Are there differences between patients with and without the homozygous--13910CC genetic variant in the MCM-6 gene upstream from the lactase gene?--A non-randomised, two armed intervention study without control group.

BACKGROUND: Patients with chronic abdominal complaints are a diagnostic challenge for general practitioners (GP). Lactose intolerance (LI) often remains undiagnosed in these patients. Genetic testing for the homozygous -13910CC variant of the MCM-6 gene (LI+) combined with a lactose-restricted diet (LRD) seems to be an acceptable approach. The primary aim of the study was to determine the effect of a LRD in patients with chronic abdominal complaints without a definite diagnosis, with or without the homozygous -13910CC variant. The secondary aim was to determine in family practices the prevalence of undiagnosed LI in these patients. METHODS: In 25 practices around Düsseldorf (Germany) all patients presenting with chronic abdominal complaints for at least 12 months without definite diagnosis were identified by their GPs. Patients participating underwent a MCM-6 gene test and all, including those not genetically predisposed, were asked to keep a LRD for eight weeks. Symptoms were evaluated three times over two months using a standardized gastrointestinal Questionnaire (GIQLI, max. score 144). RESULTS: 210 patients were included. The gene test revealed 29.5% genetically positive for the homozygous T-13910-C mutation (LI+). All patients showed a significant increase in GIQLI scores (improvement) during the observation period, i.e. after four and eight weeks on the diet (p = 0.001, two-way repeated measures ANOVA). There was no significant difference between both groups (LI+/LI-) at any point of symptom measurement. CONCLUSIONS: A lactose-restricted diet showed an unspecific positive effect for patients with chronic abdominal pain without a defined diagnosis. For the LI-group, this could be explained by an unspecific effect of a diet in general, e.g., getting special attention. This can be important for a group of patients probably having psychosomatic complaints focussed on the abdomen.

Slow and continuous application of human recombinant bone morphogenetic protein via biodegradable poly(lactide-co-glycolide) foamspheres.

Bone morphogenetic proteins (BMPs) are multifunctional cytokines that were originally identified as molecules that induce bone and cartilage formation in vivo. In order to increase the efficacy of this potent protein for application in medicine, a carrier system is needed to retain the BMP at the preferred site. Here we present and characterize a slow-release carrier system for pure human recombinant (rh)BMP. The large porous microspheres, called 'foamspheres', are biodegradable, because they consist of poly(lactide-co-glycolide) acids and release loaded rhBMP slowly and continuously. In vivo studies in rodents revealed that rhBMP-loaded foamspheres increased the thickness of the calvarial bone of rats by 222%. When the same amount of rhBMP was applied via a gelatine-based hydrogel, the increase in bone height was only 66%. Thus, the carrier system for rhBMP is an important factor for the efficacy of BMPs.

Preoperative administration of steroids: influence on adhesion molecules and cytokines after cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) is associated with tissue damage mediated by adhesion molecules and cytokines. Prebypass steroid administration may modulate the inflammatory response, resulting in improved postoperative recovery. METHODS: Fifty patients undergoing elective coronary operations under normothermic CPB were randomized into two groups: group A (n = 24) received intravenous methylprednisolone (10 mg/kg) 4 hours preoperatively, and group B (n = 26) served as controls. Cytokines (tumor necrosis factor-alpha [TNF-alpha], interleukin-2R [IL-2R], IL-6, IL-8), soluble adhesion molecules (sE-selectin, sICAM-1), C-reactive protein, and leukocytes were measured before steroid application, then 24 and 48 hours, and 6 days postoperatively. Adhesion molecules were measured by enzyme-linked immunosorbent assay, cytokines by chemiluminescent immunoassay. Postoperatively, hemodynamic measurements, inotropic agent requirements, blood loss, duration of mechanical ventilation, and intensive care unit stay were compared. RESULTS: Aortic cross-clamp and CPB time was similar in both groups. Prednisolone administration reduced postoperative levels of IL-6 (611 versus 92.7 pg/mL; p = 0.003), TNF-alpha (24.4 versus 11.0 pg/L, p = 0.02), and E-selectin (327 versus 107 ng/mL, p = 0.02). Postoperative recovery did not differ between groups. CONCLUSIONS: Preoperative administration of methylprednisolone blunted the increase of IL-6, TNF-alpha, and E-selectin levels after CPB but had no measurable effect on postoperative recovery.

