Alpha1-antitrypsin deficiency in Greece: Focus on rare variants

PURPOSE

A1Antitrypsin deficiency (AATD) pathogenic mutations are expanding beyond the PI*Z and PI*S to a multitude of rare variants.

AIM

to investigate genotype and clinical profile of Greeks with AATD.

METHODS

Symptomatic adult-patients with early-emphysema defined by fixed airway obstruction and computerized-tomography scan and lower than normal serum AAT levels were enrolled from reference centers all over Greece. Samples were analyzed in the AAT Laboratory, University of Marburg-Germany.

RESULTS

Included are 45 adults, 38 homozygous or compound heterozygous for pathogenic variants and 7 heterozygous. Homozygous were 57.9% male, 65.8% ever-smokers, median (IQR) age 49.0(42.5-58.5) years, AAT-levels 0.20(0.08-0.26) g/L, FEV1(%predicted) 41.5(28.8-64.5). PI*Z, PI*Q0, and rare deficient allele's frequency was 51.3%, 32.9%,15.8%, respectively. PI*ZZ genotype was 36.8%, PI*Q0Q0 21.1%, PI*MdeficientMdeficient 7.9%, PI*ZQ0 18.4%, PI*Q0Mdeficient 5.3% and PI*Zrare-deficient 10.5%. Genotyping by Luminex detected: p.(Pro393Leu) associated with MHeerlen (M1Ala/M1Val); p.(Leu65Pro) with MProcida; p.(Lys241Ter) with Q0Bellingham; p.(Leu377Phefs*24) with Q0Mattawa (M1Val) and Q0Ourem (M3); p.(Phe76del) with MMalton (M2), MPalermo (M1Val), MNichinan (V) and Q0LaPalma (S); p.(Asp280Val) with PLowell (M1Val); PDuarte (M4), YBarcelona (p.Pro39His). Gene-sequencing (46.7%) detected Q0GraniteFalls, Q0Saint-Etienne, Q0Amersfoort(M1Ala), MWürzburg, NHartfordcity and one novel-variant (c.1A>G) named Q0Attikon.Heterozygous included PI*MQ0Amersfoort(M1Ala), PI*MMProcida, PI*Mp.(Asp280Val), PI*MOFeyzin. AAT-levels were significantly different between genotypes (p = 0.002).

CONCLUSION

Genotyping AATD in Greece, a multiplicity of rare variants and a diversity of rare combinations, including unique ones were observed in two thirds of patients, expanding knowledge regarding European geographical trend in rare variants. Gene sequencing was necessary for genetic diagnosis. In the future the detection of rare genotypes may add to personalize preventive and therapeutic measures.

Imbalance between alpha-1-antitrypsin and interleukin 6 is associated with in-hospital mortality and thrombosis during COVID-19

Thrombosis is a hallmark of severe COVID-19. Alpha-1-antitrypsin (AAT), an inflammation-inducible serpin with anti-inflammatory, tissue protective and anticoagulant properties may be involved in severe COVID-19 pathophysiology including thrombosis onset. In this study, we examined AAT ability to predict occurrence of thrombosis and in-hospital mortality during COVID-19. To do so, we performed a monocentric cross-sectional study of 137 hospitalized patients with COVID-19 of whom 56 (41%) were critically ill and 33 (22.4%) suffered from thrombosis during hospitalization. We measured AAT and IL-6 plasma levels in all patients and phenotyped AAT in a subset of patients with or without thrombosis paired for age, sex and COVID-19 severity. We observed that AAT levels at admission were higher in both non-survivors and thrombosis patients than in survivors and non-thrombosis patients. AAT: IL-6 ratio was lower in non-survivors and thrombosis patients. In a logistic regression multivariable analysis model adjusted on age, BMI and D-dimer levels, a higher AAT: IL-6 was a protective factor of both in-hospital mortality (Odds ratio, OR: 0.07 95%CI [0.02–0.25], p < 0.001) and thrombosis (OR 0.36 95%CI [0.14–0.82], p = 0.02). AAT phenotyping did not show a higher proportion of AAT abnormal variants in thrombosis patients.Our findings suggest an insufficient production of AAT regarding inflammation intensity during severe COVID-19. AAT appeared as a powerful predictive marker of severity, mortality and thrombosis mirroring the imbalance between harmful inflammation and protective counter-balancing mechanism in COVID-19. Restoring the balance between AAT and inflammation could offer therapeutic opportunities in severe COVID-19.

Relationship Between Obesity and Ventilator-Associated Pneumonia: A Post Hoc Analysis of the NUTRIREA2 Trial

BACKGROUND

Patients with obesity are at higher risk for community-acquired and nosocomial infections. However, no study has specifically evaluated the relationship between obesity and ventilator-associated pneumonia (VAP).

RESEARCH QUESTION

Is obesity associated with an increased incidence of VAP?

STUDY DESIGN AND METHODS

This study was a post hoc analysis of the Impact of Early Enteral vs Parenteral Nutrition on Mortality in Patients Requiring Mechanical Ventilation and Catecholamines (NUTRIREA2) open-label, randomized controlled trial performed in 44 French ICUs. Adults receiving invasive mechanical ventilation and vasopressor support for shock and parenteral nutrition or enteral nutrition were included. Obesity was defined as BMI ≥ 30 kg/m² at ICU admission. VAP diagnosis was adjudicated by an independent blinded committee, based on all available clinical, radiologic, and microbiologic data. Only first VAP episodes were taken into account. Incidence of VAP was analyzed by using the Fine and Gray model, with extubation and death as competing risks.

RESULTS

A total of 699 (30%) of the 2,325 included patients had obesity; 224 first VAP episodes were diagnosed (60 and 164 in obese and nonobese groups, respectively). The incidence of VAP at day 28 was 8.6% vs 10.1% in the two groups (hazard ratio, 0.85; 95% CI 0.63-1.14; P = .26). After adjustment on sex, McCabe score, age, antiulcer treatment, and Sequential Organ Failure Assessment at randomization, the incidence of VAP remained nonsignificant between obese and nonobese patients (hazard ratio, 0.893; 95% CI, 0.66-1.2; P = .46). Although no significant difference was found in duration of mechanical ventilation and ICU length of stay, 90-day mortality was significantly lower in obese than in nonobese patients (272 of 692 [39.3%] patients vs 718 of 1,605 [44.7%]; P = .02). In a subgroup of patients (n = 123) with available pepsin and alpha-amylase measurements, no significant difference was found in rate of abundant microaspiration of gastric contents, or oropharyngeal secretions between obese and nonobese patients.

INTERPRETATION

Our results suggest that obesity has no significant impact on the incidence of VAP.

Is COPD associated with increased risk for microaspiration in intubated critically ill patients?

Background

Although COPD patients are at higher risk for aspiration when breathing spontaneously, no information is available on the risk for microaspiration in invasively ventilated COPD patients. The aim of our study was to determine the relationship between COPD and abundant microaspiration in intubated critically ill patients.

Methods

This was a retrospective analysis of prospectively collected data, provided by 3 randomized controlled trials on microaspiration in critically ill patients receiving invasive mechanical ventilation for more than 48 h. Abundant microaspiration was defined as the presence of pepsin and or alpha-amylase at significant levels in tracheal aspirates. In all study patients, pepsin and alpha-amylase were quantitatively measured in all tracheal aspirates collected during a 48-h period. COPD was defined using spirometry criteria.

