Assignment of resonances for 'acute-phase' glycoproteins in high resolution proton NMR spectra of human blood plasma.

Broad resonances at 2.04 and 2.08 ppm in 500 MHz Hahn spin-echo 1H NMR spectra of human blood plasma are assigned to the N-acetyl groups of mobile carbohydrate side-chains (largely N-acetylglucosamine and N-acetylneuraminic acid) of glycoproteins such as alpha 1-acid glycoprotein. Their intensities in spin-echo spectra correlate with clinical conditions in which an elevation of the level of 'acute-phase' glycoproteins is expected, and so may be of value in the study of certain diseases.

Transient changes of serum lipoprotein(a) as an acute phase protein.

Serum lipoprotein(a) (Lp(a)) was serially determined after acute attacks of myocardial infarction and after surgical operations. Acute phase proteins, such as C-reactive protein, alpha 1-acid glycoprotein, alpha 1-antitrypsin and haptoglobin, increased rapidly and markedly after the episodes. Initial values of serum Lp(a) concentrations were almost the same in both groups. Increases in serum Lp(a) levels were also observed during the first few days, with a return to the initial levels after more than 1 month. The periods for reaching maximal levels of acute phase proteins were similar in both groups of patients. On the contrary, the period required for Lp(a) to reach the maximal level in the myocardial infarction group was significantly longer than in the post-operative group. The present study suggests that Lp(a) has the characteristics of an acute phase reactant and may play an important role in recovery from tissue damage.

Modifications of plasma lipids, lipoproteins and apolipoproteins in advanced cancer patients treated with recombinant interleukin-2 and autologous lymphokine-activated killer cells.

Intravenous injection of recombinant interleukin-2 (r-Met-hu-IL-2(Ala-125] and LAK cells induced dramatic changes of lipoproteins in 12 patients with advanced cancer. After r-IL-2 injection (1) total cholesterol was reduced by 47% as a mean, LDL-cholesterol by 62%, HDL-cholesterol by 77%; (2) the triglyceride/cholesterol ratio was greatly increased (352%); (3) apolipoproteins B, A-I and A-II showed a mean reduction of 26%, 55% and 51%, respectively; and (4) very low density lipoproteins relatively increased, and HDL were separated into two definite fractions (I and II). LAK cell administration accentuated all the above effects and in most patients, HDL-fraction I almost completely disappeared. An action on hepatic synthesis of acute phase proteins is pointed out by the increase in C-reactive protein and apolipoprotein S concentrations contrasting with an unexpected reduction of fibrinogen. Surprisingly the drastic changes caused by treatment were quickly and completely reversible.

Depression of tissue plasminogen activator (t-PA) activity and rise of t-PA inhibition and acute phase reactants in blood of patients with acute myocardial infarction (AMI).

We determined during the acute stage of myocardial infarction selected fibrinolysis variables (tissue-type plasminogen activator, intrinsic plasminogen activators, tissue-type plasminogen activator inhibition, C1-inactivator) and related the observed changes to changes in two acute phase reactants (C-reactive protein, fibrinogen). Acute myocardial injury induce significant increases in blood of tissue-type plasminogen activator inhibition (day one, p less than 0.05), C-reactive protein (day three, p less than 0.01), fibrinogen (day six, p less than 0.01), and C1-inactivator (day eight, p less than 0.01). Tissue-type plasminogen activator activity measured as C1-inactivator resistant fibrinolytic activity showed a minimum day two after the acute attack (p less than 0.01), whereas plasminogen activator activities arising from the intrinsic system of fibrinolysis remained constant. The observed changes did not parallel the occurrence of deep vein thrombosis indicated by a positive Tc-plasmin test (41% of the patients).

Plasma IgG, IgG subclasses and acute-phase proteins in children with recurrent acute otitis media.

