Von Willebrand factor: a possible biomarker for disease activity in vasculitis

OBJECTIVE

Inflammation markers, e.g. C- reactive protein (CRP) and sedimentation rate, can be normal despite active vasculitis. Von Willebrand factor (vWF) is secreted from endothelial cells in response to vascular damage. Some reports suggest increased vWF levels in vasculitis. This study aimed to evaluate vWF serum concentration in vasculitis patients as a possible biomarker of disease activity and to review the current literature.

METHOD

Adult patients with systemic vasculitis were prospectively enrolled. Disease activity was recorded using the Birmingham Vasculitis Activity Score (BVAS) version 3. Blood group-adjusted vWF antigen serum level was evaluated at diagnosis and, when available, after treatment.

RESULTS

Twenty-five vasculitis patients were compared to 15 healthy controls. The mean age of patients was 56 ± 17 years and 56% were women. Forty percent had anti-neutrophil cytoplasmic autoantibody-associated vasculitis, 20% giant cell arteritis, 16% polyarteritis nodosa, 8% Takayasu arteritis, and the rest had other vasculitides. The mean disease duration was 3.4 ± 4.8 years. Mean vWF was higher in patients with active vasculitis than in healthy controls (212 ± 81% vs 106 ± 26%, p < 0.001). vWF levels directly correlated with BVAS. In 13 patients with active vasculitis who reached remission or low disease activity after treatment, vWF level at follow-up decreased significantly. In three out of five patients who were treated with interleukin-6 inhibitors, vWF was elevated despite normal CRP levels, while vasculitis was clinically active.

CONCLUSION

vWF antigen serum level is increased in active vasculitis and could potentially serve as a biomarker for active disease.

Outcomes in progressive systemic sclerosis treated with autologous hematopoietic stem cell transplantation compared with combination therapy

OBJECTIVES

Autologous hematopoietic stem cell transplantation (AHSCT) has been shown to improve long-term survival for early diffuse progressive systemic sclerosis (SSc) compared with cyclophosphamide. Cyclophosphamide, however, does not provide a long-term benefit in SSc. The combination of mycophenolate mofetil (MMF) and rituximab is a potent alternative regimen. We aimed to retrospectively compare the outcomes of SSc patients who underwent AHSCT to patients who met the eligibility criteria for AHSCT but received upfront combination therapy with MMF and rituximab.

METHODS

Repeated assessments of modified Rodnan Skin Score (mRSS), forced vital capacity (FVC), and diffusing capacity (DLCO) values were conducted. Clinical improvement was defined as an mRSS decrease > 25% or an FVC increase > 10%. Event-free survival (EFS) was defined in the absence of persistent major organ failure or death.

RESULTS

Twenty-one SSc patients in the combination therapy group were compared with sixteen in the AHSCT group. Age, sex and disease duration were similar between the two groups. Clinical improvement at 12 months was seen in 18 (86%) patients in the combination group compared with 13 (81%) in the AHSCT group (p= 0.7). The hazard ratio for EFS at 24 months favored the combination group (HR = 0.09, P= 0.04). During follow-up, both groups exhibited a significant and comparable reduction in mRSS and an increase in FVC values at each time interval up to 24 months.

CONCLUSION

MMF and rituximab compared with AHSCT in SSc patients eligible for AHSCT resulted in similar skin and lung clinical improvement with a better safety profile at 24 months.

Invasive Pulmonary Aspergillosis in Multiple Myeloma patients: A sizeable diagnosis in the era of novel anti-myeloma therapies

BACKGROUND

Advances in treatment for multiple myeloma (MM) patients entail a high risk for opportunistic infections such as invasive pulmonary aspergillosis (IPA).

OBJECTIVES

This study was conducted to describe the patient's profile, clinical manifestations, diagnosis and outcome of MM patients with IPA, in our large haemato-oncology centre.

PATIENTS/METHODS

We retrospectively analysed patients with MM who underwent Broncho alveolar lavage for pneumonia at Rambam Hospital during a 13-year period from July 2005 to February 2018. We focused on those with Aspergillus pneumonia.

