Short-term clinical outcome after acute symptomatic pulmonary embolism

Though studies have identified clinical variables that predict adverse events in patients with acute pulmonary embolism (PE), they have typically not differentiated short-term from long-term predictors.This multicenter prospective cohort study included consecutive outpatients with objectively confirmed symptomatic acute PE.We analyzed the incidence and time course of death, venous thromboembolism (VTE) recurrence, and major bleeding, and we compared event rates during short-term (first week) and long-term (3 months) follow-up after the diagnosis of PE.We also assessed risk factors for short-term mortality. During the first three months after diagnosis of PE, 142 of 1,338 (10.6%) patients died.Thirty-six deaths (2.7%) occurred during the first week after diagnosis of PE,and 61.1% of these were due to PE.Thirty-eight patients (2.8%) had recurrent VTE during the three-month follow-up, though none of the recurrences occurred during the first week after diagnosis of PE. During the three-month follow-up, major bleeding occurred in 48 patients (3.6%). Twenty-one (1.6%) major bleeds occurred during the first week of follow-up,and nine of these were fatal. Short-term mortality was significantly increased in patients who initially presented with systolic arterial hypotension (odds ratio [OR] 3.35; 95% CI, 1.51-5.41) or immobilization due to a medical illness (OR 2.89; 95% confidence interval [CI], 1.31-6.39).In con-clusion,during the first week after the diagnosis of PE, death and major bleeding occur more frequently than recurrent VTE. Patients with systolic arterial hypotension and immobilization at the time of PE diagnosis had an increased isk of short-term mortality.

Prognostic significance of tricuspid annular displacement in normotensive patients with acute symptomatic pulmonary embolism

BACKGROUND

Tricuspid annular plane systolic excursion (TAPSE) is an emerging prognostic indicator in patients with acute symptomatic pulmonary embolism (PE).

METHODS AND RESULTS

We prospectively examined 782 normotensive patients with PE who underwent echocardiography in a multicenter study. As compared with patients with a TAPSE of > 1.6 cm, those with a TAPSE of ≤ 1.6 cm had increased systolic pulmonary artery pressure (53.7 ± 16.7 mmHg vs. 40.0 ± 15.5 mmHg, P < 0.001), right ventricle (RV) end-diastolic diameter (3.5 ± 0.8 cm vs. 3.0 ± 0.6 cm, P < 0.001), and RV to left ventricle end-diastolic diameter ratio (1.0 ± 0.3 vs. 0.8 ± 0.2, P < 0.001), and a higher prevalence of RV free wall hypokinesis (68% vs. 11%, P < 0.001). Patients with a TAPSE of ≤ 1.6 cm at the time of PE diagnosis were significantly more likely to die from any cause (hazard ratio [HR] 2.3; 95% confidence interval [CI] 1.2-4.7; P = 0.02) and from PE (HR 4.4; 95% CI 1.3-15.3; P = 0.02) during follow-up. In an external validation cohort of 1326 patients with acute PE enrolled in the international multicenter Registro Informatizado de la Enfermedad TromboEmbólica, a TAPSE of ≤ 1.6 cm remained a significant predictor of all-cause mortality (HR 2.1; 95% CI 1.3-3.2; P = 0.001) and PE-specific mortality (HR 2.5; 95% CI 1.2-5.2; P = 0.01).

CONCLUSIONS

In normotensive patients with PE, TAPSE reflects right ventricular function. For these patients, TAPSE is independently predictive of survival.

Thrombolytic therapy and outcome of patients with an acute symptomatic pulmonary embolism

BACKGROUND

While the primary therapy for most patients with a pulmonary embolism (PE) consists of anticoagulation, the efficacy of thrombolysis relative to standard therapy remains unclear.

