Cytokines (IL1β, IL6, TNFα) and serum cortisol levels may not constitute reliable biomarkers to identify individuals with post-acute sequelae of COVID-19

Background

Post-acute sequelae of COVID-19 (PASC) comprise a broad spectrum of symptoms such as fatigue, general weakness, compromised attention and sleep or anxiety disorders. PASC represents a medical and socio-economic challenge.

Objectives

Our study evaluated cytokines (IL-1β, IL-6 and TNFα) and cortisol levels in a cohort of typical patients with PASC, suffering concentration problems, fatigue and difficulties finding words.

Design

This was a prospective cohort study. Four groups were analysed and compared: those who had never contracted SARS-CoV-2 (n = 13), infected but had no PASC (n = 34), infected with former PASC that resolved (n = 40) and patients with ongoing PASC after infection (n = 91).

Methods

Cytokine and cortisol serum levels were determined in patients' blood samples.

Results

Cytokine levels of IL-1β, IL-6, TNFα and cortisol levels did not differ between groups analysed.

Conclusion

This may indicate a non-organic/psychosomatic genesis of PASC; further studies are needed to elucidate the underlying causes of PACS, and non-organic causes should not be overlooked.

Effect of serum creatinine difference between the Jaffe and the enzymatic method on kidney disease detection and staging

Background

Serum creatinine (SCr), mainly determined by the Jaffe or an enzymatic method, is the central marker to assess kidney function. Deviations between these two methods may affect the diagnosis and staging of acute kidney injury (AKI) and chronic kidney disease (CKD).

Methods

The results of the first parallel SCr measurement (Jaffe and enzymatic method) of adult in- and outpatients in the same serum sample at the University Hospital Essen (Essen, Germany) between 2020-2022 were retrospectively evaluated. A Bland-Altman plot with 95% limits of agreement (LoAs) was used to assess the difference between the Jaffe and the enzymatic SCr (eSCr) method. We used the 2009 Chronic Kidney Disease Epidemiology Collaboration equation for determination of estimated glomerular filtration rate (eGFR) according to the Kidney Disease: Improving Global Outcomes guidelines.

Results

A total of 41 144 parallel SCr measurements were evaluated. On average, Jaffe SCr was 0.07 mg/dl higher than eSCr (LoA -0.12; 0.25 mg/dl). In 19% of all cases there was a different CKD stage when comparing eGFR between both SCr methods, of which 98% resulted in a more severe CKD stage determined with Jaffe SCr. In 1.6% of all cases Jaffe SCr was ≥0.3 mg/dl higher than eSCr.

Conclusion

The present study showed that methods of SCr measurement may affect both the diagnosis and staging of AKI and CKD. This must be taken into account when interpreting measurements of renal function in everyday clinical practice, but also when planning and comparing studies on renal diseases. One should therefore stay with one method for SCr measurement, preferably with the enzymatic method.

Electrolyte imbalance causes suppression of NK and T cell effector function in malignant ascites

BACKGROUND

Malignant ascites commonly occurs in advanced or recurrent stages of epithelial ovarian cancer during peritoneal carcinomatosis and is correlated with poor prognosis. Due to its complex composition of cellular and acellular components malignant ascites creates a unique tumor microenvironment, which mediates immunosuppression and promotes progression of disease. However, the immunosuppressive mechanisms remain poorly understood.

METHODS

In the present study, we explored the antitumor activity of healthy donor NK and T cells directed against ovarian cancer cells in presence of malignant ascites derived from patients with advanced or recurrent peritoneal carcinomatosis. A wide range of methods was used to study the effect of ascites on NK and T cells (FACS, ELISA, EliSpot, qPCR, Live-cell and confocal microscopy, Western blot and electrolyte flux assays). The ascites components were assessed using quantitative analysis (nephelometry, potentiometry and clinical chemistry) and separation methods (dialysis, ultracentrifugal filtration and lipid depletion).

