Evaluation of a nephelometric assay for haptoglobin and its clinical usefulness.

Abstract

Serum haptoglobin has been advocated as an indicator of intravascular hemolysis. We have evaluated a nephelometric determination of serum haptoglobin. The assay is sensitive and exhibits within-run precision in the range of 2.5-7.4% coefficient of variation (CV) and between-run precision of 7.0% (CV). In addition, when haptoglobin values determined with the nephelometric assay were compared with hemoglobin-binding capacity determined by electrophoresis, the correlation coefficient was 0.968. The assay is essentially independent of phenotype and free of significant interference by hemolysis. The clinical correlation of haptoglobin values obtained for 100 selected patients with the nephelometric technique correlated well, if less than 250 mg/L, with the presence of hemolytic disease.

Haptoglobin testing in hemolysis: Measurement and interpretation

“…Nephelometry, however, does require having a nephelometer as well as specific reagents. Nephelometry is more accurate than spectrophotometry but, as with all immunoreactive methods, antisera against all phenotypes are required . There is some evidence that measurement of haptoglobin using turbidimetry may be as reliable .…”

“…In our laboratory, we use a gel electrophoresis method modified from Ali et al, which has been validated against immunological and spectrophotometric methods . Free hemoglobin, haptoglobin‐hemoglobin complexes, hemopexin‐heme complexes, and methemalbumin are separated by alkaline electrophoresis.…”

Die Qualität diagnostischer Proben

“…Die Messung der Verminderung der Konzentration des Haptoglobins erlaubt eine Aussage u Èber eine abgelaufene Ha Èmolyse (Ausnahmen sind angeborene Haptoglobindefizite und Neugeborene [41]). Auch die Messung von Ha Èmopexin und/oder Metha Èmoglobin/Albumin wurde als Charakteristikum der in vivo Ha Èmolyse beschrieben [41]. Der Anstieg des indirekten Bilirubins und der Retikulozyten ist Ausdruck einer abgelaufenen Ha Èmolyse mit reaktiver Neubildung von Erythrozyten.…”

“…Dagegen ist die Konzentration von Haptoglobin im Plasma/Serum ha Èmolytischer Proben, die in vitro entstanden sind, noch unvera Èndert. Allerdings erfassen einzelne immunchemische Haptoglobin-Bestimmungsmethoden den Ha Èmoglobin-Haptoglobinkomplex anders als freies Haptoglobin [41].…”

Hemoglobin-Conjugated Gold Nanoclusters for Qualitative Analysis of Haptoglobin Phenotypes

“…To detect the precipitates, nephelometry is a commonly utilized method by light irradiation with Hp–Hb-antibody complexes in solution to obtain reflected light for further analysis. With the use of gel electrophoresis, free Hb and Hp–Hb complexes can respectively be isolated via alkaline electrophoresis [ 37 ]. Although spectrophotometry, immunoreactivity, and gel electrophoresis have been developed to detect Hp, the qualitative analysis of the three Hp phenotypes still lacks a suitable approach.…”