year old woman with congenital cyclooxygenase deficiency who had moderate bleeding tendency and severe generalized arteriosclerosis is reported.Diagnosis based on the following data: secondary platelet aggregation induced by adrenaline, ADP, ristomycin, collagen, thrombin was absent; platelet completely failed to aggregate by arachidonic acid while aggregation induced by calcium ionophore A23187 was normal; no malondialdehyde formation could be detected in the platelet rich plasma /PRP/ in four different times /for exclu- sing any drug effects/. The abnormal adrenaline and ADP induced aggregation were not corrected when patient’s PRP was mixed in equal proportions with that of a normal subject ingesting aspirin.Although our patient had been free from severe thrombotic episodes, expressed signs of generalized arteriosclerosis could be detected.Until now only five cases of congenital deficiency of cyclo-oxygenase have been described /Malmsten et al., Weiss and Lages, Lagarde et al., Pareti et al./. However, in these patients no signs of arterial vascular diseases were mentioned.The special importance of this new case comes from the fact that life-long deficiency of cyclooxygenase enzyme could not protect from progressive vascular disease which might prove again that chronic intake of large doses of aspirin cannot prevent arterial disorder.