RESULTS

Ascites rapidly inhibited NK cell degranulation, tumor lysis, cytokine secretion and calcium signaling. Similarly, target independent NK and T cell activation was impaired in ascites environment. We identified imbalanced electrolytes in ascites as crucial factors causing extensive immunosuppression of NK and T cells. Specifically, high sodium, low chloride and low potassium content significantly suppressed NK-mediated cytotoxicity. Electrolyte imbalance led to changes in transcription and protein expression of electrolyte channels and impaired NK and T cell activation. Selected inhibitors of sodium electrolyte channels restored intracellular calcium flux, conjugation, degranulation and transcript expression of signaling molecules. The levels of ascites-mediated immunosuppression and sodium/chloride/potassium imbalance correlated with poor patient outcome and selected molecular alterations were confirmed in immune cells from ovarian cancer patients.

CONCLUSION

Our data suggest a novel electrolyte-based mechanism of immunosuppression in malignant ascites of patients with peritoneal carcinomatosis. We show for the first time that the immunosuppression of NK cytotoxicity in coculture assays is correlated to patient poor survival. Therapeutic application of sodium channel inhibitors may provide new means for restoring immune cell activity in ascites or similar electrolyte imbalanced environments.

Influence of the Single Nucleotide Polymorphisms rs12252 and rs34481144 in IFITM3 on the Antibody Response after Vaccination against COVID-19

The COVID-19 mRNA vaccine is the first mRNA vaccine approved for human administration by both the U.S. Food and Drug Administration and the European Medicines Agency. Studies have shown that the immune response and the decay of immunity after vaccination with the COVID-19 vaccines are variable within a population. Host genetic factors probably contribute to this variability. In this study, we investigated the effect of the single-nucleotide polymorphisms rs12252 and rs34481144 in the interferon-induced transmembrane protein (IFITM) 3 gene on the humoral immune response after vaccination against COVID-19 with mRNA vaccines. Blood samples were collected from 1893 healthcare workers and medical students at multiple time points post-vaccination and antibody titers against the SARS-CoV-2 S1 protein receptor binding domain were determined at all time points. All participants were genotyped for the rs34481144 and rs12252 polymorphisms in the IFITM3 gene. After the second and third vaccinations, antibody titer levels increased at one month and decreased at six months (p < 0.0001) and were higher after the booster vaccination than after the basic immunization (p < 0.0001). Participants vaccinated with mRNA-1273 had a higher humoral immune response than participants vaccinated with BNT162b2. rs12252 had no effect on the antibody response. In contrast, carriers of the GG genotype in rs34481144 vaccinated with BNT162b2 had a lower humoral immune response compared to A allele carriers, which reached statistical significance on the day of the second vaccination (p = 0.03) and one month after the second vaccination (p = 0.04). Further studies on the influence of rs12252 and rs34481144 on the humoral immune response after vaccination against COVID-19 are needed.

Cardiovascular risk factors and signs of subclinical atherosclerosis in the Heinz Nixdorf Recall Study

INTRODUCTION

Modern investigation modalities allow markers of atherosclerosis to be detected at a subclinical stage. The aim of the study was to analyze the prevalence of these markers in relation to traditional risk factors.

METHODS

The population based study included 4814 participants, aged 45 to 75 years, with a response rate of 55.8% of those contacted. The patients' history, psychosocial and environmental risk factors were assessed.

RESULTS

The prevalence of obesity was 26.2% in men and 28.1% in women, 26% of men and 21% of women were smokers. Hypertension was found in 46% of men and 31% of women, diabetes in 9.3% of men and 6.3% of women. Markers of subclinical peripheral arterial disease were found in 6.4% of men and 5.1% of women, of subclinical carotid artery disease in 43.2% and 30.7%, and of subclinical coronary artery calcification in 82.3% and 55.2%, respectively. The prevalence of coronary calcification measured using an Agatston Score >100 was in 40% in men and 15% in women, using a score >400, 16.8% and 4.5%, respectively.

