Treatment of Pulmonary Sarcoidosis

In an editorial entitled "PI Blood Group, Pigeon Antigens, and Respiratory Disease" in the December 1976 issue (Chest 70:694, 1976), I suggested that individuals without the P, antigen (P, blood phenotype) may have a greater risk of respiratory disease and that this hypothesis should be tested among individuals selected for respiratory disease, rather than for handling of birds. In their reply to that editorial, Radermecker and Bruwier have tried to test this hypothesis by studying pigeon breeders who (unlike the previous study by Radermecker et all) were not selected for respiratory disease. The results of the present study by Radermecker and Bruwier indicate that 18 percent (ten) of 56 PInegative pigeon breeders had anti-P, antibody and that the proportion with precipitins to pigeon serum was nearly identical in PI-positive ( 13 percent [27/2121) and in PI-negative (16 percent [9/56]) individuals. Furthermore, Radermecker and Bruwier observed that pulmonary disease was equally reported among PI-psitive and PI-negative individuals. These investigators concluded that the Pl blood phenotype does not play a role in the occurrence of respiratory complaints among pigeon breeders. It is of interest to note that the newly reported data, which are based on unselected pigeon breeders, are in disagreement with the original data of Radermecker et al,, which were biased toward sigdcant pulmonary disease (since the breeders studied were ascertained through a respiratory disease clinic1). Although the incidence of PI-negative breeders was essentially identical in the original series (23 percent)' and in the new unselected series (21 percent [56/2681), the incidences of anti-P, antibody and of precipitins to pigeon serum are significantly lower among pigeon breeders in the unselected series, when compared to the original series1 (anti-P, antibody, xZ [Yates] = 2.74 and P < 0.05 [onetailed] precipitins, x2 [Yates] = 5.43 and P < 0.01 [onetailed]). The decreased incidence of antibodies to the P, antigen and pigeon serum among the breeders in the unselected series suggests a lesser degree of immunization and less respiratory exposure to antigen in the newly studied group. In addition, although the individuals studied were questioned with regard to respiratory disease, it was not reported if any had respiratory complaints sufficiently severe to require attendance at a respiratory disease clinic. Thus, although Radermecker and Bruwier have found an equal incidence of "respiratory disease" among PI-positive and PI-negative individuals in the present series, it is not clear whether there is a difference in the degree of seuerity between the breeders in the unselected series and the original one.' The current study of Radexmecker and Bmwier does not direct itself to the question raised originally in my editorial, which is the possible relationship between the PInegative phenotype and significant respiratory disease, but rather asks the following questions: (1) are unselected pigeon breeders as immunized as those selected for respiratory disease; and (2) does the PI blood