Increased frequency of GM-CSF secreting PBMC in patients with active systemic lupus erythematosus can be reduced by immunoadsorption

An objective was to determine the frequency of GM-CSF secreting peripheral blood mononuclear cells (PBMC) in patients with active systemic lupus erythematosus (SLE) and their relation to other cytokine secreting PBMC, activation markers on lymphocytes/monocytes, clinical manifestations and anti- dsDNA antibodies.A second objectivewas to further investigatethe influence of immunoadsorption(IA) therapy on these parameters.The number of GM-CSF, interleukin-1b (IL-1b), IL-6, interferon-g (INF-g) or tumour necrosis factor-a (TNF-a) secreting PBMC was assessed by ELISPOT assay in 10 patients with active SLE. Further, the expression of activation markers on lymphocytes and monocytes was determined by flow cytometry. Three courses of IA were performed in the patients. Seventeen healthy, age- and sex-matched volunteers served as controls. GM-CSF secreting PBMC were significantly increased whereas INF-g secreting cells were decreased in SLE patients. The expression of CD71 (transferrin receptor) on CD4 + T-cells and of the costimulatorymolecule CD86 on B-lymphocyteswas significantly increased in SLE patients. GM-CSF secreting PBMC and CD4 + /CD71 + T-cells correlated with anti-dsDNA antibody titres and decreased towards levels of controls during IA. Disease activity and anti-dsDNA autoantibody titres were significantly reduced after the treatment. Our results demonstrate significant alterations of cellular and humoral immunity in SLE patients. The impaired immunity can be modulated by IA. Thus IA may prove an immunomodulatory therapeutic option in addition to the mere depletion of anti-dsDNA autoantibodies.

Effects of isoflavones equol and genistein on bone quality in a rat osteopenia model

Phytoestrogens might be an alternative medication in prophylaxis and treatment of osteoporosis. In this study, the osteoprotective effects of genistein (GEN) and equol (EQO) were evaluated. After ovariectomy, 44 rats received soy-free food (Control, C) and developed substantial osteoporosis over the course of two months. After that period, the rats were divided into different groups and fed estradiol (E), GEN or EQO for 35 days. To analyze the osteoprotective effects of the tested substances, bone biomechanical properties and histomorphometric changes of the lumbar vertebrae were evaluated. In analyzing the vertebral body compression strength, we found that the EQO (103.8%) and GEN (96.8%) groups reached similar levels relative to the E group, while the C group reached 77.7% of the biomechanical properties of the E group. EQO was significantly superior to C. The histomorphometric evaluation demonstrated an increased number of nodes in EQO- and E-treated rats compared to GEN- and C-treated rats. E led to an improvement of cortical as well as trabecular bone, an advantage that was only partly seen in the other groups. Treatment with phytoestrogens induced improved bone quality. EQO and GEN might be alternatives for hormone replacement therapy, although further studies are needed to elucidate possible side effects.

Sex mismatch in heart transplantation is associated with increased number of severe rejection episodes and shorter long-term survival

BACKGROUND

Heart transplantation is the criterion standard for treating end-stage heart failure. Male sex of both the donor organ and the recipient is advantageous for survival, possibly owing to hemodynamic or immunologic reasons. The effect of sex mismatch on long-term survival in male heart transplant recipients is less known.

PATIENTS AND METHODS

In this prospective single-center study, we reviewed follow-up data for 57 sex-mismatched and 179 sex-matched men who underwent orthotopic heart transplantation between 1990 and 2002.

RESULTS

Median survival was significantly shorter in the sex-mismatched group (8.1 vs 12.9 years; P < .04). Subgroup analysis revealed that this was even more pronounced in male heart recipients with coronary artery disease (2.4 vs 12.9 years; P < .001). Female donor organs were significantly smaller (left ventricular end-diastolic diameter 49 vs 51 mm; P < .05), and recipients more often experienced clinically relevant episodes of cellular rejection during the first 3 months posttransplantation (International Society for Heart and Lung Transplantation grade 3, 5.6% vs 3.1%; P < .001). Global left ventricular function, and immunosuppressive and inflammatory parameters did not differ.

CONCLUSION

In male orthotopic heart transplant recipients, sex mismatch is associated with adverse outcome owing to increased number and severity of episodes of graft rejection.

Clockwork blue: on the evolution of non-image-forming retinal photoreceptors in marine and terrestrial vertebrates

This paper presents a hypothesis that could explain why blue light appears to dominate non-image-forming (NIF) ocular photoreception in marine as well as terrestrial vertebrates. Indeed, there is more and more evidence suggesting that 'novel' retinal photoreceptors, which are sensitive to blue light and were only discovered in the 1990s, could be a feature shared by all vertebrates. In our view, blue light photoreception evolved and persisted as NIF photoreception because it has been useful in the colonisation of extensive photo-dependent oceanic habitats and facilitated the move of vertebrates from an aquatic to a terrestrial environment. Because the available scattered evidence is compatible with the validity of our hypothesis, we hope that our rationale will be followed up. Indeed, it (1) involves testable predictions, (2) provides plausible explanations for previous observations, (3) unites phenomena not previously considered related to one another and (4) suggests tests that have not been carried out before. Overall, our approach not only embraces cross-disciplinary links; it, moreover, serves as a reminder of an all-embracing evolutionary history, especially with regard to a ubiquitous photoreceptive 'clockwork-blue' in marine and terrestrial vertebrates.

Interleukin-6, procalcitonin and TNF-alpha: markers of peri-prosthetic infection following total joint replacement

This prospective study evaluates the role of new laboratory markers in the diagnosis of deep implant infection in 78 patients (41 men and 37 women) with a revision total knee or hip replacement. The mean age at the time of operation was 64.0 years (19 to 90). Intra-operative cultures showed that 21 patients had a septic and 57 an aseptic total joint replacement. The white blood cell count, the erythrocyte sedimentation rate and levels of C-reactive protein, interleukin-6, procalcitonin and tumour necrosis factor (TNF)-alpha were measured in blood samples before operation. The diagnostic cut-off values were determined by Received Operating Characteristic curve analysis. C-reactive protein (> 3.2 md/dl) and interleukin-6 (> 12 pg/ml) have the highest sensitivity (0.95). Interleukin-6 is less specific than C-reactive protein (0.87 vs 0.96). Combining C-reactive protein and interleukin-6 identifies all patients with deep infection of the implant. Procalcitonin (> 0.3 ng/ml) and TNF-alpha (> 40 ng/ml) are very specific (0.98 vs 0.94) but have a low sensitivity (0.33 vs 0.43). The combination of C-reactive protein and interleukin-6 measurement provide excellent screening tests for infection of a deep implant. A highly specific marker such as procalcitonin and pre-operative aspiration of the joint might be useful in identifying patients with true positive C-reactive protein and/or interleukin-6 levels.

