Apparent total alpha1-antitrypsin deficiency: report of a case

A 29-year-old female, with chronic renal failure and chronic bilateral emphysema, was admitted with severe uremia and septicemia secondary to multiple abscesses in the right kidney. Her condition improved after right nephrectomy. Pulmonary function studies showed marked obstructive and restrictive lung disease consistent witht the diagnosis of primary emphysema. On biochemical and histological examination, the liver was found to be normal. Alpha1-antitrypsin could not be demonstrated in the patient's serum at normal pH by any of the known techniques, but protein molecules with alpha1-antitrypsin antigencity were found at pH 4.8; this suggests a pH-dependent structural difference in alpha1-antitrypsin protein. Starch gel electrophoresis gave a multibanding pattern not previously described. A new form of apparent total alpha-1-antitrypsin deficiency is postulated.     

New insights into the structural basis of alpha 1-antitrypsin deficiency

The serpin superfamily of serine proteinase inhibitors contains many members but the best-characterized is the plasma protein alpha 1-antitrypsin. its genetic deficiency is associated, in the homozygote, with hepatic damage that may progress to cirrhosis and hepatocellular carcinoma. Low levels of circulating alpha 1-antitrypsin fail to protect the lungs against proteolytic attack and predispose the homozygote to early onset pan-lobular emphysema, bronchiectasis and asthma. The major cause of alpha 1-antitrypsin deficiency, the Z mutation (Glu342Lys), results in the accumulation of protein in the endoplasmic reticulum of the liver. Using a structural approach, we have shown that the hepatic inclusions result from a protein-protein interaction between the reactive centre loop of one molecule and the beta-pleated sheet of a second. This loop-sheet polymerization is now also recognized to be the basis of deficiencies associated with mutations of C1-inhibitor, antithrombin and alpha 1-antichymotrypsin. Our recent solution of a crystal structure of a thermostable mutant of alpha 1-antitrypsin shows the detailed interactions that result in loop-sheet linkage and helps to explain the mechanism of action of this family of proteinase inhibitors.     

Alpha 1-antitrypsin deficiency

Alpha 1-Antitrypsin deficiency (PiZ) is frequent in Caucasian populations. The predominant clinical correlates of this inborn error, i.e. chronic liver disease, emphysema, and vasculitic syndromes including their pathogenetic background are discussed in the present review.     

The pallid mouse. A model of genetic alpha 1-antitrypsin deficiency

A single dose pharmacokinetic study with modified human Interleukin-1 Beta (IL-1 beta or DuP 118) was performed by injecting 5 micrograms/kg of drug into the jugular vein of three beagle dogs. Serial 5-ml plasma samples were removed from the dogs over a 120-minute period. DuP 118 plasma levels were measured using a sandwich ELISA technique capable of measuring concentrations ranging from 0.25 to 2 ng/ml with accuracy and precision constraints of less than +/- 20% variability. DuP 118 stored at -20 degrees C in dog plasma was stable for at least 1 month. Pharmacokinetic parameters were determined for the three dogs by standard model independent or non-compartmental methods. DuP 118 was rapidly distributed in the dog. The volume of distribution was approximately two-fold higher than the total body water of a lean dog. The terminal half-life was short, less than 30 minutes. Within approximately an hour after dosing, DuP 118 plasma levels were reduced 20-fold and were below the quantifiable limit of the assay.     

Frequency and significance of phenotypes for alpha1-antitrypsin deficiency in type 1 autoimmune hepatitis

To evaluate the frequency and significance of alpha1-antitrypsin deficiency in type 1 autoimmune hepatitis, 181 Caucasian patients were assessed for variant phenotypes. Three hundred three Caucasian patients with various other chronic liver diseases were similarly evaluated. Twenty-one of the 181 patients (12%) had heterozygous deficiencies, including the MS (6%) and MZ (6%) phenotypes. These patients were indistinguishable from those with normal phenotypes. Immediate outcomes after corticosteroid therapy were also similar in both groups. Variant phenotypes were present in 34 of the 303 patients with other chronic liver diseases (11%). Patients with nonalcoholic steatohepatitis had a significantly greater frequency of deficiency phenotypes than patients with chronic hepatitis C (20% vs 7%, P = 0.03). In conclusion, deficiency phenotypes are common in type 1 autoimmune hepatitis and they have no clinical or prognostic importance. In certain liver diseases, such as nonalcoholic steatohepatitis, variant phenotypes may be comorbid factors.     

