Hepatocytes corrected by gene therapy are selected in vivo in a murine model of hereditary tyrosinaemia type I.

Current strategies for hepatic gene therapy are either quantitatively inefficient or suffer from lack of permanent gene expression. We have utilized an animal model of hereditary tyrosinaemia type I (HT1), a recessive liver disease caused by deficiency of fumarylacetoacetate hydrolase (FAH), to determine whether in vivo selection of corrected hepatocytes could improve the efficiency of liver gene transfer. As few as 1,000 transplanted wild-type hepatocytes were able to repopulate mutant liver, demonstrating their strong competitive growth advantage. Mutant hepatocytes corrected in situ by retroviral gene transfer were also positively selected. In mutant animals treated by multiple retrovirus injections >90% of hepatocytes became FAH positive and liver function was restored to normal. Our results demonstrate that in vivo selection is a useful strategy for hepatic gene therapy and may lead to effective treatment of human HT1 by retroviral gene transfer.

Augmentation Therapy Modulates Systemic Inflammation in Individuals with Alpha-1 Antitrypsin Deficiency and Chronic Obstructive Pulmonary Disease.

Background: Alpha-1 antitrypsin (AAT) deficiency is a genetic disorder that leads to chronic obstructive pulmonary disease (COPD) and lower circulating levels of AAT, which is a protease inhibitor with potent anti-inflammatory effects. In order to better understand the presence of systemic inflammation in AAT-deficient individuals with COPD, we investigatedthe plasma levels of C-reactive protein (CRP). Methods: AAT-deficient individuals and a matched cohort with a normal AAT genotype were recruited from the Alpha-1 Foundation DNA and Tissue Bank. AAT genotypes were determined by a combination of a Taqman-based assay. AAT and CRP levels were determined by nephelometry. Comparisons were determined by unpaired t-test and standard Pearson's correlation. Results: Our study included 40 control participants and 742 AAT-deficient participants, of which 498 received augmentation therapy. In the AAT-deficient participants, the plasma AAT was 20.2±11.6µM and 4.5±1.3µM (P<0.0001) with and without augmentation therapy, respectively, and the CRP was 0.32±0.53mg/dL and 0.69±1.97mg/dL (P=0.0169), respectively. There was a negative correlation between the percentage predicted of forced expiratory volume in 1 second and CRP in the group not receiving augmentation therapy (r=-0.2528, P<0.05), and there was no correlation in participants receiving augmentation therapy. Conclusion: Compared to healthy individuals, AAT-deficient individuals with COPD have higher levels of circulating CRP, suggesting increased systemic inflammation. However, AAT-deficient individuals receiving augmentation therapy had lower plasma CRP levels compared to those who are not.

Intradermal alpha1-antitrypsin therapy avoids fatal anaphylaxis, prevents type 1 diabetes and reverses hyperglycaemia in the NOD mouse model of the disease.

AIMS/HYPOTHESIS: Human alpha1-antitrypsin (hAAT) gene therapy prevents type 1 diabetes in a NOD mouse model of diabetes. However, repeated i.p. injections of hAAT into NOD mice leads to fatal anaphylaxis. The aim of the study was to determine if an alternative route of administration avoids anaphylaxis and allows evaluation of hAAT's potential for diabetes prevention and reversal. We also sought to determine if the addition of granulocyte colony-stimulating factor (G-CSF), augments hAAT's capacity to prevent or reverse disease in the NOD mice. METHODS: To evaluate hAAT pharmacokinetics, serum hAAT levels were monitored in NOD mice receiving a single dose (2 mg) of hAAT by i.p., s.c. or i.d. injection. For studies of type 1 diabetes prevention and reversal, mice received i.d. hAAT (2 mg/mouse/3 days) for 8 or 10 weeks or hAAT and G-CSF (i.p., 6 microg/day) for 6 weeks. Blood glucose determinations, glucose tolerance testing and insulin tolerance tests were performed. RESULTS: Both i.p. and s.c. injections resulted in fatal anaphylaxis. The i.d. injection avoided anaphylaxis and i.d. injection of hAAT into 11-week-old NOD mice prevented disease (p = 0.005, AAT vs PBS at 40 weeks of age). Treatment of diabetic NOD mice with hAAT or hAAT plus G-CSF provided long-term (at least 100 days) reversal of diabetes in 50% of treated animals. G-CSF did not enhance the reversal rates of hAAT. Glucose tolerance and insulin levels were normalised in mice with hAAT prevention and reversal. CONCLUSIONS/INTERPRETATION: Intradermal hAAT prevents and reverses disease in a NOD mouse model of type 1 diabetes without inducing anaphylaxis.