DISCUSSION

A high prevalence of subclinical atherosclerosis was found in the older population. The follow-up period will demonstrate whether the detection of markers of subclinical atherosclerosis will improve risk stratification beyond that offered by traditional risk factors.

Analysis of Intrathecal Interleukin-6 As a Potential Predictive Factor for Vasospasm in Subarachnoid Hemorrhage

OBJECTIVE

Inflammatory response seems to be one of the relevant pathophysiological aspects for developing vasospasm in subarachnoid hemorrhage. The probable diagnostic value of intrathecal proinflammatory markers is still unclear and is assessed in this study.

METHODS

We analyzed daily clinical data and laboratory tests of the cerebrospinal fluid (CSF) of 64 patients with mostly poor-grade subarachnoid hemorrhage during a period of 14 days. Special attention was given to the relationship between the development of vasospasm and the time course of the intrathecal interleukin (IL)-6 concentrations in CSF (IL-6CSF). The potential power of IL-6CSF for predicting vasospasm was studied.

RESULTS

Vasospasm developed in 28.1% of the patients, with a mean onset of 6.4 days after bleeding, and was detected by conventional methods. Patients with vasospasm demonstrated statistically significant higher median values of IL-6CSF on Days 4 and 5 (P < 0.05). Most importantly, the increase of IL-6CSF preceded the conventional signs of vasospasm. A cut-off value of IL-6CSF of at least 2000 pg/ml on Day 4 yielded an 11.72-fold higher relative risk (95% confidence interval, 2.93-46.60) of developing vasospasm, predicting vasospasm with a sensitivity of 88.9% and a specificity of 78.3%. We found a statistically significant correlation between IL-6CSF and delayed cerebral ischemia for Day 7 (P = 0.03). However, there was no correlation with IL-6CSF on any other day and outcome.

CONCLUSION

IL-6CSF seems to be a reliable early marker for predicting vasospasm after subarachnoid hemorrhage on Days 4 and 5 before clinical onset.

Sex related cardiovascular risk stratification based on quantification of atherosclerosis and inflammation

OBJECTIVES

An ongoing population-based cohort study was used to assess the prevalence of risk factors, signs of inflammation based on the degree of high sensitive C-reactive protein (hs-CRP) and subclinical atherosclerosis using electron beam computed tomography for detection of coronary artery calcification (CAC). We evaluated the sex related cardiovascular risk stratification based on quantification of subclinical atherosclerosis and inflammation.

BACKGROUND

The National Cholesterol Education Program in Adult Treatment Panel III (NCEP ATP III) suggests using CAC and hs-CRP in individuals at intermediate risk. The effect on risk stratification was not yet tested in the general population.

METHODS

In the Heinz Nixdorf Recall study 4066 (93.2%) subjects without and 280 (6.8%) of 4345 subjects with coronary artery disease (CAD) (age 45-75 years) were screened in whom data for CAC, hs-CRP, and all risk factors for calculating the Framingham risk score (FRS) were available. This subset of participants was representative of the overall population. Age-adjusted prevalence rate ratios (RR) for prevalence of CAD in relation to risk factors were determined. Framingham risk score groups and NCEP ATP III-based risk categories were calculated. Alterations in risk classification were analyzed using three CAC and hs-CRP categories each: (1) CAC<100, 100-399 and > or =400 or >75th percentile, respectively, (2) hs-CRP< or =1, 1-3, >3mg/L, and (3) a combined CAC and hs-CRP score.

RESULTS

Highest RRs of CAD were found for high CAC versus low CAC in men (RR=18.2, 95% CI=10.6-31.3) and for the combined CAC+hs-CRP index in women (RR=11.0, 95% CI=5.1-23.6, both p<0.0001). For high versus low hs-CRP-values a significant RR was found for women only (RR=2.5, 95% CI=1.3-4.6, p<0.01). RRs for other risk factors like hyperlipidemia, HDL, smoking, BMI>30 kg/m(2) were much smaller showing sex differences as well. Thirty percent males and 71% females were classified as low NCEP ATP III risk, 38% and 20% as intermediate and 31% and 9% as high risk. Adding CAC and hs-CRP to NCEP ATP risk categories changed distribution of risk categories considerably with strong differences between sexes. This sex dependence in the magnitude of change in risk categories nearly vanished, when the combined index of CAC and hs-CRP was used.