Fibromuscular dysplasia of the internal carotid artery associated with alpha1-antitrypsin deficiency

OBJECTIVE: A deficiency of alpha1-antitrypsin has been implicated in the development of various disorders affecting medium-sized arteries, including intracranial aneurysms, cervicocephalic arterial dissections, and fibromuscular dysplasia (FMD). We performed alpha1-antitrypsin phenotyping in three consecutive patients who underwent bypass surgery for FMD of the extracranial internal carotid artery to test the hypothesis that alpha1-antitrypsin deficiency is a genetic risk factor for the development of FMD. METHODS: The study population consisted of three women (aged 37, 49, and 53 years, respectively) who had bilateral internal carotid artery stenosis caused by FMD. The indications for surgery included ocular or cerebral ischemic symptoms in two patients and progressive stenosis in one patient. The diagnosis of FMD was confirmed by histological examination of the resected segment of artery. The alpha1-antitrypsin phenotype was determined by isoelectric focusing in polyacrylamide gels. RESULTS: Two of the three patients had a heterozygous alpha1-antitrypsin deficiency (PiMZ phenotype). Pathological examination of the resected arterial segment showed typical medial FMD with focal intimal fibroplasia in both patients with the PiMZ phenotype. CONCLUSION: These findings suggest that a heterozygous alpha1-antitrypsin deficiency may be a genetic risk factor for the development of FMD of the internal carotid artery.     

Increased risk of chronic liver failure in adults with heterozygous alpha1-antitrypsin deficiency

Controversy exists whether patients who are genetically heterozygous for 1-antitrypsin deficiency (1ATD), carrying a single PI*Z allele, are at increased risk of developing chronic liver disease. In these investigations, we determined the prevalence of heterozygous 1AT phenotypes (PI MZ, PI SZ) in a well-characterized cohort of patients presenting with chronic liver failure before orthotopic liver transplantation (OLT). We analyzed data collected from all adult patients (n = 641) who underwent OLT at our tertiary referral center between March 1985 and December 1996. Study patients entered a prospective protocol designed to test for all known etiologies of liver disease. Complete testing including 1AT phenotyping was successfully performed in 599 adults. We compared the overall number of heterozygous PI*Z carriers in our OLT cohort with established prevalence figures for general and regional American populations, and examined their distribution among various liver disease subgroups. Fifty-one patients were found to be heterozygous carriers of a single PI*Z allele for 1AT. The predominant phenotype in our transplantation cohort was PI MZ, identified in 49 patients (8.2%), which is a significantly higher prevalence than that reported from previous American population studies (2%-4%). Additionally, a significantly greater number of PI MZ carriers existed in patients with cryptogenic cirrhosis compared with other liver disease categories (26.9%; P < .001). These data suggest that individuals carrying a single PI*Z allele for 1AT may be at increased risk of developing cirrhosis and liver failure, even in the absence of an identifiable coexisting liver disease.     

Two-year results after lung volume reduction surgery in alpha1-antitrypsin deficiency versus smoker's emphysema

Lung volume reduction surgery (LVRS) improves exercise capacity and relieves dyspnoea in patients with smoker's emphysema (SE). It is unclear, however, whether LVRS similarly improves lung function in alpha1-antitrypsin-deficiency emphysema (alpha1 E). To address this question, this study prospectively compared the intermediate-term functional outcome in 12 consecutive patients with advanced alpha1E and 18 patients with SE who underwent bilateral LVRS. Before surgery there were no statistically significant differences between the two groups in the six-minute walking distance, dyspnoea score, respiratory mechanics or lung function data, except for the forced expiratory volume in one second, which was lower in the deficient group (24 versus 31% of the predicted value; p<0.05). In both groups, bilateral LRVS produced significant improvements in dyspnoea, the six-minute walking distance, lung function and respiratory mechanics. In the alpha1E group, the functional data, with the exception of the six-minute walking distance, returned to baseline at 6-12 months postoperation and showed further deterioration at 24 months. The functional status of the SE group remained significantly improved over this period. In conclusion, the functional improvements resulting from bilateral lung volume reduction surgery are sustained for at least 2 yrs in most patients with smoker's emphysema, but this type of surgery offers only short-term benefits for most patients with alpha1E.     