METHODS

In this retrospective cohort study of 15,944 patients with an objectively confirmed symptomatic acute PE, identified from the multicenter, international, prospective, Registro Informatizado de la Enfermedad TromboEmbólica (RIETE registry), we aimed to assess the association between thrombolytic therapy and all-cause mortality during the first 3 months after the diagnosis of a PE. After creating two subgroups, stratified by systolic blood pressure (SBP) (< 100 mm Hg vs. other), we used propensity score-matching for a comparison of patients who received thrombolysis to those who did not in each subgroup.

RESULTS

Patients who received thrombolysis were younger, had fewer comorbid diseases and more signs of clinical severity compared with those who did not receive it. In the subgroup with systolic hypotension, analysis of propensity score-matched pairs (n = 94 pairs) showed a non-statistically significant but clinically relevant lower risk of death for thrombolysis compared with no thrombolysis (odds ratio [OR] 0.72; 95% confidence interval [CI], 0.36-1.46; P = 0.37). In the normotensive subgroup, analysis of propensity score-matched pairs (n = 217 pairs) showed a statistically significant and clinically meaningful increased risk of death for thrombolysis compared with no thrombolysis (OR 2.32; 95% CI, 1.15-4.68; P = 0.018). When we imputed data for missing values for echocardiography and troponin tests in the group of normotensive patients, we no longer detected the increased risk of death associated with thrombolytic therapy.

CONCLUSIONS

In normotensive patients with acute symptomatic PE, thrombolytic therapy is associated with a higher risk of death than no thrombolytic therapy. In hemodynamically unstable patients, thrombolytic therapy is possibly associated with a lower risk of death than no thrombolytic therapy. However, study design limitations do not imply a causal relationship between thrombolytics and outcome.

Endovascular treatment of a haemodynamically unstable massive pulmonary embolism using fibrinolysis and fragmentation. Experience with 111 patients in a single centre. Why don't we follow ACCP recommendations?

INTRODUCTION

Fibrinolysis is recommended in several consensus documents for the treatment of a haemodynamically unstable massive pulmonary embolism (HUMPE).

MATERIAL AND METHODS

A total of 111 patients were treated in a single centre from January 2001 to December 2009. They were 55 males and 56 females diagnosed with HUMPE (systolic arterial pressure>90 mmHg) with at least two of the following criteria: Miller index>0, ventricular dysfunction, and need of vasoactive drugs. Local fibrinolysis with urokinase was performed in all cases, and fragmentation with a pig-tail catheter in the majority of them. An inferior vena cava (IVC) filter was implanted in 94 patients as a prophylactic measure.

RESULTS

Technical success was 100%. The Miller index improved from 0.7 ± 0.12, pre-treatment, to 0.09 ± 0.16. The mean pulmonary arterial pressure fell from 39.93 ± 7.0 mmHg to 20.47 ± 3.3 mmHg in the 30-90 days review. Of the 94 patients with IVC filters implanted, 79% were withdrawn satisfactorily. Seven patients died: 3 due to their neoplasia, 3 due to right cardiac failure at 1, 7 and 30 days, and another died of a brain haemorrhage in the first 24 hours. There were complications in 12.6% of the cases, of which 4.5% were major.

CONCLUSION

Local fibrinolysis with fragmentation achieves a rapid return to normal of the pulmonary pressure and is a safe and effective method for the treatment of HUMPE.