Quantitation of IgG, IgG subclasses and acute-phase proteins was performed in plasma samples from 156 children, aged 2 to 162 months, with varying degrees of otitis proneness. None of the children had acute otitis media or had received any antibiotics 3 weeks before the examination. Children with recurrent acute otitis media (rAOM) had significantly higher levels of total IgG, IgG1, and significantly lower levels of IgG2 than healthy children (p less than 0.02, p less than 0.0003, and p less than 0.03, respectively). However, the low levels of IgG2 found in the rAOM children could at least, to some extent, be explained by the observation that these children were somewhat younger than the healthy children. Except for recurrent episodes of common colds, children suffering from secretory otitis media (SOM) most often show no clinical signs of inflammatory events. Nevertheless, children with SOM had raised levels of plasma IgG1, indicating recurrent polyclonal stimulation of the immune apparatus, which seems to be less pronounced than that of rAOM children. Levels of acute-phase proteins, haptoglobin, orosomucoid and alpha 1-antitrypsin were evenly distributed in the children investigated, reflecting that they had no acute illness at the time of plasma sampling.

Automated measurement of plasma viscosity by capillary viscometer.

Plasma viscosity has several advantages over the erythrocyte sedimentation rate as a measurement of an acute phase response of more than 24 hours' duration. A new capillary viscometer (Coulter Viscometer II), which gives an automated measurement of plasma viscosity, was compared with the selected manual method (Harkness viscometer) of the International Committee for Standardization in Haematology. Automated measurement of plasma viscosity at 25 degrees C showed close correlation (r = 0.979, p less than 0.002) with the selected method for 160 specimens of plasma. Satisfactory precision both within batch and between batch (coefficients of variation of 1.7% or less) was obtained at viscosity values up to 5.7 mPa.s. There was no detectable carry over between samples and viscosity values were corrected adequately for ambient temperature for the range 15-32 degrees C. Careful daily cleaning was required to prevent accumulation of protein within the automatic sampling valve of the instrument. Automated measurement of plasma viscosity is an attractive alternative to measurement of the erythrocyte sedimentation rate.

Guidelines on selection of laboratory tests for monitoring the acute phase response. International Committee for Standardization in Haematology (expert panel on blood rheology).

These guidelines refer to laboratory tests for monitoring changes in acute phase proteins in patients with an inflammatory response to tissue damage. Quantitative measurements of acute phase proteins are a valuable indicator of the presence, extent, and response of inflammation to treatment. When short term (less than 24 hours) changes in the inflammatory response are expected, quantitative assay of C reactive protein is the test of choice. The hyperproteinaemia that develops in response to a longer term (more than 24 hours) inflammatory response is complex and may vary from one disease to another. A test that is sensitive to the combined effect of several plasma proteins is therefore indicated, and appropriate tests include the erythrocyte sedimentation rate and plasma viscosity--the latter having several advantages. Tests for monitoring short term and long term changes in acute phase proteins are complementary and should be used for different clinical purposes; no one test is ideal for all clinical situations. A quality control programme is an essential component of laboratory tests for monitoring the acute phase response.

Tumor necrosis factor and endotoxin induce similar metabolic responses in human beings.

After injury, infection, or major operations a number of predictable metabolic responses occur. It has been proposed that the cytokine tumor necrosis factor (TNF)/cachectin is a primary mediator of these host responses. To test this hypothesis, we studied 16 tumor-bearing humans with normal renal and hepatic function, who received 24-hour continuous intravenous infusions of escalating doses of recombinant TNF (4 to 636/micrograms/m2/24 h). Serial measurements were made of vital signs and plasma concentrations of TNF, interleukin-1, adrenocorticotropic hormone, cortisol, iron, glucose, and C-reactive protein. Low doses of TNF had minimal metabolic effects, but infusions of greater than or equal to 545 micrograms/m2/24 hr (n = 8) resulted in fever, pituitary, and stress hormone release and acute phase changes. These alterations were compared with the changes that occurred in healthy humans (n = 13) receiving intravenous bolus injections of Escherichia coli endotoxin (4 ng/kg). TNF infusion in doses greater than or equal to 545 micrograms/m2/24 hr produced peak plasma TNF concentrations and metabolic responses that were similar to those after endotoxin injection. Interleukin-1 concentrations remained basal after TNF or endotoxin administration. TNF may represent the primary afferent signal that initiates many of the metabolic responses associated with sepsis and endotoxemia.

Hematologic, iron-related, and acute-phase protein responses to sustained strenuous exercise.