Heritability of lung function in severe alpha-1 antitrypsin deficiency.

Severe alpha-1 antitrypsin (AAT) deficiency is a proven genetic risk factor for COPD, but there is marked variation in the development of COPD among AAT deficient subjects. To investigate familial aggregation of lung function in subjects with AAT deficiency, we estimated heritability for forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) in 378 AAT deficient subjects from 167 families in the AAT Genetic Modifiers Study; all subjects were verified homozygous for the Z AAT deficiency allele. Heritability was evaluated for models that included and excluded an ascertainment correction, as well as for models that excluded, included and were stratified by a cigarette smoking covariate. In models without an ascertainment correction, and in all models without a covariate for smoking, no evidence for familial aggregation of lung function was observed. In models conditioned on the index proband with covariates for smoking, post-bronchodilator FEV1/FVC demonstrated significant heritability (0.26 +/- 0.14, p = 0.03). When we limited the analysis to subjects with a smoking history, post-bronchodilator FEV1 demonstrated significant heritability (0.47 +/- 0.21, p = 0.02). Severity rate phenotypes were also assessed as potential phenotypes for genetic modifier studies. Significant heritability was found with all age-of-onset threshold models that included smoking and ascertainment adjustments. Using the t-distribution, the heritability estimates ranged from 0.43 to 0.64, depending on the age-of-onset of FEV1 decline used for the severity rate calculation. Correction for ascertainment and consideration of gene-by-smoking interactions will be crucial for the identification of genes that may modify susceptibility for COPD in families with AAT deficiency.

Development of predictive models for airflow obstruction in alpha-1-antitrypsin deficiency.

Alpha-1-antitrypsin deficiency is a genetic condition associated with severe, early-onset chronic obstructive pulmonary disease (COPD). However, there is significant variability in lung function impairment among persons with the protease inhibitor ZZ genotype. Early identification of persons at highest risk of developing lung disease could be beneficial in guiding monitoring and treatment decisions. Using a multicenter, family-based study sample (2002-2005) of 372 persons with the protease inhibitor ZZ genotype, the authors developed prediction models for forced expiratory volume in 1 second (FEV(1)) and the presence of severe COPD using demographic, clinical, and genetic variables. Half of the data sample was used for model development, and the other half was used for model validation. In the training sample, variables found to be predictive of both FEV(1) and severe COPD were age, sex, pack-years of smoking, bronchodilator responsiveness, chronic bronchitis symptoms, and index case status. In the validation sample, the predictive model for FEV(1) explained 50% of the variance in FEV(1), and the model for severe COPD exhibited excellent discrimination (c statistic = 0.88).

Repair of the secretion defect in the Z form of alpha 1-antitrypsin by addition of a second mutation.

Homozygous inheritance of the Z-type mutant form of the alpha 1-antitrypsin (alpha 1AT) gene results in the most common form of alpha 1AT deficiency, a human hereditary disease associated with a high risk for the development of emphysema and an increased incidence of neonatal hepatitis. The alpha 1AT-synthesizing cells of individuals with the Z gene have normal alpha 1AT messenger RNA levels, but alpha 1AT secretion is markedly reduced secondary to accumulation of newly synthesized alpha 1AT in the rough endoplasmic reticulum. Crystallographic analysis of alpha 1AT predicts that in normal alpha 1AT, a negatively charged Glu342 is adjacent to positively charged Lys290. Thus the Glu342----Lys342 Z mutation caused the loss of a normal salt bridge, resulting in the intracellular aggregation of the Z molecule. The prediction was made that a second mutation in the alpha 1AT genet that changed the positively charged Lys290 to a negatively charged Glu290 would correct the secretion defect. When the second mutation was added to the Z-type complementary DNA, the resulting gene directed the synthesis and secretion of amounts of alpha 1AT similar to that directed by the normal alpha 1AT complementary DNA in an in vitro eukaryotic expression system. This suggests the possibility that a human hereditary disease can be corrected by inserting an additional mutation in the same gene.