CONCLUSIONS

NCEP ATP III risk categories are significantly and sex-dependently altered using CAC and hs-CRP. CAC is suggested to be of highest value in men; hs-CRP seems to be of complementary value only in women. Measuring atherosclerotic inflammation may improve sex-related risk prediction in a general population.

Disseminated intravascular clotting associated with Fc-receptor IIa-mediated platelet activation in a patient with endocarditis after aortic valve replacement

This report describes fatal disseminated cardiovascular thrombosis associated with Fc-receptor IIa-mediated platelet activation during surgery for aortic valve replacement in a patient with endocarditis. The patient's serum contained antibodies which strongly activated platelets via the Fc-receptor IIa. Antibodies did not bind to platelet factor 4 or aprotinin and binding was independent of heparin. The mechanisms and differential diagnosis for such a complication are discussed. Our data show for the first time in a patient with endocarditis that, beside HIT, other immune complexes can induce massive intravascular coagulation via platelet Fc-receptor IIa activation.

Serum cystatin C - a superior marker of rapidly reduced glomerular filtration after uninephrectomy in kidney donors compared to creatinine

AIMS

Acute renal failure (ARF), defined by a rapid decrease of glomerular filtration rate (GFR), is associated with high mortality. Early and accurate detection of decreasing GFR is critical to prevent the progression of ARF and to potentially improve its outcome. Serum creatinine, the conventional GFR marker, has major limitations. We prospectively evaluated whether serum cystatin C detected a rapid GFR decrease earlier and more accurately than serum creatinine.

METHODS

In ten patients undergoing nephrectomy for living related kidney transplantation, serum creatinine and cystatin C were determined daily. The decrease of GFR was quantitated preoperatively by creatinine clearance and MAG3 scintigraphy. The GFR decrease was defined by a 50-100% increase of cystatin C or creatinine from preoperative values. Ten patients without renal impairment served as controls.

RESULTS

Initially, patients had a creatinine clearance of 105 +/- 14 ml/min/1.73 m2. Due to nephrectomy, patients lost 45 +/- 3% of their renal function. Serum cystatin C significantly increased already one, serum creatinine two days after nephrectomy. Cystatin C demonstrated an increase by 50-100% 1.4 +/- 0.9 days earlier than creatinine (p = 0.009). Serum cystatin C performed well detecting the GFR decrease with higher diagnostic values compared to creatinine. This was indicated by a sensitivity of 50, 70 and 80% of cystatin C to detect the GFR decrease on the three days following nephrectomy.

CONCLUSIONS

Serum cystatin C detects rapid GFR decreases one to two days earlier than creatinine. Cystatin C is an early and accurate marker to detect rapid GFR decreases as in ARF.

Measurement of urinary cystatin C by particle-enhanced nephelometric immunoassay: precision, interferences, stability and reference range

BACKGROUND

Urinary excretion of the low molecular weight protein cystatin C is a marker of renal disorders and a good predictor of the severity of acute tubular necrosis. We evaluated the measurement of urinary cystatin C and determined its reference range.

METHODS

Measurement of urinary cystatin C by particle-enhanced nephelometric immunoassay (PENIA) in 102 patients with various renal disorders and 133 healthy controls. We assessed the influence of pH and temperature, interferences on urinary cystatin C measurement, as well as cystatin C adsorption to plastic.