Long-term therapy of alpha 1-antitrypsin-deficiency-associated pulmonary emphysema with human alpha 1-antitrypsin

alpha 1-antitrypsin (alpha 1-AT) deficiency is a genetic disorder characterized by low serum levels of alpha 1-AT and a high risk of pulmonary emphysema at a young age. The resulting surplus of proteases, mainly of neutrophil elastase, can be balanced by i.v. augmentation with alpha 1-AT. However, it is not clear if affected patients benefit from long-term augmentation therapy and no long-term safety data are available. We examined 443 patients with severe alpha 1-AT deficiency and pulmonary emphysema receiving weekly i.v. infusions of 60 mg/kg body weight alpha 1-AT in addition to their regular medication. The progression of the disease was assessed by repeated lung function measurements, particularly the decline in forced expiratory volume in 1 second (delta FEV1). 443 patients with alpha 1-AT deficiency tolerated augmentation therapy well with few adverse reactions. The delta FEV1 in 287 patients with available follow-up data was 57.1 +/- 31.1 ml per year. Stratified for baseline FEV1, the decline was 35.6 +/- 21.3 ml in the 108 patients with an initial FEV1 < 30% and 64.0 +/- 26.4 ml in the 164 with 30% < FEV1 < or = 65% of predicted normal (p = 0.0008). The remaining 15 patients had an initial FEV1 > 65%. Long-term treatment with i.v. alpha 1-antitrypsin in patients with severe alpha 1-Pi deficiency is feasible and safe. The decline in forced expiratory volume in one second is related to the initial forced expiratory volume in one second as in alpha 1-antitrypsin deficient patients not receiving augmentation therapy.     

Molecular biology analysis: hereditary hemochromatosis, Wilson disease, alpha 1-antitrypsin deficiency and Dubin-Johnson syndrome

The molecular pathology of hereditary hemochromatosis, Wilson's disease, alpha 1-antitrypsin-deficiency and Dubin-Johnson syndrome could be well characterised during the last years. Diagnosis of hereditary hemochromatosis is reliably confirmed by PCR-augmentation and restriction-analysis. Wilson's disease is a monogenetic disease, which is characterised by over 50 mutations. Molecular diagnosis is complicated by the lack of a single specific mutation. Diagnosis of Dubin-Johnson syndrome and alpha 1-antitrypsin-deficiency is possible by PCR-analysis and hybridisation with specific oligonucleotides.     

Vasculitis and bronchiectasis in a patient with antibodies to bactericidal/permeability-increasing protein and alpha1-antitrypsin deficiency

A patient with alpha1-antitrypsin deficiency is reported herein; this subject developed aggressive bronchial disease and recurrent cutaneous vasculitis after pulmonary infection with Pseudomonas aeruginosa. Autoantibodies to neutrophil cytoplasmic antigens were detected, which produced granular cytoplasmic staining by indirect immunofluorescence with specificity for a newly characterized antigen: bactericidal/permeability-increasing protein (BPI). The bronchial disease and vasculitis improved, and the IgA anti-BPI titer fell after antipseudomonal treatment. This raises the possibility that anti-BPI antibodies contributed to both the bronchial disease and vasculitis.     

Effect of environmental and clinical factors on lung function and respiratory symptoms in adolescents with alpha1-antitrypsin deficiency