RESULTS

Of the 669 patients with multiple myeloma, mean age 62.6 (±7.6) years, forty-two patients (6.2%) were diagnosed with IPA. Among them, 60% had a probable diagnosis and 40% possible. Clinical presentation was similar for IPA and other pulmonary infections. Compared to those with other pulmonary infections, IPA was more commonly diagnosed in patients with long-standing disease (p = .00012) and among patients receiving 3 or more lines of myeloma therapies (p = .04). Thirty-day mortality rates following diagnostic bronchoscopy did not differ between IPA and non-IPA patients. (p = .85).

CONCLUSIONS

Multiple myeloma patients had an increased risk for IPA, most notably in patients with 3 or more lines of anti-myeloma treatment and more advanced disease. This clearly emphasises the vigilance needed for IPA in these patients.

Baseline Chest Computed Tomography for Early Diagnosis of Invasive Pulmonary Aspergillosis in Hemato-oncological Patients: A Prospective Cohort Study

Invasive pulmonary aspergillosis (IPA) has dire consequences in hemato-oncological patients. We report our experience with performing routine baseline chest computed tomography for early diagnosis of IPA. We found high rates of proven or probable IPA diagnosed on admission among patients with newly diagnosed acute myeloid leukemia.

Heparan sulfate chains contribute to the anticoagulant milieu in malignant pleural effusion

Background

While malignant pleural effusion (MPE) is a common and significant cause of morbidity in patients with cancer, current treatment options are limited. Human heparanase, involved in angiogenesis and metastasis, cleaves heparan sulfate (HS) side chains on the cell surface.

Aims

To explore the coagulation milieu in MPE and infectious pleural effusion (IPE) focusing on the involvement of heparanase.

Methods

Samples of 30 patients with MPE and 44 patients with IPE were evaluated in comparison to those of 33 patients with transudate pleural effusions, using heparanase ELISA, heparanase procoagulant activity assay, thrombin and factor Xa chromogenic assays and thromboelastography. A cell proliferation assay was performed. EMT-6 breast cancer cells were injected to the pleural cavity of mice. A peptide inhibiting heparanase activity was administered subcutaneously.

Results

Levels of heparanase, factor Xa and thrombin were significantly higher in exudate than transudate. Thromboelastography detected almost no thrombus formation in the whole blood, mainly on MPE addition. This effect was completely reversed by bacterial heparinase. Direct measurement revealed high levels of HS chains in pleural effusions. Higher proliferation was observed in tumour cell lines incubated with exudate than with transudate and it was reduced when bacterial heparinase was added. The tumour size in the pleural cavity of mice treated with the heparanase inhibitor were significantly smaller compared with control (p=0.005).

Conclusions

HS chains released by heparanase form an anticoagulant milieu in MPE, preventing local thrombosis and enabling tumour cell proliferation. Inhibition of heparanase might provide a therapeutic option for patients with recurrent MPE.

Diagnostic role of polymerase chain reaction in bronchoalveolar lavage fluid for invasive pulmonary aspergillosis in immunocompromised patients - A retrospective cohort study

BACKGROUND

This study aimed to evaluate the diagnostic role of PCR detection of Aspergillus DNA in the broncho-alveolar lavage (BAL) fluid in a large cohort of patients suspected to have invasive pulmonary aspergillosis (IPA).

METHODS

Consecutive immunocompromised patients who underwent bronchoscopy with BAL sampling and PCR detection of Aspergillus DNA for the diagnosis of pulmonary infiltrates were included in the study. Galactomannan (GM) antigen testing in BAL and serum and BAL fungal culture were also performed. Patients were classified as having IPA (proven/probable/possible) or no-IPA according to the EORTC/MSG diagnostic criteria.

RESULTS

During 12 years (2005-2016), 1248 bronchoscopies were performed for 1072 patients. 77% had hematological malignancy, of them 40% had AML and 35.6% underwent HSCT. IPA was diagnosed in 531 patients (42.5%), 7-proven, 280-probable and 244-possible. PCR was positive in 266 cases, of them 213 had IPA, indicating a true positive rate of 80% (213/266) and a false positive rate of 20% (53/266). These results establish the diagnostic performance of PCR to have sensitivity of 40%, specificity of 93%, PPV- 80% and NPV-68%. Of 244 patients with possible IPA, 80 had positive PCR. Including PCR in the diagnostic criteria would move 80 cases from the possible group to the probable one. A combination of positive PCR and/or BAL-GM increases sensitivity to 74%, while positivity of both tests elevates PPV to 99.4%.

