Complement activation and its prognostic role in post-cardiac arrest patients.

Cardiac arrest causes generalized ischaemia/hypoxia, and subsequent resuscitation inflicts reperfusion injury, the pathology of which is not fully understood. Moreover, predicting the prognosis of comatose, post-cardiac arrest patients is a complex clinical challenge. We hypothesized that the extent of complement activation might be a reliable predictor of mortality in this population. Forty-six comatose cardiac arrest patients were enrolled into our prospective cohort study, conducted in a tertiary care university clinic. All subjects were cooled to 32-34 °C body temperature for 24 h and then allowed to rewarm to normothermia. All patients underwent diagnostic coronary angiography. On admission, at 6 and 24 h, blood samples were taken from the arterial catheter. In these, complement products (C3a, C3, C4d, C4, SC5b9 and Bb) were measured by ELISA in blood samples. Patients were followed up for 30 days; 22 patients (47.8%) died by the end of this period. We observed that complement activation (determined as the C3a to C3 ratio) was higher in non-survivors than in survivors at each time point. In the multivariate Cox regression analysis, the C3a/C3 ratio determined 24 h after the initiation of therapeutic hypothermia predicted 30-day mortality regardless of age, sex and the APACHE II score. Complement activation occurs in post-cardiac arrest patients, and its extent correlates with 30-day survival. The C3a/C3 ratio might prove useful for estimating the prognosis of comatose post-cardiac arrest patients.

Short-term prophylaxis in hereditary angioedema due to deficiency of the C1-inhibitor--a long-term survey.

BACKGROUND: Hereditary angioedema is a potentially life-threatening disorder, because edema occurring in the mucosa of the upper airways can lead to suffocation. The management of HAE consists of avoiding the triggering factors, prophylaxis, and the acute treatment of edematous episodes. Medical procedures can also provoke edematous attacks, and therefore, short-term prophylaxis (STP) is recommended before such interventions. Our aim was to evaluate the efficacy and safety of STP administered before medical procedures. METHODS: We conducted a retrospective analysis before and a prospective survey after establishing the diagnosis in a group of 137 (60 males, 77 females; 20 pediatric and 117 adult) patients with HAE. Both were implemented using questionnaires, patient diaries and hospital charts focusing on medical interventions provoking edematous attack, and the medicinal products (C1-INH concentrate, tranexamic acid, and danazol) administered for STP. RESULTS: Comparing surgical interventions performed without pre-event STP (in 39/89 patients before HAE was diagnosed), or after STP (in 3/55 cases after diagnosis), we found a significant (P < 0.0001, Fisher's exact test) reduction in the number of edematous episodes. Evaluating the efficacy of the drugs administered for STP revealed that C1-INH concentrate (Berinert(®) , CSL Behring, Marburg, Germany) was significantly (P = 0.0096, Fisher's exact test) superior to orally administered drugs in reducing the instances of postprocedural edema. None of the medicinal products caused adverse events potentially related to STP. CONCLUSIONS: STP reduces the number of postprocedural edematous episodes. C1-INH concentrate is safe and effective for prophylaxis. When this agent is not available, danazol is a potential alternative for prophylaxis before elective medical interventions.

Comparative analysis of IL6 promoter and receptor polymorphisms in myelodysplasia and multiple myeloma.

The serum levels of interleukin 6 (IL6) are known to be elevated in two diseases of the elderly age, myelodysplastic syndrome (MDS) and multiple myeloma (MM). Authors suppose that one of the possible causes of this elevation could be a difference between these patients and healthy subjects in the frequency of polymorphic variants of the genes regulating IL6 levels. Scarce and contradictory comparative data are available for MM and to our best knowledge this is the first study on IL6 promoter and IL6 receptor (IL6R) polymorphism in MDS. Therefore we determined the Asp358Ala polymorphism of the IL6 receptor gene and the -174 G>C promoter polymorphism of the IL6 gene in blood samples of 102 MDS and 100 MM patients and 99 age- and sex-matched hospitalized controls had been tested for this purpose as well. There was no significant difference between patients with either disease and controls regarding IL6 promoter/L-6R. Authors therefore assume other mechanisms causing high IL6 levels are not related to either of these polymorphisms. Moreover authors consider important to propose a hypothesis how elements of signal transduction in iron metabolism might be involved in the development of MM and MDS in elderly age.

Association of elevated serum heat-shock protein 70 concentration with transient hypertension of pregnancy, preeclampsia and superimposed preeclampsia: a case-control study.

