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PubMed1999

A new method for haptoglobin phenotyping.

Haptoglobin is an acute-phase protein with three major phenotypes: Hp 1-1, Hp 2-1 and Hp 2-2. Studies have shown that functional differences between these phenotypes have important consequences in a number of pathological disorders (e.g. cardiovascular disease, autoimmune disorders, infectious disease), making phenotype determination of potential use in the clinical field. Previous methods for haptoglobin phenotyping have involved electrophoresis (starch, acetate and polyacrylamide gels) with phenotype visualization by peroxidase-sensitive stains that were often carcinogenic. Less hazardous immunoblotting and isoelectric focusing procedures are also available but the methods are lengthy, expensive and often complex. Here, we describe a new method for haptoglobin phenotyping using commercially available agarose gels and a non-carcinogenic stain (3,3',5,5'-tetramethylbenzidine). Our method showed 100% agreement with starch gel electrophoresis and reliably distinguished between commercial haptoglobin phenotype standards and serum samples from patients (n = 125). We obtained a sensitivity of 0.4 g/L for all phenotypes and the gels were stable for up to 2 months. This safer and easier to use method may permit increased access to knowledge of haptoglobin phenotype, allowing improved patient management and better tailoring of treatment in a variety of clinical conditions.

Electrophoresis, Agar Gel↗

PubMed1999

Detection of haptoglobin in the high-density lipoprotein and the very high-density lipoprotein fractions from sera of calves with experimental pneumonia and cows with naturally occurring fatty liver.

In addition to the lipoprotein-deficient d > 1.25 fraction, haptoglobin was detected in the high-density lipoprotein (HDL) and the very high-density lipoprotein (VHDL) fractions from sera of calves with experimental pneumonia and cows with naturally occurring fatty liver. It was not found in the chylomicrons, very low-density lipoprotein and low-density lipoprotein fractions. Washing of the HDL fraction did not decrease the haptoglobin concentration. Transferrin and immunoglobulin G were immunoblotted to examine the possibility of contamination of the lipoprotein fractions by the d > 1.25 fraction. The two serum proteins were detected only in the d > 1.25 fraction, not in any lipoprotein fractions. The distribution pattern of haptoglobin in the lipoprotein fractions was distinct from that of serum albumin. Concentrations of haptoglobin in the HDL fractions from pneumonic sera were largely proportional to those in whole sera. Cholesteryl ester concentrations were decreased in sera from calves with pneumonia, as in cows with fatty liver. A protein immunologically related to hemoglobin was also detected in particular in the VHDL fractions from sera of both groups. These results suggest that haptoglobin or a complex with the hemoglobin-like protein may have a role or roles related to the lipid metabolism.

Animals↗

PubMed1998

Effect of haptoglobin phenotypes on growth of Streptococcus pyogenes.

The haptoglobin (Hp) 2-1 and 2-2 phenotypes have been shown to agglutinate Streptococcus pyogenes carrying the membrane antigen T4. In this study, the growth rate of two strains of Streptococcus pyogenes (T1 and T4) in human serum was compared among haptoglobin phenotypes in vitro. During incubation for 16 hours in serum of different haptoglobin types, only Hp 2-1 and Hp 2-2 sera showed an inhibitory effect on growth, Hp 2-2 being 1.85 times more potent than Hp 2-1. Growth of Streptococcus pyogenes T4 negatively correlated with the serum concentration of Hp 2-1 (r = -0.908) and Hp 2-2 (r = -0.953). Haptoglobin-depleted serum had no inhibitory effect on bacterial growth. Addition of haemoglobin and ferric citrate to the serum accelerated the growth of Streptococcus pyogenes T4 (P <0.05) but not in Hp 2-2 serum. Haptoglobin types 2-1 and 2-2 can be regarded as inhibitors of Streptococcus pyogenes growth in vitro. These data point towards a potential protective role of Hp 2-2 in Streptococcus pyogenes infection in vivo, independently of iron uptake.

Antigens, Bacterial↗

PubMed2000

A new method for fast haptoglobin phenotyping and hemoglobin binding capacity calculation based on capillary zone electrophoresis.