Heterozygosity for the factor V Leiden (G1691A) mutation predisposes renal transplant recipients to thrombotic complications and graft loss.

BACKGROUND: Heterozygosity for a mutation in the coagulation factor V gene (factor V Leiden; FVL) leads to resistance to activated protein C and represents the most common cause of inherited thrombophilia. FVL is associated with a high risk for thromboembolic events and might be a risk factor for venous thrombosis and early graft loss in renal transplant recipients. METHODS: We studied a cohort of 202 renal allograft recipients to assess the impact of the FVL mutation on thrombotic events and graft loss within 1 year after transplantation. We recorded the occurrence of deep venous thrombosis, pulmonary embolism, early graft perfusion defect, and graft loss. The occurrence of these events was then correlated with the presence or absence of heterozygosity for the FVL mutation. RESULTS: Heterozygosity for FVL was detected in 8 (4%) of 202 patients. The incidence of deep venous thrombosis or pulmonary embolism was higher in heterozygous compared with wild-type patients (25% vs. 5.7%, P=0.09). Furthermore, early graft perfusion defect (25% vs. 2.6%; P=0.03) and graft loss within 7 days after transplantation (2/8 vs. 1/194; P=0.004) were significantly more frequent among heterozygous carriers of FVL. All eight FVL carriers were negative for protein C or S deficiency and antiphospholipid and anticardiolipin antibodies, and were not carriers of the G20210A prothrombin mutation. CONCLUSIONS: Heterozygosity for the FVL mutation predisposes renal allograft recipients to venous thromboembolic complications, graft perfusion defects, and early transplant loss. Screening for the FVL mutation and appropriate peri- and postoperative anticoagulation after renal transplantation might prevent these thromboembolic complications.

Genetic predisposition in patients undergoing cardiopulmonary bypass surgery is associated with an increase of inflammatory cytokines.

OBJECTIVE: Cardiopulmonary bypass (CPB) surgery induces a transient rise in pro-inflammatory cytokines typically released by activated monocytes. The E4 variant of apolipoprotein E is a recognized risk factor for atherosclerosis. It has recently been shown that apolipoprotein E affects monocyte functions in vitro and leads to higher levels of median lipoprotein (a) in humans. The aim of the study is to investigate if the E4 genetic variant of apolipoprotein E affects cytokine release after CPB surgery. METHODS: 22 patients were operated on with standard coronary artery bypass grafting. Concentrations of interleukin 8 (IL-8) and tumor necrosis factor (TNF-alpha) were measured by automated Immulite immunoassay at regular intervals within 48 h after surgery. Total apparent cytokine outputs were calculated as area under the curve. Results are expressed as mean+/-standard deviation and compared by unpaired t-test. RESULTS: In the presented patient population 6 (27%) carried the E4 allele. Sixteen (63%) showed no E4 allele. Mean cross clamp time (CCT) was 56.2+/-13.5 min versus 55.7+/-12.1 min and CPB time was 91.8+/-17.5 versus 93.5+/-15.7 min. No statistical difference between E4-carriers and E4 non-carriers regarding CCT and CPB was observed. The total amount of IL-8 and TNF-alpha was higher in patients carrying the E4 genetic variant of apolipoprotein E in comparison to E4 non-carriers (P<0.08, P<0.039). CONCLUSION: The presence of the E4 allele is associated with increased release of IL-8 and TNF-alpha after CBP surgery. The preoperative determination of E4 in patients undergoing cardiac surgery may lead to additional perioperative measures for the treatment of an increased systemic inflammatory response.

Disulfide bridge conformers of mature BMP are inhibitors for heterotopic ossification.