CONCLUSIONS

Inclusion PCR for the detection of Aspergillus-DNA in BAL in the mycological criteria of the EORTC/MSG definitions increases the rate and the certainty of IPA diagnosis.

Hemodynamics of the diastolic pressure gradients in acute heart failure: implications for the diagnosis of pre-capillary pulmonary hypertension in left heart disease

The diastolic pressure gradient (DPG) has been proposed as the metric of choice for the diagnosis of pulmonary vascular changes in left heart disease. We tested the hypothesis that this metric is less sensitive to changes in left atrial pressure and stroke volume (SV) than the transpulmonary gradient (TPG). We studied the effect of dynamic changes in pulmonary capillary wedge pressure (PCWP), SV, and pulmonary artery capacitance (PAC) on DPG and TPG in 242 patients with acute heart failure undergoing decongestive therapy with continuous hemodynamic monitoring. There was a close impact of PCWP reduction on TPG and DPG, with a 0.13 mmHg (95% confidence interval [CI] 0.07–0.19, P < 0.0001) and 0.21 mmHg (95% CI 0.16–0.25, P < 0.0001) increase for every 1 mmHg decrease in PCWP, respectively. Changes in SV had a negligible effect on TPG and DPG (0.19 and 0.13 mmHg increase, respectively, for every 10-mL increase in SV). Heart rate was positively associated with DPG (0.41-mmHg increase per 10 BPM [95% CI 0.22–0.60, P < 0.0001]). The resistance-compliance product was positively associated with both TPG and DPG (2.65 mmHg [95% CI 2.47–2.83] and 1.94 mmHg [95% CI 1.80–2.08] for each 0.1-s increase, respectively). In conclusion, DPG is not less sensitive to changes in left atrial pressure and SV compared with TPG. Although DPG was not affected by changes in PAC, the concomitant increase in the resistance-compliance product increases DPG.

Community-acquired respiratory infections are common in patients with non-Hodgkin lymphoma and multiple myeloma

PURPOSE

Available data suggest that respiratory infections are associated with increased morbidity and mortality in patients hospitalized due to acute leukemia and allogeneic stem cell transplantation (allo-SCT). However, the precise incidence, risk factors, and severity of respiratory infection, mainly community-acquired, in patients with lymphoma and multiple myeloma (MM) are not fully determined. The current study aimed to investigate risk factors for respiratory infections and their clinical significance in patients with B cell non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) in the first year of diagnosis.

METHODS

Data of consecutive patients diagnosed with NHL or MM and treated at the Rambam Hematology Inpatient and Outpatient Units between 01/2011 and 03/2012 were evaluated. Information regarding anticancer treatment, incidence and course of respiratory infections, and infection-related outcomes was analyzed.

RESULTS

One hundred and sixty episodes of respiratory infections were recorded in 103 (49%) of 211 (73-MM, 138-NHL) patients; 126 (79%) episodes were community-acquired, 47 (29%) of them required hospitalization. In univariate analysis, age < 60 years, MM diagnosis, and autologous SCT increased the respiratory infection risk (P = 0.058, 0.038, and 0.001, respectively). Ninety episodes (56% of all respiratory episodes) were examined for viral pathogens. Viral infections were documented in 25/90 (28%) episodes, 21 (84%) of them were community-acquired, requiring hospitalization in 5 (24%) cases. Anti-flu vaccination was performed in 119 (56%) patients. Two of the six patients diagnosed with influenza were vaccinated.

CONCLUSIONS

Respiratory infections, including viral ones, are common in NHL and MM. Most infections are community-acquired and have a favorable outcome. Rapid identification of viral pathogens allows avoiding antibiotic overuse in this patient population.