Processing of stored packed red blood cells using autotransfusion devices decreases potassium and microaggregates: a prospective, randomized, single-blinded in vitro study

The aim of the study was to compare the potential of autotransfusion devices to reduce non-infectious complications related to transfusion of long-stored packed red blood cells (PRBC; n= 57), such as changes in electrolytes, blood cells and the load of free microaggregates. Following a baseline measurement, a blood pool of three PRBC was divided into three equal volumes and washed with either the Haemonetics Cell Saver (HCS) or the continuous autotransfusion system (C.A.T.S), using the quality (CATS(quality)) and emergency (CATS(emergency)) mode. After the washing procedure, measurements for electrolytes, blood cells and free microaggregates were repeated (n= 19 each). Compared with baseline, the investigated autotransfusion devices reduced the median load of potassium (baseline: 52 mEq L(-1); HCS: 4 mEq L(-1); CATS(quality): 4 mEq L(-1); CATS(emergency): 17 mEq L(-1); each P < 0.001), restored a physiologic electrolyte balance and significantly decreased the load of leucocytes, glucose and protein. Whereas the quantity of microaggregates was not reduced by HCS, CATS(emergency) decreased the load of cell fragments below 7.8 microm (P < 0.05 vs. baseline). Using CATS(quality) decreased the load of cell fragments not only to a diameter below 7.8 microm (P < 0.001 vs. baseline) but also of microaggregates between 7.8 and 17.6 microm (P < 0.05 vs. baseline). In situations where long-stored PRBC have to be transfused, the procedure described here may be feasible to reduce clinically relevant side effects, i.e. hyperkalaemia and microvascular obstruction secondary to free cell fragments. This approach could be especially useful in patients undergoing massive transfusion and/or suffering from renal failure.

Can fat explain the human brain's big bang evolution?-Horrobin's leads for comparative and functional genomics

When David Horrobin suggested that phospholipid and fatty acid metabolism played a major role in human evolution, his 'fat utilization hypothesis' unified intriguing work from paleoanthropology, evolutionary biology, genetic and nervous system research in a novel and coherent lipid-related context. Interestingly, unlike most other evolutionary concepts, the hypothesis allows specific predictions which can be empirically tested in the near future. This paper summarizes some of Horrobin's intriguing propositions and suggests as to how approaches of comparative genomics published in Cell, Nature, Science and elsewhere since 1997 may be used to examine his evolutionary hypothesis. Indeed, systematic investigations of the genomic clock in the species' mitochondrial DNA, the Y and autosomal chromosomes as evidence of evolutionary relationships and distinctions can help to scrutinize associated predictions for their validity, namely that key mutations which differentiate us from Neanderthals and from great apes are in the genes coding for proteins which regulate fat metabolism, and particularly the phospholipid metabolism of the synapses of the brain. It is concluded that beyond clues to humans' relationships with living primates and to the Neanderthals' cognitive performance and their disappearance, the suggested molecular clock analyses may provide crucial insights into the biochemical evolution-and means of possible manipulation-of our brain.

Receptor assay based on surface plasmon resonance for the assessment of the complex formation activity of cyclosporin A and its metabolites

OBJECTIVE

A new automated receptor assay has been used to determine the complex formation activity of cyclosporin A (CsA) and its metabolites in whole blood.

METHODS

CsA in vivo forms a complex with cyclophilin A and calcineurin leading to an inhibition of the calmodulin-dependent phosphatase activity of calcineurin. The equilibrium complex formation gives information about the potential immunosuppressive activity of CsA and its metabolites. To measure the amount of this complex the authors developed an automated receptor assay based on an optical biosensor (Biacore) with surface plasmon resonance (SPR) technology.

RESULTS

In the range of 50-300 nM CsA, the intra-day coefficient of variation (CV) was 7.2%, and the inter-day CV was 10.1%. Measuring range of the assay was 10-500 nM with a detection limit of 5 nM and a processing time of 10 min. Recovery rate for sample pretreatment was 74 +/- 5%. 193 blood specimens from heart transplant recipients were analyzed with 3 different methods. The results determined with the receptor assay were correlated with those obtained by fluorescence polarization immunoassay (FPIA; r = 0.599) and high-performance liquid chromatography (HPLC; r = 0.615).

CONCLUSION

The receptor assay determines the complex formation activity of CsA and its metabolites with high sensitivity and precision.

Interleukin 1beta and tumour necrosis factor alpha secreting cells are increased in the peripheral blood of patients with primary Sjögren's syndrome

OBJECTIVE

To study systemic alterations of cytokine secreting peripheral blood mononuclear cells (PBMC) in primary Sjögren's syndrome (pSS) and their relation to common clinical and immunological manifestations of this disease.

METHODS

PBMC spontaneously secreting tumour necrosis factor alpha (TNFalpha), interleukin 1beta (IL1beta), and interleukin 6 (IL6) were assessed by enzyme linked immunospot (ELISPOT) analysis in a cohort of 31 patients with pSS fulfilling the modified European classification criteria. Nineteen healthy volunteers served as controls. ELISPOT results were correlated with glandular and extraglandular manifestations and autoantibody titres-that is, rheumatoid factor (RF) isotypes, anti-Ro/SS-A, anti-La/SS-B as determined by an enzyme linked immunosorbent assay (ELISA) technique.

RESULTS

The number of TNFalpha and IL1beta secreting cells was significantly higher in patients with pSS than in controls. No differences were detected in the number of IL6 secreting PBMC. Patients with recurrent parotid swelling (RPS) had a significantly increased number of IL1beta secreting PBMC. Moreover, the number of IL1beta secreting PBMC correlated with the disease duration (r(s)=0.479; p<0.01) and with the concentration of IgM RF (r(s)=0.63; p<0.01) and IgG RF (r(s)=0.42; p<0.05). Other autoantibodies did not correlate with cytokine secreting PBMC.

CONCLUSION

The increased systemic secretion of IL1beta and TNFalpha in patients with pSS points to a pathogenic impact of these cytokines in this autoimmune disease. In particular the correlation of IL1beta secreting PBMC with RPS and RF production indicates that IL1beta is a crucial regulator in the development of local and systemic disease manifestations.

