Synthesis of stress proteins is increased in individuals with homozygous PiZZ alpha 1-antitrypsin deficiency and liver disease.

Individuals who are homozygous for the protease inhibitor phenotype Z (PiZ) genetic variant of alpha 1-antitrypsin (alpha 1-AT) have reduced plasma concentrations of alpha 1-AT, and are susceptible to premature development of pulmonary emphysema. A subset of this population develops chronic liver disease. The reduction in plasma concentrations of alpha 1-AT results from a selective defect in secretion as the abnormal PiZ alpha 1-AT protein accumulates within the cell. It has recently been shown in several experimental systems that the heat shock/stress response, a response characterized by the synthesis of a family of highly evolutionarily conserved proteins during thermal or chemical stress, may also be activated by the presence of abnormal proteins within the cell. Therefore, we predicted that the heat shock/stress response would be induced in the absence of thermal or chemical stress in alpha 1-AT-synthesizing cells of PiZZ individuals. In the following study, however, we show that net synthesis of proteins in the heat shock/stress gene family (SP90, SP70, ubiquitin) is increased only in a subset of the population, PiZZ individuals with liver disease. It is not significantly increased in PiZZ individuals with emphysema or in those without apparent tissue injury. Net synthesis of stress proteins is not increased in individuals with another variant of the alpha 1-AT gene (PiS alpha 1-AT) and is not increased in individuals with severe liver disease but a normal alpha 1-AT haplotype (PiM alpha 1-AT). These results demonstrate that the synthesis of stress proteins is increased in a subset of individuals with homozygous PiZZ alpha 1-AT deficiency, those also having liver disease.     

External respiratory function in patients with primary pulmonary emphysema etiologically related to alpha 1-antitrypsin deficiency

To improve the diagnosis of primary lung emphysema etiologically linked with alpha-trypsin deficiency, the authors provide the results of a detailed clinico-functional study of 6 patients with an appreciable deficiency of this enzyme. According to the clinical and functional signs, all the patients were diagnosed to have a typical, pronounced lung emphysema. Therefore, the measurement of the alpha-antitrypsin content plays the crucial part in differential diagnosis of primary (hereditary determined) and secondary (obstructive) emphysema.     

Molecular diagnosis of intermediate and severe alpha(1)-antitrypsin deficiency: MZ individuals with chronic obstructive pulmonary disease may have lower lung function than MM individuals

BACKGROUND: We tested whether intermediate (MZ, SZ) and severe (ZZ) alpha(1)-antitrypsin deficiency affects lung function in the population at large. METHODS: We performed spirometry [forced expiratory volume in 1 s (FEV(1)) and forced vital capacity (FVC)] and genotyping of 9187 individuals from the adult general population of Copenhagen, Denmark. RESULTS: As expected, the frequencies of individuals with MM, MS, SS, MZ, SZ, and ZZ genotypes were 0.891, 0.054, 0.001, 0.052, 0.001, and 0.001, respectively. Genotype interacted with clinically established chronic obstructive pulmonary disease (COPD) on the percentage of the predicted FEV(1) (P = 0. 004): the percentage of the predicted FEV(1) was reduced in MZ compared with MM individuals among those with clinically established COPD, but not among those without COPD. Furthermore, SZ compound heterozygotes had lower FEV(1)/FVC ratios than MM individuals (P <0.05), and ZZ homozygotes had lower percentages of the predicted FEV(1) and FEV(1)/FVC ratios than MM, MS, SS, and MZ individuals (all Ps <0.01). Reduced lung function in SZ and ZZ vs MM individuals could be demonstrated in current and ex-smokers, but not in nonsmokers. Compared with MM individuals in the same groups, FEV(1) was reduced 655 mL in MZ individuals with clinically established COPD, 364 mL in SZ current smokers, and 791 mL in ZZ current smokers. CONCLUSIONS: In the population at large, MZ was associated with reduced pulmonary function in individuals with clinically established COPD, whereas SZ and ZZ were associated with reduced pulmonary function in smokers. The presence of the alpha(1)-antitrypsin MZ genotype may in certain circumstances produce marked aggravation of airway obstruction in individuals prone to develop COPD.     

alpha 2-Macroglobulin in patients with obstructive lung disease, with and without alpha 1-antitrypsin deficiency

Serum alpha 2-macroglobulin concentrations were measured in 178 patients with emphysema and 115 control subjects of similar age and sex distribution. The study group included 59 PI type Z patients with alpha 1-antitrypsin deficiency, five with the rare alpha 1-antitrypsin null genotype (PI Q0 or --), and seven with alpha 1-antitrypsin deficiency of the rare PI types MmaltonZ or MduarteZ. Individuals with all types of alpha 1-antitrypsin deficiency were found to have significantly increased serum concentrations of alpha 2M (p less than 0.001). These increased concentrations were associated with all types of alpha 1-antitrypsin deficiency, not only with the PI type Z. The highest alpha 2-macroglobulin concentrations were found in the PI Q0 patients (5 with emphysema, 2 with no lung disease), and these patients had almost no circulating alpha 1-antitrypsin. Raised concentrations of serum alpha 2-macroglobulin were not due to emphysema: 86 patients with emphysema, of PI type M, and the normal control subjects had similar average concentrations of alpha 2-macroglobulin. One control subject with an average alpha 2-macroglobulin concentration of only 41% of normal was found.     