Results

Among the 515 included patients, 70 (14%) had proven COPD. Pepsin and alpha-amylase were quantitatively measured in 3873 and 3764 tracheal aspirates, respectively. No significant difference was found in abundant microaspiration rate between COPD and non-COPD patients (62 of 70 patients (89%) vs 366 of 445 (82%) patients, p = 0.25). Similarly, no significant difference was found in abundant microaspiration of gastric contents (53% vs 45%, p = 0.28), oropharyngeal secretions (71% vs 71%, p = 0.99), or VAP (19% vs 22%, p = 0.65) rates between the two groups. No significant difference was found between COPD and non-COPD patients in duration of mechanical ventilation, ICU length of stay, or ICU mortality.

Conclusions

Our results suggest that COPD is not associated with increased risk for abundant microaspiration in intubated critically ill patients.

Measurement of Elastase and Cysteine Proteinases in Synovial Fluid of Patients with Rheumatoid Arthritis, Sero-Negative Spondylarthropathies, and Osteoarthritis

Synovial fluid samples were collected from 45 patients with rheumatoid arthritis, spondylarthropathy, or osteoarthritis, to study their content of elastase (EC 3.4.21.37) and of cysteine proteinases (EC 3.4.22.1, 3.4.22.15). We measured both elastase complexed with alpha 1-proteinase inhibitor and elastase activity toward the substrate L-pyroglutamyl-L-prolyl-L-valine-p-nitroanilide. Cysteine proteinase activities were measured with the substrates N-benzyloxycarbonyl-L-phenylalanyl-L-arginine-7-amido-4-methylcoumarin (Z-Phe-Arg-AMC) and Z-Arg-Arg-AMC and the inhibitor E-64 [L-trans-epoxysuccinyl-leucyl-amido-(4-guanidino)-butane]. In all these enzyme assays, higher median values were obtained in inflammatory arthropathies than in osteoarthritis. The concentration of the elastase-alpha 1-proteinase inhibitor complex and of elastase and cysteine proteinase activities were statistically higher in patients with rheumatoid arthritis than in patients with osteoarthritis. The difference in results between patients with spondylarthropathy and patients with osteoarthritis was statistically significant only for the elastase-alpha 1-proteinase inhibitor complex. The median values of the complex and of both enzyme activities were higher in patients with rheumatoid arthritis than in patients with spondylarthropathy; however, the difference was statistically significant only for the cysteine proteinase activity measured with Z-Arg-Arg-AMC substrate. These results suggest that both elastase and cysteine proteinases, which are increased in patients with inflammatory arthritis, are involved in cartilage degradation in these arthropathies.

Impact of nutrition route on microaspiration in critically ill patients with shock: a planned ancillary study of the NUTRIREA-2 trial

BACKGROUND

Microaspiration of gastric and oropharyngeal secretions is the main mechanism of entry of bacteria into the lower respiratory tract in intubated critically ill patients. The aim of this study is to determine the impact of enteral nutrition, as compared with parenteral nutrition, on abundant microaspiration of gastric contents and oropharyngeal secretions.

METHODS

Planned ancillary study of the randomized controlled multicenter NUTRIREA2 trial. Patients with shock receiving invasive mechanical ventilation were randomized to receive early enteral or parenteral nutrition. All tracheal aspirates were collected during the 48 h following randomization. Abundant microaspiration of gastric contents and oropharyngeal secretions was defined as the presence of significant levels of pepsin (> 200 ng/ml) and salivary amylase (> 1685 UI/ml) in > 30% of tracheal aspirates.

RESULTS

A total of 151 patients were included (78 and 73 patients in enteral and parenteral nutrition groups, respectively), and 1074 tracheal aspirates were quantitatively analyzed for pepsin and amylase. Although vomiting rate was significantly higher (31% vs 15%, p = 0.016), constipation rate was significantly lower (6% vs 21%, p = 0.010) in patients with enteral than in patients with parenteral nutrition. No significant difference was found regarding other patient characteristics. The percentage of patients with abundant microaspiration of gastric contents was significantly lower in enteral than in parenteral nutrition groups (14% vs 36%, p = 0.004; unadjusted OR 0.80 (95% CI 0.69, 0.93), adjusted OR 0.79 (0.76, 0.94)). The percentage of patients with abundant microaspiration of oropharyngeal secretions was significantly higher in enteral than in parenteral nutrition groups (74% vs 54%, p = 0.026; unadjusted OR 1.21 (95% CI 1.03, 1.44), adjusted OR 1.23 (1.01, 1.48)). No significant difference was found in percentage of patients with ventilator-associated pneumonia between enteral (8%) and parenteral (10%) nutrition groups (HR 0.78 (0.26, 2.28)).

CONCLUSIONS

Our results suggest that enteral and parenteral nutrition are associated with high rates of microaspiration, although oropharyngeal microaspiration was more common with enteral nutrition and gastric microaspiration was more common with parenteral nutrition.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03411447 . Registered 18 July 2017. Retrospectively registered.

Impact of subglottic secretion drainage on microaspiration in critically ill patients: a prospective observational study

Background

Microaspiration is a major factor in ventilator-associated pneumonia (VAP) pathophysiology. Subglottic secretion drainage (SSD) aims at reducing its incidence.

Methods

Single-center prospective observational study, performed in a French intensive care unit (ICU) from March 2012 to April 2013, including adult patients mechanically ventilated for at least 24 hours divided in two groups: patients in the SSD group intubated using tracheal tubes allowing SSD and patients in the control group intubated with standard tracheal tubes. Pepsin and salivary amylase concentrations were measured for 24 hours in all tracheal aspirates. Primary objective was to determine the impact of SSD on gastric or oropharyngeal microaspiration using pepsin or amylase concentration in tracheal aspirates.

Results

Fifty-five patients were included in the SSD group and 45 in the control group. No difference was found between groups regarding the incidence of microaspiration defined as at least one tracheal aspirate positive for either pepsin or amylase [49 (89%) vs. 37 (82%), P=0.469]. Percentage of patients with VAP [16 (29%) vs. 11 (24%), P=0.656], ventilator-associated tracheobronchitis (VAT) [7 (13%) vs. 4 (9%), P=0.750] or early airway colonization [15 (35%) vs. 8 (18%), P=0.219] were not significantly different in study groups.

Conclusions

SSD did not reduce the incidence of microaspiration, VAP, VAT or airway colonization in this observational study.

Description of 22 new alpha-1 antitrypsin genetic variants

Alpha-1 antitrypsin deficiency is an autosomal co-dominant disorder caused by mutations of the highly polymorphic SERPINA1 gene. This genetic disorder still remains largely under-recognized and can be associated with lung and/or liver injury. The laboratory testing for this deficiency typically comprises serum alpha-1 antitrypsin quantification, phenotyping according to the isoelectric focusing pattern and genotyping if necessary. To date, more than 100 SERPINA1 variants have been described and new genetic variants are frequently discovered. Over the past 10 years, 22 new genetic variants of the SERPINA1 gene were identified in the daily practice of the University Medical laboratories of Lille and Lyon (France). Among these 22 variants, seven were Null alleles and one with a M1 migration pattern (M1_Cremeaux) was considered as deficient according to the clinical and biological data and to the American College of Medical Genetics and Genomics (ACMG) criteria. Three other variants were classified as likely pathogenic, three as variants of uncertain significance while the remaining ones were assumed to be neutral. Moreover, we also identified in this study two recently described SERPINA1 deficient variants: Trento (p.Glu99Val) and S_Donosti (p.Ser38Phe). The current data, together with a recent published meta-analysis, represent the most up-to-date list of SERPINA1 variants available so far.