[Malignomas following heart transplantation]

Up to 30% of patients with an organ transplantation develop precancerous lesions and malignant tumors, especially of the skin. All 241 patients who underwent heart transplantation from 1990 to 2000 were evaluated with regard to the development of neoplasias. Those alive in September 1999 were referred for a standardized dermatological exam (n=156) which detected malignancy in 28 patients being transplanted for 4.98 years on average. The skin was the organ most frequently involved (64%, n=18). 18% (n=5) of tumors were found in the urinary and genital tract, 7% (n=2) each in the respiratory and gastrointestinal tract, and 4% (n=1 ) in the breasts. The average age of patients who developed tumors was significantly higher as compared to the overall mean age (59.5+/-5 vs 49.8+/-14.7 years, p=0.00027). There was no correlation between development of malignancy and HLA matching, immunosuppressive drugs used, dosage and serum levels of immunosuppressive medication, and episodes of transplant rejection. Our study shows that the risk to develop tumors is at least doubled after heart transplantation. Due to the high incidence of skin tumors, transplant patients should undergo dermatological examinations on a regular basis.

Prediction of clinical outcome after cardiac surgery: the role of cytokines, endotoxin, and anti-endotoxin core antibodies

Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) can lead to a systemic inflammatory response syndrome with organ failure and increased morbidity and mortality. The mechanisms of these findings are still under discussion. We investigated whether anti-endotoxin core antibodies, endotoxin, and proinflammatory cytokines influence the clinical course after cardiac surgery. Seventy-eight patients undergoing CABG using CPB were investigated. Anti-endotoxin core antibodies, endotoxin, interleukin (IL)-6, IL-8, IL-1beta, and TNF-alpha were measured 24 h preoperatively and up to 72 h postoperatively. Patients with a postoperative mechanical ventilation time below 24 h (n = 65; Group A) were compared to patients with prolonged respirator therapy (>24 h; n = 13; Group B). Preoperative antibody levels were significantly lower in Group B (P < 0.001). In this group, antibody levels remained decreased during the observation period (P < 0.001). Endotoxin significantly increased 30' postoperatively in both groups (P < 0.002). The increase in Group B was 3-fold higher (P< 0.001). IL-8 increased postoperatively in both groups, peaking 3 h after surgery (P < 0.001). In Group B, the IL-8 release was significantly higher than in Group A (P < 0.001). IL-6 significantly increased in both groups, reaching its maximum 24 h postoperatively (P < 0.001). No differences between groups were observed. No significant changes of IL-1beta and TNF-alpha were observed. We conclude that anti-endotoxin core antibodies may be predictive of adverse outcome after cardiac surgery. The imbalance between antibodies and endotoxin results in an exaggerated increase in endotoxin and IL-8 with an impact on clinical outcome.

Activation of the cardiac interleukin-6 system in advanced heart failure

OBJECTIVES

The study objective was to assess the cardiac expression of interleukin-6 (IL6) and its receptor (IL6R) in advanced heart failure.

BACKGROUND

While IL6 plasma levels are elevated and associated with an impaired prognosis in advanced heart failure, little is known about the intracardiac expression of the IL6 system.

METHODS

Heart tissue was obtained from 20 patients (n=10, idiopathic dilated cardiomyopathy, age 44+/-15 years; n=10, ischemic cardiomyopathy, age 55+/-8 years) at the time of transplantation. Left and right ventricular tissue was subjected to in situ hybridization, Northern blot analysis, and RT-PCR. Signals were quantified by densitometric scanning and corrected for G3PDH-mRNA levels. Right ventricular biopsy specimens (n=11) of patients with arrhythmias and normal cardiac function served as controls. In addition, data were correlated with cardiac catheterization and echocardiography data obtained at transplant evaluation.

RESULTS

Ventricular IL6 and IL6R transcripts were detected in all explant specimens examined. Expression of both mRNA species was higher than in controls (P=0.001). Left ventricular IL6 mRNA levels correlated positively with heart rate (r=0.77; P=0.009), pulmonary capillary wedge pressure (r=0.53; P=0.03), right atrial pressure (r=0.77; P=0.003), and inversely with left ventricular ejection fraction (r=-0.61; P=0.03). Right ventricular IL6 mRNA levels correlated inversely with cardiac index (r=-0.48; P=0.05). IL6R expression did not correlate with hemodynamic data.

CONCLUSIONS

In advanced heart failure, cardiac IL6/IL6R mRNA expression is increased and may play a role in the pathophysiology of advanced heart failure.

The impact of anti-endotoxin core antibodies on endotoxin and cytokine release and ventilation time after cardiac surgery

OBJECTIVES

We hypothesized that a temporary cardiopulmonary bypass (CPB)-induced reduction of endotoxin antibody levels contributes to elevated endotoxin levels and the associated inflammatory consequences, with a significant influence on the postoperative ventilation time period.

BACKGROUND

Cardiac surgery using CPB induces a systemic inflammatory response syndrome with an associated risk of increased postoperative morbidity and mortality.

METHODS

A total of 100 consecutive patients undergoing elective coronary artery bypass graft surgery using CPB were prospectively investigated. Endotoxin core antibodies (immunoglobulin [Ig] M/IgG against lipid A and lipopolysaccharide), endotoxin, interleukin (IL)-1-beta, IL-6, IL-8 and tumor necrosis factor-alpha were measured serially from 24 h preoperatively until 72 h postoperatively.

RESULTS

Eighty-five patients had no complications (group 1), whereas 15 patients required prolonged ventilation (group 2). In both groups, there was a decrease of all antibodies 5 min after CPB onset, compared with baseline values (p < 0.001), an increase of endotoxin and IL-8 peaking at 30 min postoperatively (p < 0.001) and an increase of IL-6 peaking 3 h postoperatively (p < 0.001). In group 2, preoperative antibody levels were lower (p < 0.01)--specifically, the decrease in IgM was significantly stronger and of longer duration (p < 0.002)--and levels of endotoxin (p < 0.001) and IL-8 (p < 0.001) were higher at 30 min postoperatively.

CONCLUSIONS

We conclude that an CPB-associated temporary reduction of anti-endotoxin core antibody levels contributes to elevated endotoxin and IL-8 release. Furthermore, lower levels of IgM anti-endotoxin core antibodies were associated with a greater rise in endotoxin and IL-8, as well as prolonged respirator dependence.

Prediction of morbidity and mortality from cardiac allograft vasculopathy

For assessing clinical events associated with cardiac allograft vasculopathy, parameters relating to nonimmunological or immunological risk factors, epicardial coronary vessels, microvasculature, or left ventricular function may be utilized.