Heterotopic ossification is a frequent complication in patients who have suffered head and neck traumas or undergone total hip replacement. Heterotopic ossification occurs when osteogenic precursor cells present at the ectopic site receive the necessary signal(s) to differentiate into osteoblasts. At the protein level, the key factors in differentiation of cells to the osteogenic lineage are BMPs. Stable BMP variants derived from the identical amino acid sequence but with different disulfide bridge configurations have been investigated and found to be capable of inhibiting ossification in vitro and in vivo in rodents. These findings provide a concept for the straightforward development of a novel class of BMP antagonists that could lead to new treatments for traumatically and genetically induced heterotopic ossification and also, possibly, for disorders in which other members of the TGF-beta superfamily are involved.

Diminished insulin secretory response to glucose but normal insulin and glucagon secretory responses to arginine in a family with maternally inherited diabetes and deafness caused by mitochondrial tRNA(LEU(UUR)) gene mutation.

OBJECTIVE: The effects of glucose, arginine, and glucagon on beta-cell function as well as alpha-cell response to arginine were studied in a family with mitochondrial diabetes. RESEARCH DESIGN AND METHODS: The function of alpha- and beta-cells was assessed in all five siblings carrying the mitochondrial tRNA Leu(UUR) gene mutation at position 3243 and compared with six sex-, age-, and weight-matched control subjects. Insulin and C-peptide responses were evaluated by intravenous glucagon application, intravenous arginine stimulation test, and intravenous glucose tolerance test. Glucagon secretion was assessed during the arginine stimulation test. RESULTS: The glucose disappearance constant (K(g)) value (mean +/- SEM 0.61 +/- 0.04 vs. 1.1 +/- 0.04, P = 0.0002) as well as the acute insulin response to glucose (area under the curve [AUC] 0-10 min, 77.7 +/- 50.7 vs. 1,352.3 +/- 191.5 pmol/l, P = 0.0004) were decreased in all patients. Similarly, glucagon-stimulated C-peptide response was also impaired (728 +/- 111.4 vs. 1,526.7 +/- 157.7 pmol/l, P = 0.005), whereas the insulin response to arginine (AUC) was normal (1,346.9 +/- 710.8 vs. 1,083.2 +/- 132.5 pmol/l, P = 0.699). Acute glucagon response to arginine (AUC) was normal but tended to be higher in the patients than in the control subjects (181.7 +/- 47.5 vs. 90.0 +/- 21.1 pmol/l, P = 0.099). CONCLUSIONS: This study shows impaired insulin and C-peptide secretion in response to a glucose challenge and to glucagon stimulation in diabetic patients with mitochondrial tRNA Leu(UUR) gene mutation, although insulin and glucagon secretory responses to arginine were normal.

Genetic predisposition to bleeding during oral anticoagulant therapy: evidence for common founder mutations (FIXVal-10 and FIXThr-10) and an independent CpG hotspot mutation (FIXThr-10).

The recent discovery of five patients with coumarin sensitive FIX-variants due to a missense mutation in the FIX propeptide, either Ala-10Val or Ala-10Thr, has highlighted a novel type of genetic predisposition to bleeding during oral anticoagulant therapy (OAT). In the present study, we report six additional patients with such FIX variants. Haplotype analysis of FIX polymorphisms revealed a founder effect in the five German and Swiss patients with the Val-10 variant. Also, four Thr-10 variants detected in Germany, Switzerland and Great Britain derived from a common founder. Two Thr-10 variants from USA showed an independent de novo origin at a CpG dinucleotide that in general represents a mutation hotspot. These findings implicate the existence of additional subjects with corresponding variants in the populations of various countries. Even though the rare occurrence of these variants does not justify a general aPTT screening during OAT, it is recommended to monitor each bleeding event during OAT in males in order to exclude a genetic predisposition to bleeding by means of the following testing strategy: a) aPTT-testing in each bleeding complication of male patients during OAT, b) if aPTT is disproportionately prolonged, determination of FIX:C, and c) if FIX:C is disproportionately decreased as compared to FII:C, FVII:C and FX:C, sequencing of exon 2 of the FIX gene. This strategy will provide a cost-effective and safe procedure to identify patients that carry the FIX variants. Moreover, such a strategy accumulates data about the prevalence of these FIX mutations in a given population.

