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The validity of the Hardy-Weinberg equilibrium for Pi phenotypes was tested in a population of 1,653 randomly selected, healthy blood donors in Lyon, France. A significant departure from the equilibrium was found, with an excess of FF and SS homozygotes and a deficiency of FM heterozygotes.

Alpha-1-antitrypsin Pi phenotyping was performed by thin-layer isoelectric focusing on samples from 1653 healthy white blood donors. The variants were confirmed by the acid-starch gel technique and crossed immunoelectrophoresis, with complete agreement between the two methods. The allele frequencies in this population were PiM, 0.9019; PiS, 0.0713;PiZ,0.0142; PiI, 0.0036; PiF, 0.0036; PiV, 0.0024. In addition, some rare phenotypes (MX, IS, LM) were noted. No difference was noted in the distribution of the variant alleles between males and females. The significance of the high frequency of the S allele is related to the ethnic origin of this population. The agreement of the results obtained by our technique and by acid-starch gel electrophoresis confirms the validity of Pi determination by thin-layer isoelectric focusing.

(1951). Les Hormones Cortico-Surrenales Et Le Metabolisme Des Glucides Par. Acta Clinica Belgica: Vol. 6, No. 5-6, pp. 717-771.

We evaluated nephelometers from Behring, Hyland, and Beckman for IgG, IgA, and IgM quantitation in sera from patients with monoclonal gammopathies. The intra-batch precision of each instrument for each immunoglobulin class and for different concentrations of the same immunoglobulin was compared to the one obtained with the radial immunodiffusion method. No nephelometer showed a clearly better precision. The correlation with cellulose acetate electrophoresis was good for each of the three nephelometers. The mean value by the radial immunodiffusion method was higher than corresponding determinations by nephelometry.

A patient (Mia) with a monoclonal IgM(kappa) cryoglobulin (cryo IgM) developed additional heavy chain disease proteins of the gamma3 subclass 8 years later. Biochemical studies of the cryo IgM indicated that the heavy chain was VHI, but the NH2-terminal amino acid sequence of the light chain did not permit a definite assignment of its Vkappa subgroup. Two major fragments of the gamma3 chain were distinguishable by electrophoresis in sodium dodecyl sulfate polyacrylamide gel. The smaller component (designated Mia F) had a molecular weight of approximately 30 000 and the larger component (designated Mia S) 35 000. Both fragments had G3m(21) and G3m(27) allotypic determinants. These data and the NH2-terminal amino acid sequence of the gamma chain fragments suggested that Mia S consists of the major part of the gamma3 hinge region plus the CH2 and CH3 domains of the gamma3 chain, whereas Mia F may be derived from the former as a result of postsynthetic cleavage. The partial amino acid sequence of the Mia S fragment is homologous to the hinge region amino acid sequence of human gamma3 chains reported in the literature, with only one amino acid difference out of the 11 residues compared. This difference may represent an allotypic difference within the gamma3 subclass. Alternatively, the production of Mia S may have resulted from the accidental derepression of a "silent" constant region gene not expressed in normal individuals.

SUMMARY An analytical technique, using thin-layer-gel electrofocusing in polyacrylamide gel, has been applied to the study of plasma α 1 -AT polymorphism (Pi system). With pH ranging from 4.5 to 5.5, we obtained at least eight bands which belong to the α 1 -AT system, as confirmed by crossed immunoelectrophoresis of these bands with a specific antiserum. As with classical acid starch-gel electrophoresis, we easily differentiate the fast, slow, and Z-migration bands, which arrangement gives the normal and deficient phenotypes. Moreover, we can also identify some rare phenotypes. This method is highly reproducible and gives a better resolution than previously described procedures. Furthermore, it proves that the observed multibanding, which allows the determination of Pi phenotypes, is closely related to the heterogeneity of α 1 -AT with respect to isoelectric pH.