This study was undertaken to gain insight into the mechanisms responsible for the hypoferremia occurring after severe exercise. To this end, 18 athletes who were competing in a 160-km triathlon involving canoeing, cycling, and running were evaluated before the race, immediately after the finish, and thereafter at 30 min, 24 h, and 48 h. The evaluation included plasma iron, total iron-binding capacity, lactoferrin, ferritin, haptoglobin, cortisol, various enzymes, and white cell count. The cortisol, white cell count, and lactoferrin were significantly increased immediately after the race, while the plasma iron and transferrin saturation were significantly decreased. There was a 40% but nonsignificant rise in the plasma ferritin at the completion of the race, while the C-reactive protein was raised by nearly 300% at 24 h. In contrast, haptoglobin declined significantly by 24 h but was normal again 24 h later. Quantitative considerations suggested that the lactoferrin was not responsible for removing transferrin iron from circulation and hence causing the hypoferremia. Instead, it seemed more likely that the iron-related changes were occurring as part of an acute phase response initiated by muscle injury.

Thermal stimulation of the hypothalamus does not evoke the acute-phase reaction.

Interleukin-1 (IL1) injected into the preoptic-anterior hypothalamus (POAH) induces, besides fever, the hepatic synthesis of acute-phase glycoproteins. Since the febrigenic action of IL1 may involve thermosensitive neurons in the POAH, this study examined whether such neurons also might mediate the acute-phase response (APR). The POAH of six adult NZW rabbits was cooled (Tpo = 34.4 +/- 0.4 degrees C [mean +/- SD]) or heated (40.6 +/- 0.2 degrees C) continuously for 2.5 hr (so as to mimic the mean febrile course following a bolus microinjection of IL1 into the POAH). The ambient temperature (Ta) was 23.5 +/- 1.0 degrees C. Expectedly, core temperature fell and skin temperature rose on POAH heating, and the opposite occurred on POAH cooling. However, no statistically significant changes in the plasma levels of Fe, Zn, Cu, and N-acetylneuraminic acid, as indices of the APR, were induced by these treatments. These results indicate, therefore, that the central actions of IL1 in inducing fever and the APR are separate, and that the APR is not mediated through stimulation of thermosensitive units in the POAH.

Effects of severe burns on glycan microheterogeneity of four acute phase proteins.

In serum from 8 severely burned patients, haptoglobin (Hp), alpha 1-acid glycoprotein (AG) and alpha 1-antitrypsin (AT) were found to be increased by factors of 5, 6 and 2 respectively. Ceruloplasmin (Cp) was slightly decreased. In order to appreciate possible modifications to the structure of their attached N-glycans, whole sera were fractionated on concanavalin A (Con A)-Sepharose and respective glycoproteins measured by laser nephelometry using a monospecific antiserum. In the serum from normal as well as burned patients Hp was almost entirely bound to the immobilized lectin (but eluted with 300 mmol/l alpha 1-methylglucoside) and Cp was bound at about 92%. For AG, in contrast, the fraction without affinity for Con A, 25% in normal serum, decreased to 5% in patients, whereas the retained species increased in proportion. A very weakly reactive fraction (which was only retarded and eluted without alpha-methylglucoside) amounted to 72% in both types of serum. When reduced and alkylated, this intermediate fraction gave rise to both non-retained and retained species always in a proportion of about 1/3. On the whole one concludes that there is a significant shift for AG in burned patients towards species enriched in bi-antennary (Con A-reactive) glycans. For AT a minor part was not recognized by the lectin and about 27% was retarded. The latter, which increased in burned patients, gave rise mainly to retained species after reduction and alkylation. This again suggests a shift to bi-antennary glycans.

Circulating acute phase reactive proteins as indicators of infection in poorly controlled diabetes mellitus.

Serum levels of six acute phase proteins (APP)--C-reactive protein (CRP), serum amyloid A (SAA), alpha 1-antitrypsin, haptoglobin and complement fractions C3 and C4--were serially studied in 24 patients with poorly controlled diabetes mellitus, ten of whom had unequivocal evidence of an underlying infection. In diabetic patients without infection, no change in APP levels was noted suggesting that hyperglycaemia per se does not quantitatively influence the acute phase response. No correlation between the presence of infection, and fever, leukocytosis, a raised erythrocyte sedimentation rate, or serum levels of alpha 1-antitrypsin, haptoglobin or complement was apparent in these patients. However, serum CRP and SAA were initially increased 10-100 times above normal in diabetic patients with an underlying infection (P less than 0.01); during the following week circulating levels of CRP and SAA decreased steadily in response to the infection being brought under control. We conclude that serial measurement of CRP and/or SAA is a sensitive, albeit non-specific, parameter to detect and monitor the activity of infection in patients with diabetes.