[DIAGNOSIS AND TREATMENT OF BRONCHIECTASIS: POSITION PAPER OF THE ISRAELI PULMONOLOGY SOCIETY AND THE ISRAELI PEDIATRIC PULMONOLOGY SOCIETY]

Bronchiectasis is anatomically defined by irreversible distortion of the bronchi. Clinically, its manifestations are cough with sputum production and a predisposition to pulmonary infections. Unlike asthma and COPD, where ample clinical data are present regarding the course and effective treatment, knowledge of bronchiectasis has yet to evolve. Lately, bronchiectasis is gaining renewed attention among the medical community, with growing basic and clinical research-based data. In Israel, no registered treatments exist for bronchiectasis, which makes it difficult to treat these patients. This paper is a summary of the position of the Israeli Pulmonology Association and the Israeli Pediatric Pulmonology Association for diagnosis and treatment of bronchiectasis.

Does molecular analysis increase the efficacy of bronchoalveolar lavage in the diagnosis and management of respiratory infections in hemato-oncological patients?

OBJECTIVES

The identification of the specific pathogen responsible for a respiratory infection in patients with hematological malignancies (HM) would ensure relevant treatment and prevent toxicity associated with anti-infective therapy. This large-scale study aimed to explore the clinical impact of fiberoptic bronchoscopy with bronchoalveolar lavage (FOB-BAL) in conjunction with molecular analysis on the diagnosis and management of respiratory infections in hemato-oncological patients.

METHODS

All consecutive patients with HM and pulmonary infiltrates, who underwent FOB-BAL between January 2008 and January 2013, were included in the analysis. Clinical characteristics, FOB-BAL results, and treatment adjustments were recorded, and factors predicting a positive BAL were assessed.

RESULTS

Four hundred and twenty-five FOB-BAL procedures were analyzed. BAL revealed a specific diagnosis in 219 (51.5%) patients, 208 of them with a pulmonary infection. Infectious etiological agents found were mainly Aspergillus spp (n=142), bacterial species (n=44), and Pneumocystis jirovecii (n=34). Multivariate analysis showed that a lymphoproliferative disease, ≥2 symptoms (dyspnea/cough/hemoptysis/pleuritic pain), and less than 4 days between symptom appearance and FOB-BAL, predicted a positive FOB-BAL result. BAL results prompted a treatment modification in 48% of subjects.

CONCLUSIONS

FOB-BAL in conjunction with molecular assays is efficient in the rapid detection of life-threatening infections, allowing for adjustment of anti-infective therapy, which may result in better outcomes and reduce treatment-related toxicity.

Long-term follow-up of patients with scleroderma interstitial lung disease treated with intravenous cyclophosphamide pulse therapy: a single-center experience

BACKGROUND

Scleroderma lung disease (ILD-SSc) is treated mainly with cyclophosphamide (CYC). The effectiveness of CYC was judged after 12-24 months in most reports.

OBJECTIVES

To analyze the effect of monthly intravenous CYC on pulmonary function tests including forced vital capacity (FVC) and diffusing lung capacity (DLCO), as well as Rodnan skin score (mRSS), during long-term follow-up.

METHODS

We retrospectively collected the data on 26 ILD-SSc patients who began CYC treatments before 2007. Changes in FVC, DLCO and mRSS before treatment, and at 1,4 and 7 years after completion of at least six monthly intravenous CYC treatments for ILD-SSc were analyzed.

RESULTS

Mean cumulative CYC dose was 8.91 ± 3.25 G. More than 30% reduction in FVC (0%, 8%, and 31% of patients), DLCO (15%, 23%, 31%), and mRSS (31%, 54%, 62%) at years 1, 4 and 7 was registered. During the years 0-4 and 4-7, annual changes in FVC, DLCO and mRSS were 3.2 vs. 0.42% (P < 0.040), 4.6 vs. 0.89% (P < 0.001), and 1.8 vs. 0.2 (P = 0.002). The greatest annual FVC and DLCO reduction over the first 4 years correlated with mortality (P = 0.022). There were no differences in the main variables regarding doses of CYC (< 6 G and > 6 G).