Individuals identified in the Swedish neonatal alpha1-antitrypsin (AAT) screening study were followed prospectively from their first to their eighteenth year of life. The aim of this study was to analyse the effect of environmental factors, i.e. active and passive smoking, and of clinical factors on lung function and the occurrence of respiratory symptoms in AAT-deficient adolescents. The study group consisted of 88 protease inhibitor (Pi)ZZ and 40 PiSZ adolescents. Medical history including respiratory symptoms, and active and passive smoking were recorded at each follow-up up to the age of 18 y. Lung function tests were performed at the present check-up. At the age of 18 y, both forced expiratory volume in one second (FEV ) and FEV1/vital capacity (VC) were significantly lower in the smoking than in the non-smoking subgroup, and significantly more smokers than non-smokers reported the presence of phlegm. The mean FEV1/VC ratio was lower for those presently exposed to parental smoking. Multiple linear regression analysis indicated that clinical liver disease in early life, active smoking and parental smoking were independent determinants of FEV1/VC. The results suggest that marginal deviations in lung function and the symptom of phlegm among AAT-deficient adolescents occur characteristically early in the subgroup of smokers. Parental smoking may contribute to decreased lung function.     

Probing the native strain iin alpha1-antitrypsin

OBJECTIVE: To study the relationship between the plasma concentration of stiripentol (STP), a new antiepileptic drug, and its inhibitory effect on the formation of carbamazepine epoxide (CBZE) in epileptic children treated with carbamazepine (CBZ) either alone or in combination with another antiepileptic drug. METHODS: Minimum plasma concentration of antiepileptic drugs was measured before initiation of STP therapy (day 0) and on days 28 (STP 60 mg.kg-1.day-1) and 84 (STP 90 mg.kg-1.day-1) by HPLC. RESULTS: The CBZE/CBZ plasma concentration ratio decreased exponentially with increasing minimum plasma STP concentration (r = 0.80). The asymptote of the curve allowed the calculation of the minimum plasma STP concentration required to obtain the maximum inhibitory effect, i.e. 6.7 mg.l-1. CONCLUSION: The inhibitory effect of STP on CBZ metabolism expressed as the CBZE/CBZ plasma concentration ratio is dependent on STP plasma concentration, with a maximum effect at an average of 7 mg.l-1. The present data suggest that in order to evaluate the anticonvulsant efficacy of STP as add-on therapy, the minimum plasma STP concentration should be maintained above 7 mg.l-1 and the dosage of CBZ should simultaneously be decreased in steps by more than 50% to minimize the change in CBZ plasma concentration.     

Detection of alpha 1-antitrypsin in unfertilized ova of albino rats

500--700 rat oocytes were solubilized in 0.3--0.6 ml of 1% sodium dodecyl sulphate (SDS) --0.06 tris-HCl, pH 6.7. The excess of SDS was removed in the form of unsoluble Ba2 (SDS) and the lysate was placed on the surface of 1% agarose microgel, performed in a glass capillar with the inner diameter 600 and the length of gel 7--8 nm. The microvolume (1.3 mcl) of monospecific antiserum against alpha1-human antitrypsin was placed on the opposite surface of the agarose gel. After 48 hours, the amount of microimmunoprecipitate was determined by staining the gel with Amido Black 10 B, followed by quantitative scanning using a double wave microspectrophotometer. The mean value of alpha1-antitrypsin was about 2.3+/-1.4 pcg per ovum. It is supposed that this antienzyme may terminate the "zone" and "cortical" reactions during the fertilization in mammals.     

Severe alpha1-antitrypsin deficiency (PiZ homozygosity) with membranoproliferative glomerulonephritis and nephrotic syndrome, reversible after orthotopic liver transplantation

BACKGROUND/AIMS: Nephropathy associated with alpha1-antitrypsin deficiency is assumed to be an unusual entity. We describe the case of a 23-year-old woman with severe alpha1-antitrypsin (PiZ homozygosity) deficiency who developed hepatic cirrhosis in childhood, and glomerulonephritis and nephrotic syndrome in adult life. METHODS/RESULTS: A renal biopsy was consistent with membranoproliferative glomerulonephritis. An immunofluorescence study revealed the presence of alpha1-antitrypsin (PiZ) in the subendothelial region of the glomerular basement membrane. The renal disease was reversible after orthotopic liver transplantation. CONCLUSIONS: The presence of abnormal PiZ protein in the subendothelial region of the glomerular basement membrane may suggest a possible role for this protein in the pathogenesis of glomerulonephritis. The case should add impetus to the search for alpha1-antitrypsin deficiency in any patient presenting with combined liver and renal disease, in the absence of evidence of hepato-renal syndrome, and illustrates that liver transplantation alone may reverse the nephropathy associated with alpha1-antitrypsin deficiency.     