Effects of hypobaric hypoxia on vascular endothelial growth factor and the acute phase response in subjects who are susceptible to high-altitude pulmonary oedema.

In order to investigate whether vascular endothelial growth factor (VEGF) and inflammatory pathways are activated during acute hypobaric hypoxia in subjects who are susceptible to high-altitude pulmonary oedema (HAPE-S), seven HAPE-S and five control subjects were exposed to simulated altitude corresponding to 4000 m in a hypobaric chamber for 1 day. Peripheral venous blood was taken at 450 m (Zürich level) and at 4000 m, and levels of erythropoietin (EPO), VEGF, interleukin-6 (IL-6) and the acute-phase proteins complement C3 (C3), alpha1-antitrypsin (alpha1AT), transferrin (Tf) and C-reactive protein (CRP) were measured. Peripheral arterial oxygen saturation (SaO2) was recorded. Chest radiography was performed before and immediately after the experiment. EPO increased during altitude exposure, correlating with SaO2, in both groups (r = -0.86, P < 0.001). Venous serum VEGF did not show any elevation despite a marked decrease in SaO2 in the HAPE-S subjects [mean (SD) HAPE-S: 69.6 (9.1)%; controls: 78.7 (5.2)%]. C3 and alpha1AT levels increased in HAPE-S during hypobaric hypoxia [from 0.94 (0.11) g/l to 1.07 (0.13) g/l, and from 1.16 (0.08) g/l to 1.49 (0.27) g/l, respectively; P < 0.05], but remained within the clinical reference ranges. No significant elevations of IL-6, Tf or CRP were observed in either group. The post-exposure chest radiography revealed no signs of oedema. We conclude that VEGF is not up-regulated in HAPE-S and thus does not seem to increase critically pulmonary vascular permeability during the 1st day at high altitude. Furthermore, our data provide evidence against a clinically relevant inflammation in the initial phase of exposure to hypoxia in HAPE-S, although C3 and alpha1AT are mildly induced.

Modified ultrafiltration lowers adhesion molecule and cytokine levels after cardiopulmonary bypass without clinical relevance in adults.

OBJECTIVE: Cardiac surgery with cardiopulmonary bypass (CPB) results in expression of cytokines and adhesion molecules (AM) with subsequent inflammatory response. The purpose of the study was to evaluate the clinical impact of modified ultrafiltration (MUF) and its efficacy in reducing cytokines and AM following coronary artery bypass grafting (CABG) in adults. METHODS: A prospective randomized study of 97 patients undergoing elective CABG was designed. Fifty patients were operated on using normothermic and 47 patients using hypothermic CPB. The normothermic group was subdivided into a group with modified ultrafiltration (n = 30) and a group without MUF (n = 20). In the hypothermic group 30 patients received MUF compared to 17 patients serving as controls. MUF was instituted after CPB for 15 min through the arterial and venous bypass circuit lines. Cytokines (IL-6, IL-8, TNF-alpha, IL-2R) and adhesion molecules (sE-selectin, sICAM-1) were measured preoperatively, pre-MUF, in the ultrafiltrate, 24 h, 48 h and 6 days after surgery by chemiluminescent enzyme immunometric assay or enzyme-linked immunosorbent assay (ELISA). Clinical parameters were collected prospectively until discharge. RESULTS: In all patients AM and cytokines were significantly elevated after normothermic and hypothemic CPB. AM and cytokines were significantly higher in hypothermia compared to normothermia. In hypothermic CPB sE-selectin was decreased after 24 h by 37% (P < 0.0063) and by 40% (P < 0.0027) after 48 h postoperatively. ICAM-1 was reduced by 43% (P < 0.0001) after 24 h and by 60% (P < 0.0001) after 6 days. Similar results were seen in cytokines with reduction up to 60% after 24 h. Changes after 48 h were noticeable but not significant. Reduction of AM and cytokines after normothermic CPB was minimal. Neither in normothermia, nor in hypothermia has sIL-2R been effectively removed from the circulation. There were no significant differences in the clinical variables between the patients with or without MUF. CONCLUSION: AM and cytokines are significantly elevated after hypothermic CPB compared to normothermic CPB. MUF led to a significant reduction in cytokine and AM levels after hypothermic CPB, except for IL-2R. MUF showed minimal effect in normothermia. We conclude that MUF is an efficient way to remove cytokines and AM. However, we were unable to demonstrate any significant impact of MUF in outcome of adults after elective CABG.