Alpha1 antitrypsin deficiency due to an homozygous PI* Null Q0Cairo mutation: Early onset of pulmonary manifestations and variability of clinical expression

Alpha-1 antitrypsin deficiency is an autosomal, codominant disorder caused by mutations of the SERPINA1 gene. This genetic disorder is mainly associated with development of pulmonary emphysema and/or chronic liver disease and cirrhosis. Here we report a very rare alpha-1 antitrypsin Null Q0cairo homozygous mutation characterized by a complete absence of alpha-1 antitrypsin in the plasma, in a non-consanguineous Moroccan family. This mutation has been previously described in heterozygosis in only three cases worldwide: an Italian/Egyptian family and two Italian families (Zorzetto et al., 2005). The main clinical features in two members of this Moroccan family were the severity and precocity of bronchiectasis, quickly spreading and seriously limiting respiratory function and physical activity by the second decade of age. Moreover, the index case presented with many episodes of pulmonary infections concomitant with severe neutropenia. The third member of the family presented with ankylosing spondyloarthritis and developed panniculitis later but had no respiratory symptoms. The presence of this alpha-1-antitrypsin Q0cairo homozygous mutation could explain the severity of clinical manifestations. Moreover, our observations highlight a great variability of clinical expression for the same mutation: early severe bronchiectasis, panniculitis, rheumatologic manifestations. This study further underlines the importance of genotyping by whole SERPINA1 gene sequencing in addition to serum alpha-1 antitrypsin determination, to enable detection of alpha-1 antitrypsin deficiency due to rare genotypes.

Identification of a novel alpha1-antitrypsin variant

Alpha-1-antitrypsin deficiency (A1ATD) is a genetic condition caused by SERPINA1 mutations, which results into decreased protease inhibitor activity in the serum and predisposes to emphysema and/or to liver disease due to accumulation of the abnormal protein in the hepatic cells. In most cases the clinical manifestations of A1ATD are associated with PIZZ (p.Glu366Lys; p.Glu366Lys (p.Glu342Lys; p.Glu342Lys)) or PISZ (p.Glu288Val; p.Glu366Lys (p.Glu264Val; p.Glu342Lys)) genotype, less frequently, deficient or null alleles may be present in compound heterozygous or homozygous A1AT deficient patients. We report the identification of a novel alpha1-antitrypsin variant in a 64-year old woman presenting with dyspnea on exertion. Imaging revealed bilateral bronchiectasis associated with moderate panacinar emphysema. The pulmonary function tests (PFTs) were subnormal but hypoxemia was noticed and A1AT quantitative analysis revealed a severe deficiency. DNA sequencing showed compound heterozygosity for the PIZ variant and a novel missense variant p.Phe232Leu (p.Phe208Leu). No specific treatment was proposed since PFTs were within the normal range at this stage of the disease. Close follow-up of pulmonary and hepatic parameters was recommended.

Health-related quality of life in patients with alpha-1 antitrypsin deficiency: the French experience

The French registry of patients with alpha-1 antitrypsin deficiency (AATD)-associated emphysema was launched in 2006. Here, we aimed to report on the baseline characteristics of these patients, their health-related quality of life (HRQoL) and factors associated with HRQoL. Another goal was to survey the practices of French physicians regarding augmentation therapy. We included 273 patients with AATD, emphysema, obstructive-pattern [forced expiratory volume in 1 sec/forced volume capacity (FEV1/FVC) < 0.7], FEV1 ≤ 80% predicted. Mean (SD) age was 51.8 (11.1) years, 240 (87.9%) of patients were smokers or ex-smokers, mean (SD) FEV1 was 40.5% (15.7) predicted. Mean (SD) SGRQ score was 49.0 (20.0) and was higher for females than males (52.7 [20.7] vs 46.8 [18.2]; p = 0.01). Dyspnea showed the strongest association with SGRQ score (r = 0.65; p < 0.0001), followed by chronic bronchitis (r = 0.33; p < 0.0001) and wheezing (r = 0.32; p < 0.0001). Number of exacerbations in the year before inclusion was also significantly associated with SGRQ score (r = 0.36; p < 0.0001). The SGRQ score was associated with the 6-min walking distance (r = -0.53, p < 0.0001), FEV1 (% predicted, r = -0.53, p < 0.0001) and DLCO (% predicted, r = -0.52, p < 0.0001). It was also associated with the GOLD 2006 (r = 0.53; p < 0.0001) and GOLD 2011 (r = 0.63; p< 0.0001) classifications and with the BODE index (r = 0.37; p < 0.0001). Age, history of tobacco smoking or current smoking did not show any association with SGRQ total scores. On multivariate analysis, a model including age, chronic bronchitis, dyspnea (MRC scale), diffusing lung capacity and 6-min walking distance explained 57% of the variation in the score. The French registry provides important insights into the clinical characteristics of French patients with AATD-related emphysema.

Diagnosis of alpha-1 antitrypsin deficiency: modalities, indications and diagnosis strategy

Alpha-1 antitrypsin (α1-AT) deficiency is an autosomal recessive genetic disorder, which predisposes affected patients to development of pulmonary emphysema or liver cirrhosis. Despite the guidelines from the American Thoracic Society and the European Respiratory Society about α1-AT deficiency screening, it remains significantly under recognized. So, it seems necessary to propose an efficient and suitable biological approach to improve diagnosis and management of α1-AT deficiency. α1-AT is a 52 kDa glycoprotein predominantly produced in the liver and its physiological serum concentration for adults ranges from 0.9 to 2.0g/L (17-39 μmol/L). It is encoded by the SERPINA1 gene, which is highly pleomorphic, and to date, more than 100 alleles have been identified. α1-AT testing would initially involve quantification of serum α1-AT concentration with possible complementary measurement of the elastase inhibitory capacity of serum. If the serum α1-AT concentration is reduced below the reference value, two strategies for laboratory testing can be used: (i) serum α1-AT phenotyping by isoelectric focusing which allows identification of the most common variant designated as the PI M variant but also of various deficient variants besides the predominant PI S and PI Z ones; (ii) genotyping by allele-specific PCR methods which allows only identification of the deficient PI S and PI Z alleles. Identification of the null alleles or of other rare deficient alleles can be performed by direct sequencing of the whole SERPINA1 gene as a reflex test.

Accuracy of alpha amylase in diagnosing microaspiration in intubated critically-ill patients

OBJECTIVES

Amylase concentration in respiratory secretions was reported to be a potentially useful marker for aspiration and pneumonia. The aim of this study was to determine accuracy of α-amylase in diagnosing microaspiration in critically ill patients.

METHODS

Retrospective analysis of prospectively collected data collected in a medical ICU. All patients requiring mechanical ventilation for at least 48 h, and included in a previous randomized controlled trial were eligible for this study, provided that at least one tracheal aspirate was available for α-amylase measurement. As part of the initial trial, pepsin was quantitatively measured in all tracheal aspirates during a 48-h period. All tracheal aspirates were frozen, allowing subsequent measurement of α-amylase for the purpose of the current study. Microaspiration was defined as the presence of at least one positive tracheal aspirate for pepsin (>200 ng.mL-1). Abundant microaspiration was defined as the presence of pepsin at significant level in >74% of tracheal aspirates.

RESULTS

Amylase was measured in 1055 tracheal aspirates, collected from 109 patients. Using mean α-amylase level per patient, accuracy of α-amylase in diagnosing microaspiration was moderate (area under the receiver operator curve 0.72±0.05 [95%CI 0.61-0.83], for an α-amylase value of 1685 UI.L-1). However, when α-amylase levels, coming from all samples, were taken into account, area under the receiver operator curve was 0.56±0.05 [0.53-0.60]. Mean α-amylase level, and percentage of tracheal aspirates positive for α-amylase were significantly higher in patients with microaspiration, and in patients with abundant microaspiration compared with those with no microaspiration; and similar in patients with microaspiration compared with those with abundant microaspiration. α-amylase and pepsin were significantly correlated (r2 = 0.305, p = 0.001).