RESULTS

The upper reference value for urinary cystatin C was 0.28 mg/L, independent of age and gender. Accuracy and linearity (r(2)=0.996) were excellent. Intra- and inter-assay precision were < or =4.8% and < or =5.2%, respectively. Albumin (< or =160 g/L), bilirubin (< or =500 micromol/L) and haemoglobin (< or =210 micromol/L) did not show interferences. Urinary cystatin C was stable, at urine pH> or =5, at -20 degrees C and 4 degrees C for 7 days, and at 20 degrees C for 48 h. Freezing and thawing did not influence urinary cystatin C concentration. There was no adsorption of cystatin C to plastic.

CONCLUSION

Urinary cystatin C measurement by PENIA is precise. High stability and no interference add to the practicability of urinary cystatin C as a routine biochemical test.

Cardiovascular risk factors and probability for cardiovascular events in HIV-infected patients - part III: age differences

OBJECTIVE

In recent years, concerns have been growing about an elevated rate of cardiovascular diseases in HIV-infected patients due to side effects of antiretroviral therapy. The present study analyses the cardiovascular risk profile and the probability of cardiovascular events with regard to the age of HIV-infected patients.

METHODS

Cardiovascular risk factors of 309 HIV-infected adults were analysed. Patients were divided into four groups: 18-30 years (group 1), 31-40 years (group 2), 41-50 years (group 3), > 50 years (group 4). Overall 10-years probability for cardiovascular events was evaluated by the Framingham algorithm.

RESULTS

Differences between the groups were detected in cardiovascular risk factors including changes in lipid- and glucose metabolism. Lipid values increased with elevated age, such as total cholesterol concentration (Mean +/- SEM in group 1 vs. group 4: 4.71 +/- 0.20 to 6.36 +/- 0.21 mmol/L, p < 0.05), LDL-cholesterol concentration (2.86 +/- 0.17 vs. 4.17 +/- 0.21 mmol/L, p < 0.05) and triglyceride concentration (1.56 +/- 0.14 vs. 3.48 +/- 0.40 mmol/L, p < 0.05). HDL-cholesterol concentration did not show a significant difference (1.15 +/- 0.03 mmol/L). Glucose concentration increased with elevated age in HIV-infected patients (5.28 +/- 0.19 vs. 6.46 +/- 0.24 mmHg, p < 0.05), but there was no significant difference in HbA1c - concentration, blood pressure and smoking rate between the groups. The overall 10-years probability for cardiovascular events was higher in group 1 (median: 1.9%) than in group 4 (20.5%; p < 0.01).

CONCLUSIONS

The risk of cardiovascular events is related to the age in HIV-infected patients. Therefore, an increased duration of life due to a more effective antiretroviral therapy will have a significant impact on the rate of cardiovascular events in this patient population. In the future, further increase of cardiovascular events in HIV-infected patients may be expected.

Cardiovascular risk factors and probability for cardiovascular events in HIV-infected patients. Part II: gender differences

OBJECTIVE

Due to the side effects of antiretroviral therapy and long term survival there is an increasing concern of an elevated rate of cardiovascular diseases in HIV-infected patients. The present study analysed the cardiovascular risk profile and the probability of cardiovascular events in HIV-infected patients, due to differences of gender.

METHODS

Cardiovascular risk factors of 309 HIV-infected adults, including 240 males were analysed. Overall 10-years probability for cardiovascular events was evaluated by the Framingham algorithm.

RESULTS

Gender differences were detected in cardiovascular risk factors such as lipid values, blood pressure and the rate of smoking. Tobacco use was much more common in HIV-infected males compared with HIV-infected females (67.5% vs. 49.3%; p<0.001). Although no significant difference was noticed in total cholesterol (5.49 +/- 0.09 vs. 5.53 +/- 0.19 mmol/L, p = 0.84), the HDL-cholesterol concentration was significantly lower (1.09 +/- 0.03 vs. 1.36 +/- 0.06 mmol/L, p < 0.001) and the triglyceride concentration higher (3.01 +/- 0.21 vs. 2.06 +/- 0.26 mmol/L, p = 0.02) in HIV-infected males compared to HIV-infected females. Additionally, systolic blood pressure was higher in HIV-infected males compared with HIV-infected females (123.1 +/- 1.1 vs. 115.4 +/- 2.1 mmHg, p < 0.01). No significant differences were detected in HbA1c concentrations between both groups (5.15 +/- 0.07 vs. 5.31 +/- 0.11, p = 0.26). The overall 10-years probability for cardiovascular events was 8.7% (median) in HIV-infected males and 1.7% in HIV-infected females (p < 0.0001).