Effects of diets containing olive oil, sunflower oil, or rapeseed oil on the hemostatic system

Various studies have already shown that the fatty acid composition of dietary fat has different effects on hemostasis and platelet function. However, knowledge on this topic is incomplete. In the present study, fifty-eight healthy students received either a 4-week rapeseed oil [high content of monounsaturated fatty acids (MUFA) and high n-3/n-6 PUFA ratio], an olive oil (high content of MUFA, low n-3/n-6 PUFA ratio) or a sunflower oil (low content of MUFA, low n-3/n-6 PUFA ratio) diet. In each group, effects on hemostatic parameters were compared with a wash-in diet rich in saturated fatty acids with respect to intermediate-time effects on the hemostatic system and platelet function. With the olive oil diet, a reduction of coagulation factors VIIc, XIIc, XIIa, and Xc was found, whereas sunflower oil led to lower values of coagulation factors XIIc, XIIa, and IXc. In all study groups levels of plasmin-alpha2-antiplasmin were lower in week 4 than at baseline. Lower fibrinogen binding on platelets was found after the sunflower oil diet, whereas expression of CD62 and spontaneous platelet aggregation were slightly higher after the olive oil diet. However, given the major differences in the fatty acid compositions of the diets, the differences between the groups with respect to hemostasis tended to be small. Therefore, the clinical significance of the present findings remains to be evaluated.

Mesenteric blood flow during cardiopulmonary bypass in pigs

BACKGROUND

Gastrointestinal complications represent a serious problem after cardiopulmonary bypass. Hypoperfusion of the gastrointestinal tract during bypass has been implicated as the cause. We therefore investigated blood flow in the superior mesenteric artery during cardiopulmonary bypass.

METHODS

Mature female pigs (n = 12) were investigated. While six sham-operated animals served as control (group I), six pigs underwent normothermic cardiopulmonary bypass for 180 minutes (group II). Bypass flow was 2.4 l/m2/minute. Standard regimens for anesthesia and cardiopulmonary bypass were used. Blood flow in the superior mesenteric artery was assessed by Doppler flowmetry.

RESULTS

Blood flow in the superior mesenteric artery did not change significantly in group I. In group II, mesenteric blood flow increased significantly from baseline at 120, 150, and 180 minutes. Oxygen consumption in the mesenteric circulation increased significantly in group II at 90 and 180 minutes compared to baseline, as well as oxygen extraction. Lactate content in the mesenteric vein in group II increased compared to control at 30, 90 and 180 minutes.

CONCLUSION

Overall gastrointestinal blood flow is not impaired during cardiopulmonary bypass in this animal model. Instead, gastrointestinal blood flow increased during normothermic cardiopulmonary bypass as well as oxygen consumption.

Transplant vasculopathy: a model for coronary artery disease?

Although transplant vasculopathy and native atherosclerosis are clinically and pathologically different entities, the pathogenesis of both diseases exhibits some common mechanisms. Both may be regarded as responses to injury within a broadened concept of the immune system. Alloantigens (e.g. on donor endothelial cells) or autoantigens (e.g. oxydized LDL cholesterol) are presented by antigen presenting cells to the T cells of the body's immune system. With the appropriate costimulatory signal, this signal pattern generates a differentiated T cell, B cell, and inflammatory cell response whereas without the second signal, the immune cells undergo apoptosis. In case of immune cell proliferation and differentiation, a coordinated pattern of cytokine release is initiated. Monocyte-derived macrophages are also involved in this process which culminates in rolling, sticking, and diapedesis through the coronary vascular endothelium and phenotype switch of medial smooth muscle cells mediated by generation of growth-promoting cytokines. Thus, viewed within a broadened paradigm of the immune system's role both disease entities may represent different vignettes of an integrated pathophysiological response to an endothelial injury.

Metallothionein: localization in human transplant endomyocardium, relation to cytokines and allograft function

BACKGROUND

The aim of this study was to investigate the role of metallothionein in cardiac transplants in relation to cytokines and allograft function. Recent studies have revealed an association of allograft dysfunction with elevated proinflammatory cytokines independent of cellular rejection. In animal experiments, cytokines induced overexpression of metallothionein, a low-molecular-weight protein implicated in cellular stress response.

METHODS

In 105 consecutive biopsies from 15 patients during the first 3 months after heart transplantation, metallothionein expression was investigated immunohistochemically. Its relation to serum interleukin-6, tumor necrosis factor-alpha, interleukin-2 (IL-2), soluble interleukin-2 receptor rejection, and echocardiographic parameters was determined. Forty-three biopsies of 12 patients with idiopathic ventricular tachycardia served as controls.

RESULTS

Metallothionein expression was demonstrated in small vessels, cardiomyocytes, fibrocytes, and interstitial round cells. A positive relation between interleukin-6 levels and the number of metallothionein-positive small vessels (p < 0.028) was observed. Patients with lower serum IL-2 levels showed significantly higher numbers of metallothionein-positive small vessels (p < 0.043). Grafts with prolonged ischemic time (>150 minutes) showed a significantly higher myocardial metallothionein score (p < 0.021). Metallothionein expression was associated with lower fractional shortening, larger left ventricular end-systolic diameter, and lower mean arterial pressure but not with acute cellular rejection.

CONCLUSIONS

Metallothionein expression is associated with elevated interleukin-6 and decreased interleukin-2 serum levels and left ventricular allograft dysfunction in the absence of rejection.

Systemic inflammatory parameters in patients with atherosclerosis of the coronary and peripheral arteries

Plasma concentration of markers of inflammation are increased in patients with atherosclerosis. However, it is unclear whether the pattern and magnitude of this increase vary with the site and extent of disease. In 147 patients undergoing semiquantitative coronary angiography, we measured the acute-phase reactants C-reactive protein (CRP) or serum amyloid A (SAA); the proinflammatory cytokine interleukin 6 (IL-6); the active and total fractions of the anti-inflammatory cytokine transforming growth factor-beta (TGF-beta); the macrophage activation marker neopterin; and the infection marker procalcitonin. Compared with 62 patients without either coronary artery disease (CAD) or peripheral artery disease (PAD), 57 patients with CAD but no PAD showed greater median CRP (0. 4 versus 0.2 mg/dL, P=0.004) and IL-6 (3.8 versus 1.6 pg/mL, P=0. 007) levels and a lower level of active-TGF-beta (57 versus 100 ng/mL, P=0.038). Moreover, CRP, IL-6, and neopterin levels showed a positive and the active TGF-beta level a negative correlation with the extent of coronary atherosclerosis. Compared with these 57 patients with CAD alone, 15 patients with PAD and CAD had higher median levels of SAA (17 versus 7 mg/mL, P=0.008), IL-6 (12 versus 4 pg/mL, P=0.002), neopterin (14 versus 11 mg/dL, P=0.006), and total TGF-beta (11834 versus 6417 ng/L, P=0.001). However, these strong univariate associations of markers of inflammation and atherosclerosis were lost in multivariate analysis once age, sex, and high density lipoprotein cholesterol or fibrinogen were taken into account. Increased plasma levels of CRP, SAA, IL-6, TGF-beta, neopterin, and procalcitonin constitute an inflammatory signature of advanced atherosclerosis and are correlated with the extent of disease but do not provide discriminatory diagnostic power over and above established risk factors.