CONCLUSIONS

In patients with ILD-SSc, CYC stabilized the reduction of FVC during treatment, but this effect was not persistent. The vascular characteristic of ILD-SSc (DLCO) was not affected by CYC treatment. CYC rapidly improved the mRSS. This effect could be achieved with at least 6 G of CYC. Higher rates of annual reduction in FVC and DLCO in the first 4 years indicate the narrow window of opportunity and raise the question regarding ongoing immunosuppression following CYC infusions.

Outcome of Pneumocystis jirovecii pneumonia diagnosed by polymerase chain reaction in patients without human immunodeficiency virus infection

BACKGROUND AND OBJECTIVE

Pneumonia caused by Pneumocystis jirovecii (PCP) in patients without human immunodeficiency virus (HIV) infection is associated with high mortality. The diagnosis of PCP at our institution is based on detection of DNA using a polymerase chain reaction (PCR) assay. The aim of this study was to describe the clinical manifestations, outcomes and factors associated with mortality due to PCP, as diagnosed by PCR, in patients without HIV infection.

METHODS

Over a 6-year period, all HIV-negative immunocompromised patients suspected of having an opportunistic pulmonary infection underwent diagnostic bronchoscopy. A multigene PCR assay that detects Pneumocystis jirovecii DNA was used for the diagnosis of PCP. Patients were considered to have PCP if they had underlying immunodeficiency, compatible signs and symptoms, abnormal radiological findings, and Pneumocystis jirovecii DNA was detected in a bronchoalveolar lavage fluid sample. Data was collected retrospectively.

RESULTS

PCP was diagnosed in 58 patients. The underlying conditions included haematological malignancies (60.3%), solid tumours (17.2%) and immunosuppressive treatment (22.4%). The most common clinical features in patients with PCP were fever (94.6%), dyspnoea (67.2%) and cough (36.2%). The overall in-hospital mortality was 17.2% (10/58). Mortality was associated with co-infections, high lactate dehydrogenase levels, female gender, and higher pneumonia severity index and acute physiology and chronic health evaluation III scores.

CONCLUSIONS

In this study, the mortality of HIV-negative patients with PCP was low compared with previous reports. We hypothesize that this finding resulted from the increased sensitivity of a PCR-based assay, as compared with traditional methods, for the diagnosis of PCP in HIV-negative patients.

The increased risk for pneumocystis pneumonia in patients receiving rituximab-CHOP-14 can be prevented by the administration of trimethoprim/sulfamethoxazole: a single-center experience

Recent studies suggest an increased risk for Pneumocystis jirovecii pneumonia (PJP) in adults receiving short-interval rituximab-CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) therapy for diffuse large cell B cell lymphoma (DLBCL). This retrospective study evaluates precise PJP incidence and the efficacy of anti-PJP prophylaxis in DLBCL. Patients with DLBCL, aged ≥18 years and treated between December 2004 and December 2010, were included. Details of treatment-related respiratory infections, focusing on PJP incidence, risk factors and prophylaxis, were assessed. A total of 132 patients were analyzed; 47 were treated with rituximab-CHOP therapy every 21 days (R-CHOP-21) and 85 were treated every 14 days (R-CHOP-14). The incidence of treatment-related respiratory infections was higher in patients receiving R-CHOP-14. PJP was diagnosed in 5 patients: 4 in the R-CHOP-14 (6.6%) and 1 in the R-CHOP-21 cohort (2.6%), using triplex polymerase chain reaction (PCR) for PJ in bronchoalveolar fluid. None of the patients receiving P.jirovecii prophylaxis (n = 33) developed PJP, compared with 6.6% of those treated with R-CHOP-14 without such prophylaxis. An older age and R-CHOP administered every 14 rather than every 21 days increased the PJP risk. Trimethoprim/sulfamethoxazole prophylaxis is found to be highly efficient in preventing this life-threatening complication and, therefore, should be recommended for patients receiving the R-CHOP-14 regimen.