VEGF levels in asthmatic airways do not correlate with plasma extravasation.

BACKGROUND: Vascular permeability/vascular endothelial growth factor (VEGF) is a multifunctional cytokine which plays a role in chronic inflammation and angiogenesis. Its expression in bronchoalveolar lavage (BAL) has not been determined although VEGF may be relevant to the pathophysiology of asthma in which oedema is an important feature. METHODS: We studied VEGF, albumin and IgA immunoreactive levels in the BAL fluids obtained from 27 chronic stable asthmatics, nine untreated chronic bronchitis patients and 15 control subjects. RESULTS: BAL fluid levels of VEGF and VEGF normalized to IgA were not significantly different in any patient group. Both asthmatic steroid- and non-steroid-treated groups had significantly lower albumin levels in their BAL fluids explaining most of the 179% increased VEGF normalized to albumin ratios in non-steroid treated asthmatics. Moreover, VEGF and albumin markers correlated in control subjects (r = 0.73, P = 0.006) and in chronic bronchitics (r = 0.75, P = 0.03, Spearman test), but not in asthmatics. VEGF was inversely correlated with asthma severity (GINA/NHLBI scores) in non-steroid treated asthmatics (tau = - 0.52, P = 0.009, Kendall test). CONCLUSIONS: Thus, the potential role of VEGF in asthma requires further studies on bronchial biopsies and induced sputum.

Within-patient comparison of effects of different dosages of enalapril on functional capacity and neurohormone levels in patients with chronic heart failure.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibitors are established as first-line therapy in chronic heart failure (CHF). However, conflicting results exist regarding the dose-effect relation of ACE inhibitors. METHODS: We investigated 45 patients (age 55 +/- 10 years) with stable CHF who presented with a maintenance dosage of enalapril of either 5 mg given twice daily (E10; n = 16), 10 mg given twice daily (E20; n = 18), or 20 mg given twice daily (E40; n = 11). This dosage was changed 3 times to treat all patients with lower, higher, and the initial dosages for 4 weeks each. Neurohormones (atrial natriuretic peptide [ANP], brain natriuretic peptide [BNP], and norepinephrine) and enalaprilat trough levels were measured, and ergospirometry was performed. RESULTS: Changes in enalapril dose and enalaprilat level were concordant in 82% of patients, indicating good compliance. After augmentation of enalapril to 40 mg daily, patients in the E10 group showed an increase in maximal oxygen consumption and a decrease in neurohormonal stimulation, whereas the opposite changes were observed after reduction of enalapril to 10 mg daily in patients in the E20 and E40 groups (maximal oxygen consumption: Delta1.1 +/- 2.0 vs -1.0 +/- 1.9 mL. kg(-1). min(-1), P <.01; ANP: Delta-63 +/- 106 vs 19 +/- 54 pg/mL, P <.01; BNP: Delta-62 +/- 104 vs 18 +/- 89 pg/mL, P <.05; norepinephrine: Delta-1.3 +/- 2.9 vs 0.6 +/- 1.8, P <.05). Within-patient comparison showed that neurohormone levels were higher and exercise capacity lower while patients were receiving 10 mg of enalapril per day than when they were receiving 40 mg per day (ANP: 172 +/- 148 vs 139 +/- 122 pg/mL, P <.01; BNP: 193 +/- 244 vs 152 +/- 225 pg/mL, P <.005; norepinephrine: 4.2 +/- 2.2 vs 3.5 +/- 1. 6 nmol/L, P <.05; maximal oxygen consumption 22.0 +/- 4.4 vs 21.3 +/- 4.3 mL. kg(-1). min(-1) P <.05). Similar differences were observed when comparing these variables, and patients had lowest and highest enalaprilat trough levels. CONCLUSIONS: High doses of enalapril resulted in an improvement of exercise capacity and reduction of neurohumoral stimulation, whereas these parameters worsened after reduction of enalapril dose. Thus patients with congestive heart failure may benefit from increasing dosage of ACE inhibitors.