Short-term clinical outcome after acute symptomatic pulmonary embolism

Though studies have identified clinical variables that predict adverse events in patients with acute pulmonary embolism (PE), they have typically not differentiated short-term from long-term predictors. This multicenter prospective cohort study included consecutive outpatients with objectively confirmed symptomatic acute PE. We analyzed the incidence and time course of death, venous thromboembolism (VTE) recurrence, and major bleeding, and we compared event rates during short-term (first week) and long-term (3 months) follow-up after the diagnosis of PE. We also assessed risk factors for short-term mortality. During the first three months after diagnosis of PE, 142 of 1,338 (10.6%) patients died. Thirty-six deaths (2.7%) occurred during the first week after diagnosis of PE, and 61.1% of these were due to PE. Thirty-eight patients (2.8%) had recurrent VTE during the three-month follow-up, though none of the recurrences occurred during the first week after diagnosis of PE. During the three-month follow-up, major bleeding occurred in 48 patients (3.6%). Twenty-one (1.6%) major bleeds occurred during the first week of follow-up, and nine of these were fatal. Short-term mortality was significantly increased in patients who initially presented with systolic arterial hypotension (odds ratio [OR] 3.35; 95% CI, 1.51-5.41) or immobilization due to a medical illness (OR 2.89; 95% confidence interval [CI], 1.31-6.39). In conclusion, during the first week after the diagnosis of PE, death and major bleeding occur more frequently than recurrent VTE. Patients with systolic arterial hypotension and immobilization at the time of PE diagnosis had an increased risk of short-term mortality.

[Standards of care in pulmonary hypertension. Consensus statement of the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) and the Spanish Society of Cardiology (SEC)]

Substantial progress in the diagnosis and treatment of patients with pulmonary hypertension in recent years has led to significant improvement in survival. Evidence-based clinical practice guidelines issued by scientific societies reflect these new developments. However, certain clinically relevant issues have not been covered in consensus guidelines because of the lack of conclusive scientific evidence. Therefore, the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) and the Spanish Society of Cardiology (SEC) have promoted the present consensus statement in order to define national standards of care in the evaluation and management of pulmonary hypertension in its various forms, as well as to outline a clinical pathway and the basic principles for organizing health care in this clinical setting, with special emphasis on the requirements for and functions of specialized referral units. To prepare the statement, SEPAR and SEC formed a task force composed of national experts in various aspects of pulmonary hypertension. The resulting consensus is based on international clinical guidelines, a review of available scientific evidence, and panel discussion among the task force members. The final statement, approved by all participants, underwent external review.

[Standards of care in pulmonary hypertension. Consensus Statement of the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) and the Spanish Society of Cardiology (SEC)]

Substantial progress in the diagnosis and treatment of patients with pulmonary hypertension in recent years has led to significant improvement in survival. Evidence-based clinical practice guidelines issued by scientific societies reflect these new developments. However, certain clinically relevant issues have not been covered in consensus guidelines because of the lack of conclusive scientific evidence. Therefore, the Spanish Society of Pulmonology and Thoracic Surgery (SEPAR) and the Spanish Society of Cardiology (SEC) have promoted the present consensus statement in order to define national standards of care in the evaluation and management of pulmonary hypertension in its various forms, as well as to outline a clinical pathway and the basic principles for organizing health care in this clinical setting, with special emphasis on the requirements for and functions of specialized referral units. To prepare the statement, SEPAR and SEC formed a task force composed of national experts in various aspects of pulmonary hypertension. The resulting consensus is based on international clinical guidelines, a review of available scientific evidence, and panel discussion among the task force members. The final statement, approved by all participants, underwent external review.

[Longitudinal incidence of tuberculosis in a cohort of contacts: factors associated with the disease]

OBJECTIVE

To investigate the incidence of tuberculosis (TB) in a cohort of contacts and to analyze the variables associated with the disease.

METHODS

A prospective analysis was undertaken of all the contact investigations carried out in a health district in the Basque Country in northern Spain between January 1, 1995 and December 31, 2004. The dependent variable was the number of cases of TB detected among the contacts. Independent variables were age, sex, tuberculin skin test result, and the degree of contact. In index cases, additional variables were the site of the disease and smear test result.