A capillary zone electrophoresis method was developed for haptoglobin (Hp) phenotyping in hemoglobin (Hb) supplemented serum. The method allows a complete resolution of the major haptoglobin phenotypes Hp 1-1, Hp 2-1, and Hp 2-2 based on the difference in charge-to-mass ratio of their Hb-Hp complexes. Identification of these phenotypes was achieved by their significant differences in migration times and their marked difference in electrophoretic pattern. Our method showed full agreement with starch gel electrophoresis. Furthermore, following neuraminidase treatment of the serum, the Hp subtypes Hp1-1FF, FS and SS could be resolved, based on the same criteria as the phenotyping. The new electrophoretic method allowed typing of the rare phenotypes Hp 2-1 modified (Hp 2-1M) and Hp Johnson. The calculated hemoglobin binding capacity of serum correlates well with the nephelometrically determined haptoglobin concentration. The new method for typing haptoglobin gives prospectives for fast haptoglobin typing and Hp 1-1 subtyping.

Electrophoresis, Capillary↗

PubMed1979

Effects of obesity, total fasting and re-alimentation on L-thyroxine (T4), 3,5,3'-L-triiodothyronine (T3), 3,3',5'-L-triiodothyronine (rT3), thyroxine binding globulin (TBG), cortisol, thyrotrophin, cortisol binding globulin (CBG), transferrin, alpha 2-haptoglobin and complement C'3 in serum.

UNLABELLED: The effects of total fasting for 31 +/- 10 days followed by re-alimentation with an 800 calorie diet on thyroid function, i.e. T4,T3,rT3,RT3U (resin T3 uptake), and TSH, and on TBG levels in serum were studied sequentially in obese hospitalized patients (N=18). Additionally, cortisol, growth hormone, prolactin, parathyrin and free fatty acids were followed as hormonal and metabolic parameters, respectively. Further, CBG, transferrin, alpha 2-haptoglobin and complement C'3 were measured as representatives of other serum proteins. Results before fasting: T4, T3, TBG, cortisol, CBG, alpha 2-haptoglobin and complement C'3 of the obese patients were elevated when compared with healthy normal weight controls, whereas rT3, T4/TBG ratio, T3/TBG ratio, TSH, coritsol/cbg ratio, growth hormone, prolactin, parathyrin and transferrin of the obese group were normal. RT3U and fT4 index were decreased in the obese patients. Results during fasting: Significant decreases were observed during fasting for the following parameters -- T3, TBG, T3/TBG ratio, transferrin, alpha 2-haptoglobin complement C'3. rT3, T4/TBG ratio, RT3U, fT4 index and FFA increased. T4, tsh response to TRH stimulation, cortisol, CBG, cortisol/cbg ratio, parathyrin, growth hormone and prolactin did not change. Results during re-alimentation: T3, TBG, T3/TBG ratio, TSH response to TRH, transferrin, alpha 2-haptoglobin and complement C'3 increased. Conversely, fT3, RT3U, FFA, cortisol and cortisol/cbg ratio decreased whereas the other parameters did not change. CONCLUSIONS: 1) There is no evidence for primary hypothyroidism in obese patients during prolonged fasting and re-alimentation. 2) The rapid decrease of T3 and increase of RT3U after initiation of fasting are not fully explained by the observed slower decreases in TBG. 3) The alterations of T3, rT3 and RT3U resemble in their kinetics the changes in FFA levels. 4) Fasting reduced the levels of only certain serum proteins, interestingly TBG, transferrin, alpha 2-haptoglobin and complement C'3, all of which, except transferrin, are elevated in obesity. 5) The magnitude of the observed decreases does not suggest any clinically relevant deficiencies in serum proteins. 6) Re-alimentation reverses rapidly all observed changes.

Adult↗

PubMed1986

Simple spectrophotometric determination of haptoglobin-haemoglobin complex in haemolysed samples.