The biologic lower detection limit of six ultrasensitive PSA assays

BACKGROUND

The benefit of monitoring patients with prostate cancer (PCA) by ultrasensitive measurement of prostate specific antigen (PSA) is frequently discussed. Usually, the analytic lower detection limit of an ultrasensitive assay is determined by the manufacturer. As the analytic lower detection limit does not take into account interfering factors of human serum, the biologic lower detection limit, which is defined as PSA concentration detected in PSA-free human serum, plus 3 standard deviations, is of greater interest.

MATERIALS AND METHODS

We investigated the biologic lower detection limit of six ultrasensitive PSA assays. Sera from 15 men with bladder cancer after radical cystoprostatectomy and from 30 healthy women were applied. Hence, we expected no PSA of prostatic origin.

RESULTS

The biologic lower detection limit obtained using these sera was up to 30 fold higher (men, 0.29-0.63 ng/ml; women, 0.03-0.69 ng/ml) than the analytic lower detection limit (0.01-0.09 ng/ml).

CONCLUSIONS

PSA measurement in sera obtained from men without prostate and women results in PSA values above the ultrasensitive range. Therefore, advantages provided by ultrasensitive PSA measurement in monitoring PCA patients after radical prostatectomy are limited.

High thoracic epidural anesthesia, but not clonidine, attenuates the perioperative stress response via sympatholysis and reduces the release of troponin T in patients undergoing coronary artery bypass grafting

In this prospective study, we evaluated whether high thoracic epidural anesthesia (TEA) or i.v. clonidine, in addition to general anesthesia, affects the cardiopulmonary bypass- and surgery-associated stress response and incidence of myocardial ischemia by their sympatholytic properties. Seventy patients scheduled for elective coronary artery bypass graft (CABG) received general anesthesia with sufentanil and propofol. TEA was randomly induced before general anesthesia and continued during the study period in 25 (anesthetized dermatomes C6-T10). Another 24 patients received i.v. clonidine as a bolus of 4 microg/kg before the induction of general anesthesia. Clonidine was then infused at a rate of 1 microg x kg(-1) x h(-1) during surgery and at 0.2-0.5 microg x kg(-1) x h(-1) postoperatively. The remaining 21 patients underwent general anesthesia as performed routinely (control). Hemodynamics, plasma epinephrine and norepinephrine, cortisol, the myocardial-specific contractile protein troponin T, and other cardiac enzymes were measured pre- and postoperatively. During the preoperative night and a follow-up of 48 h after surgery, five-lead electrocardiogram monitoring was used for ischemia detection. Both TEA and clonidine reduced the postoperative heart rate compared with the control group without jeopardizing cardiac output or perfusion pressure. Plasma epinephrine increased perioperatively in all groups but was significantly lower in the TEA group. Neither TEA nor clonidine affected the increase in plasma cortisol. The release of troponin T was attenuated by TEA. New ST elevations > or = 0.2 mV or new ST depression > or = 0.1 mV occurred in > 70% of the control patients but only in 40% of the clonidine group and in 50% of the TEA group. We conclude that TEA (but not i.v. clonidine) combined with general anesthesia for CABG demonstrates a beneficial effect on the perioperative stress response and postoperative myocardial ischemia.

IMPLICATIONS

Thoracic epidural anesthesia combined with general anesthesia attenuates the myocardial sympathetic response to cardiopulmonary bypass and cardiac surgery. This is associated with decreased myocardial ischemia as determined by less release of troponin T. These findings may have an impact on the anesthetic management for coronary artery bypass grafting.

Left ventricular assist system support is associated with persistent inflammation and temporary immunosuppression

BACKGROUND

In patients undergoing left-ventricular assist system support, it has not been elucidated to which extent mechanical circulatory support itself as opposed to the underlying condition of endstage heart-failure contributes to perturbation of immune homeostasis.

METHODS

In eleven heart transplant candidates who had to undergo Novacor left-ventricular assist device bridging, we prospectively sampled interleukin-6, T-cell and monocyte subsets and compared them to fifteen UNOS status II patients awaiting cardiac transplantation on medical heart failure treatment as outpatients at the time of LVAS implantation/listing decision as well as 2.0+/-1.2 months and 4.5+/-2.3 months later. In order to assess deviations in both groups from normal values, thirty-two healthy subjects served as reference group.

RESULTS

Patients undergoing Novacor bridging had higher C-reactive protein, leukocyte, neutrophil, and monocyte levels at all three times, and exhibited lower CD3 +, CD4+, CD3+/CD45 RO T-cell and natural killer cell counts than medically treated patients awaiting transplantation 2 months after the LVAS implantation/listing decision. In comparison to controls, both groups had higher levels of inflammatory activation and lower levels of immunocompetence at all three times.

CONCLUSIONS

While both groups of endstage heart failure patients show immunological alterations compared to controls, patients who have to be bridged by the Novacor LVAS exhibit a more pronounced activation of inflammatory markers. This may be due to more advanced heart failure but the device itself also may contribute to more pronounced inflammation and a temporary suppression of immunocompetent cells.

Hemostasis in normotensive and hypertensive men: results of the PROCAM study. The prospective cardiovascular Münster study

BACKGROUND

The greater than normal cardiovascular risk of hypertensive patients could be partly due to an impairment of hemostatic balance found in such individuals.

OBJECTIVE

To examine the relationship between hemostatic variables and blood pressures in 1950 apparently healthy male participants in the prospective cardiovascular Münster study aged 40-65 years.

METHODS

Blood pressure and other variables were determined, including fibrinogen level, coagulation factor VII clotting activity, protein C level, antithrombin III level, plasminogen activator inhibitor-1 level, euglobulin fibrinolytic activity, and von Willebrand factor level.