RESULTS

Analysis of 5444 contacts of 596 patients with TB yielded 66 secondary cases of TB (40 at the time of the contact investigation and 26 at a later stage); the majority (73%) developed the disease within 12 months. Multivariate analysis revealed a significant relationship between the detection of secondary cases and the following variables: close contact (odds ratio [OR], 3.05; 95% confidence interval [CI], 1.75-5.31), positive smear test (OR, 8.54; 95% CI, 2.06-35.43), induration of 10 mm or larger (OR, 10.18; 95% CI, 4.27-24.26), and age under 30 years (OR, 3.35; 95% CI, 1.88-5.98). The final predictive model constructed on the basis of these 3 variables had a sensitivity of 77.4%, a specificity of 80.3%, and an area under the curve of 0.83 (95% CI, 0.78-0.88).

CONCLUSIONS

The contact investigation is a valid strategy for the detection of new cases of TB. Prophylactic treatment should be implemented at an early stage and priority should be given to young contacts of smear positive patients using an induration size of 10 mm or more as a reference.

Prognostic Models for Selecting Patients With Acute Pulmonary Embolism for Initial Outpatient Therapy

OBJECTIVE

To assess the performance of two prognostic models in predicting short-term mortality in patients with pulmonary embolism (PE).

SUBJECTS AND METHODS

We compared the test characteristics of two prognostic models for predicting 30-day outcomes (mortality, thromboembolic recurrences, and major bleeding) in a cohort of 599 patients with objectively confirmed PE. Patients were stratified into the PE severity index (PESI) risk classes I-V and the Geneva low-risk and high-risk strata. We compared the discriminatory power of both prognostic models.

RESULTS

The PESI classified fewer patients as low risk (strata I and II) [36%; 216 of 599 patients; 95% confidence interval (CI), 32 to 40%] compared to the Geneva prediction rule (84%; 502 of 599 patients; 95% CI, 81 to 87%) [p < 0.0001]. Using either prediction rule, the low-risk groups showed statistically relevant 30-day mortality difference (PESI, 0.9%; 95% CI, 0.3 to 2.2; vs Geneva, 5.6%; 95% CI, 3.6 to 7.6) [p < 0.0001], although nonfatal recurrent venous thromboembolism or major bleeding rates were statistically similar (PESI, 2.8%; 95% CI, 0.6 to 5.0%; vs Geneva, 4.2%; 95% CI, 2.4 to 5.9%). The area under the receiver operating characteristic curve was higher for the PESI (0.76; 95% CI, 0.69 to 0.83) than for the Geneva score (0.61; 95% CI, 0.51 to 0.71) [p = 0.002].

CONCLUSIONS

The PESI quantified the prognosis of patients with PE better than the Geneva score. This study demonstrated that PESI can select patients with very low adverse event rates during the initial days of acute PE therapy and assist in selecting patients for treatment in the outpatient setting.

Development and validation of a clinical prediction rule for severe community-acquired pneumonia

RATIONALE

Objective strategies are needed to improve the diagnosis of severe community-acquired pneumonia in the emergency department setting.

OBJECTIVES

To develop and validate a clinical prediction rule for identifying patients with severe community-acquired pneumonia, comparing it with other prognostic rules.

METHODS

Data collected from clinical information and physical examination of 1,057 patients visiting the emergency department of a hospital were used to derive a clinical prediction rule, which was then validated in two different populations: 719 patients from the same center and 1,121 patients from four other hospitals.

MEASUREMENTS AND MAIN RESULTS

In the multivariate analyses, eight independent predictive factors were correlated with severe community-acquired pneumonia: arterial pH < 7.30, systolic blood pressure < 90 mm Hg, respiratory rate > 30 breaths/min, altered mental status, blood urea nitrogen > 30 mg/dl, oxygen arterial pressure < 54 mm Hg or ratio of arterial oxygen tension to fraction of inspired oxygen < 250 mm Hg, age > or = 80 yr, and multilobar/bilateral lung affectation. From the beta parameter obtained in the multivariate model, a score was assigned to each predictive variable. The model shows an area under the curve of 0.92. This rule proved better at identifying patients evolving toward severe community-acquired pneumonia than either the modified American Thoracic Society rule, the British Thoracic Society's CURB-65, or the Pneumonia Severity Index.