CONCLUSION

Accuracy of mean α-amylase in diagnosing microaspiration is moderate. Further, when all α-amylase levels were taken into account, α-amylase was inaccurate in diagnosing microaspiration, compared with pepsin.

Performance of the BODE index in patients with α1-antitrypsin deficiency-related COPD

The BODE (body mass index, airflow obstruction, dyspnoea and exercise capacity) index is used to decide on referral and transplantation of patients with chronic obstructive pulmonary disease (COPD). The BODE index has not been validated in patients with α1-antitrypsin deficiency, who account for 15% of COPD patients undergoing lung transplantation. We sought to validate the BODE index in α1-antitrypsin deficiency-related COPD. We assessed the prognostic value of the BODE index in 191 patients followed from 2006 to 2012 in a French prospective cohort of patients with α1-antitrypsin deficiency. 20 patients died during follow-up and 22 underwent lung transplantation. Survival (95% CI) was 93.0% (91.7-94.3%) at 3 years and 76.0% (72.9-79.1%) at 5 years. The 3-year survival was 97.4% (96.6-98.2%), 98.0% (96.7-99.3%), 87.7% (84.5-90.9%) and 75.3% (66.0-84.6%) for patients with BODE index 0-2, 3-4, 5-6 and 7-10, respectively. Survival discrimination of the BODE index was better than with both forced expiratory volume in 1 s and Global Initiative for Chronic Obstructive Lung Disease classification. Regarding calibration, expected survival by BODE index was noticeably lower than observed survival. The BODE index showed very good survival discrimination in patients with α1-antitrypsin deficiency-related COPD. Larger studies are needed to support its use to drive patient referral for lung transplantation.

Efficiency of a pneumatic device in controlling cuff pressure of polyurethane-cuffed tracheal tubes: a randomized controlled study

Background

The primary objective of this study was to determine the efficiency of a pneumatic device in controlling cuff pressure (P_cuff) in patients intubated with polyurethane-cuffed tracheal tubes. Secondary objectives were to determine the impact of continuous control of P_cuff, and cuff shape on microaspiration of gastric contents.

Methods

Prospective randomized controlled study. All patients requiring intubation and mechanical ventilation ≥48 h were eligible. The first 32 patients were intubated with tapered polyurethane-cuffed, and the 32 following patients were intubated with cylindrical polyurethane-cuffed tracheal tubes. Patients randomly received 24 h of continuous control of P_cuff using a pneumatic device (Nosten®), and 24 h of routine care of P_cuff using a manometer. Target P_cuff was 25 cmH₂O. P_cuff was continuously recorded, and pepsin was quantitatively measured in all tracheal aspirates during these periods.

Results

The pneumatic device was efficient in controlling P_cuff (med [IQ] 26 [24, 28] vs 22 [20, 28] cmH₂O, during continuous control of P_cuff and routine care, respectively; p = 0.017). In addition, percentage of patients with underinflation (31% vs 68%) or overinflation (53% vs 100%) of tracheal cuff, and percentage of time spent with underinflation (0.9 [0, 17] vs 14% [4, 30]) or overinflation (0 [0, 2] vs 32% [9, 54]) were significantly (p < 0.001) reduced during continuous control of P_cuff compared with routine care.

No significant difference was found in microaspiration of gastric content between continuous control of P_cuff compared with routine care, or between patients intubated with tapered compared with cylindrical polyurethane-cuffed tracheal tubes.

Conclusion

The pneumatic device was efficient in controlling P_cuff in critically ill patients intubated with polyurethane-cuffed tracheal tubes.

Trial registration

The Australian New Zealand Clinical Trials Registry (NCT01351259)

Microaspiration in intubated critically ill patients: diagnosis and prevention

Microaspiration of contaminated oropharyngeal secretions and gastric contents frequently occurs in intubated critically ill patients, and plays a major role in the pathogenesis of ventilator-associated pneumonia. Risk factors for microaspiration include impossible closure of vocal cords, longitudinal folds in high-volume low-pressure polyvinyl chloride cuffs, and underinflation of tracheal cuff. Zero positive end expiratory pressure, low peak inspiratory pressure, tracheal suctioning, nasogastric tube and enteral nutrition increase the risk for microaspiration. Other patient related factors include supine position, coma, sedation, and hyperglycemia. Technetium 99 labelled enteral feeding is probably the most accurate marker of microaspiration in critically ill patients. However, use of this radioactive marker is restricted to nuclear medicine departments. Blue methylene is a reliable qualitative marker of microaspiration. However, fiberoptic bronchoscopy is required to diagnose microaspiration of blue dye in ICU patients. Quantitative pepsin measurement in tracheal aspirates is accurate in diagnosing microaspiration of gastric contents in critically ill patients. In addition, this marker is easy to use in routine practice. However, pepsin should be detected rapidly after aspiration. In vitro, and clinical studies suggested that semirecumbent position, polyurethane cuffs, positive end expiratory pressure, low-volume low-pressure cuff, and continuous control of cuff pressure were efficient in reducing microaspiration in ICU patients. Other preventive measures such as subglottic aspiration, tapered shape cuff, guayule latex cuff, lateral horizontal patient position, gastrostomy tube, and postpyloric feeding require further investingation.

Evaluation of a new Sebia isoelectrofocusing kit for alpha 1-antitrypsin phenotyping with the Hydrasys System

BACKGROUND

Laboratory evaluation of alpha 1-antitrypsin (A1AT) deficiency is generally performed by determination of A1AT concentrations and identification of specific allelic variants by phenotyping. For this purpose, we evaluated a new Hydragel 18 A1AT Isofocusing kit on the semi-automatic Hydrasys System (Sebia) for the determination of A1AT phenotypes by isoelectrofocusing on ready-to-use agarose gels with specific immunological detection.

METHODS

Serum samples from 66 patients were analysed with this new kit in comparison with the conventional and manually performed isoelectrofocusing method on polyacrylamide gels with Coomassie Blue staining.

RESULTS

A1AT phenotypes showed comparable iso-electrofocusing patterns in both systems. The good within-gel reproducibility of this kit was demonstrated using two normal serum samples (M1 and M1M2 phenotypes) and six pathological serum samples with different phenotypes (MS, SS, SZ, MZ, ZZ). A sensitivity study was undertaken by performing serial dilutions on a serum with a ZZ phenotype containing 0.27 g/L A1AT. The detection limit was 0.050 g/L.

CONCLUSIONS

This new method is highly specific, rapid and simple to perform. It improves identification of not only the most common but also various rare A1AT phenotypes. It appears to be suitable for routine analysis and screening applications in a clinical laboratory setting.