CONCLUSIONS

In the present study, we observed gender differences in the cardiovascular risk profile of HIV-infected individuals. The risk of premature atherosclerosis and associated cardiovascular events was significantly higher in HIV-infected males.

Cardiovascular risk factors and probability for cardiovascular events in HIV-infected patients: part I. Differences due to the acquisition of HIV-infection

OBJECTIVE

Due to side effects, such as hyperlipidaemia and insulin resistance, there is an increasing concern that antiretroviral drugs lead to an epidemic of cardiovascular diseases in HIV-infected patients. The present study characterizes the cardiovascular risk profile of HIV-infected individuals, due to the acquisition of HIV-infection.

METHODS

Cardiovascular risk factors of 309 HIV-infected adults (HIV-acquisition: 59.2% by homosexual contact (group 1), 28.5% by heterosexual contact (group 2), 9.1% by intravenous drug abuse (group 3) and 3.2% by blood transfusion (group 4)) were analysed. Overall 10-years probability for cardiovascular events was analysed by the Framingham algorithm.

RESULTS

Tobacco use was more common in group 1 subjects compared with group 2 subjects (67% vs. 52%; p<0.05). Additionally, group 1 subjects exhibited elevated total cholesterol (5.6 +/- 0.1 mmol/L vs. 4.8 +/- 0.3), LDL-cholesterol (3.6 +/- 0.1 mmol/L vs. 2.8 +/- 0.2) and triglyceride concentrations (3.2 +/- 0.3 mmol/L vs. 1.7 +/- 0.2) compared with group 3 (all p<0.05). No significant differences between the groups were detected in glucose metabolism. The overall 10-years probability for cardiovascular events was significantly higher in group 1 compared with group 2 and group 3 (12.2 +/- 0.8% vs. 6.6 +/- 0.9% and 7.9 +/- 1.6%, p<0.05).

CONCLUSIONS

The cardiovascular risk profile differs between subgroups of HIV-infected individuals, leading to significant higher probability of cardiovascular events in group 1 subjects. The risk of premature atherosclerosis by HIV-infected individuals and therapeutic options remains to be established.

Preprocedural statin medication reduces the extent of periprocedural non-Q-wave myocardial infarction

BACKGROUND

Stenting-related myocardial injury has been recognized as a frequent and prognostically important event, the extent of which depends on microcirculatory impairment in association with platelet aggregation, inflammation, and increased oxidative stress. Recent studies underscored the non-lipid-lowering effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) with antithrombotic, antiinflammatory, and antioxidative aspects. Thus, we tested the hypothesis that preprocedural statin therapy is associated with a reduction in the extent of stenting-related myocardial injury.

METHODS AND RESULTS

We stratified 296 consecutive patients who were undergoing stenting of a de novo stenosis according to the preprocedural status of statin therapy (229 statin-treated and 67 control patients). Incidence of periprocedural myocardial injury was assessed by analysis of creatine kinase (CK; upper limit of normal [ULN] 70 IU/L for women, 80 IU/L for men) and cardiac troponin T (cTnT; bedside test; threshold 0.1 ng/mL) before and 6, 12, and 24 hours after the intervention. Relative to control patients, the incidence of CK elevation >3x ULN was more than 90% lower in statin-treated patients (0.4% versus 6.0%, P=0.01). Statin therapy was the only factor independently associated with a lower risk of CK elevation >3x ULN (OR: 0.08, 95% CI: 0.01 to 0.75; P=0.03). The overall incidences of CK and cardiac troponin T elevation were slightly lower in statin-treated than in control patients (14.4% versus 20.9%, P=0.3, and 17.9% versus 22.4%, P=0.5, respectively).