RESULTS

Age-adjusted mean values of coagulation factor VII clotting activity, plasminogen activator inhibitor-1 level, antithrombin III level, and protein C level in hypertensives and borderline hypertensives were significantly higher than those in normotensive men (e.g. for hypertensive versus normotensive men, coagulation factor VII clotting factor activity 111.5 versus 106.1%, plasminogen activator inhibitor-1 level 5.05 versus 3.22 arbitrary units/ml, and protein C level 111.1 versus 107.0%, P < 0.05-0.01). For most of the hemostatic variables we found positive bivariate correlations to blood pressure (P < or = 0.05). Exceptions were von Willebrand factor level (no correlation to blood pressure), and euglobulin fibrinolytic activity (a negative correlation to systolic blood pressure and no correlation to diastolic blood pressure). Significance persisted in the multiple logistic regression analysis with the exception of the relationships between systolic and diastolic blood pressures and fibrinogen level as well as euglobin fibrinolytic activity after adjustment for age. After adjustment for age and body mass index significance for relationships between systolic blood pressure and coagulation factor VII clotting activity as well as protein C level was also lost.

CONCLUSIONS

We conclude that the greater than normal cardiovascular risk of hypertensive patients is partly due to an imbalance in hemostasis.

T-cell and monocyte subsets, inflammatory molecules, rejection, and hemodynamics early after cardiac transplantation

BACKGROUND

In the early period after cardiac transplantation, differential diagnosis of graft failure due to rejection, infection, and other causes is important but difficult.

METHODS

In 22 consecutive patients undergoing heart transplantation, we prospectively determined levels of interleukin-6 as well as T-cell and monocyte subsets at eight points in time during biopsy and right heart catheterization and within 12 hr of echocardiography during the first 3 months after transplantation.

RESULTS

Worse hemodynamic parameters, as characterized by dichotomization according to median values (pulmonary capillary wedge pressure >10 mmHg, mean pulmonary arterial pressure > 18 mmHg, pulmonary vascular resistance > 115 dyn x sec x cm(-5), right atrial pressure > 5 mmHg, cardiac index <3 L/min/m2, early mitral deceleration time < 135 msec, and isovolumic relaxation time <80 msec), were associated with higher levels of interleukin-6, C-reactive protein, polymorphonuclear cells, CD71+/CD14+ monocytes, and IgM levels and, in contrast, with lower levels of immunocompetence markers such as CD3+ T cells, CD4+ T cells, CD8+ T cells, CD3+/CD25+ T cells, CD4+/ CD45RO+ T cells, NK cells, and lower biopsy scores.

CONCLUSION

Early after cardiac transplantation, elevated levels of inflammatory cells and soluble inflammatory molecules and lower levels of immunocompetence markers are associated with impaired allograft function in the absence of cellular rejection.

Ischemic versus idiopathic cardiomyopathy: differing neurohumoral profiles despite comparable peak oxygen uptake

OBJECTIVE

We tested the hypothesis that neurohormonal and immunological activation differs in ischemic and idiopathic dilated cardiomyopathy since recent intervention trials indicate that ischemic cardiomyopathy seems to carry a worse prognosis than idiopathic cardiomyopathy of comparable clinical severity.

METHODS

In ten patients with ischemic cardiomyopathy undergoing spiroergometric evaluation venous levels of norepinephrine, epinephrine, renin, angiotensin, atrial natriuretic peptide as well as soluble interleukin-2-receptor were determined before, during and 10 min after exercise. Results were compared to sixteen patients with idiopathic cardiomyopathy with similar peak oxygen uptake (13.3+/-3 vs. 13.6+/-3 ml/kg/min; P=ns).

RESULTS

In ischemic patients, norepinephrine, angiotensin, and interleukin-2 receptor levels were significantly higher before, during and after exercise. Interleukin-2-receptor levels correlated with angiotensin.

CONCLUSIONS

We conclude that in ischemic as compared to idiopathic cardiomyopathy, a more pronounced activation of the sympathetic, renin-angiotensin and T-cell immune system is present at rest, during and after exercise. These data may contribute to explain differences in response to intervention and in prognosis. They warrant further investigation.

[Proinflammatory cytokines and cardiac pump function]

In situations of depressed myocardial function, the role of immunological mechanisms has been studied recently. In different pathophysiological situations, such as chronic heart failure, open heart surgery with extracorporal circulation, cardiac transplantation, myocardial infarction and angina pectoris, patterns have been described with elevation of proinflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1, interleukin-6, and reversible myocardial dysfunction, which may represent a final common pathway. The available data suggest a modulation of important determinants of pump function, i.e., contractility, preload, afterload, and heart rate, by cytokines. Potential mechanisms include the beta-adrenoceptor- and nitric oxide pathway, as well as a direct impact on intracellular calcium homeostasis. Interventional strategies based on this understanding are beginning to emerge.

Increased plasma concentrations of serum amyloid A: an indicator of the acute-phase response after cardiopulmonary bypass

OBJECTIVES

To assess the expression of mixed and hepatic venous serum amyloid A (SAA) concentrations and its relationship to plasma concentrations of C-reactive protein, interleukin-6 (IL-6), and endotoxin during and after cardiopulmonary bypass (CPB).

DESIGN

Prospective, consecutive sample with repeated measurements.

SETTING

Surgical intensive care unit (ICU) in a university hospital.

PATIENTS

Twenty patients who underwent elective coronary bypass grafting.

INTERVENTIONS

A radial artery catheter, pulmonary artery catheter, and right hepatic vein catheter were inserted. Blood samples were collected to determine the different mediators, lactate concentrations, and oxygen saturations.

MEASUREMENTS AND MAIN RESULTS

After induction of anesthesia, baseline values were obtained and the following parameters were determined 20 mins after onset of CPB, 20 mins after termination of CPB, at admission to the ICU, and 6, 8, 12, and 24 hrs later: hemodynamics, body core temperature, hepatic venous oxygen saturation, and mixed and hepatic venous lactate, endotoxin, interleukin (IL)-6, C-reactive protein (CRP), and SAA concentrations. Endotoxin and IL-6 plasma concentrations increased during CPB, peaked 6 hrs after admission to the ICU (endotoxin: 23.1 +/- 6.2 pg/mL; IL-6: 646 +/- 104 pg/mL), and decreased thereafter; SAA and CRP concentrations began to increase after 6 and 8 hrs, respectively, with the highest concentrations reached 24 hrs postoperatively (CRP: 14 +/- 3.6 mg/L; SAA: 668 +/- 114 micrograms/mL). Lactate concentrations began to increase 20 mins after CPB, and continued to increase until 12 hrs postoperatively. There were no significant differences between mixed and hepatic venous values of endotoxin, IL-6, CRP, SAA, and lactate (p < .05). Body core temperature, which was < 37.5 degrees C before surgery for all patients, increased 6 hrs after admission to the ICU and peaked 12 hrs postoperatively (38.3 +/- 1.1 degrees C). Hepatic venous oxygen saturation did not change. Correlations were obtained between IL-6 values and heart rate (r2 = .20; p < .005), and endotoxin concentrations and systemic vascular resistance (r2 = .18; p < .001). Body core temperature correlated significantly closer with SAA (r2 = .52; p < .0001) values than with IL-6 (r2 = .27; p < .0001) or CRP (r2 = .16; p < .001) values (p < .05).