Urinary bikunin determination provides insight into proteinase/proteinase inhibitor imbalance in patients with inflammatory diseases

Bikunin (BK) is a Kunitz-type proteinase inhibitor responsible for most of the antitryptic activity of urine and so is known as the urinary trypsin inhibitor. As its excretion increases in inflammatory conditions, it is often considered to be a positive acute phase protein (APP). However, the gene for BK is downregulated in inflammation. In human plasma the major part of BK is covalently linked through a glycosaminoglycan chain to one or two homologous peptide heavy chains, thus forming high molecular weight proteinase inhibitors called pre-alpha-inhibitor (PalphaI) and inter-alpha-inhibitor (IalphaI), respectively. The C-terminal parts of these heavy chains are very sensitive to proteolysis. Neutrophil proteinases in particular are able to release from IalphaI and PalphaI BK (M, about 25,000) which retains its antitryptic activity and is quickly excreted in urine. It was therefore an early supposition that the higher urinary excretion of BK occurring during inflammatory diseases should be, at least in some respect, related to a partial proteolysis of IalphaI and PalphaI. In this study we observed that BK, determined as antitryptic activity, was clearly increased in urine from 35 patients with inflammatory diseases varying in origin and severity (76.5 +/- 75.5 IU/g vs. reference value <10 IU/g creatinine). This increase seems mainly to be associated with polymorphonuclear leukocyte activation, monitored by human leukocyte elastase (HLE) determination rather than with the acute phase response assessed by C-reactive protein (CRP) measurement. For all the patients we found that the urinary levels of BK and serum concentration of intact IalphaI correlated inversely (r=-0.36; p=0.03), in agreement with the presumed precursor-product relationship linking IalphaI and BK. We also proved that urinary BK was significantly higher, and serum IalphaI was significantly lower, in samples with plasma HLE values above the reference: 90 microg/l. Taken together, our results demonstrate that BK, the urinary excretion of which is increased in inflammatory conditions, originates, at least partly, from IalphaI and PalphaI by proteolytic cleavage. Consequently, urinary BK determination provides information on the severity of systemic proteolysis occurring in inflammation. We also demonstrated that during inflammatory diseases IalphaI and PalphaI concentrations in serum are dependent on their increased utilization as well as on the regulation of their biosynthesis.

Heterozygous M3Mmalton α1-Antitrypsin Deficiency Associated with End-Stage Liver Disease: Case Report and Review

α1-Antitrypsin (α1AT) deficiency is an autosomal recessive disorder that can cause pulmonary emphysema and liver disease. We report here the case of a 59-year-old woman who was admitted to hospital for evaluation of jaundice. She had no history of hepatitis or childhood liver disease. She had never received a blood transfusion, nor had she abused drugs or alcohol. Transjugular liver biopsy was then performed and revealed a micronodular cirrhosis. Ten months later, because of persistent liver cell failure and ascites, she underwent an orthotopic liver transplantation. Investigation of α1AT system in the proband revealed a substantial decrease in serum α1AT associated with a low elastase inhibitory capacity. The Pi phenotype revealed a PiM-like profile. Sequencing of exons 1–5 demonstrated the presence of the M3 allele. Moreover, a triple nucleotide deletion was detected in exon 2 of one allele. This caused an “in-phase” frameshift, coding for a protein deficient in a single Phe residue, which corresponded to the Mmalton variant. After liver biopsy, periodic acid-Schiff-positive acidophilic bodies resistant to diastase digestion were observed in the cytoplasm of hepatocytes. These results demonstrated that our patient had a heterozygous M3Mmalton α1AT genotype related to a deficiency phenotype. This observation is the first of a patient with heterozygous Mmalton genotype associated with an α1AT deficiency that induced severe liver disease requiring orthotopic liver transplantation.

Heterozygous M3Mmalton alpha1-antitrypsin deficiency associated with end-stage liver disease: case report and review

Alpha1-antitrypsin (alpha1AT) deficiency is an autosomal recessive disorder that can cause pulmonary emphysema and liver disease. We report here the case of a 59-year-old woman who was admitted to hospital for evaluation of jaundice. She had no history of hepatitis or childhood liver disease. She had never received a blood transfusion, nor had she abused drugs or alcohol. Transjugular liver biopsy was then performed and revealed a micronodular cirrhosis. Ten months later, because of persistent liver cell failure and ascites, she underwent an orthotopic liver transplantation. Investigation of alpha1AT system in the proband revealed a substantial decrease in serum alpha1AT associated with a low elastase inhibitory capacity. The Pi phenotype revealed a PiM-like profile. Sequencing of exons 1-5 demonstrated the presence of the M3 allele. Moreover, a triple nucleotide deletion was detected in exon 2 of one allele. This caused an "in-phase" frameshift, coding for a protein deficient in a single Phe residue, which corresponded to the Mmalton variant. After liver biopsy, periodic acid-Schiff-positive acidophilic bodies resistant to diastase digestion were observed in the cytoplasm of hepatocytes. These results demonstrated that our patient had a heterozygous M3Mmalton alpha1AT genotype related to a deficiency phenotype. This observation is the first of a patient with heterozygous Mmalton genotype associated with an alpha1AT deficiency that induced severe liver disease requiring orthotopic liver transplantation.

The chondroitin sulfate chain of bikunin-containing proteins in the inter-alpha-inhibitor family increases in size in inflammatory diseases

Inter-alpha-inhibitor (IalphaI) and pre-alpha-inhibitor (PalphaI) are the main members of a set of multichain serine proteinase inhibitors. Present in human plasma, they may be involved in control of the inflammatory process. They are composed of homologous heavy chains (H1 and H2 for IalphaI; H3 for PalphaI) covalently linked by a protein-glycosaminoglycan-protein cross-link to bikunin, which is a chondroitin 4-sulfate proteoglycan. During the acute-phase response, biosynthesis of IalphaI and PalphaI is downregulated and upregulated, respectively. In this work, we provide evidence that, in inflammatory diseases, the chondroitin sulfate chain of bikunin increases in size proportionally to the severity of the inflammatory response. As a consequence, all IalphaI-related components that contain bikunin are structurally modified. Therefore, the changes in glycosylation of the acute-phase proteins are not restricted to N-linked glycans but also affect glycosaminoglycans. The implications of these findings are discussed with regard to biosynthesis and biological role, especially the anti-inflammatory effects of IalphaI-related proteinase inhibitors.

Specific expression of matrix metalloproteinases 1, 3, 9 and 13 associated with invasiveness of breast cancer cells in vitro

Several matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) were studied in highly invasive (MDA-MB-231) and slightly invasive (MCF-7, T47D, BT-20) breast cancer cell lines. Investigations were carried out at the protein level and/or at the mRNA level, either in cells cultured as monolayers on plastic, or in cells seeded on a thin layer of Matrigel basement membrane matrix. Analysis of MMP expression by RT-PCR showed expression of MMP-1. MMP-3, and MMP-13 in highly invasive MDA-MB-231 cells, but not in slightly invasive cell lines. The extracellular secretion of MMP-1 and MMP-3 by MDA-MB 231 cells could be also shown by ELISA. TIMP-1 and TIMP-2 mRNAs were found in all cell lines, however, the extracellular secretion of both TIMPs was much higher in MDA-MB-231 cells than in the other cell lines. When the cells were cultured on Matrigel matrix, MMP-9 expression was induced in MDA-MB-231 cells only, as assessed by RT-PCR and zymography experiments. The invasive potential of MDA-MB-231 cells evaluated in vitro through Matrigel was significantly inhibited by the MMP inhibitor BB-2516, by 25% and 50% at the concentrations of 2 x 10(-6) M and 10(-5) M, respectively. In conclusion, our data show that highly invasive MDA-MB-231 cells but not slightly invasive T47D, MCF-7 and BT-20 cells express MMP-1, MMP-3, MMP-9 and MMP-13. MMP-9 which is specifically up-regulated by cell contact to Matrigel, may play a key role in the invasiveness of MDA-MB-231 cells through basement membranes.

Oxidative markers in diabetic ketoacidosis

Oxidative stress has been implicated in the pathogenesis of the chronic complications of diabetes mellitus but little is known in diabetic ketoacidosis (DKA). The aim of this work was to determine whether lipid peroxidation, as assessed by measuring malondialdehyde (MDA, a prooxidant) and antioxidant status (TAS, an index of antioxidant defenses), is modified in DKA, and also whether any observed abnormalities were related to metabolic disturbances.