CONCLUSIONS

A simple score using clinical data available at the time of the emergency department visit provides a practical diagnostic decision aid, and predicts the development of severe community-acquired pneumonia.

Complicaciones precoces en pacientes con embolia de pulmón

BACKGROUND AND OBJECTIVE

Mortality, recurrences and hemorrhages are the most serious early complications of pulmonary embolism (PE). We intended to ascertain the frequency and mechanisms of complications within the first 10 days after PE was diagnosed.

PATIENTS AND METHOD

We included patients suspected of suffering PE between December 2003 and August 2004 from 8 hospitals. We performed a multicenter observational prospective study of 8 Spanish hospitals with consecutive outpatients diagnosed with PE. Database of clinical variables: computerized Registry of Patients with Venous Thromboembolism (RIETE). Statistic analysis included chi2 and Student's t test to compare the 2 groups of patients (with and without complications).

RESULTS

Six hundred eighty one patients were included, 336 men and 345 women (mean age 66 and 70, respectively). During the first 10 days, 33 (4.8%) of them died, and 22 (3.2%) had an hemorrhage yet no recurrences appeared. Previous immobilization and the presence of respiratory failure, cancer or renal failure were significantly associated with early complications while previous surgery and thoracic pain were not associated with those.

CONCLUSIONS

Early complications and some of the associated factors were in agreement with published data. Other situations such as previous surgery or thoracic pain appeared to be protective factors.

Prevalence of Helicobacter pylori in NSAID users with gastric ulcer

OBJECTIVE

Regarding the interaction of Helicobacter pylori and non-steroidal anti-inflammatory drugs (NSAIDs), we cannot accept unanimous conclusions in inducing gastric ulcer. We therefore evaluated the role of Helicobacter pylori and NSAIDs in inducing gastric ulcer.

METHODS

Dyspeptic patients receiving NSAIDs underwent endoscopic examination. Gastric ulcer formation and H. pylori status were investigated. Biopsy specimens from the antrum and lower body of the stomach were prepared for the rapid urease test and pathological evaluation. Anti-H. pylori antibody was measured by enzyme-linked immunosorbent assay.

RESULTS

Two hundred and twenty-six patients receiving NSAIDs (220 chronic and six on-demand users) underwent gastrofibrescopic examination. There were 110 patients with gastric ulcer and 111 non-ulcer patients with gastritis. The remaining five patients had neither. NSAID users with gastric ulcer showed a low prevalence of H. pylori compared with those without them [55/110 (50.0%) vs 79/111 (71.2%), P < 0.01]. The same tendency was seen when patients receiving low-dose aspirin and those with rheumatoid arthritis were analysed separately [13/29 (44.8%) vs 50/62 (80.6%), P < 0.01, and 11/33 (33.3%) vs 16/26 (61.5%), P < 0.06 with Yates' correction, respectively].

CONCLUSION

Helicobacter pylori infection appeared to be a risk factor for developing gastritis, but we found no evidence that it increases gastric ulcer formation in NSAID users with dyspepsia.

Use of venous thromboembolism prophylaxis for surgical patients: a multicentre analysis of practice in Spain

OBJECTIVE

To assess the use of venous thromboembolism prophylaxis in surgical patients.

DESIGN

Retrospective multicentre study.

SETTING

Eight acute-care teaching hospitals with more than 400 beds, Spain.

PATIENTS

Medical records of all consecutive patients undergoing operations in the general surgical and trauma and orthopaedic services during the month of April, 1997, were randomly selected.

INTERVENTION

The sample size for each type of operation (general, trauma-orthopaedic) was calculated from the number of operations done at each hospital (with an absolute precision of 5%, and an alpha error of 5%) and the prevalence of the use of venous thromboembolism prophylaxis obtained from a random sample of 50 records (25 from patients in general surgery and 25 from patients in orthopaedic surgery) from each centre.