CONCLUSIONS

SAA is an additional and sensitive marker of the acute-phase response following CPB; the increase in SAA concentrations parallels the temporary increase in body core temperature and is preceded by endotoxemia and IL-6 secretion.

Effects of dopexamine on creatinine clearance, systemic inflammation, and splanchnic oxygenation in patients undergoing coronary artery bypass grafting

Impairment of splanchnic and peripheral tissue perfusion during cardiopulmonary bypass (CPB) may be responsible for endotoxin-mediated systemic inflammation and acute phase responses. We examined the effects of dopexamine on hemodynamic parameters, creatinine clearance, systemic and splanchnic oxygenation, gastric mucosal pH (pHi), and mixed and hepatic venous plasma levels of endotoxin, interleukin-6 (IL-6), serum amyloid A (SAA), and C-reactive protein (CRP) in 44 patients scheduled for coronary artery bypass grafting. Patients were randomized to receive continuous infusions of 0.5, 1.0, or 2 micrograms.kg-1.min-1 dopexamine (n = 10 per group) or placebo (n = 14) prior to surgery, intraoperatively, and postoperatively. Dopexamine infusion increased systemic oxygen delivery (P < or = 0.01). Hepatic venous oxygen saturation did not change, and pHi decreased during and after CPB in all patients (P < or = 0.01). Postoperative increases in IL-6 were smallest in patients who received 2.0 micrograms.kg-1.min-1 dopexamine (P < or = 0.02). SAA and CRP increases during the postoperative period were less pronounced with dopexamine throughout the study. Creatinine clearance was elevated in all dopexamine groups (P < or = 0.025). This elevation was higher with lower dopexamine doses (P < or = 0.025). We conclude that dopexamine improves creatinine clearance and reduces systemic inflammation without affecting splanchnic oxygenation.

Interleukin-6 correlates with hemodynamic impairment during dobutamine administration in chronic heart failure

Proinflammatory cytokines have been implicated in the pathophysiology of chronic heart failure. We determined mixed venous levels of interleukin-6 (IL6) in 18 heart transplant candidates before, 1, 4, and 24 h after initiation of dobutamine infusion (3 micrograms/kg/min) during hemodynamic evaluation. During the first 4 h of dobutamine, systemic vascular resistance decreased (1358 to 1024 dyn x s x cm-5, P = 0.01) while cardiac index (2.3 to 2.9 l/min/m2, P = 0.008) increased. Both returned to baseline after 24 h. IL6 was elevated at baseline compared to age-matched controls (1.5 (0/4.3) vs. 0 (0/0.5) P = 0.003). There was an increase in IL6 from 1.5 (0/4.3) to 3.6 (0.3/5.3) pg/ml after 24 h (P = 0.04). We found higher IL6 levels in the sicker half of patients as defined by pulmonary capillary wedge pressure > 24 mmHg (P = 0.005), mean pulmonary arterial pressure > or = 35 mmHg (P = 0.01), right atrial pressure > 13 mmHg (P = 0.02), and heart rate > or = 87/min (P = 0.02) as well as mean arterial pressure < 82 mmHg (P = 0.005). In conclusion, in this pilot study IL6 correlates with the severity of chronic heart failure during low dose dobutamine infusion.

Characterization of glucuronidated phase II metabolites of the immunosuppressant cyclosporine in urine of transplant patients using time-of-flight secondary-ion mass spectrometry

The immunosuppressant, cyclosporine, is metabolized in the liver and small intestine to > 30 metabolites. Metabolism and immunosuppressive and toxic potentials of the metabolites are still unclarified. Therefore, search and determination of new metabolites remain an important part of cyclosporine research. In this study, cyclosporine metabolites were determined in 42 urine samples of transplant patients using time-of-flight secondary-ion MS. Besides the known metabolites of phase I and phase II, other groups of new phase II metabolites were detected, and most of them were identified as glucuronidated phase I metabolites. All metabolites were found in the urine of heart, kidney, and bone marrow graft patients, with frequencies in the range of 74% and 12%. The most intensive group of these metabolites was also detected in a HPLC fraction, together with the known glucuronidated AM1c. The concentration of this new metabolic group could be estimated to < or = 5/ml. In conclusion, this work demonstrated that time-of-flight secondary-ion MS is a powerful tool in pharmacological investigations. Furthermore this study showed that phase II metabolism is an important metabolic pathway of cyclosporine in transplant patients.

Impact of left ventricular dysfunction on cytokines, hemodynamics, and outcome in bypass grafting

BACKGROUND

Although patients with reduced left ventricular ejection fraction undergoing cardiac operation experience a higher rate of perioperative complications, the contribution of proinflammatory cytokines released during extracorporeal circulation is not well defined.

METHODS

We compared arterial and mixed venous levels of interleukin-6, tumor necrosis factor-alpha, soluble interleukin-2 receptor, and interleukin-2 at 10 points in time (24 hours before until 48 hours after extracorporeal circulation) in 21 patients with an ejection fraction of less than 0.45 (study group) to 15 patients with an ejection fraction of more than 0.55 (control group) undergoing elective coronary artery bypass grafting. The study and control group differed with regard to left ventricular ejection fraction (0.37 +/- 0.05 versus 0.66 +/- 0.11, p < 0.05) and reperfusion time (35 +/- 42 minutes versus 18 +/- 4 minutes, p = 0.07), but not age, sex, vessel involvement, number of grafts performed, cross-clamp time, extracorporeal circulation time, core temperature, and duration of ventilation.

RESULTS

Six patients in the study group required mechanical support and 1 died. There were no complications in the control group. In the study group, there were higher preoperative interleukin-2 and tumor necrosis factor-alpha levels and a higher maximum cytokine response to extracorporeal circulation for interleukin-2, soluble interleukin-2 receptor, interleukin-6, and tumor necrosis factor-alpha (all p < 0.05). Interleukin-6 correlated with duration of extracorporeal circulation, dose of norepinephrine and epinephrine support, pulmonary capillary wedge pressure, mean pulmonary arterial pressure, right atrial pressure, heart rate, cardiac index, and inversely with systemic vascular resistance. Interleukin-6 was highest in patients with complications. Arterial and venous cytokine levels correlated closely.