Characterization of pulmonary venous hypertension patients with reactive pulmonary hypertension as compared to proportional pulmonary hypertension

BACKGROUND

Patients with pulmonary venous hypertension (PVH) secondary to left heart disease can be further classified according to their hemodynamic profile: pulmonary hypertension (PH) in proportion to the pulmonary capillary wedge pressure (PCWP) and PH out of proportion to the PCWP or reactive PH. Currently, there are no measures that enable prediction of the development of reactive PH in patients with left heart disease.

OBJECTIVES

In this study, we aim to characterize PVH patients with reactive PH as compared to proportional PH in an attempt to create a distinct profile for patients with left heart disease carrying a high risk for the development of reactive PH.

METHODS

Thirty-three PVH patients with reactive PH and 29 PVH patients with proportional PH were analyzed retrospectively over a 6-year period. Clinical, laboratory, echocardiographic and hemodynamic parameters were noted and compared between subgroups.

RESULTS

There was no significant difference between PVH patients with reactive and proportional PH with regard to gender, age (65.91 ± 11.9 vs. 66.69 ± 10.5 years) and body surface area (1.89 ± 0.24 vs. 1.9 ± 0.23 m(2)). Prevalence of the metabolic syndrome components was similar in both groups. Interestingly, PCWP was similar in both groups, as were the structural and functional parameters of the left heart.

CONCLUSIONS

PVH patients with reactive PH have a similar profile as patients with proportional PH; consequently, the evolution of reactive PH is unpredictable. Therefore, it is imperative that physicians maintain a high index of suspicion for the development of reactive PH even in the early stage of heart disease.

Preliminary prospective explanatory observation on the impact of 3-month steroid therapy on the objective measures of sleep-disordered breathing

BACKGROUND

Excess endogenous steroids are a risk factor for obstructive sleep apnea (OSA). The role of exogenous steroids in this setup is not known. In this study, we prospectively looked at the consequences of a 3-month steroid treatment on the objective measures of sleep-disordered breathing.

METHODS

Patients scheduled for long-term steroids treatment underwent two sleep studies, the first before initiation and the second after 3 months of steroid therapy. Their weight and neck girth were measured. Correlations between the changes in the body weight, neck girth, and cumulative steroids dose to apnea/hypopnea index (AHI) change were examined. A group of untreated mild OSA patients (n = 23) served as control.

RESULTS

Seventeen patients, five males and 12 females, mean age 52.4 ± 12.6 years, were studied. Fifteen patients increased their mean AHI by 56% from 9.8 ± 11.8 to 15.4 ± 15.8, p = 0.004. This increment was significantly higher when compared to the control group. Body weight and neck girth changes and cumulative steroid dose were not correlated to the AHI increment (Spearman's correlation coefficient r = 0.18 and p = 0.49, r = -0.23 and p = 0.37, r = -0.17 and p = 0.51, respectively).

CONCLUSIONS

We found that the objective measures of sleep-disordered breathing worsened after the 3-month steroid treatment. Future studies to define pertinent mechanisms and clinical relevance are warranted.

Idiopathic pulmonary arterial hypertension or chronic thromboembolic pulmonary hypertension: can we be certain?

Idiopathic pulmonary arterial hypertension (IPAH) is an isolated small-vessel disease comprising vasoconstriction, remodeling and thrombosis of small pulmonary arteries. However, there is evidence that IPAH does not respect anatomic boundaries and might extend into large vessels such as large central thrombi. On the other hand, chronic thromboembolic pulmonary hypertension (CTEPH) represents a distinct category of pulmonary hypertension as it is thought to be due to an occlusion of the major pulmonary arteries following a thromboembolic event. However, it is currently evident that in most patients there is a concomitant small-vessel disease. The involvement of both small and large vessels in both IPAH and CTEPH, together with a high incidence of silent thromboembolic events, might create difficulties in identifying the true cause of pulmonary hypertension. An accurate diagnosis of the cause determines the management and prognosis. Patients with CTEPH can potentially be offered curative surgery in the form of pulmonary endarterectomy; however, oxygen, vasodilators, anticoagulation, and lung transplantation are more feasible options for IPAH.