Effect of sex hormones on plasma T-kininogen in the rat.

The influence of sex hormones on rat plasma T-kininogen concentration was examined. The level of T-kininogen in the post-pubertal female rat is about 3-times that of the male animal. Female rats castrated as adults or 15 days after birth, had low T-kininogen concentrations, near those of male rats. In contrast, castration of mature or immature male animals induced no change in T-kininogen. Treatment of castrated female or male rats with 17 alpha-ethinylestradiol significantly increased the T-kininogen level, whereas administration of testosterone or progesterone had no effect. The influence of estrogen was specific for T-kininogen, since plasma HMW kininogen concentration was the same in male and female rats and was not affected by castration or sex hormone treatment. T-kininogen concentration was not significantly changed in pregnant rat between the 12th and the 20th day of pregnancy, but increased after parturition. It was high in the newborn rat at birth and then decreased similarly over the next 3 weeks in males and females. It continued to decrease in the males, reaching the level of the adult rat, but it increased in the female from 3-4 weeks of age and reached the adult level at about 6-8 weeks. These data indicate that natural estrogens have a physiological influence on the plasma level of T-kininogen in female rats whereas testosterone had no effect on either male or castrated female rats. HMW kininogen is not physiologically dependent on sex hormones.

Enzymes and acute phase reactants in serum of selenium treated rats bearing adenocarcinoma.

Sodium selenite was administered to the rats bearing subcutaneously transplanted adenocarcinoma. The following determinations were carried out in serum: gamma-glutamyl transferase, aminotransferases, alkaline phosphatase and its placental isoform, haptoglobin, protein- and lipid-bound sialic acid. Changes observed in catalytic activities and concentrations of the examined parameters could be ascribed rather to the presence of the tumor than to the effect of the selenium treatment.

The relative merits of acute phase proteins in the recognition of inflammatory conditions.

A study has been undertaken on the relative merits of a variety of acute phase proteins in the assessment of patients with inflammatory conditions. Five acute phase proteins (alpha 1-antitrypsin, alpha 1-antichymotrypsin, orosomucoid, haptoglobin and C-reactive protein) and the ESR were measured in 171 patients presenting to the gastroenterologists (gastrointestinal disease: 130, other disease: 41). Assessment of the sensitivity and specificity of the proteins and the ESR showed alpha 1-antichymotrypsin to be the most sensitive test (95%) with specificity (81%) similar to the other acute phase proteins measured. Factors such as oestrogens, renal failure and genetic variants affected the value of alpha 1-antitrypsin, orosomucoid and haptoglobin. In the routine protein laboratory the combination of a 'short' half-life and 'long' half-life protein is likely to offer the most useful screen for inflammation in samples obtained from a wide range of patients. The two acute phase proteins C-reactive protein and alpha 1-antichymotrypsin fulfil these criteria.

Serum protein changes after abdominal surgery.

Changes in the concentrations of 11 serum proteins following surgery for a variety of conditions have been investigated. Protein changes were analogous to those observed after injury or trauma, but showed differences in the detailed behaviour of the pattern of change. Marked increases in the concentrations of five acute-phase reactant proteins (APRP) were seen, with maximum concentrations usually being reached 2 days after surgery in patients who made an uncomplicated recovery from their operations. Considerable differences were observed between the patterns of change of APRP in patients who developed complications during recovery and in patients who made an uncomplicated recovery from surgery. Concentrations of C-reactive protein and alpha-1 antichymotrypsin (ACT) were much higher in the patients who developed complications, with ACT concentrations providing the clearest separation between the groups. The main factor influencing the changes in APRP during the recovery period appeared to be the development of sepsis. Preoperative concentrations of APRP had no prognostic value for identifying patients at risk of developing complications. The study suggests that the localisation of inflamed tissue involved in the disease processes may influence the detailed behaviour of the acute-phase reactant proteins.