CONCLUSIONS

Preoperative left ventricular dysfunction is associated with a higher degree of proinflammatory cytokine release during elective coronary artery bypass grafting. This response is associated with impaired hemodynamics and a higher incidence of perioperative complications.

The relation of interleukin-6, tumor necrosis factor-alpha, IL-2, and IL-2 receptor levels to cellular rejection, allograft dysfunction, and clinical events early after cardiac transplantation

Immunoregulatory cytokines have been implicated in the pathophysiology of graft dysfunction after heart transplantation (HTx). In 15 consecutive patients undergoing HTx we prospectively determined levels of interleukin-6 (IL-6), tumor-necrosis-factor-alpha (TNF-alpha), interleukin-2 (IL-2), and soluble-interleukin-2-receptor (sIL-2-R) at eight points in time during biopsy and right heart catheterization and within 12 hr of echocardiography during the first three months after HTx. Blood was taken from the pulmonary arterial line. IL-6-levels correlated positively with hemodynamic and echocardiographic parameters of pump dysfunction--namely, pulmonary capillary wedge pressure, pulmonary arterial pressure, right atrial pressure, heart rate--and negatively with isovolumic relaxation time and stroke volume independent of the degree of cellular rejection as classified by the ISHLT criteria. A similar pattern was found for TNF-alpha- and sIL-2-R, while IL-2 correlated negatively with left and right heart filling pressures and positively with fractional shortening. In the three patients who died of sepsis or multiorgan failure within the study period IL-6-, TNF-alpha, and sIL-2-R-levels were elevated and IL-2-levels were suppressed compared with the 12 patients with a stable clinical course. IL-6 and sIL-2-R correlated positively while IL-6 and IL-2 correlated negatively. In this pilot study, a cytokine pattern with elevated levels of IL-6, TNF-alpha, and sIL-2-R as well as suppressed levels of IL-2 in the early period after HTx corresponds to impaired hemodynamics independent of cellular rejection and may indicate an unfavorable prognosis. These cytokines may therefore be useful for monitoring and warrant further study.

Arterial and venous cytokine response to cardiopulmonary bypass for low risk CABG and relation to hemodynamics

During and after cardiopulmonary bypass (CPB), cytokines may affect cardiac performance and the immune response and are therefore of diagnostic and therapeutic interest. We have used EIA/EASIA kits to measure arterial and venous levels of interleukin-1-beta (IL-1-beta), IL-2, IL-2 receptor (IL-2-R), IL-6, tumor necrosis factor (TNF)-alpha and interferon (IFN)-gamma in 12 men and 3 women (mean age 59.4 +/- 8.5 years, mean left ventricular ejection fraction 66 +/- 11%, average of 2.5 +/- 0.64 vessels affected by disease) undergoing elective coronary artery bypass grafting (CABG). On average each patient received 3 +/- 0.85 bypass grafts and required a postoperative maximum dopamine-dose of 3.8 micrograms/kg per min. Mean CPB and operation times were 60 +/- 21 min, and 132 +/- 16 min, respectively. During CPB, the venous levels of IL-2 temporarily decreased from 234 to 0 (p < 0.05) pg/ml and arterial and venous levels of IL-2-R temporarily decreased from 28 to 16, and 36 to 18 pM (p < 0.05), respectively. After termination of CPB, there was an increase in the arterial and venous levels of IL-6 from below 3 to 253 and 277 pg/ml (p < 0.05) and TNF-alpha from 1.1 to 5.7 and 0.7 to 4.0 pg/ml, respectively (p < 0.05). Tumor necrosis factor-alpha-increases peaked 30 min, and IL-6 increases peaked 4 h after termination of CPB. Twenty-four hours after the end of CPB, IL-6 showed a tendency to return to baseline, but still remained significantly elevated.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonsynonymous polymorphic sites in the apolipoprotein (apo) A-IV gene are associated with changes in the concentration of apo B- and apo A-I-containing lipoproteins in a normal population

The aims of this study were to detect polymorphic sites in the apolipoprotein (apo) A-IV gene, to establish their frequencies, to determine potential haplotypes, and to investigate the role of these polymorphisms in lipid metabolism. A sequencing study of four individuals led to the identification of two synonymous mutations (codons 9 and 54) and three nonsynonymous mutations (Val-8----Met, Gln360----His, and Thr347----Ser) and of a VNTR polymorphism within a series of three or four CTGT repeats in the noncoding region of exon 3. Frequencies of these polymorphisms were determined in 291 students by using naturally occurring (BstEII for the synonymous mutation in codon 54, HinfI for Thr347----Ser, and Fnu4HI for Gln360----His) or artificially introduced restriction-enzyme cutting sites (BstEII for the synonymous mutation in codon 9 and MamI for Val-8----Met), subsequent to PCR amplification. The four-base deletion/insertion polymorphism and its localization cis or trans to the mutations in codons 347 and 360 were studied by direct sequencing of PCR-amplified DNA from 87 students. Frequencies of the rarer alleles were .007 for apo A-IV-8:Met, .04 for the synonymous mutation in codon 9, .14 for the synonymous mutation in codon 54, .16 for apo A-IV347:Ser, .07 for apo A-IV360:His, and .39 for the four-base of insertion. Apo A-IV360:His in all cases was cis-localized to the (CTGT)3 repeat and apo A-IV347:Thr; and apo A-IV347:Ser was cis-localized to the (CTGT)4 repeat and apo A-IV360:Gln. Four haplotypes formed from these three polymorphic sites were thus found. The apo A-IV347:Ser allele was associated both with significantly lower plasma apo B concentrations in both sexes and with significantly lower LDL-cholesterol concentrations in men. Heterozygous carriers of apo A-IV360:His exhibited significantly higher concentrations of LDL-cholesterol and lower Lp(a) concentrations, compared with apo A-IV360:Gln homozygotes. We could not confirm the previously reported association of apo A-IV360:His with elevated HDL-cholesterol concentrations. In the population, the Val-8----Met polymorphism was not associated with significantly different lipid concentrations, but in a family study the Met-8 allele was associated with lower HDL-cholesterol and higher LDL-cholesterol concentrations. In conclusion, our results indicate an important role of the apo A-IV gene locus in the metabolism of apo B and, to a lesser extent, apo A-I containing lipoproteins.