METHODS

four groups of patients were studied, comprising 19 patients with DKA, massive ketonuria and plasma standard bicarbonate levels below 16 mmol/l (group 1); 20 patients with poorly controlled diabetes, glycated hemoglobin (HbA1c) above 8% and plasma bicarbonate levels above 16 mmol/l (group 2); 11 patients with well-controlled diabetes and HbA1c below 8% (group 3); and 10 non-diabetic, non-obese control subjects (group 4). Metabolic parameters, MDA levels and TAS were assessed in the plasma of the four groups of subjects.

RESULTS

mean plasma MDA and TAS values were significantly different among the four groups (respectively p < 0.001 and p < 0.01). Mean plasma MDA value was significantly higher in group 1 than in group 3 (p < 0.02) and group 4 (p < 0.001) but was not different from that in group 2. Mean plasma MDA value in group 2 was significantly lower than that in group 4 (p = 0.002). Mean plasma TAS value in group 1 was significantly lower than in groups 3 (p < 0.002) and 4 (p < 0.05). Mean plasma TAS value was significantly lower in group 2 than in group 4 (p<0.05). Plasma MDA values in the diabetic patients (groups 1+2+3) were not related to any clinical characteristics (BMI, age, duration of the disease) or metabolic parameters (glycemia, HbA1c bicarbonates, blood urea nitrogen, phosphatemia, lipids), while plasma TAS values correlated negatively with glycemia, osmolality and HbA1c. A significant relationship was also found between TAS and HbA1c in group 1 (p < 0.05) and between MDA and HbA1c in group 3 (p < 0.05). Correlations were also found between TAS and phosphatemia in group 1 (p < 0.01) and between MDA and phosphatemia in group 2 (p < 0.01). A positive relationship between MDA and cholesterol levels was found in group 1 (p < 0.01). In conclusion, MDA values are increased and TAS values decreased in DKA and poorly controlled diabetes, and tend to correlate more with markers of diabetic imbalance than with markers of acute metabolic disturbances of DKA.

Modification of the proteinase/anti-proteinase balance in the respiratory tract of Sprague-Dawley rats after single intratracheal instillation of benzo[A]pyrene-coated onto Fe(2)O(3) particles

Available data suggest that repeated concurrent exposure to haematite (Fe(2)O(3)) and benzo[A]pyrene (B[A]P) results in a decreased latency and an increased incidence of lung tumours in rodents compared to exposure to B[A]P alone. Moreover, the reactive oxygen species (ROS) formed by the lung cells themselves and/or by activated inflammatory cells may possibly contribute to the development of pulmonary disorders such as cancer formation. In order to investigate the precise role of iron in the injury induced by B[A]P-coated onto Fe(2)O(3) particles, we tend to address the hypothesis that Fe(2)O(3) and B[A]P, alone or in association, can induce oxidative stress conditions (malondialdehyde) and/or inflammatory reactions (interleukin-6) and thereby disrupt the proteinase/anti-proteinase balance (cathepsins B and L, polynuclear neutrophil (PNN) elastase, alpha-1 proteinase inhibitor (alpha(1)PI) and its inhibitory capacity) in the rat respiratory tract. Thus, Fe(2)O(3) or B[A]P-coated onto Fe(2)O(3) particles produce oxidative stress conditions through not only iron-catalysed oxidative reactions but also inflammatory processes. However, B[A]P initiates only inflammatory responses. These pollutants generate increased levels of proteases and decrease the concentrations of free alpha(1)PI. There is also a clear relationship between the partial inactivation of alpha(1)PI and the occurrence of ROS after exposure to Fe(2)O(3), alone or as a carrier of B[A]P. Hence, the proteinase/anti-proteinase balance might be more disrupted by Fe(2)O(3) or B[A]P-coated onto Fe(2)O(3) particles than by B[A]P alone. These results suggest a mechanism that can explain why B[A]P-coated onto Fe(2)O(3) particles are more injurious than B[A]P alone.

Overexpression level of stromelysin 3 is related to the lymph node involvement in non-small cell lung cancer

Proteases contribute to tumor invasion and metastasis via their potential to degrade basement membranes and extracellular matrix. Our aim was to compare the level of several proteases: urokinase-type plasminogen activator (u-PA), matrix metalloproteinase 2 (MMP-2; 72-kDa type IV collagenase, also known as gelatinase A), MMP-11 [also known as stromelysin 3 (STR3)], and cathepsins B and L in resected non-small cell lung cancer. Between June 1996 and March 1998, samples of lung tumor tissues were taken from 119 surgically treated patients. Thirty out of the 119 tumor samples were matched with corresponding adjacent normal tissue. u-PA was measured by a commercially available immunoluminometric assay. Metalloproteinases and cathepsins have been evaluated at the RNA level by Northern blot and quantified with a PhosphorImager. Expression of these proteases was compared to the following clinicopathological parameters: pathological diagnosis, tumor size, exposure to asbestos, radiotherapy, neo-adjuvant chemotherapy, tumor-node-metastasis stage, lymph node involvement, presence of metastasis. u-PA, MMP-2, MMP-11/STR3, and cathepsin B were significantly increased in tumor (the tumor:normal ratio was on average increased by 5.4-, 2.2-, 83.5-, and 2.2-fold, respectively). The tumor:normal ratio of MMP-11/ STR3 was found to be significantly linked to the lymph node involvement (P < 0.05). Our results suggest that several proteases are involved in the invasive potential of non-small cell lung cancer and that the quantification of MMP-11/ STR3 could represent an useful prognostic marker.

Inflammation-induced systemic proteolysis of inter-alpha-inhibitor in plasma from patients with sepsis

Inter-alpha-inhibitor (IalphaI) is a human plasma serine proteinase inhibitor. It contains one light peptide chain called bikunin that exerts antiproteinase activity and other antiinflammatory functions. Bikunin is covalently linked to two heavy chains that, after tissular diffusion, stabilize the extracellular matrix. Owing to its negative acute-phase reactant character and its susceptibility to proteolysis, IalphaI has been implicated in the pathophysiology of sepsis. Moreover, IalphaI has been shown to exert a protective effect on a pig model of endotoxic shock. Twenty patients admitted to the intensive care unit (ICU) for a septic syndrome were included in the present study. IalphaI and antithrombin III (ATIII) levels were measured on admission. Sequential measurements of IalphaI could be done in 4 patients. We demonstrate that IalphaI levels are significantly decreased in plasma samples collected on admission from patients with sepsis (59 +/- 32 mg/L vs 241 +/- 70 mg/L; P < .0001). This decrease was greater in severe sepsis and septic shock than in sepsis. Death was not predictable from initiol IalphaI levels. In 2 patients with a favorable course, IalphaI values regularly increased during the ICU stay. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblot analysis and microsequencing, we characterized IalphaI-related components in plasma from several patients; they obviously arise from IalphaI through proteolytic cleavage. Thus, systemic proteolysis and decreased biosynthesis both contribute to the fall in the plasma level of IalphaI. Because IalphaI is very sensitive to proteolysis by polymorphonuclear granulocytes (PMNs) that are stimulated during sepsis, we suggest that IalphaI plasma level would be a useful marker for neutrophil proteinase activity. ATIII, as well as IalphaI, is considered a negative acute phase protein. Because in vitro ATIII is less susceptible than IalphaI to proteolysis by PMNs and because their relative levels weakly correlated, we suggest that an unspecific systemic proteolysis is not significantly involved in the ATIII deficiency occurring in sepsis.