Our aim was to investigate the association between serum heat-shock protein (Hsp) 70 concentration and hypertensive disorders of pregnancy. One hundred and forty-two pregnant women with hypertensive disorders (93 with preeclampsia, 29 with transient hypertension of pregnancy and 20 with superimposed preeclampsia) and 127 normotensive, healthy pregnant women were included in the study. Serum Hsp70 concentration was measured using enzyme-linked immunosorbent assay. The serum Hsp70 concentration was significantly higher in patients with transient hypertension of pregnancy, in preeclamptic patients and in patients with superimposed preeclampsia than in the control group (median (25-75 percentile): 0.66 (0.52-0.84), 0.55 (0.42-0.80), 0.61 (0.42-0.91) ng/ml vs 0.31 (0.27-0.39) ng/ml, respectively; P<0.001). Multivariate logistic regression analysis showed independent association of elevated serum Hsp70 level with transient hypertension of pregnancy, preeclampsia and superimposed preeclampsia. The difference in serum Hsp70 concentration between preeclamptic patients and the control group was statistically significant in each gestational age category. In the groups of preeclamptic and superimposed preeclamptic patients, there was no significant difference in serum Hsp70 concentration between mild and severe preeclamptic patients, between patients with late and early onset of the disease, as well as between preeclamptic patients without and with foetal growth restriction. In conclusion, serum Hsp70 concentration is elevated in transient hypertension of pregnancy, in preeclampsia and in superimposed preeclampsia. Circulating Hsp70 may not only be a marker for these conditions, but might also play a role in their pathogenesis. However, further studies are needed to explore its role in the pathogenesis of hypertensive disorders of pregnancy.

Changes in the plasma concentration of soluble thrombomodulin in patients with severe carotid artery stenosis after eversion endarterectomy.

OBJECTIVE AND DESIGN: The purpose of the study was to investigate the putative role of soluble thrombomodulin (sTM) in severe carotid artery stenosis. MATERIALS AND METHODS: We prospectively studied 64 patients who were undergoing carotid endarterectomy (2001-2003). Plasma sTM concentration was determined in each patient before surgery and at 14 months postsurgery. -308 TNF-alpha promoter polymorphism was also determined. RESULTS: Strong negative correlation was found between the preoperative duplex scan values and the plasma sTM concentrations (R = -0.418, p = 0.0006). Patients with 308 A TNF-alpha genotype had significantly lower (p = 0.0415) preoperative sTM values than their counterparts with no such polymorphism. Soluble TM concentrations measured in plasma samples taken at the end of the postsurgical follow-up period of 14 months duration were significantly higher compared to the preoperative values (p < 0.0001). CONCLUSIONS: Our present findings indicate that sTM may be adsorbed to the atherosclerotic plaques or inflamed endothelium in carotid arteries. The pathological significance of this adsorption remains to be determined.

Correlation of serum ghrelin levels with body mass index and carbohydrate metabolism in patients treated with atypical antipsychotics.

The prevalence of diabetes mellitus and metabolic syndrome is higher in patients with schizophrenia than in the normal population. Atypical antipsychotic drugs are used in psychiatry since the beginning of 1990. These drugs differ from the "typical" antipsychotics used previously, as they have less extrapyramidal side effects, and because of this they are tolerated better, but are associated with weight-gain and disturbances in carbohydrate metabolism. Ghrelin is an orexigen hormone partaking in body weight regulation. It is produced in the enteroendocrine P/D1 cells of the gastric mucosa and secreted to the circulation. The aim of our study was to determine ghrelin levels of atypical antipsychotic-treated patients in relationship with their body mass index (BMI) and carbohydrate metabolism. We measured the fasting serum ghrelin levels in 56 patients (male/female: 16/40, age mean+/-S.D.: 50.6+/-5.6 years) treated with atypical antipsychotics (clozapine, olanzapine, risperidon and quetiapine), and in 75 healthy control subjects, age and gender matched (RIA Linco, USA) in relationship with their BMI and their fasting and 75 g OGTT 120 min blood glucose values. The serum ghrelin levels of the patient group were notably higher (1333+/-659 pg/ml) than in the control group (368+/-103, p<0.0001; Mann-Whitney). We found no difference among the four antipsychotics in weight-gain, diabetes prevalence and the serum ghrelin levels. The BMI of the patient group was significantly higher (29.3+/-7.2 kg/m2 versus 24.3+/-3.7 kg/m2, p<0.0001; Mann-Whitney); 32% of them had blood glucose abnormality (18/56). There was no difference between the ghrelin levels in diabetic and non-diabetic patients. We found a significant negative linear correlation between the serum ghrelin and BMI (r=-0.35, p=0.0078; Spearman), the ghrelin and fasting blood glucose (r=-0.32, p=0.015) and OGTT 75 g 120 min blood glucose levels (r=-0.27, p=0.036). The orexigen effect of elevated serum ghrelin levels can contribute to the weight-gain and high diabetes prevalence associated with atypical antipsychotic treatment. The link between atypical antipsychotic treatment and elevated serum ghrelin levels is unknown so far, but a dysregulation of the central feedback mechanism can be hypothesised.

