Abstract
Serum protein electrophoresis is routinely used to identify pathologies involving dysproteinemia. The electropherogram mainly represents the most abundant serum proteins, one of which is the polymorphic haptoglobin (Hpt), characterized by a molecular heterogeneity with three major phenotypes (Hpt 1β1, 2β1, and 2β2). To improve the interpretation of electropherogram and possibly to extend its applicability, we aimed to explore the relationship between Hpt phenotypes (determined by immunoblotting) and protein profiles. Serum samples were separated by CZE with PROTEIN 6 and highβresolution methods. The PROTEIN 6 analysis showed significant associations between Ξ±2 zone profiles and Hpt phenotypes (chiβsquare=154.06, p<0.0001). The highβresolution method indicated significant differences between Hpt 2β2 and Hpt 1β1 peak mobilities, evidenced by receiver operating characteristic analysis, (area under the receiver operating characteristic curve=0.98, p<0.0001, standard error=0.01346, likelihood ratios=21.39), with 98.7% sensitivity, and 95.4% specificity. However, the structural heterogeneity of Hpt 2β1 made it difficult to relate with a particular profile. Thus, we developed an alternative approach that excluded the Hpt 1β1 or Hpt 2β2 phenotypes. This may prove to be a useful technique in clinical applications considering the involvement of Hpt 2β2 or Hpt 1β1 in various pathologies.