Human pre-alpha-inhibitor is a positive acute-phase protein that is more susceptible than inter-alpha-inhibitor to proteolysis by stimulated neutrophils

BACKGROUND

Pre-alpha-inhibitor (PalphaI) is a human plasma serine-proteinase inhibitor that is structurally related to inter-alpha-inhibitor (IalphaI). It is composed of a heavy chain named H3 covalently linked to bikunin by means of a glycosaminoglycan chain. We developed an ELISA procedure making it possible to measure PalphaI for the first time and we investigated its levels in sera from patients with inflammatory diseases.

MATERIALS AND METHODS

We generated rabbit anti-H3 immunoglobulins, which were used on solid phase and biotinylated antibikunin immunoglobulins to detect trapped PalphaI.

RESULTS

We demonstrate that PalphaI is more susceptible than IalphaI to in vitro proteolysis by stimulated neutrophils. However, the degradation products thus released as well as the other members of the IalphaI family present in serum do not affect the ELISA test. In a panel of control sera we observed PalphaI concentrations of 25.6 +/- 7.8 mg L-1 (mean +/- SD; n = 30). These values increased to 64.2 +/- 16.06 mg L-1 (mean +/- SD; n = 15) in patients with inflammatory diseases, concording with the positive acute-phase protein nature of PalphaI. However, for all these patients, the serum concentrations of PalphaI and C-reactive protein poorly correlated (r = 0.476; P = 0.076). Indeed, four patients had a relatively weaker increase in their PalphaI level than that of C-reactive protein. More often than not their plasma elastase content was then elevated.

CONCLUSION

During inflammatory diseases plasma PalphaI levels may be dependent on increased synthesis in combination with enhanced catabolism, perhaps implicating neutrophil or other proteinases.

Acute inflammatory intestinal vascular lesions and in situ abnormalities of the plasminogen activation system in Crohn's disease

OBJECTIVES

The distribution of the intestinal vascular lesions and their relation with the fibrinolysis process are poorly known in Crohn's disease (CD). The mediators of the plasminogen activator system, namely urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1), are a key complex involved in fibrinolysis. The aims of this study were: (1) to further define vascular lesions and their distribution in the intestine; and (2) to study concomitantly the qualitative in situ expression and the levels of u-PA, t-PA and PAI-1 in the ileum of patients with CD.

PATIENTS AND METHODS

Histological, immunohistochemical and ultrastructural studies of vascular lesions in the resected ileum of 27 patients with CD were performed and compared with 36 control patients. Levels of u-PA, t-PA and PAI-1 measured by ELISA methods were compared in healthy and inflamed ileal tissues of 17 patients with CD.

RESULTS

Acute vascular lesions involving mainly serosal venules and capillaries were present in 63% of patients with CD vs 3/36 controls and were associated with PAI-1 expression. They were prominent on the mesenteric border beneath macroscopically normal mucosa. In contrast, chronic vascular lesions were present in all layers beneath mucosal ulcerations, where a significant increase of PAI-1 levels was found.

CONCLUSIONS

These results suggest that vascular involvement associated with abnormalities of PAI-1 expression is an early and widespread event in CD. Their prominence on the mesenteric border might explain the characteristic location of CD ulceration along the mesenteric margin.

Changes in serum amylase, lipase and leukocyte elastase during diabetic ketoacidosis and poorly controlled diabetes

Diabetic ketoacidosis (DKA) is frequently associated with pancreatic enzyme abnormalities. In order to determine the main factors that lead to this increase, serum total amylase (TA), pancreatic amylase (PA), lipase (L) and leukocyte elastase (LE), an early predictor of acute pancreatitis, were measured in four groups of patients on admission. Group 1 consisted of 52 patients with DKA (age: 41.9 +/- 19.2 years; blood glucose (Glc): 27.4 +/- 11.5 mmol/L; pH: 7.20 +/- 0.16; plasma bicarbonate: 10.5 +/- 6.2 mmol/L; blood urea nitrogen (BUN): 0.60 +/- 0.44 g/L; HbA(1C): 12.5% +/- 2.8%). Group 2 consisted of 90 patients with poorly controlled non-ketotic diabetes (age: 53.4 +/- 16.0; Glc: 14.3 +/- 0.6; HCO(3)(-): 26.6 +/- 3.2; BUN: 0.38 +/- 0.20; HbA(1C): 11.3 +/- 2.1). Group 3 consisted of 22 patients with well-controlled diabetes (age: 53.7 +/- 12.8; Glc: 10. 1 +/- 5.2; HCO(3)(-): 27.4 +/- 3.8; BUN: 0.36 +/- 0.19; HbA(1C): 6.8 +/- 0.8). Group 4 (controls) comprised 27 non-diabetic patients (age: 46.0 +/- 15.0; Glc: 4.9 +/- 0.5; HCO(3)(-): 28.4 +/- 2.5; BUN: 0.30 +/- 0.16; HbA(1C): 5.2 +/- 0.7) (means +/- SD). Increased enzyme activities were more frequent in group 1 (TA: 30.7; PA: 27.0; L: 36.5; LE: 73%) than in groups 2 (TA: 8.9; PA: 7.1; L: 8.9; LE: 45. 5%), 3 (TA: 13.6; PA: 9.0; L: 18.1; LE: 31.8%) and 4 (TA: 7.0; PA: 3. 0; L: 0.0; LE: 29.6%). Mean serum enzyme activities were significantly different in the 4 groups (ANOVA, P < 0.01) and were higher in group 1 than in groups 2, 3 and 4 (Student's t-test; group 1 vs 2 or 3 or 4: P < 0.001). In groups 1 + 2 + 3 + 4 (all patients), the four enzymes correlated with one another and also with Glc, BUN and HCO(3)(-) (P < 0.001). In group 1, TA correlated negatively with HCO(3)(-) (P < 0.001) and pH (P < 0.05); PA and L correlated positively with Glc and BUN (P < 0.01) and negatively with HCO(3)(-) (respectively, p < 0.01 and 0.05). PA correlated positively with pH (P < 0.01); LE correlated with Glc (P < 0.05) and BUN (P < 0.01). In conclusion, this study suggests that the serum levels of pancreatic enzymes increase with the degree of diabetic disequilibrium, and mainly correlate with metabolic factors such as hyperglycaemia, dehydration and acidosis. Increased pancreatic enzyme activities in patients with DKA, even in combination with abdominal pain, should not be diagnosed as acute pancreatitis; this could be important, particularly for younger clinicians.

Glycosylation pattern of human inter-alpha-inhibitor heavy chains

Human inter-alpha-inhibitor (IalphaI) is a plasma serine-proteinase inhibitor. It consists of three polypeptide chains covalently linked by a glycosaminoglycan chain: a light chain named bikunin carrying the anti-proteinase activity and two heavy chains, H1 and H2, which exhibit specific properties, e.g. they interact with hyaluronan thus stabilizing the extracellular matrix. In this study, using matrix-assisted laser desorption ionization-time-of-flight MS and amino acid sequencing of tryptic peptides, we provide a detailed analysis of the glycosylation pattern of both heavy chains. H1 carries two complex-type N-glycans of predominantly biantennary structure linked to asparagine residues at positions 256 and 559 respectively. In contrast, the oligosaccharides attached to H2 are a complex-type N-glycan in the N-terminal region of the protein (Asn64) and three to four type-1 core-structure O-glycans mono- or di-sialylated, clustered in the C-terminal region. We propose that these O-glycans might function as a recognition signal for the H2 heavy chain. The biological implications of this hypothesis, notably for the biosynthetic pathway of IalphaI, are discussed.