High levels of C-reactive protein with low total cholesterol concentrations additively predict all-cause mortality in patients with coronary artery disease.

BACKGROUND: This study aimed to investigate independent and additive predictive effects of raised C-reactive protein (CRP) levels and decreased total cholesterol levels on mortality in patients with chronic coronary artery disease (CAD). Low total cholesterol (TC) levels are associated with worsened survival in chronic and acute diseases. Elevated CRP level is an important predictor of vascular events and mortality in patients with CAD. Potential inhibition of immune activation by circulating lipoproteins could be a link between cholesterol and inflammatory markers. MATERIALS AND METHODS: A group of 387 patients (median age 59 years) with CAD and with or without severe heart failure (HF) were followed for a median of 5.06 years. Serum total cholesterol and CRP concentrations were measured at enrollment. RESULTS: The relationship between lipoproteins, CRP and survival was explored. High CRP concentrations were in significant association with severity of HF and predicted worsened survival in patients with CAD (hazard ratio 5.214, 95% CI 1.762-15.427). The association between CRP levels and mortality was independent of potential confounding factors such as age, body-mass index, severity of HF, smoking habits, hypertension and TC levels. The prediction of mortality by low TC levels was significant (hazard ratio 2.932, 95% CI 1.021-8.422). Furthermore, patients with increased CRP and decreased TC (additive predictive effect) phenotype had 11.714-times higher risk (95% CI 2.619-52.385) of being nonsurvivors than patients with low CRP/high TC. CONCLUSIONS: High CRP levels and low TC concentrations are independent and additive predictors of mortality in patients with CAD. Our data indicate that joint analysis of circulating lipoproteins and inflammatory biomarkers may improve prediction of survival in patients with CAD.

Sex hormones in hereditary angioneurotic oedema.

OBJECTIVE: The fluctuations in sex hormone levels at the beginning of adolescence, in the perimenopausal period, during pregnancy or during the use of oral contraceptives can precipitate oedematous attacks in hereditary angioneurotic oedema (HANO). Attacks usually disappear after the onset of menopause. This study was undertaken to establish any relationship between the serum levels of sex hormones and the incidence of HANO attacks. PATIENTS AND MEASUREMENTS: Serum levels of LH, FSH, progesterone, oestradiol, testosterone, PRL and SHBG were measured in 78 patients [mean age 30.3 years (range 4-70 years)] with HANO. A questionnaire was used to explore the medical history of adult patients to characterize the evolution and the characteristics of attacks. RESULTS: The number of attacks was significantly higher [odds ratio (OR) 6.36 (1.31-30.81); P = 0.022] in females with high progesterone levels (> or = 4 nmol/l), irrespective of age, menstrual cycle and danazol dose. The OR was even higher [13.4 (2.2-81.4); P = 0.005] when only subcutaneous attacks were considered. Multiple logistic regression analysis demonstrated a significantly lower attack frequency during 1-year follow-up in patients with a higher (40 nmol/l) SHBG level (OR 0.25 (0.07-0.90); P = 0.034). This difference existed independently of age and danazol dose. CONCLUSION: In view of these results, the monitoring of progesterone and SHBG levels can prove useful in the prediction of attacks in hereditary angioneurotic oedema.

Marked decrease in the levels of two inflammatory markers, hs-C-reactive protein and fibrinogen in patients with severe carotid atherosclerosis after eversion carotid endarterectomy.