The concentration of haptoglobin-haemoglobin complex in haemolysed serum was measured by reducing the sample with sodium hydrosulphite. The absorption spectra of serum before and after sodium hydrosulphite treatment were compared, and the absorbance change was used to determine the amount of haemoglobin in the sample. By analysing the difference absorption spectra of various types of haemoglobin-containing samples, it was also possible to determine the haptoglobin level in samples haemolysed severely beyond their haemoglobin-binding capacities. When the present methods are used, along with the spectrophotometric method for free haptoglobin, one can measure separately the amounts of free haptoglobin, haptoglobin-haemoglobin complex, and free haemoglobin in samples with varying degrees of haemolysis.

Bilirubin↗

PubMedDate not supplied

[Zonal distribution of haptoglobin and ceruloplasmin synthesis in the liver].

Effect of hepatotoxic agents (carbon tetrachloride and dimethyl nitrosamine) on the rate of the haptoglobin and ceruloplasmin synthesis in liver tissue was studied. In impairment of hepatocytes in the central zone of liver lobes, the distinct decrease in content of haptoglobin was shown to occur with a simultaneous increase in content of ceruloplasmin in blood serum. When parenchyma of the central zone of liver lobes regenerated, the haptoglobin content tended to normalization. The data obtained suggest that the synthesis of haptoglobin and ceruloplasmin is carried out in different zones of liver tissue lobes: haptoglobin is mainly found in the central zone and ceruloplasmin -- in the peripheral one.

Animals↗

PubMed2002

Haptoglobin polymorphism and iron homeostasis.

BACKGROUND: There is a marked difference in the degree of expression of the homozygous C282Y HFE genotype that is associated with hereditary hemochromatosis. It has been reported that individuals with the haptoglobin 2-2 type manifest increased iron concentrations, including serum iron, transferrin saturation, and ferritin. METHODS: We studied 232 patients, 115 homozygous for the c.845G-->A (C282Y) mutation and 117 matched controls with the wild-type HFE genotype, for haptoglobin phenotypes. Haptoglobin types were determined by electrophoresis of the denatured protein. The HFE genotype was determined by allele-specific oligonucleotide hybridization. Ferritin and transferrin saturation were measured by standard methods. RESULTS: There was no relationship between haptoglobin type and ferritin concentration or transferrin saturation. CONCLUSIONS: The effect of haptoglobin type on iron homeostasis cannot account for the marked phenotypic variation that is seen in patients homozygous for the HFE C282Y mutation.

Genotype↗

PubMed1976

Fluorescent probe studies of haptoglobin type 2-1.

Haptoglobin is an alpha2 serum protein that forms an irreversible complex with hemoglobin. The combination between these two macromolecules resembles the binding of an antigen to its antibody except that the complex remains soluble. This investigation was undertaken to determine the nature of the hydrophobic sites on haptoglobin type 2-1. The interaction of 1-anilinonphthalene-8-sulfonate (ANS) with haptoglobin type 2-1 is characterized by a flourescence intensity in solutions containing ANS and haptoglobin as the pH is decreased from 9 to 4. The dissociation constant for the ANS interaction with haptoglobin 2-1 is 5.8 x 10--5 M at pH 7.0, 5.2 X 10--5 M at pH 5.0 AND 30.3 X 10--5 M at pH 4.0. Fmax shows no change in the pH range 6-9 but does show an increase at pH 4.0 when compared to the neutral region.

Anilino Naphthalenesulfonates↗

PubMed2005

Haptoglobin phenotype 2-2 as a potentially new risk factor for spontaneous venous thromboembolism.