Pig I alpha I appears unmodified in plasma in case of endotoxin-induced disseminated intravascular coagulation

The unrestricted activity of leukocyte proteinases is thought to contribute to the degradation of plasma proteins and thus amplify the coagulation disorders occurring in septic shock. Inter-alpha-inhibitor (I alpha I) is a plasma protein particularly susceptible to their action. Therefore we investigated its behavior in a porcine model of endotoxin shock which reproduces the coagulation changes observed in human sepsis. We did not detect any qualitative or quantitative modification of porcine I alpha I in plasmas collected from pigs after endotoxin infusion. To explain these data, I alpha I was incubated with polymorphonuclear neutrophils (PMN) stimulated by FMLP in the presence of cytochalasin B. We found that, unlike human PMN, porcine cells were unable to proteolyze I alpha I. Moreover, in the incubation medium of pig PMN, triggered either by FMLP or PMA, no measurable elastase activity was evidenced. Therefore, we urge to better take into account species differences in functional responses of PMN, to explain the experimental results obtained in animal models of septic shock.

Inter-alpha-inhibitor as marker for neutrophil proteinase activity: an in vitro investigation

Human neutrophil proteinases have been implicated in the pathogenesis of a wide variety of inflammatory diseases. The degradation of plasma proteins such as coagulation and fibrinolysis factors has been attributed to the excessive release of elastase in septicemia and in other conditions in which heightened proteolysis occurs. Inter-alpha-inhibitor (IalphaI) is particularly sensitive to cleavage by leukocyte proteinases. For this reason, the determination of IalphaI has been proposed as a method for evaluating plasma protein proteolysis by neutrophil enzymes. In this article we provide evidence that intact residual IalphaI can be accurately quantified by enzyme-linked immunosorbent assay (ELISA) determination without interference from fragments released from IalphaI by incubation with triggered neutrophils. We demonstrate that under these conditions IalphaI was quickly and steadily proteolyzed in a cell dose-dependent manner. Alpha-1 proteinase inhibitor (alpha1PI) partially protected IalphaI; however, the proteolysis persisted when IalphaI was incubated with stimulated neutrophils in the presence of a large relative excess of alpha1PI over the amount of elastase theoretically present in cells. For the same amount of alpha1PI, serum provided a better protection than alpha1PI alone but did not completely inhibit the IalphaI degradation. Therefore, ELISA determination of IalphaI might be useful for monitoring the in vivo activity of neutrophil proteinases in systemic proteolytic states.

Development of an enzyme-linked immunosorbent assay for human plasma inter-alpha-trypsin inhibitor (ITI) using specific antibodies against each of the H1 and H2 heavy chains

Inter-alpha-trypsin inhibitor (ITI) is a serine-proteinase inhibitor of human plasma enzymes. ITI is composed of three polypeptide chains covalently linked: bikunin, responsible for the antiprotease activity and two heavy chains H1 and H2. Human plasma also contains other components immunologically related to ITI such as pre-alpha-trypsin inhibitor (paI), inter-alpha-like inhibitor (IalphaLI) and free bikunin. The ELISA procedure we propose exclusively measures native ITI within the range 12.5-200 microgram/l. The intra- and interassay coefficients of variation were less than 5.6% and 8.7%, respectively. When ITI was added to plasma samples, full recovery was obtained. EDTA-plasma from 30 healthy individuals revealed a mean level of 241.5 mg/l (range 145.5-506). The high specificity, sensitivity, reproducibility and accuracy of the present assay should facilitate the specific measurement of native ITI in blood and thus might represent a useful tool for further physiopathological studies.

Toxicity of ferric oxide and benzo[a]pyrene alone or in combination in respiratory tract of Sprague Dawley rats

The association of small quantities of ferric oxide with Benzo[a]Pyrene (BaP) appears to increase in vivo the toxic effect of BaP. The effect of Fe2O3 may be mediated by the recruitment of alveolar macrophages. These cells would contribute to the production of toxic and carcinogenic BaP metabolites and would stimulate development of tumors by producing cellular mediators of inflammation. In order to understand the mechanism of the synergic effect, we have instillated male Sprague Dawley rats 3 weeks of age with a single dose: Fe2O3 (3 mg) or BaP (3 mg)/combination Fe2O3-BaP (3 mg-3 mg) in 200 microliters of physiological saline solution. Control group of identical size (treated with physiological saline solutions and untreated) were used for this study. Animals were sacrificed 48 hours after instillation and a bronchoalveolar lavage (BAL) was performed. With each BAL we have obtained protein measurement, cells were stained with May-Grünwald-Giemsa method and slides were studied with polarised light. The malonaldehyde (MDA) was measured by High Performance Liquid Chromatography. The PMN elastase determination was performed by IMAC (immuno-activation) technology. An automated kinetic method for measuring cathepsins B and L was carried out using a fluorogenic substrate: Z-Phe-Arg-AMC, a specific inhibitor E64 and AMC as an internal standard. After a quantitative Dot-Blot of the samples of BAL, an immunodetection of alpha(1)-antitrypsin (alpha(1)AT) was performed. The inhibitory capacity of alpha(1)AT was determined by an enzymatic reaction with porcine pancreatic elastase. We have observed an increased MDA level for rats intoxicated with Fe2O3 (123%), BaP (31%) and Fe2O3 + BaP (56%). The levels of PMN elastase and cathepsin B and L were increased: Fe2O3 (51-58%), BaP (52-27%). This effect was not seen for rats intoxicated by Fe2O3 + BaP. The free alpha(1)AT was decreased with the three toxics (Fe2O3: 44%--BaP: 42%--Fe2O3: 41%). The inhibitory capacity of alpha(1)AT was lower in groups of rats instilled with toxics.

Relationship between a mild alpha 1 proteinase inhibitor deficiency and respiratory symptoms in a family

A 34-year-old man with pulmonary emphysema was found to have a mild alpha 1 proteinase inhibitor (alpha 1 PI) deficiency. alpha 1 PI status was investigated in this patient and in 35 members of his family. The alpha 1 PI investigations included alpha 1 PI concentration and phenotype and serum inhibitory capacity for trypsin and pancreatic elastase. Fifteen members of the family had alpha 1 PI concentration and inhibitory capacities below the lower normal limit. Five of these members were characterized by the heterozygous MP phenotype and the 10 others by an apparently homozygous M phenotype, in which the M allele may be associated with another unidentified deficiency allele. Two members of the family had alpha 1 PI concentration and elastase inhibitory capacity below the lower normal limits and trypsin inhibitory capacity within the normal range. They were both characterized by the MP phenotype. Six of these 17 members (three of PI type M and three of PI type MP) showed chronic pulmonary symptoms, whereas among the 19 alpha 1 PI non deficient members, no member had a history of significant pulmonary symptoms.

Cathepsin B, L, and D activities in colorectal carcinomas: relationship with clinico-pathological parameters

Cathepsins, which are secreted by tumour and/or stromal cells, are thought to be involved in the degradative processes of tumour invasion and metastasis. The purpose of our study was to compare the cytosolic content of cathepsin B, L, and D in a series of matched malignant and adjacent normal colorectal tissues. Further we attempted to correlate these different proteinase values to classical clinico-pathological prognostic variables. Cathepsin B, L, and D activities were higher in tumour tissues than in normal mucosa (P < 10(-6), P < 0.004, P < 0.004, respectively) with median tumour/normal ratios of 7.9, 5.9, and 1.4, respectively. We found no difference in cathepsin B, L, and D activities either as a function of gender (except for cathepsin B values), age at time of surgery, tumour site, tumour differentiation, tumour stage (TNM or Astler-Coller staging system) or whether or not we found a mucinous component. Based on our data, cathepsin B seems to be the most discriminant parameter of the three proteinases that we studied, suggesting that cathepsin B expression may be of critical value in the progression of colorectal cancers.