Plasma levels of enalaprilat in chronic therapy of heart failure: relationship to adverse events.

Angiotensin-converting enzyme (ACE) inhibitors are established as first-line therapy in chronic heart failure (CHF). However, little is known about the dosage-plasma-level relationship of ACE inhibitors in CHF and its relation to drug-induced adverse effects. We investigated 45 patients (age 55 +/- 10 years) with stable CHF who presented with a maintenance dosage of enalapril of either 5 mg b.i.d. (E10, n = 16), 10 mg b.i.d. (E20, n = 18), or 20 mg b.i.d. (E40, n = 11). This dosage was changed three times to treat all patients with lower, higher, and, finally, the initial dosage for 4 weeks each. Patients were examined clinically, by questionnaire, and by spiroergometry. In addition, neurohormones (atrial and brain natriuretic peptide and norepinephrine), enalaprilat trough levels, and serum potassium and creatinine were measured. Enalaprilat trough levels differed significantly between the three groups at study entry but also varied markedly within each group. In addition to the dose of enalapril, serum creatinine, severity of CHF, basal metabolic rate, and body weight significantly influenced enalaprilat trough levels (R2 =.84, p <.001). Within-patient comparisons revealed that serum creatinine (107 +/- 26 versus 102 +/- 20 micromol/liter) and potassium (3.8 +/- 0.4 versus 3.7 +/- 0. 3mmol/liter) were higher, cough was more common (scored on a scale of 0-8: 1.7 +/- 2.1 versus 1.4 +/- 1.8), and blood pressure was lower (systolic, 112 +/- 14 versus 117 +/- 13 mm Hg; diastolic, 66 +/- 9 versus 69 +/- 11 mm Hg) on the highest than on the lowest enalaprilat trough level (all p <.05). Highly variable enalaprilat trough levels and the fact that adverse effects were more common on high enalaprilat trough levels provide a rationale for individually adjusting ACE-inhibitor dose in case of adverse effects.

Oxygen uptake kinetics during low level exercise in patients with heart failure: relation to neurohormones, peak oxygen consumption, and clinical findings.

OBJECTIVE: To investigate whether oxygen uptake (VO2) kinetics during low intensity exercise are related to clinical signs, symptoms, and neurohumoral activation independently of peak oxygen consumption in chronic heart failure. DESIGN: Comparison of VO2 kinetics with peak VO2, neurohormones, and clinical signs of chronic heart failure. SETTING: Tertiary care centre. PATIENTS: 48 patients with mild to moderate chronic heart failure. INTERVENTIONS: Treadmill exercise testing with "breath by breath" gas exchange monitoring. Measurement of atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), and noradrenaline. Assessment of clinical findings by questionnaire. MAIN OUTCOME MEASURES: O2 kinetics were defined as O2 deficit (time [rest to steady state] x DeltaVO2 -sigmaVO2 [rest to steady state]; normalised to body weight) and mean response time of oxygen consumption (MRT; O2 deficit/DeltaVO2). RESULTS: VO2 kinetics were weakly to moderately correlated to the peak VO2 (O2 deficit, r = -0.37, p < 0.05; MRT, r = -0.49, p < 0.001). Natriuretic peptides were more closely correlated with MRT (ANF, r = 0.58; BNP, r = 0.53, p < 0.001) than with O2 deficit (ANF, r = 0.48, p = 0.001; BNP, r = 0.37, p < 0.01) or peak VO2 (ANF, r = -0.40; BNP, r = -0.31, p < 0.05). Noradrenaline was correlated with MRT (r = 0. 33, p < 0.05) and O2 deficit (r = 0.39, p < 0.01) but not with peak VO2 (r = -0.20, NS). Symptoms of chronic heart failure were correlated with all indices of oxygen consumption (MRT, r = 0.47, p < 0.01; O2 deficit, r = 0.39, p < 0.01; peak VO2, r = -0.48, p < 0. 01). Multivariate analysis showed that the correlation of VO2 kinetics with neurohormones and symptoms of chronic heart failure was independent of peak VO2 and other variables. CONCLUSIONS: Oxygen kinetics during low intensity exercise may provide additional information over peak VO2 in patients with chronic heart failure, given the better correlation with neurohormones which represent an index of homeostasis of the cardiovascular system.