Alpha-1-antitrypsin aerosolised augmentation abrogates neutrophil elastase-induced expression of cathepsin B and matrix metalloprotease 2 in vivo and in vitro.

BACKGROUND: Neutrophil elastase (NE) activity is increased in lung diseases such as alpha(1)-antitrypsin (A1AT) deficiency and pneumonia. It has recently been shown to induce expression of cathepsin B and matrix metalloprotease 2 (MMP-2) in vitro and in a mouse model. It is postulated that increased cathepsin B and MMP-2 in acute and chronic lung diseases result from high levels of extracellular NE and that expression of these proteases could be inhibited by A1AT augmentation therapy. METHODS: Cathepsin and MMP activities were assessed in bronchoalveolar lavage (BAL) fluid from patients with A1AT deficiency, pneumonia and control subjects. Macrophages were exposed to BAL fluid rich in free NE from patients with pneumonia following pretreatment with A1AT. MMP-2, cathepsin B, secretory leucoprotease inhibitor (SLPI) and lactoferrin levels were determined in BAL fluid from A1AT-deficient patients before and after aerosolisation of A1AT. RESULTS: BAL fluid from both patients with pneumonia and those with A1AT deficiency containing free NE had increased cathepsin B and MMP-2 activities compared with BAL fluid from healthy volunteers. The addition of A1AT to BAL fluid from patients with pneumonia greatly reduced NE-induced cathepsin B and MMP-2 expression in macrophages in vitro. A1AT augmentation therapy to A1AT-deficient individuals also reduced cathepsin B and MMP-2 activity in BAL fluid in vivo. Furthermore, A1AT-deficient patients had higher levels of SLPI and lactoferrin after A1AT augmentation therapy. CONCLUSION: These findings suggest a novel role for A1AT inhibition of NE-induced upregulation of MMP and cathepsin expression both in vitro and in vivo.

Human alpha 1-antitrypsin therapy induces fatal anaphylaxis in non-obese diabetic mice.

Previous studies have shown that human alpha-1 antitrypsin (hAAT) gene delivery prevents type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. Furthermore, hAAT protein administration prolongs acceptance of islet allografts. Therefore, we evaluated the use of purified hAAT protein therapy to prevent T1D in NOD mice. Female NOD, non-obese resistant (NOR), Balb/c and C57BL/6 mice were injected intraperitoneally with vehicle alone or vehicle containing hAAT, human albumin or mouse albumin (or mg/injection/mouse; 2x/week). Preparations of clinical-grade hAAT included API(R), Aralast, Prolastin and Zemaira. Surprisingly, hAAT administration was associated with a high rate of fatal anaphylaxis. In studies seeking T1D prevention at 4 weeks of age, 100% mice died after six injections of hAAT. When administrated at 8-10 weeks of age, most (80-100%) NOD mice died following the fourth injection of hAAT, while 0% of Balb/c and C57BL/6 mice and 10% of NOR mice died. Interestingly, repeated injections of human albumin, but not mouse albumin, also induced sudden death in NOD mice. Antibodies to hAAT were induced 2-3 weeks after hAAT administration and death was prevented by treatment with anti-platelet-activating factor along with anti-histamine. In studies of disease reversal in NOD mice, using the four pharmaceutical grade formulations of hAAT, anaphylactic deaths were observed with all hAAT preparations. The propensity for fatal anaphylaxis following antigenic administration appears to be NOD- but not hAAT-specific. The susceptibility of NOD mice to hypersensitivity provides a significant limitation for testing of hAAT. Development of strategies to avoid this unwanted response is required to use this promising therapeutic agent for T1D.

