The lipoprotein abnormality in Tangier disease: quantitation of A apoproteins.

Assmann, Gerd; Smootz, E; Adler, Kenneth B.; Capurso, Antonio; Oette, K.

doi:10.1172/jci108672

Cited by 104 publications

(43 citation statements)

References 32 publications

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“…Provided that similar methods are used for the pretreatment of the sera, our data are in good agreement with data from other authors (4)(5)(6)(7)(8). Both methods, RIA and EID, produce comparable results, but reproducibility seems to be slightly higher with the EID.…”

Section: Discussionsupporting

confidence: 90%

“…Several assays for the quantitative determination of apolipoproteins A-I and A-II, the two major apolipoproteins of HDL, have been published during the last few years (4)(5)(6)(7)(8)(9). The objective of this study was to compare an electroimmunoassay (EID) for apolipoproteins A-I and A-II with our previously described radioimmunoassay (RIA) (9).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Electroimmunoassay and Radioimmunoassay for the Quantitation of High Density Apolipoproteins A-I and A-II

Mordasini¹,

Riesen²

1980

CCLM

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Summary: An electroimmunodiffusion assay (EID) for the quantitative determination of the major apolipoproteins of the human high density lipoprotein fraction, apolipoproteins A-I and A-II, was compared with a solid phase radioimmunoassay (RIA), previously described by us. Data obtained by both methods largely depended on the pretreatment of the sera. Pretreatment consisted either of delipidation with an ether/ethanol mixture or tetramethyl urea, or of denaturation by heating the sera to 52 °C for 3 hours. Delipidation with ether/ethanol produced a decrease of apolipoprotein A-I values in both methods as compared to treatment with tetramethyl urea. In contrast, the ether/ ethanol treatment did not alter apolipoprotein A-II values in the RIA, while in the EID this procedure led to an increase of apolipoprotein A-II values. Heating gave an increase of both apolipoproteins A-I and A-II in both assays, but results obtained by EID were difficult to interpret because of the appearance of indistinct or double rockets. Comparable results by both methods were obtained, when sera were pretreated with tetramethyl urea. Handling and reproducibility seemed to be slightly better with the EID than with the RIA. Vergleich zwischen Elektroimmunoassay und Radioimmunoassay zur Bestimmung der Apolipoproteine A-I und A-IIZusammenfassung: Ein Elektroimmunodiffusionstest (EID) zur quantitativen Bestimmung der häufigsten Apoproteine der menschlichen High Density Lipoprotein Fraktion, Apolipoprotein A-I und A-II, wurde mit dem von uns früher beschriebenen Festphasen-Radioimmunoassay (RIA) verglichen. Die Resultate, welche mit den beiden Methoden erhalten wurden, hingen in hohem Maße von der Vorbehandlung der Seren ab. Die Vorbehandlung bestand entweder aus der Delipidierung mit einem Ether/Ethanol-Gemisch oder mit Tetramethyl-Harnstoff oder aus Erhitzen auf 52 °C während 3 Stunden. Die Delipidierung mit Ether/Ethanol führte bei beiden Methoden zu einer Erniedrigung der Apolipoprotein Arl-Werte gegenüber Werten, welche nach Tetramethyl-Harnstoff-Behandlung erhalten wurden. Die mit RIA erhaltenen Apolipoprotein --Werte erfuhren dagegen durch die Ether/Ethanol-Behandlung keine Änderung, während beim EIA, im Gegensatz zu Apolipoprotein A-I, eine Erhöhung der Apolipoprotein A-H-Werte festgestellt wurde. Das Erhitzen der Seren ergab bei beiden Methoden eine Erhöhung sowohl der Apolipoprotein A-I-wie der Apolipoprotein A-II-Werte, wobei beim EID die Resultate schwer interpretierbar waren, weil undeutliche oder doppelte "Rockets" auftraten. Vergleichbare Resultate bei beiden Methoden wurden erhalten, wenn die Seren mit Tetramethyl-Hanistoff vorbehandelt wurden. Die Handhabung und die Reproduzierbarkeit schienen beim EID besser als beim RIA zu sein. Introductionexert a P rotective effect against coronary heart disease