Serum alpha 1-antitrypsin in patients with hepatocellular carcinoma.

To evaluate the diagnostic value of alpha 1-antitrypsin (alpha-AT) as a tumor marker for hepatocellular carcinoma (HCC), we studied the serum levels of alpha-AT by rocket immunoelectrophoresis and alpha-fetoprotein (alpha-FP) by radioimmunoassay in 46 proven HCC patients, 43 cirrhosis patients and 200 healthy blood donors. The mean alpha-AT level of the 46 patients with HCC (4.8 +/- 2.7 mg/ml) was significantly higher than that of 200 healthy control subjects (1.7 +/- 0.7 mg/ml) (P less than 0.0001). The sensitivity of alpha-AT in 24 patients with high level of alpha-FP (greater than 400 ng/ml) and 22 patients with low level of alpha-FP (less than 400 ng/ml) were 96% and 64%, respectively. There was no substantial correlation between alpha-FP and alpha-AT in the two groups (alpha-FP greater than 400 ng/ml, alpha-FP less than 400 ng/ml) (r = 0.078, 0.064). The sensitivity for HCC using alpha-FP level alone (greater than 400 ng/ml) was only 52%, and the sensitivity using alpha-AT level alone (greater than 3.2 mg/ml) was 76% of the 46 patients. Combining both tests, sensitivity was improved only to 80%.     

Development of an assay for in vivo human neutrophil elastase activity. Increased elastase activity in patients with alpha 1-proteinase inhibitor deficiency.

Leukocyte extracts contain enzymes that digest fibrinogen and release a fibrinopeptide A-containing fragment. This study was undertaken to identify the responsible proteinase and to characterize the fibrinopeptide A-containing fragment so that it could be used as an index of enzyme activity. Both the fibrinogenolytic activity and the release of the fibrinopeptide A-containing fragment mediated by the leukocyte extracts were shown to be due to human neutrophil elastase (HNE) by the following criteria: activity was completely blocked by a specific HNE inhibitor or by adsorbing HNE from the extracts with a monospecific antibody and reconstitution with purified HNE restored the ability to release the fibrinopeptide A-containing fragment. This fragment was not released by a variety of other proteinases or by HNE-inhibitor complexes indicating that, at least with respect to the enzymes tested, it is a specific product of HNE and its release requires the free enzyme. By separating the products of HNE digestion of fibrinogen using high performance liquid chromatography, identifying the immunoreactive fractions and subjecting them to amino acid analysis, the fragment was identified as A alpha 1-21, indicating an HNE cleavage site at the Val(A alpha 21)-Glu(A alpha 22) bond. The mean plasma A alpha 1-21 level was markedly higher in patients with alpha 1-proteinase inhibitor deficiency as compared to healthy controls (0.2 nM vs. 7.9 nM; P less than 0.0001), consistent with increased in vivo HNE activity in these individuals.     

A null deficiency allele of alpha 1-antitrypsin, QOludwigshafen, with altered tertiary structure.

The most common deficiency allele of the plasma protease inhibitor alpha 1-antitrypsin (alpha 1AT) is PI*Z. Some rare deficiency alleles of alpha 1AT produce low but detectable amounts of plasma alpha 1AT (1-20% of normal), which can be differentiated by isoelectric focusing. Others, designated null (QO) alleles, produce no alpha 1AT detectable by routine quantitative methods. We have previously described a method using DNA polymorphisms, haplotypes, and polyacrylamide isoelectric focusing gels, to differentiate various deficiency alleles. Based on haplotypes, we previously identified, in eight patients, five different null alleles, four of which had been previously sequenced. We have now analyzed all 12 null alleles in these eight patients, using allele-specific oligonucleotide probes, and have identified six different null alleles. We have cloned and sequenced one of these, PI*QOludwigshafen, which has a base substitution in exon II, replacing isoleucine 92 in the normal sequence with an asparagine. This substitution of a polar for a nonpolar amino acid occurs in one of the alpha-helices and is predicted to disrupt the tertiary structure. A total of 13 different alpha 1AT deficiency alleles, 6 of them null alleles, have been sequenced to date.     