Alpha 1-antitrypsin deficiency caused by the alpha 1-antitrypsin Nullmattawa gene. An insertion mutation rendering the alpha 1-antitrypsin gene incapable of producing alpha 1-antitrypsin.

alpha 1-Antitrypsin (alpha 1AT) deficiency is a hereditary disorder associated with reduced serum alpha 1AT levels and the development of pulmonary emphysema. An alpha 1AT gene is defined as "Null" when no alpha 1AT in serum is attributed to that alpha 1AT gene. Although all alpha 1AT Null genes have identical phenotypic consequences (i.e. no detectable alpha 1AT in the serum), different genotypic mechanisms can cause the Null state. This study defines the molecular basis for the alpha 1AT gene Nullmattawa, identified and cloned from genomic DNA of an individual with the Null-Null phenotype and emphysema resulting from the heterozygous inheritance of the Nullmattawa and Nullbellingham genes. Sequencing of exons Ic-V and all exon-intron junctions of the Nullmattawa gene demonstrated it was identical to the common normal M1(Val213) alpha 1AT gene except for the insertion of a single nucleotide within the coding region of exon V, causing a 3' frameshift with generation of a premature stop signal. Family analysis using oligonucleotide probes specific for the Nullmattawa sequence demonstrated the gene was inherited in an autosomal fashion. Examination of blood monocytes demonstrated that a normal-sized, 1.8-kb alpha 1AT mRNA transcript is associated with the Nullmattawa gene and in vitro translation of mRNA with the Nullmattawa mutation showed it translated at a normal rate but produced a truncated alpha 1AT protein. Additionally, retroviral transfer of the alpha 1AT Nullmattawa cDNA to murine fibroblasts demonstrated no detectable intracellular or secreted alpha 1AT, despite the presence of alpha 1AT Nullmattawa mRNA transcripts. These findings are consistent with the concept that the molecular pathophysiology of Nullmattawa is likely manifested at a posttranslational level. The identification of the Nullmattawa gene supports the concept that Null alpha 1AT alleles represent a heterogenous group in which very different mechanisms cause the identical phenotypic state.

Inhibition of intracellular degradation increases secretion of a mutant form of alpha1-antitrypsin associated with profound deficiency.

The mutant Z form of alpha1-antitrypsin (alpha1AT) is responsible for > 95% of all individuals with alpha1AT deficiency, an important inherited cause of emphysema and liver disease. Since secreted Z alpha1AT is a functional antiprotease, we hypothesized that interrupting catabolism of retained Z alpha1AT might increase its transport out of cells, causing an increase in extracellular protease protection. Both the protein translation inhibitor cycloheximide and the specific inhibitor of proteasome function, lactacystin, prevented intracellular degradation of Z alpha1AT. Moreover, this inhibition of degradation was associated with partial restoration of Z alpha1AT vesicular transport. This effect was observed in a model system of transfected CHO cells as well as in human alveolar macrophages synthesizing Z alpha1AT. This study supports the hypothesis that altering the intracellular fate of a mutant protein may be an option in the treatment of diseases associated with misfolded but potentially functional proteins.

Evaluation of "at risk" alpha 1-antitrypsin genotype SZ with synthetic oligonucleotide gene probes.