MAIN OUTCOME MEASURES

Appropriate and inappropriate pharmacological prophylaxis defined according to a combination of risk categories for venous thromboembolism, doses of antithrombotic agents given, time of starting prophylaxis, and its duration.

RESULTS

A total of 1848 medical records (general surgery, n = 1025; trauma-orthopaedic surgery, n = 823) were included. Physical methods (elastic stockings, intermittent pneumatic compression) were used in only 0.3% of patients. Pharmacological prophylaxis consisted of low molecular weight heparin in 99% of cases. The percentage given heparin-based prophylaxis was 54%. Overall, appropriate prophylaxis was given in 1175 patients (64%). Use of thromboprophylaxis ranged from 27% to 70% among the participating hospitals. Prophylaxis was more likely to be appropriate in orthopaedic patients (577, 70%) than in general surgical patients (598, 58%) in both the high and moderate risk categories.

CONCLUSIONS

Given the large variability between the participating hospitals, more specific protocols and recommendations about prophylaxis of thromboembolism in surgical patients are needed.

[The gammagraphic diagnosis of acute pulmonary thromboembolism]

We aimed to determine the prevalence of acute pulmonary embolism (APE) in our population and to establish the diagnostic reliability of pulmonary scintigraphy (PS), as well as the influence of the clinical context (CC). During a 2-year prospective study, patients were diagnosed by either pulmonary angiography or normal-perfusion PS. A diagnosis of APE was made in 73 (75%) of a total of 97 patients. In the group of 58 patients diagnosed by ventilation/perfusion (V/Q) PS, 33 were classified as "highly probably" having APE; 32 of these in fact had the syndrome (sensitivity 88%, specificity 94%). Combining the "highly probable" patients with the "highly suspected" patients diagnosed by ventilation/perfusion PS, we obtained a sensitivity of 51% and specificity of 100%. Ventilation scintigrams were unobtainable in 28 older patients with greater dyspnea and tachypnea, who were unable to perform the maneuvers. Of the 21 "highly probable" patients as assessed by PS, 19 were diagnosed as having APE (sensitivity 86%, specificity 85%). Combining the "highly probable" patients with the "highly suspected" group, we obtained a sensitivity of 32% and specificity of 100%. Normal perfusion PS excludes clinically relevant APE. "Intermediate" or "slight" probability PS results, even when combined with CC, have no diagnostic validity.

Probucol-induced QT prolongation and syncope

We report a patient who experienced a reversible prolongation of the QT interval and episodes of syncope while receiving probucol. A 64-year-old woman experienced syncopal attacks 8 and 11 weeks after beginning probucol treatment (500 mg twice daily). The pre-treatment ECG showed a slight prolongation of the corrected QT interval (QTc) (0.46 sec). Her QTc increased to 0.62 sec 12 weeks after beginning probucol treatment and decreased to about the baseline value (0.48 sec) 6 weeks after treatment was discontinued. Probucol is known to prolong the QT interval. A long QT interval has been linked to an increased risk of ventricular arrhythmias, syncope or sudden death. However, clinical reports which causally relate probucol treatment to syncope are very rare. Although an ECG during the episodes of syncope was not available, this patient's syncope might be due to ventricular tachyarrhythmia associated with probucol-induced QT prolongation. This case emphasizes the need for careful evaluation of the QT interval before and during probucol treatment.

Efficacy of additive DMARD therapy in patients with rheumatoid arthritis. Double blind controlled trial using bucillamine and placebo with maintenance doses of gold sodium thiomalate

OBJECTIVE

To examine the efficacy of the addition of small doses of additional disease modifying antirheumatic drugs (DMARD) to ongoing DMARD treatment [additive DMARD therapy (ADT)].