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Section: Discussionsupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Electroimmunoassay and Radioimmunoassay for the Quantitation of High Density Apolipoproteins A-I and A-II

Mordasini¹,

Riesen²

1980

CCLM

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“…These lipoproteins would be predicted to float at density 1.21 g/ml in the ultracentrifuge. Thus, the nature of the A-I-and/ or A-Il-containing particles in IM appeared to be comparable to those in a subject with apo A-I deficiency heterozygous for a 45-bp deletion in exon 4 of the apo A-I gene (38) and in Tangier disease where most ofthe A-Il was reported to be located in the plasma lipoproteins with alpha electrophoretic mobility whereas most of the A-I was found in the lipoprotein-free plasma fraction and migrated with prebeta mobility (46,47 The distribution of all four usually "HDL-associated" proteins was somewhat abnormal in the patient. First, most of her A-I and A-Il were found in separate particles whereas, in normal individuals, approximately two thirds of A-I and essentially all A-II were associated with each other (7,9,32).…”

Section: Resultsmentioning

confidence: 67%

Characterization of apolipoprotein A-I- and A-II-containing lipoproteins in a new case of high density lipoprotein deficiency resembling Tangier disease and their effects on intracellular cholesterol efflux.

et al. 1993

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A 48-yr-old Caucasian female of central European origin (subject IM) with low plasma cholesterol and normal plasma triglyceride (TG) had extremely low apo A-I (6 mg/dl), A-II (5 mg/dl), and HDL cholesterol (2 mg/dl) levels. She had most of the clinical symptoms typically associated with Tangier disease, including early corneal opacities, yellow-streaked tonsils, hepatomegaly, and variable degrees of peripheral neuropathy, but had no splenomegaly. She had a myocardial infarction at age 46. Since HDL are postulated to be involved in the transport of excess cholesterol from peripheral tissues to the liver for degradation, and the ability of an HDL particle to promote cellular cholesterol efflux appears to be related to its density, size, and apo A-I and A-II contents, we isolated and characterized the HDL particles of this patient and all her first degree relatives (mother, a brother, and two children). The plasma A-I, A-II, and HDL cholesterol levels of all five relatives were either normal or high. Using anti-A-I and anti-A-II immunosorbents, we found three populations of particles in IM: one contained both apo A-I and A-II, Lp(AI w All); one contained apo A-I but no A-II, Lp(AI w/o All); and the third (an unusual one) contained apo A-Il but no A-I, Lp(AII). Two-thirds of her plasma A-I and A-II existed in separate HDL particles, i.e., in Lp(AI w/o AII) and Lp(AII), respectively. Only Lp(AI w All) and Lp(AI w/o All) were present in the plasma of the relatives. All three populations of the patient's HDL particles had a normal core/ surface lipid ratio, but the cores were enriched with TG. The apo A-I-containing particles, however, were considerably smaller and contained much less lipid than Lp(AII). Despite these unusual physicochemical characteristics, the apo A-I-containing particles and Lp(AII) were effective suppressors of intracellular cholesterol esterification in cholesterol-loaded human skin fibroblast. The patient's plasma apo D and lecithin cholesterol acyltransferase levels were reduced, with an increased proportion located in non-HDL plasma fractions. These findings are discussed in light of

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“…The lower reactivity following delipidation was thought to result from denaturation of the protein. Radioimmunoassays described by Assmann et al, 11 Schonfeld et al, 10 and Goldberg et al 13 all detected close to 100% of the apo A-ll in HDL without delipidation. Schonfeld et al, however, noted that some antisera prepared against apo HDL and HDL 2 recognized somewhat more apo A-ll in intact HDL than other antisera prepared with the purified protein as immunogen.…”

Section: Discussionmentioning

confidence: 93%