Alpha 1-antitrypsin (alpha 1AT), a 52,000-mol-wt serum glycoprotein produced by hepatocytes and mononuclear phagocytes, functions as the major inhibitor of neutrophil elastase. The alpha 1AT haplotype S is associated with childhood liver disease and/or adult emphysema when inherited with the Z haplotype to give the phenotype SZ. To accurately identify the SZ phenotype at the level of genomic DNA, four 32P-labeled 19-mer synthetic oligonucleotide probes were prepared; two to identify the M and S difference in exon III, and two to identify the M and Z difference in exon V. These probes were hybridized with various cloned DNAs and genomic DNAs cut with the restriction endonucleases BgII and EcoRI; the genomic DNAs represented all six possible phenotype combinations of the M, S, and Z haplotypes (MM, MS, MZ, SS, ZZ, and SZ). Using the four probes to evaluate 42 samples of genomic DNA, the "at risk" SZ and ZZ phenotypes were correctly identified in all cases, as were the "not at risk" phenotypes SS, MS, MM, and MZ, demonstrating that both exon III and exon V directed probes are necessary to properly identify all of the major "at risk" alpha 1AT genes. However, when used to evaluate a very rare family carrying a null allele, these four oligonucleotide probes misidentified the "at risk" null-null and S null phenotypes as "not at risk" MM and SM combinations. These observations indicate that oligonucleotide gene probes yielded reliable and accurate assessment of "at risk" alpha 1AT genotypes in almost all situations, but in the context of prenatal diagnosis and genetic counseling this approach must be used with caution and in combination with family studies so as not to misidentify rare genotypes that may be associated with a risk for disease.

Prevalence of alpha-1 antitrypsin deficiency in poorly controlled asthma--results from the ALA-ACRC low-dose theophylline trial.

In a study comparing low-dose theophylline to montelukast in poorly controlled asthmatics, 285 subjects consented to be screened for alpha-1 antitrypsin deficiency. Of the 284 for which complete data was available, 10.5% carried a deficiency gene and 2.4% were mildly deficient with an alpha-1 antitrypsin serum level of less than 20 mu M. In the non-African-American cohort, an abnormal phenotype occurred in 12% and 2.9% were mildly deficient. Baseline pulmonary function and asthma scores were not significantly different between those with normal and abnormal AAT phenotype. However those with the deficiency tended to show a greater bronchodilator response.

Is rotavirus a population of reassortants?

Rotaviruses appear to exist as heterogeneous populations of reassortants and related variants. This phenomenon is consistent with the quasispecies concept of RNA viruses, and suggests that gene reassortment is a crucial evolutionary mechanism for this segmented virus. It also explains puzzling epidemiological findings and controversial results of vaccine-efficacy studies.

Molecular basis of alpha-1-antitrypsin deficiency.

Alpha-1-antitrypsin (A1AT) deficiency is an autosomal hereditary disorder associated with a major reduction in serum A1AT levels. Clinically, A1AT deficiency is associated with emphysema in adults and, less commonly, liver disease in neonates. A1AT is a 52-kDa, 394-amino acid, single-chain glycoprotein normally present in serum at 150 to 350 mg/dl. The A1AT gene, composed of seven exons dispersed over 12 kb of chromosomal segment 14q31-32.3, is expressed in hepatocytes and mononuclear phagocytes. The A1AT protein, a member of the class of protease inhibitor proteins known as serpins (serine protease inhibitors), is a globular molecule composed of nine alpha-helices and three beta-pleated sheets. The major function of A1AT is to inhibit neutrophil elastase; A1AT does so through an active site centered around Met358 contained within an external stressed loop on the surface of the molecule. A1AT is a highly pleomorphic protein with greater than 75 variants determined at the protein and/or gene level. These variants can be categorized into four groups according to their serum A1AT level and function: normal, deficient, dysfunctional, and absent. There are two important salt bridges within the A1AT molecule (Glu342-Lys290; Glu263-Lys387); a mutation in the A1AT gene causing disruption of either salt bridge causes distinct molecular pathology resulting in reduced serum A1AT levels. Clinically relevant variants can be distinguished by a combination of isoelectric focusing of serum, restriction fragment length analysis of genomic DNA, oligonucleotide probes, and direct sequencing of the variant A1AT genes.

Formation and current results of a patient-organized registry for alpha(1)-antitrypsin deficiency.