OBJECTIVE AND DESIGN: To study changes in the levels of two acute phase proteins, plasma fibrinogen and serum C-reactive protein (hs-CRP) in patients with severe carotid stenosis after eversion endarterectomy. MATERIAL AND SUBJECTS: A total of 117 consecutive patients who underwent eversion endarterectomy were included in the study. Blood samples for acute phase protein measurement were taken before operation as well as 5.7 weeks and 13.8 months (median) post-surgery. Plasma fibrinogen and serum hs-CRP concentrations were promptly determined. RESULTS: During the follow-up period sharp, highly significant (p < 0.0001) drop occurred in the serum concentrations of both acute phase proteins. The drop in the hs-CRP levels during the follow up period was mainly due to decrease in patients with highest baseline CRP levels. CONCLUSIONS: Our present findings indicate that removal of atherosclerotic plaques from the carotid arteries markedly decreases the production of two acute phase proteins due to the decrease of the inflammatory burden or the removal of the advanced plaques able to produce these proteins.

Acute abdominal attack of hereditary angioneurotic oedema associated with ultrasound abnormalities suggestive of acute hepatitis.

UNLABELLED: Hereditary angioneurotic oedema (HANO) is an autosomal dominant disorder caused by a deficiency of the inhibitor protein Cl-esterase. Recurrent subcutaneous and/or submucosal oedema formation is a hallmark of this disease. HANO is a rare, but potentially life-threatening disorder with a mortality around 20-30%. Acute oedematous abdominal attacks of HANO can mimic a surgical emergency; this is exemplified by the case of a 14-y-old male patient with HANO admitted for such clinical manifestations. CONCLUSION: Diagnostic clues include ascites and abnormalities of hepatic structure visible with ultrasound during the oedematous attack. The importance of appropriate treatment is emphasized.

Role of endothelin-1 in the development of a special type of cardiomyopathy.

The role of endothelin-1 (ET-1) in certain pathological states is still unclear. We have investigated the effect of anthracyclines (maximum dose, 450 mg/m(2) of body surface) on left ventricular systolic and diastolic function and how it influences the level of plasma ET-1 in 21 patients (12 female and nine male) with Hodgkin and non-Hodgkin lymphoma. We also studied the association between plasma ET-1 concentration and echocardiographic parameters. Serum ET-1 was measured by ELISA. Left ventricular function was analysed by echocardiography: ejection fraction (EF), velocity-time integral, E- and A-waves, E:A ratio, deceleration time (DT) and Doppler index were all measured. Statistical analysis was made by the Wilcoxon rank test. EF and serum ET-1 level decreased significantly (EF, 56.29+/-5.0% to 48.57+/-5.9%, P<0.0001; ET-1, 6.45+/-4.0 pg/ml to 2.9+/-1.0 pg/ml, P<0.0001). DT increased significantly (179.8+/-47.8 ms to 215.5+/-66.7 ms, P<0.01) after anthracycline therapy. There was no difference in other echocardiographic parameters before and after therapy. The decrease in serum ET-1 concentration might be a result of anthracycline's direct cytotoxic effect and the decreasing level of ET-1 can play a role in the reduction of EF. However, more studies are needed to evaluate the presence and severity of endothelial damage.

Complement activating antibodies against the human 60 kDa heat shock protein as a new independent family risk factor of coronary heart disease.

BACKGROUND: Several groups have reported high levels of antibodies against 60 kDa heat shock proteins (hsp) associated with coronary heart disease. METHODS AND RESULTS: Complement activating (CA) antihsp60 autoantibodies were measured by the AtheroRisk kit (CardioPath Ltd, Alloa, UK), in parallel with IgG antibodies to human hsp60 and mycobacterial hsp65 by ELISA in 32 healthy children (18 boys, 14 girls, 11.8 +/- 4.0 years). At least one of the parents of these children had a history of myocardial infarction before 55 years of age (high family risk (HFR) group). The control group consisted of 63 healthy children (31 boys, 32 girls, 9.0 +/- 3.6 years) without known family history of coronary heart disease (CHD), hypertension, and diabetes mellitus. Concentrations of CA antihsp60 antibodies were significantly (P = 0.021) higher in the HFR group than in the control group. Also in the HFR group, significantly (P = 0.004) lower high-density lipoprotein cholesterol (HDL-C)-cholesterol (measured enzymatically) and significantly (P = 0.020) higher low-density lipoprotein cholesterol (LDL-C)-cholesterol levels (calculated by the Friedewald formula) were observed when compared with the controls. The difference in the CA antihsp60 antibody levels between the HFR and control groups remained significant even after adjustments for age, smoking, HDL-cholesterol, LDL-cholesterol levels, and white blood cell count. Children with high (in the highest quartile) CA antihsp60 antibody levels compared with those with normal levels of these antibodies also had adjusted odds ratios (OR) of 9.80 (2.15-44.58, P = 0.003), indicating high family risk. No significant difference in the IgG antihsp antibody levels was observed. CONCLUSIONS: These findings indicate that high levels of CA autoantibodies against hsp60 can be considered to be a novel family risk factor of CHD, independent of HDL- and LDL-cholesterol levels.