Nitrofurantoin pulmonary toxicity: neglected threat

Nitrofurantoin lung toxicity was diagnosed among ten patients receiving 50 mg/day to prevent recurrent urinary tract infection. In six patients a symptomatic period of 3-36 months preceded the diagnosis. All but one patient, with irreversible lung injury at presentation recovered completely, five after drug discontinuation and four after steroids therapy. Large amount of data regarding unexpected, sometimes severe pulmonary toxicity during nitrofurantoin therapy should maintain a high index of suspicion for the drug usage among patients with non-resolving pulmonary symptoms. Alternatively, the use of other anti-microbial agents with a better risk-to-benefit ratio should be considered.

The response to bronchodilators in adults is not predictive of bronchial-hyperreactivity

BACKGROUND

In some subjects with suspected asthma who have normal spirometry, administration of bronchodilators (BD) improves expiratory flow rates. The predictive value of this phenomenon in adults is not known.

OBJECTIVES

To evaluate the predictive value of the response to BD for bronchial hyper-responsiveness (BHR) using the metacholine challenge test (MCT). Patients and methods. The study population included 62 non-smoking adult patients (41.9% women) 29.5 +/- 15.5 years of age (range 18-64 years) with suspected asthma with normal spirometry that underwent MCT within 1 week. The response to BD (200 mu g inhaled salbutamol) was compared between subjects with positive and negative MCT using cutoff levels of provocative concentrations of metacholine causing a 20% decrease in forced expiratory volume in 1 second (FEV(1)) (PC(20)) of 4 and 8 mg/mL.

RESULTS

Mean (+/- SD) baseline FEV(1) was 87.8 +/- 12% of predicted. After BD administration the mean FEV(1) increased by 4.3 +/- 3.9%. The prevalence of BHR was 17.7% and 25.8% for PC(20) for PC(20) of 4 mg/mL and 8 mg/mL, respectively. The post-BD FEV(1) increment for subjects with positive and negative MCT tests was 3.9% +/- 3.3% versus 4.4% +/- 4.1%, respectively; p = 0.89, using cutoff of 4 mg/mL. The corresponding figures for cutoff of 8 mg/ml were 4.3% +/- 3.1% vs. 4.3% +/- 4.2%, respectively; p = 0.8465. There was no correlation between post-BD FEV(1) increment and PC(20) values in patients with positive MCT test for the above-mentioned cutoff levels (correlation coefficient r = 0.1645, p = 0.6289; and r = 0.2417, p = 0.4051, respectively).

CONCLUSIONS

In adults with suspected asthma who have normal spirometry, the response to BD cannot be used to predict BHR.

Human serum paraoxonases (PON1) Q and R selectively decrease lipid peroxides in human coronary and carotid atherosclerotic lesions: PON1 esterase and peroxidase-like activities

BACKGROUND

Human serum paraoxonase (PON1) exists in two polymorphic forms: one that differs in the amino acid at position 192 (glutamine and arginine, Q and R, respectively) and the second one that differs in the amino acid at position 55 (methionine and leucine, M and L, respectively). PON1 protects LDL from oxidation, and during LDL oxidation, PON1 is inactivated.

METHODS AND RESULTS

The present study compared PON1 isoforms Q and R for their effect on lipid peroxide content in human coronary and carotid lesions. After 24 hours of incubation with PON1Q or PON1R (10 arylesterase units/mL), lipid peroxides content in both coronary and carotid lesion homogenates (0.1 g/mL) was reduced up to 27% and 16%, respectively. The above incubation was associated with inactivation of PON1Q and PON1R by 15% and 45%, respectively. Lesion cholesteryl linoleate hydroperoxides and cholesteryl linoleate hydroxides were hydrolyzed by PON1 to yield linoleic acid hydroperoxides and linoleic acid hydroxides. Furthermore, lesion and pure linoleic acid hydroperoxides were reduced to yield linoleic acid hydroxides. These results thus indicate that PON1 demonstrates esterase-like and peroxidase-like activities. Recombinant PON1 mutants in which the PON1-free sulfhydryl group at cysteine-284 was replaced with either alanine or serine were no longer able to reduce lipid peroxide content in carotid lesions.

CONCLUSIONS

We conclude that PON1 may be antiatherogenic because it hydrolyzes lipid peroxides in human atherosclerotic lesions.