CONCLUSIONS

Preprocedural statin therapy is associated with a reduction in the incidence of larger-sized, stenting-related myocardial infarctions. Prospective, randomized trials are warranted to further assess this cardioprotective effect of statins in coronary intervention.

Prognostic implication of cardiac troponin T increase following stent implantation

OBJECTIVE

To identify the incidence and clinical significance of myocardial injury following elective stent implantation.

DESIGN

Prospective clinical study with 278 consecutive patients undergoing stenting of de novo coronary or saphenous vein graft lesions. Incidence of periprocedural myocardial injury was assessed by analysis of 12 lead ECG, creatine kinase (CK; upper limit of normal (ULN) 70 IU/l for women, 80 IU/l for men), and cardiac troponin T (cTnT; point of care test; threshold 0.1 ng/ml) before and 6, 12, and 24 hours after the intervention. Major adverse cardiac events (MACE: acute myocardial infarction, bypass surgery, and cardiac death) were recorded during clinical follow up (mean (SD) 7.8 (5.3) months).

RESULTS

Following elective stenting, the rate of a positive cTnT status was 17.3%, the rate of CK increase of 1-3x ULN 14.7%, the rate of CK increase of > 3x ULN 1.4%, and the rate of Q wave myocardial infarction 0.4%. Cardiac mortality during follow up was higher in patients with postprocedurally increased CK (7.1% v 1.3%, p = 0.01, log rank) and cTnT (9.1% v 0.9%, p < 0.001, log rank). In addition, postprocedurally increased cTnT was associated with a higher overall incidence of MACE (13.1% v 4.0%, p < 0.01, log rank) and was identified as an independent factor for MACE during follow up (hazard ratio 3.27, 95% confidence interval 1.14 to 9.41, p = 0.028).

CONCLUSIONS

Following elective stent implantation, a positive cTnT status identified patients at risk of a worse long term outcome. Treatment strategies have to be developed that lead to prognostic improvement by reducing periprocedural myocardial injury.

Abnormal Coronary Flow Velocity Reserve After Coronary Intervention Is Associated With Cardiac Marker Elevation

Background —Residual reduction of relative coronary flow velocity reserve (rCVR) after successful coronary intervention has been related to microvascular impairment. However, the incidence of cardiac enzyme elevation as a surrogate marker of an underlying embolic myocardial injury in these cases has not been studied.

Methods and Results —A series of 55 consecutive patients with successful coronary stenting, periprocedural intracoronary Doppler analysis, and determination of creatine kinase (CK; upper limit of normal [ULN] for women 70 IU/L, for men 80 IU/L) and cardiac troponin T (cTnT; bedside test, threshold 0.1 ng/mL) before and 6, 12, and 24 hours after intervention were studied. Postprocedural rCVR was the only intracoronary Doppler parameter that independently correlated with cTnT ( r =−0.498, P <0.001) and CK outcome ( r =−0.406, P =0.002). Receiver operating characteristic analysis identified a postprocedural rCVR of 0.78 as the best discriminating value, with a sensitivity of 83.3% and 69.2% and a specificity of 79.1% and 76.2% for detection of cTnT and CK elevation, respectively. Stratified according to this cutoff value, the incidence of cTnT elevation was 52.6% in patients with (n=19) and 5.6% in patients without (n=36) a postprocedural rCVR <0.78 ( P <0.001), associated with a CK elevation >1 times the ULN in 36.8% and 5.6% ( P =0.005) of patients, respectively.

Conclusions —Cardiac marker elevation can frequently be found after coronary procedures that are associated with a persistent reduction of rCVR, indicating procedural embolization of atherothrombotic debris with microvascular impairment and myocardial injury as a potential underlying mechanism.