The pathophysiological influence of leptin and the tumor necrosis factor system on maternal insulin resistance: negative correlation with anthropometric parameters of neonates in gestational diabetes.

The contribution of the tumor necrosis factor (TNF) system and leptin was studied in insulin resistance and neonatal development during the course of normal pregnancy and gestational diabetes mellitus (GDM). Thirty patients with GDM and their neonates (n = 30), 35 healthy pregnant women (15 in the first, nine in the second and 11 in the third trimester) and their neonates (n = 20), and 25 healthy matched non-pregnant women participated in the study. Significantly elevated levels of maternal TNF-alpha, sTNF receptor (R)-1 and R-2, leptin (detected by enzyme-linked immunosorbent assay) and fasting C-peptide (measured by radioimmunossay and raised body mass index (BMI) were found in GDM patients and in the third trimester of normal pregnancies. TNF-alpha, sTNFR-2, C-peptide, leptin concentrations and BMI positively correlated with each other in GDM. An inverse relationship between the body length, head circumference and body weight of the newborns, and maternal TNF-alpha, leptin and C-peptide concentrations was shown in GDM. In healthy pregnancies the maternal serum leptin level was in a negative linear correlation with the head circumference of the newborns. In conclusion, increased TNF-alpha and leptin levels may contribute to insulin resistance in GDM and in the third trimester of normal pregnancy and may negatively influence the anthropometric parameters of the newborns.

Eradication of Helicobacter pylori and improvement of hereditary angioneurotic oedema.

Helicobacter pylori infection is thought to be a causal factor in various dermatological disorders. We assessed the frequency of H pylori infection in 65 patients with hereditary angioneurotic oedema. We measured the serum concentration of antibodies against H pylori and did the carbon-14-urease breath test in patients with positive H pylori serology. 19 of 65 patients had H pylori infection. All patients with infection, and 11 of 46 without infection, had a history of recurrent episodes of acute abdominal pain. We successfully eradicated H. pylori infection in 18 patients. The frequency of abdominal symptoms was significantly higher in the infected group (p=0.002 after adjustment for age). In nine of 19 patients with dyspepsia, the frequency of oedematous episodes decreased from 100 over 10 months before eradication to 19 during the 10-month follow-up period. Screening for, and eradication of, H pylori infection seems to be justified in patients with hereditary angioneurotic oedema.

Ultrasonography in the diagnosis and monitoring of ascites in acute abdominal attacks of hereditary angioneurotic oedema.

BACKGROUND: Hereditary angioneurotic oedema (HAE) is a rare cause of ascites. As acute abdominal attacks of the disease can mimic surgical emergencies, prompt and accurate diagnosis is essential. This study was undertaken to evaluate the usefulness of serial abdominal ultrasound (US) examinations. PATIENTS AND METHODS: Seventy patients with HAE were followed up for almost a decade. All patients presenting with an acute oedematous attack underwent abdominal US, which was then repeated 24 and 48 h after appropriate therapy. RESULTS: Twenty-two acute oedematous attacks with abdominal complaints severe enough to justify hospital admission occurred in the study population. Abdominal US performed during the attack showed oedematous thickening of the intestinal wall in 80% of cases and invariably demonstrated the presence of free peritoneal fluid in all patients. Rapid symptomatic relief achieved by treatment was accompanied by the significant regression of US abnormalities. CONCLUSIONS: Transitory ascites demonstrated by abdominal US is a clue to the diagnosis of an acute abdominal attack of HAE. The possibility of HAE should always be considered whenever unexplained abdominal pain recurs with or without ascites.

Angiooedema due to acquired deficiency of C1-esterase inhibitor associated with leucocytoclastic vasculitis.

A hereditary and an acquired type of C1-esterase inhibitor deficiency have been described. Manifestations characteristic of both forms include recurrent subcutaneous and submucosal angiooedema. Acquired C1-esterase inhibitor deficiency has been observed in association with lymphoproliferative disorders, malignancy, autoimmune diseases and infections. We report on a case with the acquired form of the disease accompanied by leucocytoclastic vasculitis. Treatment with antimalarial agents resulted in complete resolution of symptoms and signs. Furthermore, C1-esterase inhibitor concentration and activity, as well as C1 levels, all returned to normal.

