Genetic characteristics of the HeLa cell.

The genotype of the patient Henrietta Lacks from whose cervical carcinoma the HeLa cell was derived was deduced from the phenotypes of her husband and children, and from studies of the HeLa cell. Hemizygous expression of glucose-6-phosphate dehydrogenase in HeLa, together with the deduced heterozygosity of Mrs. Lacks, is consistent with clonal origin of her neoplasm.

Characterization of HLA class I specific antibodies by ELISA using solubilized antigen targets: I. Evaluation of the GTI QuikID assay and analysis of antibody patterns.

The development of solid phase immunoassays using solubilized HLA molecules as targets has provided a means of detecting HLA-specific antibodies that overcomes many of the shortcomings of lymphocyte based assays. We have evaluated a commercially available assay, the GTI QuikID (QID), that uses solubilized class I molecules from 40 subjects selected for their HLA phenotype, to characterize HLA-specific antibodies. We tested 595 sera from 319 subjects and compared the results obtained with QID to those obtained with cytotoxicity (CYT) and with GTI QuikScreen (QS) as well as to historic data. The correlation of QID with CYT (r = 0.54) was comparable to that between QID and QS (r = 0.60). The majority of disparities between QS and QID were apparent false negatives with QID that could be overcome by analyzing QID data at lower cutoff values. In contrast, most of the disparities between QID and CYT were false negatives in CYT due to the relatively low sensitivity of that assay. As expected, the ELISA was more sensitive (97%) than CYT (78%) but had a somewhat lower specificity (87% vs. 92%) due, most likely, to selection of sera that excluded most sera that were known to be nonspecific by CYT. Determination of antibody specificity could be achieved quickly by manual analysis of the QID data because of the way the data are presented by the manufacturer's software. Interestingly, the frequencies of different antibodies detected by ELISA differed from those detected by CYT with ELISA identifying more sera containing antibodies to both A and B locus antigens.

Characterization of HLA class I specific antibodies by ELISA using solubilized antigen targets: II. Clinical relevance.

Until recently, the nature of humoral sensitization to HLA has been characterized by data from lymphocyte-based assays, predominantly cytotoxicity tests. We have examined the characteristics, determined by enzyme-linked immunosorbent assay (ELISA), of sera from 191 subjects known to have produced HLA-specific antibody. We found that ELISA detected higher frequencies compared with cytotoxicity of many (74.5%), but not all, HLA-specific antibodies; in many cases (42.6%) the frequencies of these antibodies were higher than predicted from population frequencies whereas some antibodies (23.4%) occurred with lower than expected frequencies. Some of the increase in frequencies can be accounted for by crossreactivity, i.e., sensitization to epitopes shared among two or more allelic products. The presence of epitopes shared between a recipient's antigen and a mismatched antigen in a donor also tended to narrow the specificity of antibody produced. However the data also indicate differences in immunogenicity among different antigens suggesting that crossreactive group matching would be beneficial in some but not all cases. Finally, we present case studies to illustrate the value of ELISA in predicting humoral rejection episodes and in monitoring the efficacy of rejection therapies.

Inheritance of mixed cryoglobulinemia.

This paper describes a family in which 10 members of 3 generations have IgM-IgG cryoglobulinemia. Their pedigree is characteristic of autosomal dominant inheritance. No underlying disease that could account for the cryoglobulinemia has been identified in any patient, and no linkage of the cryoglobulinemia to HLA-A and -B locus haplotypes, blood group antigens, or immunoglobulin Gm allotypes has been detected. The rheumatoid factors of this kindred react with some, but not all, human IgG; however, their rheumatoid factors are not antibodies to any known human Gm or Km allotype. This family demonstrates that "essential" mixed cryoglobulinemia can be inherited, and that the clinical manifestations of an inherited cryoglobulinemia may vary among family members.