BACKGROUND AND OBJECTIVES: Haptoglobin (Hp) is a plasma protein that binds free hemoglobin and thus prevents catalysis of reactive oxygen species by the Fenton reaction. A genetic polymorphism has been described that leads to the generation of two distinct alleles, Hp1 and Hp2, which define three major haptoglobin phenotypes, denoted Hp1-1, Hp2-1 and Hp2-2. Hp2-2 has been reported to be associated with the risk of atherosclerosis and coronary heart disease. In our study we investigated the association of haptoglobin genotype and phenotype with the risk of spontaneous venous thromboembolism (VTE). DESIGN AND METHODS: One hundred and twenty-eight patients with a history of spontaneous deep vein thrombosis (70 women, 58 men), 105 with spontaneous symptomatic pulmonary embolism (58 women, 47 men) and 122 healthy controls (60 women, 62 men) were enrolled. Haptoglobin levels were measured immunonephelometrically and phenotypes were detected by polyacrylamide gel electrophoresis and subsequent immunoblotting. RESULTS: The Hp2-2 phenotype was significantly more prevalent in patients (42%) than in controls (30%) and significantly increased the risk for VTE in univariable (odds ratio=1.6, 95% confidence interval [1.0-2.6], p=0.04) and multivariable analyses (odds ratio=1.9 [1.0-3.4], p=0.04). Hp2-2 (n=134) was associated with significantly lower haptoglobin levels (median=89.7 mg/dL) than Hp2-1 (n=170, median = 123.5 mg/dL, p<0.001) or Hp1-1 (n=51, median=142.8 mg/dL, p<0.001). INTERPRETATION AND CONCLUSIONS: Our study gives the first evidence that Hp2-2 represents a risk factor for spontaneous VTE, presumably through a pathophysiological mechanism similar to that in arterial disease.

Adult↗

PubMed1990

[Administration of haptoglobin in ABO incompatible bone marrow transplantation].

Haptoglobin was administered i.v. in 2 cases of ABO incompatible bone marrow transplantation for the prevention of hemoglobinuria due to acute hemolysis. The first case was a 25-year-old woman with severe aplastic anemia. The transplantation was both major and minor mismatch, where the donor was type A and the recipient was type B. The second case was a 31-year-old man with chronic phase of chronic myelogenous leukemia. The transplantation was major mismatch, where the donor was type B and the recipient was type O. After the administrations of haptoglobin 8,000 units we transfused bone marrow infusates from which incompatible erythrocytes were removed. Though prominent hemoglobinemia was observed in both cases, the serum haptoglobin values were not saturated and hemoglobinuria was not detectable. Haptoglobin appears to be useful for the prevention of acute renal failure associated with acute hemolysis in ABO incompatible bone marrow transplantation. Intravenous haptoglobin supplement therapy makes transplantation safer and may contribute to improve the recovery rate of total nucleated bone marrow cells after the erythrocyte depletion without worrying much about their contamination.

ABO Blood-Group System↗

PubMed1979

[Haptoglobin study of sheep during the development process].

The development of haptoglobin blood system was studied in the sheeps during intrauterine development and early postnatal period. The haptoglobin content was shown to decrease with the foetus age, two peaks of its reliable increase having been, however, noted -- on the 55th and 105th days of development. After the birth the haptoglobin concentration in blood is relatively low, increases gradually and attains by the 8th month of life that in adult animals. In the blood serum of 45--120 days old foetuses two phenotypes of fetal haptoglobin were found; the adult haptoglobin is present only beginning from the 1st month of life.

Animals↗

PubMed1979

Haptoglobin in the serum of thoroughbreds in training.

A method is described for the measurement of haptoglobin in equine serum using the peroxidase activity of the haemoglobin-haptoglobin complex. The problems of interference with Fe2+ and Fe3+ ions are described. Normal values for haptoglobin in 629 blood samples from thoroughbreds in training are presented showing a log normal distribution with a 5 per cent to 95 per cent range of 0.42 to 1.7 g/litre. There was no consistent alteration in haptoglobin concentration throughout the season in spite of a change in red cell size and total bilirubin concentration. It is concluded that the measurement of haptoglobin is useful in the detection of frank haemolytic states but is insufficiently sensitive to detect mild red cell destruction. The test, after further investigation, might be used as an adjunct to the current batch of blood tests employed to assess liver function.

Animals↗

PubMed1983

Hemoglobin-binding site on haptoglobin probed by selective proteolysis.