METHODS

A 3-month prospective, double blind, randomized, placebo controlled study was performed using either 100 mg/day of bucillamine (Buc) or an inactive placebo (P1). Two groups of 12 patients each who had experienced an insufficient benefit from gold sodium thiomalate (GSTM) alone were enrolled in the study.

RESULTS

The addition of Buc proved more beneficial than P1 regarding improvement in disease activity (p = 0.0032) and drug usefulness (p = 0.0025). A significant within group improvement was observed in joint swelling count, the Lansbury activity index, erythrocyte sedimentation rate and C-reactive protein. However, the difference in the clinical variables between the 2 groups was minimal.

CONCLUSION

The usefulness of ADT was suggested by this trial; however, further confirmation by additional studies is still needed.

Relationship among malondialdehyde, TBA-reactive substances, and tocopherols in the oxidation of rapeseed oil

Relationship among malondialdehyde (MDA), 2-thiobarbituric acid (TBA)-reactive substances (TBA-RS), and tocopherols in the oxidation of rapeseed oil was investigated. MDA was determined by a new HPLC method with chemical derivatization. When the oil was heated at 170 degrees C, TBA-RS and MDA increased. The contents of TBA-RS were approximately 1.6 times higher than those of MDA. Correlation between the increase in formed MDA and the decrease in tocopherols was observed. When the oxidation of the oil was initiated using 2,2'-azobis-(2,4-dimethylvaleronitrile) at 40 degrees C, TBA-RS dramatically increased during the initial stage and reached plateau. Thereafter, little increase was observed. The relative ratio of MDA to TBA-RS was much lower in the reaction performed at 40 degrees C than that observed at 170 degrees C. These results indicated that the decrease of tocopherols was accompanied by the increase of MDA but TBA-RS did not correlate with the change of tocopherols.

Determination of malondialdehyde with chemical derivatization into the pyrimidine compound and HPLC

A new HPLC method to determine malondialdehyde (MDA) was developed. Malondialdehyde was reacted with alpha-N-benzoyl-L-arginine ethyl ester and converted into alpha-N-benzoyl-delta-N-(2-pyrimidinyl)-L-ornithine ethyl ester, which is sufficiently hydrophobic to allow us its specific determination utilizing a reversed-phase C18 column at the level of 1 pmol.

Serum alkaline ribonuclease derived from vascular endothelial cells is raised in patients with rheumatoid vasculitis

We investigated the mechanisms of the marked increase of alkaline ribonuclease (RNase) in the sera of patients with rheumatoid arthritis associated with vasculitis. Among various tissues examined, blood vessels contained higher levels of alkaline RNase than acid RNase. Cultured human endothelial cells contained significantly higher amounts of alkaline RNase than acid RNase. In contrast, acid RNase was predominant in most other tissues and cells. Endothelial cells cultured with sera from patients with vasculitis released alkaline RNase into the extracellular medium. The phosphocellulose chromatographic profile of these sera differed from that of sera from healthy subjects. These results imply that the alkaline RNase in sera of patients with vasculitis is derived from blood vessels, probably from endothelial cells.

Serum factors from patients with systemic lupus erythematosus enhancing superoxide generation by normal neutrophils

It has been suggested that human neutrophils exposed to performed immune complexes or activated complement fragments generate O2- anions in extracellular medium. In vivo studies have revealed that oxygen intermediates produced by immune complex-activated neutrophils play an important role in subsequent tissue damage. Since it is difficult to obtain direct evidence that O2- is released into plasma in patients with systemic lupus erythematosus (SLE), we studied the capacities of their sera to stimulate O2- release by human neutrophils in vitro. Sera from patients with SLE significantly enhanced O2- generation by neutrophils compared to normal sera. The enhancing activity of serum in the induction of increased O2- generation correlated positively with the presence of serum immune complexes and negatively with serum complement levels. The enhancing factors were analyzed by serum fractionation on Sephadex G-200 gel filtration, and were concluded to be immune complexes of intermediate size containing an activated complement fragment.