Liver diseases in children and their relatives with homozygous and heterozygous alpha 1-antitrypsin deficiency

Over a 6-year period 26 infants and children with homozygous (2 Z and 6 ZZ) or heterozygous alpha 1-antitrypsin deficiency (12 MZ, 6 MS) were observed prospectively and their families investigated. 7 of 8 homozygous patients had neonatal hepatitis, whereby 3 of these showed maximum transferase activities during the 5th to 9th months of life. At the age of 7 years 2 of these patients were clinically normal, but only one patient had normal transferases. One patient had cirrhosis with portal hypertension at the age of 16 years 6 months; her nephew showed hypersplenism. Family studies revealed a further 5 relatives of phenotype Z, 16 of phenotype MZ, 3 of phenotype SZ and 1 of phenotype MS; 6 of these had slightly elevated serum transferase activities. 6 patients of phenotype MZ and 2 patients of phenotype MS had neonatal hepatitis but generally with a much better prognosis than in homozygous patients. The other heterozygous patients (6 MZ and 4 MS) had a variety of additional factors determining the disease and the prognosis. Family studies showed a further 7 family members of phenotype MZ, and 2 of phenotype MS; 2 of these had slightly elevated transferase activities, 3 parents had hereditary hyperbilirubinaemia.     

Plasma elastase alpha 1-antitrypsin and lactoferrin in sepsis: evidence for neutrophils as mediators in fatal sepsis.

Increased vasopermeability and vasodilation, presumably the result of endothelial perturbation, are considered among the basic pathogenetic mechanisms in septic shock. Neutrophils have been implicated as a source for mediators in endothelial injury. We measured elastase-alpha 1-antitrypsin (alpha 1AT) complexes and lactoferrin as markers for release of neutrophil granule contents in plasma from patients with sepsis on admission to the Intensive Care Unit, and we delineated the relationship of neutrophil activation to other inflammatory parameters and to hemodynamic and biochemical parameters. Levels of elastase-alpha 1AT and lactoferrin significantly correlated with each other (r = 0.58; p less than 0.008), and were increased (greater than 3.33 and 5 nmol/L, respectively) in 96% and 71% of the patients, respectively. Lactoferrin, but not elastase-alpha 1AT, correlated with the number of white blood cells (r = 0.38; p = 0.008). Elastase-alpha 1 AT levels were significantly higher (p = 0.008), whereas white blood cell counts were lower (p = 0.015) in patients with shock when compared with patients without abnormal blood pressure. Both elastase-alpha 1AT and lactoferrin levels correlated with lactate levels (r = 0.33; p = 0.024 and r = 0.30; p = 0.04), suggesting a role for neutrophil activation in the pathogenesis of hypoxygenation. In addition, elastase-alpha 1AT correlated with the concentrations of interleukin 6 (IL-6) (r = 0.46; p = 0.001) and C3a (r = 0.38; p = 0.009), suggesting that cytokines and complement may contribute to the degranulation of neutrophils in sepsis. Elastase-alpha 1AT complexes were inversely related to C1-inhibitor (r = -0.33; p = 0.028) and to platelet numbers (r = -0.42; p = 0.003). Levels of elastase-alpha 1AT complexes in plasma appeared to be of prognostic significance; levels were higher in 27 patients who died than in 21 patients who survived (p = 0.01). The mortality in 27 patients with concentrations below 10 nM was 37%, whereas it was 81% in 21 patients with higher levels. The overall mortality in this study was 56%. These results provide further evidence that activation and degranulation of neutrophils, induced by multiple agonists, are involved in the development of fatal complications in patients with sepsis.     

The effect of tamoxifen in intermediate alpha 1-antitrypsin deficiency associated with the phenotype PiSZ

Three patients, one with lung disease and two with liver disease, with intermediate alpha 1-antitrypsin (AAT) deficiency phenotype PiSZ, (plasma AAT concentration approximately 1/3 of normal) were treated with the anti-oestrogen drug, tamoxifen, for 2-24 months. Patients responded with 50-70% increases in plasma AAT concentrations. Progress of emphysema appeared to be retarded in one case but no improvement in liver function was recorded in the other two patients.     

Neutrophil accumulation in the lung in alpha 1-antitrypsin deficiency. Spontaneous release of leukotriene B4 by alveolar macrophages.