Selective proteolysis has been used to delineate the hemoglobin-binding site on haptoglobin heavy chain. Haptoglobin was cleaved specifically by plasmin, trypsin, chymotrypsin, staphylococcal protease, and thermolysin. Haptoglobin-hemoglobin complex was treated with these enzymes to determine which sites were protected from cleavage by the hemoglobin. The modified haptoglobins were tested for changes in their hemoglobin and hemoglobin alpha chain-binding properties. The sites of proteolytic cleavage were identified from the newly generated NH2 termini by automated Edman degradation amino acid-sequencing techniques. The results suggest that residues 128 through 131, 136 and 137, as well as 9 and 10 of the heavy chain may be involved in the binding of hemoglobin. On the other hand, residues 159 and 160, which lie in the 17-residue additional loop that is unique to haptoglobin among its homologous serine protease family, and residues 73 and 74, which lie close to the carbohydrate-binding residues, appear to be remote from the hemoglobin-binding site.

Amino Acid Sequence↗

PubMed1982

Catabolism of haemoglobin-haptoglobin complexes in haemolytic uraemia-like syndromes of different etiologies.

The catabolism of haemoglobin-haptoglobin complexes was studied in four patients with increased vascular haemolysis as part of acute or subacute haemolytic uraemic syndromes. The apparent volumic substance elimination rates for haemoglobin (Fe) bound to haptoglobin in plasma were 1.1 mumol/h/l and 2.9 mumol/h/l in two patients suffering from sublimate and hydrochloric acid poisoning, respectively. This is estimated to correspond to a normal catabolism, when the increased haptoglobin synthesis is taken into account. In the other two patients suffering from serum-sickness there was reduced clearance and thereby an accumulation of haemoglobin-haptoglobin complexes in plasma during penicillin administration. When the offending drug was withdrawn the plasma concentration of haemoglobin bound to haptoglobin remained high for about three days and then fell rapidly (approximately with 3.8 mumol/l/h and 1.9 mumol/l/h). Thus, also in these patients the clearance capacity could be normalized after discontinuation of the drug.

Adult↗

PubMed1981

[Determination of serum haptoglobin concentration in the acute phase of myocardial infarct by means of Mancini's simple radial immunodiffusion test].

In 14 patients with an according to the WHO-criteria definitive myocardial infarction quantitative serum haptoglobin course controls were performed in the first week after the pain event. The haptoglobin estimations were performed by means of simple radial immunodiffusion after Mancini on M-partigen plates. Up to the fifth day after the pain event an increase of the haptoglobin concentration could be established. On the two following days a decreasing tendency could be observed. In a comparative group of five with chronic ischaemic heart diseases and angina pectoris syndrome under the same conditions of examination no increase of haptoglobin could be observed during the first five days after the pain event. These examination results correspond with the literary data, that in disease with tissue destruction increases of haptoglobin are to be observed.

Coronary Disease↗

PubMed1981

Haptoglobin-hemoglobin complex. Subunit interaction probed by cross-linking.

Haptoglobin-hemoglobin complex has been cross-linked using the bifunctional reagent 1,5-difluoro-2,4-dinitrobenzene. Sodium dodecyl sulfate-acrylamide gel electrophoresis indicated that specific cross-linking was obtained between haptoglobin H chain and a hemoglobin chain. The cross-linked complex was reduced and denatured, and the cross-linked subunits were separated from the unreacted haptoglobin and hemoglobin chains by molecular sieve chromatography. Peptide analysis on the purified cross-linked subunits showed that haptoglobin H chain was cross-linked to hemoglobin beta chain only. This result indicates that the H and beta chains are in close proximity in the haptoglobin-hemoglobin complex.

Amino Acids↗

PubMed1980

The predictive value of serum haptoglobin in hemolytic disease.

Using a rapid, highly sensitive immunoprecipitin nephelometric technique, a retrospective study was undertaken to evaluate the clinical usefulness of determining serum haptoglobin in the diagnosis of hemolysis. Haptoglobin assays were performed shortly after admission in 100 patients with a variety of hematologic and nonhematologic conditions and the results correlated with the clinical diagnosis. An ad hoc boolean computer program allowed for the separation of hemolytic from nonhemolytic disorders with a haptoglobin limit of 25 mg/dL or less. The sensitivity and specificity of the test are high (83% and 96%, respectively), providing 87% probability of predicting hemolytic disease when the serum haptoglobin level falls below this limit. These data support the routine use of serum haptoglobin determinations in the diagnosis of hemolytic disease.

Adult↗