Sources of interindividual variation in the quantitative levels of apolipoprotein B in pedigrees ascertained through a lipid clinic.

The quantitative level of apolipoprotein (apo) B associated with low-density lipoprotein (LDL) varies among individuals within the population. This variation in level of the LDL receptor ligand appears to have predictive value, and may have an etiologic role, in coronary artery disease. Complex segregation analysis was used to compare eight different models of transmission.

Failure to detect association of isolated cleft palate with HLA antigens.

HLA antigen frequencies have been determined in 282 controls and in 33 individuals with isolated cleft palate or the related birth defect velopharyngeal incompetence. No association of particular HLA antigens with this birth defect was found. A previously reported association of HLA A2 with cleft palate, in males, was not confirmed.

HLA antigens, phytohemagglutinin stimulation, and corticosteroid response.

Although it is clear that the major histocompatibility complex is associated with lymphocyte glucocorticoid sensitivity in mice, there has been less evidence for a similar relationship in man. We have typed 158 individuals for: (1) 13 A locus and 16 B locus antigens, (2) degree of stimulation of their purified lymphocytes by phytohemagglutinin A (PHA), and (3) degree of inhibition of the PHA stimulation by prednisolone and prednisolone-21-hemisuccinate. In contrasts of individuals with a particular antigen (homozygous or heterozygous) with all remaining individuals, HLA-B7 was found to be associated with an enhancing effect on the log stimulation by PHA while other antigens of these series did not have significant associations.

HLA-B18 is associated with decreased levels of isoproterenol-stimulated cAMP in lymphocytes.

One hundred fifty-nine individuals were typed for HLA-A and B antigens and levels of isoproterenol-stimulated, lymphocyte cAMP. No significant age, sex, or caffeine effects on the natural log of the lymphocyte cAMP variable (ln cAMP) were found. A comparison of mean ln cAMP levels between individuals who carried a particular antigen (homozygous or heterozygous) and individuals who did not carry the antigen identified a highly significant decrease in ln cAMP levels associated with the HLA-B18 antigen.