Alpha 1-antitrypsin deficiency and asthma. The continuing search for the relationship

Patients with alpha 1-antitrypsin (AAT) deficiency, like those with asthma and chronic obstructive pulmonary disease, usually present with dyspnea, wheeze, and cough. The similarity in presentation and unfamiliarity among clinicians with AAT deficiency account for much of the delay in diagnosis. Normally, AAT inhibits serine proteases, which cause alveolar destruction, and alters the function of cells that release mediators of inflammation. Diagnostic findings suggesting deficiency include irreversible airflow obstruction, a decreased diffusing capacity of the lung for carbon monoxide, bibasilar bullous disease on chest films, and a low serum level of AAT. Asthma is usually diagnosed on the basis of clinical findings and response to inhaled beta agonists. The presence of inflammation is believed to be necessary for development of clinically significant asthma. Inflammation added to a deficiency of antiprotease inhibitor activity significantly worsens bronchial hyperreactivity. This is only one mechanism by which AAT deficiency may potentiate allergic and bronchospastic responses. The prevalence of bronchial asthma in patients with AAT deficiency is unknown. Studies by the National Institutes of Health regarding the natural history of AAT deficiency and its response to therapy are under way. Perhaps more will be discovered about the relationship between the disorder and bronchial asthma.     

Regulation of the acute phase response genes alpha 1-acid glycoprotein and alpha 1-antitrypsin correlates with sensitivity to thermal injury

BACKGROUND: The response to thermal injury is a complex physiologic process requiring communication between sites of injury and distal target organs. The liver, one of these target organs, synthesizes a family of secretory proteins, the acute phase reactants (APRs), that carries out specific protective functions. This study investigates the response of positively regulated (alpha 1-acid glycoprotein and alpha 1-antitrypsin) and negatively regulated (albumin) APR genes to severe thermal injury in three rat strains with differing abilities to survive thermal stress. METHODS: Age and weight matched male Buffalo, Sprague-Dawley, and Fischer 344, 12- to 16-week-old rats (275 to 325 gm) received a 40% total body surface area scald burn. Total RNA was isolated from livers at 0, 2, 5, 12, 24, and 48 hours. Northern blot hybridization was performed with 32P-labeled rat alpha 1-glycoprotein, rat albumin, and mouse alpha 1-antitrypsin cDNAs. Relative amounts of alpha 1-glycoprotein, alpha 1-antitrypsin, and albumin mRNAs were determined by means of densitometric analyses. RESULTS: All three strains elicit both a positive and negative acute phase (AP) response. Significant differences were observed in the degree and kinetics between strains. Those more sensitive to thermal injury exhibited a more intense positive AP response and possibly a delayed recovery. The AP response between these strains correlates with the variation in ability to survive severe trauma. CONCLUSIONS: The differences in the kinetics and intensity of induction of APR genes between Buffalo, Sprague-Dawley, and Fischer rat strains suggest that the least intense AP response and its timely recovery correlated with the ability to survive a severe thermal injury and that, conversely, the more intense and prolonged response correlated with sensitivity to severe thermal injury. We propose that this may be a basis for variation in survival to thermal injury.     

Fecal excretion and the clearance of alpha 1-antitrypsin in patients with Crohn's disease

In previous work we defined the normal values of faecal alpha-1 antitrypsin (A1ATF) and their plasmatic clearance (CLAT) in 25 healthy patients. The aim of the present study is to compare these previous results with new results obtained when we applied this test to 30 patients with Crohn's disease (CD). We also show the good performance of the mentioned tests as indicators of the intestinal inflammatory activity. We compare the values of A1ATF and CLAT of healthy patients with those of CD patients. We also compare the Crohn's Disease Activity Index (CDAI) and Simple Index between active and inactive CD patients. Our results show significant differences between A1ATF excretion and CLAT as measured in healthy and CD patients. The relationship between those parameters could be explained by the equation CLAT = 0.325 x A1ATF. Active and inactive CD patients only differ significantly with respect to their leucocytes and C reactive protein values. In our group the A1ATF excretion is larger in CD patients with colonic disease.