[Biochemical markers of ischemic and non-ischemic myocardial damage]

BACKGROUND

Biochemical markers have been an integrative part of non-invasive diagnostic strategies in cardiology for nearly 50 years, experiencing a renascence by the recently acknowledged prognostic potential of cardiac troponins in acute coronary syndromes.

DIAGNOSIS

According to the guidelines of the National Academy of Clinical Biochemistry and the International Federation of Clinical Chemistry cardiac troponin T and cardiac troponin I should be considered as the new "gold markers" of ischemic myocardial injury. One characteristic feature of these new markers is the improved diagnostic potential, reflected by the choice of two cut-off values to distinguish minor myocardial injury from acute myocardial infarction. In addition, cardiac troponins allow risk stratification in the clinical setting of acute coronary syndromes: approximately threefold higher mortality rate for patients with rest angina or ST segment elevation and cardiac troponin elevation on admission. Other indications for cardiac marker analysis are monitoring of therapeutic success in case of invasive and non-invasive reperfusion strategies and non-invasive diagnosis of non-ischemic myocardial injury (myocarditis, cardiac contusion and chemotherapy).

CONCLUSION

Biochemical cardiac markers are a useful tool in the diagnosis of both ischemic and non-ischemic myocardial injury. Among these, cardiac troponins seem to become the gold markers for the new millennium.

Elevation of intracranial pressure in acute AIDS-related cryptococcal meningitis

Prior to the AIDS-era, elevation of intracranial pressure was known to be a typical complication of cryptococcal meningitis associated with an increased risk of early death. In AIDS-patients, however, the prevalence and clinical significance of this complication are as yet unclear. We analysed clinical features and courses, CSF findings, serological results and neuroimaging scans in acute cryptococcal meningitis in eight patients with AIDS. Five showed symptoms and signs compatible with raised intracranial pressure, which was life-threatening in one and the most probable cause of death in another. Serial monitoring of intracranial pressure together with repeated CSF analysis revealed that severe intracranial pressure elevation in AIDS related cryptococcal meningitis can occur in spite of effective antimycotic treatment, does not depend on an increased CSF/serum osmolality ratio or CSF overproduction and can be associated with normal cranial computed tomography and magnetic resonance imaging findings. Our data support the hypothesis that CSF reabsorption failure plays the crucial role in the pathophysiological mechanism. External lumbar drainage may be of benefit in selected cases of acute AIDS related cryptococcal meningitis with persisting life threatening elevation in intracranial pressure and normal computed tomogram.

Oleic acid inhibition of Na+/D-glucose transport in isolated renal brush-border membranes: role of lipid physical parameters and trans Na(+)-inhibition

Inhibition of Na+/D-glucose transport by oleic acid was investigated in renal brush-border membrane vesicles (BBMV). Lipid physical parameters were determined by spectrofluorometry. cis-Unsaturated C16-C22 long-chain fatty acids (LCFA) as oleic acid reduced nonzero limiting anisotropy r infinity with DPH and 12-AS as probes and decreased rotational correlation time phi of 12-AS. At 8 s and 15 s Na+/D-glucose transport was competitively inhibited. A positive correlation existed between decrease in r infinity (acyl chain order) or decrease in rotational correlation time phi (= increase in 'fluidity') and inhibition of Na+/D-glucose transport. Except elaidic acid trans unsaturated and saturated LCFA had no effect on fluorescence anisotropy and Na+/D-glucose transport. Per cent transport inhibition was unaffected by 0 voltage clamping and by FCCP. Ki for trans Na(+)-inhibition of D-glucose transport was 29 mmol/l. Na(+)-transport was stimulated by oleic acid, exceeding the Ki value for trans Na+ inhibition.

CONCLUSION

oleic acid inhibits Na+/D-glucose transport by a decrease in lipid acyl chain order and an increase in 'fluidity', by trans Na(+)-inhibition and presumably by a third unknown mechanism.