The emphysema of alpha 1-antitrypsin (alpha 1AT) deficiency is conceptualized to result from insufficient alpha 1AT allowing neutrophil elastase to destroy lung parenchyma. In addition to the deficiency of alpha 1AT in these individuals resulting from mutations in the alpha 1AT gene, it is recognized that, for unknown reasons, there are also increased numbers of neutrophils in their lungs compared with normal individuals. With the knowledge that alveolar macrophages have surface receptors for neutrophil elastase, we hypothesized that the neutrophil accumulation in the lower respiratory tract in alpha 1AT deficiency may result, in part, from release of neutrophil chemotactic activity by alveolar macrophages as they bind uninhibited neutrophil elastase. Consistent with this hypothesis, alpha 1AT-deficient alveolar macrophages spontaneously released nearly threefold more neutrophil chemotactic activity than normal alveolar macrophages. Analysis of alpha 1AT-deficient macrophage supernates by reverse-phase HPLC, molecular sieve chromatography, radioimmunoassay, and absorption with anti-LTB4 antibody revealed that the majority of the chemotactic activity was leukotriene B4 (LTB4), a mediator absent from normal macrophage supernates. Consistent with this hypothesis, incubation of normal macrophages with human neutrophil elastase resulted in the release of the same neutrophil chemotactic mediator. Furthermore, purified human alpha 1AT was able to prevent the neutrophil elastase from stimulating the macrophages to release the chemotactic factor. Together, these findings suggest that the absence of a normal antineutrophil elastase screen in the lower respiratory tract permits free neutrophil elastase to bind to alveolar macrophages, resulting in the release of LTB4, a process which attracts neutrophils to the alveoli of alpha 1AT deficient individuals, thus accelerating the lung destruction that characterizes this disorder.     

Human bocavirus-1 screening in infants with acute lower respiratory tract infection

BackgroundRecent studies have reported associations between, human bocavirus (HBoV), and respiratory tract diseases in children. However, there is limited information on the epidemiology of HBoV in infants. This prospective study investigated the prevalence and clinical characteristics of HBoV infection in infants with acute lower respiratory tract infection (ALRTI) in eastern China.MethodsNasopharyngeal aspirates and throat swab samples were collected from infants with ALRTI and age-matched healthy infants between January 2016 and December 2019. HBoV was identified by polymerase chain reaction. Laboratory data and clinical characteristics were analyzed.ResultsOf 2510 infants, 145 tested positive for HBoV. The highest prevalence of HBoV was detected during the winter. Co-infection was frequently observed during this period of high viral transmission. There were no HBoV-positive infants in the control group. Clinical signs and symptoms included cough, wheezing, fever, nasal discharge, vomiting, diarrhea, hypoxemia, and tachypnea. Co-infections included: Streptococcus pneumoniae, Staphylococcus aureus, Mycoplasma pneumoniae, Chlamydophila pneumoniae, respiratory syncytial virus, and adenovirus.ConclusionsHBoV was frequently detected in infants with ALRTI in China. The prevalence of HBoV was highest in winter. Co-infection was common, especially in infants requiring intensive care unit admission. Comprehensive clinical evaluation may facilitate optimal treatment.     

Urinary excretion of tetrahydroxylated bile acids in children with alpha 1-antitrypsin deficiency and neonatal cholestasis

Urinary excretion of bile acids was investigated in seven infants with alpha 1-antitrypsin deficiency and neonatal cholestasis. The infants were followed prospectively and the bile acid analysis was repeated after 2-8 years in four of the patients. Bile acid excretion during 24 h was quantified by gas-liquid chromatography and the bile acids were identified by gas-liquid chromatography-mass spectrometry. In contrast to healthy controls, all the patients excreted tetrahydroxylated bile acids during cholestasis and in the postcholestatic period. The patients who developed cirrhosis during the observation period had lower concentration of tetrahydroxylated bile acids than those with a more favourable course. Our findings suggest that tetrahydroxylation of bile acids might be an alternative pathway for elimination of bile acids in cholestasis of infancy, and that those infants exhibiting a good capacity of polyhydroxylation might have a better prognosis.     

Pulmonary abnormalities in intermediate alpha-1-antitrypsin deficiency.

Pulmonary function studies were carried out in a group of asymptomatic nonsmoking adults with intermediate alpha-1-antitrypsin deficiency who were attending an early disease detection unit in Rochester, N. Y. All subjects were identified by specific protease inhibitor (Pi) typing. Fifteen MZ and 14 MS subjects who had never smoked cigarettes were matched by sex and age to MM controls. Spirometry, static lung volumes, and single breath-diffusing capacity were identical in all Pi type groups with no statistically significant differences noted. Maximal expiratory flow volume curves were obtained in all subjects. MZ subjects demonstrated statistically impaired maximal flow rates at 75%, 50%, and 25% of vital capacity compared to their MM controls. Total pulmonary resistance by the oscillometric method was measured at 3, 5, 7, and 9 cycle/s in the same subjects. Increased frequency dependence of resistance (defined as the difference between total pulmonary resistance at 3 cycle/s and 9 cycle/s) was observed in MZ subjects compared to MM controls. No differences were noted by this method in MS-MM pairs. The data suggest that detectable mechanical abnormalities are present in subjects with the MZ phenotype, even in the absence of established risk factors such as cigarette smoking and high air pollution.