Analysis of specific immunoglobulin G subclass antibodies for serological diagnosis of Echinococcosis by a standard enzyme-linked immunosorbent assay.

The potential roles of specific antibodies of the different immunoglobulin G (IgG) subclasses in the serological diagnosis of cystic echinococcosis (CE) and alveolar echinococcosis (AE) were investigated by an enzyme-linked immunosorbent assay based on hydatid fluid as antigen. Specific antibodies of subclass 1 were found to be of major importance. In sera collected at the time of diagnosis (i.e., before any therapeutic intervention was initiated) they could be demonstrated in 14 of 15 sera from patients with CE and in all 12 sera from patients with AE. The most discriminatory and the most specific antibodies found in this study belonged to IgG subclass 4. Only one false-positive reaction was observed with 253 sera from healthy volunteers, and no cross-reactions occurred in 80 sera from patients with different parasitic infections. Specific IgG4 antibodies could be demonstrated in 61.0 to 66.7% (CE) or 47.6 to 66.7% (AE) of the cases. Antibody levels of IgG subclass 2 were elevated only moderately, and subclass 3 antibodies were detected in a few cases only. In addition, nonspecific reactions in sera of healthy volunteers or patients with other parasitic infections could partially be attributed to antibodies of subclasses 2 and 3.

Free/total prostate-specific antigen ratio can prevent unnecessary prostate biopsies.

OBJECTIVES: To evaluate the ability of free/total prostate-specific antigen (PSA) ratio to improve specificity of prostate cancer detection, compare Diagnostic Products Corporation (DPC) Immulite and Ciba Corning ACS 180 total (t)PSA assay, and define an assay-specific cutoff point and reflex range for DPC PSA ratio (PSAR). METHODS: In a prospective study, 206 men were enrolled with measurement of both assays. Group 1 consisted of 173 men with a suspicion of prostate cancer (PCA). Thirteen men with known PCA (group 2) and 20 men younger than 32 years (group 3) were used as control groups. RESULTS: Our results in group 1 (115 with benign prostatic hyperplasia [BPH], 58 with PCA) revealed a sensitivity of 82.7%, a specificity of 45.2%, and an accuracy of 57.8% for the DPC tPSA assay (cutoff point more than 4.0 ng/mL) within the entire PSA range. tPSA values of the ACS 180 assay were 1.97-fold higher. Within the tPSA gray zone of 2.5 to 10 ng/mL (66 BPH, 23 PCA), specificity and accuracy of DPC tPSA can be improved by using the DPC PSAR (cutoff point less than 19%) from 33.3% to 71.2% and 42.7% to 70.8%, respectively, maintaining the same sensitivity level of 69.6%. CONCLUSIONS: By combining tPSA testing with PSAR within the gray zone, 39.7% (25 of 63) of unnecessary biopsies can be saved, without missing any additional cancers compared with tPSA testing alone. The optimal reflex range for DPC PSAR is 2.5 to 10 ng/mL and the best PSAR cutoff point for biopsy criterion is less than 19% in our high-risk population, with a cancer yield of 34%. Because we still do not have an international PSA standard, it is important to use assay-specific "normal values" and PSAR cutoff points.