Inflammatory competence of fetal rat: acute-phase plasma protein response of the fetus treated by turpentine in utero.

Using crossed immunoelectrophoresis, immunoelectrodiffusion, autoradiography, and equilibrium binding techniques, we demonstrate that the rat fetus, directly challenged in utero at 18 days by a single subcutaneous turpentine injection, presents a complex acute-phase plasma inflammatory response. A number of fetal serum proteins, 48 h after the injection, increase in concentration by factors of about 2-5. These positive acute-phase reactants (APR) are alpha 1-acute-phase globulin (alpha 1-AP), alpha 2-macroglobulin (alpha 2-M), alpha 1-acid glycoprotein (alpha 1-AG), haptoglobin (Hp), and hemopexin (Hpx). A number of proteins decrease, behaving like negative APRs. These are albumin, alpha 1-fetoprotein (AFP), transferrin, GHR-P63, thyroxine-binding prealbumin (TBPA), and transcortin (CBG). The marked fall in concentration of two of the high-affinity hormone-binding proteins of the fetal rat, i.e., the estrophilic AFP and TBPA, induce significant decreases (by 25-40%) of the estrogen- and thyroxine-binding abilities of the fetal serum. While the plasma inflammatory response of the fetus is qualitatively similar to that of the adult, the fetal reactions are, as a rule, quantitatively weaker. The characteristics of the plasma inflammatory response of the fetus are discussed in relation to the highly dynamic state of its development.

Acute phase proteins and clinical synovitis activity in patients with rheumatoid arthritis.

A number of laboratory variables, including Hb., ESR and several phase proteins, fluctuated in concord with the clinical signs of synovitis activity in patients with rheumatoid arthritis during a controlled study of 3 disease-modifying anti-rheumatic drugs (DMARD). The correlation between laboratory variables and clinical synovitis was significant in a large patient population but the correlation coefficients were not of such magnitude that any of the laboratory variables reflected clinical synovitis activity in a reliable manner in the individual patients. In patients treated with azathioprine, the response of the Hb, (and consequently of the ESR), was reduced compared to patients given other DMARD. This phenomenon was caused by the bone marrow suppressing effect of azathioprine. However, the effect of azathioprine on the clinical synovitis activity did not differ from that of the 2 other drugs. Similar results were found by reviewing the literature about controlled trials of DMARD. In the present trial the clinical evaluation was performed under optimal conditions. In daily clinical practice the evaluations of the joints may be less than optimal since they may be performed by different rheumatologists with varying experience. Consequently, it may be difficult to do without the unreliable laboratory variables mentioned in the routine assessments of disease activity, unless the quality of routine evaluations of synovitis activity is improved considerably.

Acute phase proteins in patients with abdominal aortic aneurysms.

Both stenosis and aneurysmal dilatation are associated with atherosclerosis of the distal aorta. As part of an investigation into factors predisposing to aneurysmal dilatation we compared the levels of acute phase proteins in patients with stenosing and aneurysmal disease. Increased levels of acute phase proteins were found in patients with abdominal aortic aneurysms compared with patients with stenosing aortic disease. In 20 aneurysm patients the C-reactive protein was 56 +/- 10 mg/l, alpha 1-proteinase inhibitor 2.5 +/- 0.13 g/l and ceruloplasmin 0.41 +/- 0.01 g/l. In 20 patients with stenosing aortic disease the C-reactive protein was 28 +/- 8 mg/l, alpha 1-proteinase inhibitor 1.65 +/- 0.11 g/l and ceruloplasmin 0.35 +/- 0.03 g/l. These results argue for the participation of an inflammatory process in the aortic wall in the pathogenesis of all aneurysms.

Inhibition of elastase by canine serum: demonstration of an acute phase response.

Canine serum alpha 1-proteinase inhibitor is not a major acute phase reactant in the dog, unlike the equivalent protein in humans. The possibility that an alternative protease inhibitor system is stimulated during the acute phase response in the dog was investigated. alpha 2-macroglobulin was not an acute phase reactant, but an inhibitor of elastase was identified in canine serum which could be separated from proteinase inhibitor by gel filtration and which was shown to be an acute phase reactant. This protein has been named canine elastase inhibitor.