High level of anticholesterol antibodies (ACHA) in HIV patients. Normalization of serum ACHA concentration after introduction of HAART.

Anticholesterol antibodies (ACHA) are natural antibodies against the 3beta-OH group of cholesterol. Since lipid disorders are common in HIV infection and HAART may further enhance dislipidaemia, we determined by using an ELISA method serum ACHA concentrations in HIV patients and healthy HIV-seronegative controls. ACHA levels were almost 4 times higher in the sera of 46 patients than in 110 controls. No difference in the specificity of ACHA was found between HIV-seropositive and HIV-seronegative sera. Binding of ACHA to cholesterol-coated plates from a HIV-seropositive serum was dose-dependently inhibited by preincubation with HIV-1(BA-L) preparation. Serum concentration of ACHA was significantly higher in the patients with low serum cholesterol levels than in those with normal cholesterol levels. HAART induced a marked drop of ACHA concentration. We found a significant negative correlation between the length of HAART and the ACHA levels. By contrast, HAART did not significantly influence total IgG concentration and titers of antibodies against 60 kD heat shock protein. Our findings indicate that high levels of ACHA in HIV-infection may contribute to the development of hypocholesterolaemia frequently observed in this disease.

The association of serum lipoprotein(a) levels, apolipoprotein(a) size and (TTTTA)(n) polymorphism with coronary heart disease.

BACKGROUND: The association between lipoprotein(a) levels, apolipoprotein(a) size and the (TTTTA)(n) polymorphism which is located in the 5' non-coding region of the apo(a) gene was studied in 263 patients with severe coronary heart disease and 97 healthy subjects. METHODS: Lp(a) levels were measured by ELISA, apo(a) isoform size was determined by SDS-agarose gel electrophoresis, and analysis of the (TTTTA)(n) was carried out by PCR. For statistical calculation, both groups were divided into low (at least one apo(a) isoform with < or = 22 Kringle IV) and high (both isoforms with >22 KIV) apo(a) isoform sizes, and into low number (<10 in both alleles) and high number of (> or =10 at least one allele) TTTTA repeats. RESULTS: Lp(a) levels were higher (P=0.007), apo(a) isoforms size < or =22 KIV and TTTTA repeats > or = 10 were more frequent (P=0.007 and 0.01) in cases than in controls. Lp(a) levels were found to be increased with low apo(a) weight in both groups (both P<0.0001). In multivariate logistic regression analysis, only the Lp(a) levels (P=0.005) and (TTTTA)(n) polymorphism (P=0.002) were found to be significantly associated with CHD. CONCLUSION: Nevertheless, these results indicate that in CHD patients the (TTTTA)(n) polymorphism has an effect on Lp(a) levels which is independent of the apo(a) size.

Anti-cholesterol antibodies (ACHA) in patients with different atherosclerotic vascular diseases and healthy individuals. Characterization of human ACHA.

In animal experiments the protective role of anti-cholesterol antibodies (ACHA) in the development of atherosclerosis has been demonstrated. Despite the fact that ACHA are present in the serum of healthy humans, no data on the occurrence of these antibodies in human diseases are available. We determined serum concentrations of IgG type ACHA by an enzyme immunosorbent assay in 600 patients with atherosclerotic vascular diseases (86 patients with peripheral occlusive atherosclerosis, 146 patients with cerebrovascular diseases, 341 patients with severe coronary heart disease (CHD) who received aorto-coronary by-pass, 27 patients with myocardial infarction who did not undergo by-pass operation), in 57 patient controls (complaints of CHD, without coronarographic alterations) and in 218 healthy individuals. ACHA were present in the sera of all persons tested. No serum cofactor is needed for the binding of human ACHA to solid phase cholesterol, binding can be inhibited dose-dependently by LDL and even more strongly with LDL/VLDL preparations purified from human serum. ACHA levels were found to be considerably lower in patients with peripheral occlusive atherosclerosis and cerebrovascular diseases compared with the levels in healthy individuals. By contrast, the ACHA levels of patients with CHD were considerably higher. No differences in the IgG subclass distribution and binding efficiency of ACHA in the sera of CHD patients and controls were found. Thus, our present findings indicate that both low and high ACHA production may be associated with different atherosclerotic vascular diseases.