During the 3 year period 1970–1972 a total of 554 patients were notified for the first time as having bacillary or abacillary pulmonary tuberculosis in the Municipality of Copenhagen; 99 per cent of these patients were typed according to the ABO and rhesus system.
The bacillary patients showed an excess of group O and AB and a deficit of A and B as compared to the general population. The deviations were statistically highly significant for group O and A. The distribution according to the rhesus system did not deviate from the expected pattern. The ABO and rhesus distribution of the abacillary patients did not differ significantly from the expected pattern.
During a follow-up period of 2–5 years after the initial diagnosis 104 bacillary patients died; the ABO pattern among the survivors was now closer to the normal; this resulted from a high number of deaths from tuberculosis among patients of group O and a low number among those belonging to group A. More rhesus negative patients died from tuberculosis than rhesus positive.
It is concluded that a study of the ABO and rhesus pattern among tuberculosis patients becomes biased if a break-down by bacteriological findings and history is not made. It is also important that the study covers all patients who contract tuberculosis within a certain period, as the longevity of the patients is apparently to some extent dependent on their blood group.