BACKGROUND: Significant challenges exist to investigating uncommon illnesses because too few patients are seen at any single clinical center to permit appropriate research studies. Recognizing this impediment to clinical research in alpha(1)-antitrypsin deficiency, the Alpha One Foundation, a patient-organized research foundation, has collaborated with clinician-scientists to organize a voluntary registry of individuals with alpha(1)-antitrypsin deficiency. PURPOSE: To facilitate clinical research in alpha(1)-antitrypsin deficiency by organizing a registry of affected individuals willing to be approached to participate in clinical studies. METHODS: Elements of the Alpha One Foundation Research Network Registry include a Medical and Scientific Advisory Committee, composed of physician-investigators and patient advocates, designated clinical resource centers at medical institutions with expertise in the management of individuals with alpha(1)-antitrypsin deficiency, and a data coordinating center with responsibility for database management and analysis. Questionnaires requesting information about demographic features, alpha(1)-antitrypsin phenotype, smoking history, and health-care utilization were distributed to prospective registrants through the following channels: mailings from the Alpha One Foundation; mailings from the clinical resource centers; and distribution by home-care and pharmaceutical companies. Information from this questionnaire formed the basis of the initial registry database. RESULTS: Between May 1997 and June 1999, 7,789 forms were distributed, and forms were returned by 712 unique registrants. Registrants have the following characteristics: mean (+/- SD) age, 49.3+/-13.2 years; women, 47.7%; white, 96.2%; PI*ZZ phenotype, 70.7%; ex-smokers, 73.3%; COPD patients, 87.2% (emphysema patients, 54.2%; chronic bronchitis patients, 33%); and self-reported liver disease, 6.4%. The mean number of physician visits reported by registrants in the preceding 12 months was 7.8+/-9.4, 59% reported currently receiving IV augmentation therapy, and 35% reported using supplemental oxygen at home. Examples of ongoing research studies using this unique database include: (1) a case-control study to evaluate occupational risk factors for obstructive lung disease in individuals with alpha(1)-antitrypsin deficiency and (2) a study to evaluate the health-care costs for affected individuals. CONCLUSIONS: A registry currently including 712 individuals with alpha(1)-antitrypsin deficiency has been organized through a collaboration between physician-investigators and a patient-organized research foundation. Use of the registry has already facilitated studies that were previously difficult because of the paucity of identifiable study subjects. The registry cohort promises to provide an important resource for future clinical and epidemiologic studies.

Pulmonary function and high-resolution CT findings in patients with an inherited form of pulmonary fibrosis, Hermansky-Pudlak syndrome, due to mutations in HPS-1.

OBJECTIVE: To describe and correlate pulmonary function and high-resolution CT (HRCT) scan scores in individuals with a high risk for development of pulmonary fibrosis, ie, Hermansky-Pudlak syndrome (HPS) patients with mutations in the HPS-1 gene. DESIGN: Cross-sectional analysis of consecutive, eligible patients. PATIENTS: Thirty-eight HPS inpatients at the National Institutes of Health Clinical Center with HPS-1 mutations. RESULTS: Thirty-seven patients were Puerto Rican and exhibited the typical 16-base pair (bp) duplication in exon 15 of HPS-1. One non-Puerto Rican was homozygous for a different mutation (intervening sequence 17 -2 A-->C) previously reported in the HPS-1 gene; he died at age 35 of pulmonary insufficiency. For the 23 patients who had pulmonary symptoms, the mean age of onset was 35 years. For all 38 patients (mean age, 37 +/- 2 years), the mean FVC was 71% of predicted; the mean FEV(1), 76%; mean total lung capacity (TLC), 72%; mean vital capacity (VC), 68%; and mean diffusing capacity of the lung for carbon monoxide (DLCO), 72%. When patients were grouped according to the extent of their reduction in FVC, the other four pulmonary function parameters followed the FVC. Seventeen patients had abnormal chest radiographs, and 31 (82%) had abnormal HRCT scans of the chest, for which a scoring system of 0 (normal) to 3 (severe fibrosis) is presented. The mean +/- SEM HRCT score for 38 patients was 1.30 +/- 0.17. HRCT scores correlated inversely with FVC and DLCO. CONCLUSIONS: Mutations in the HPS-1 gene, whether or not they involve the typical 16-bp duplication seen in Puerto Rican patients, are associated with fatal pulmonary fibrosis. In affected patients, the FVC, FEV(1), TLC, VC, and DLCO fall in concert, and this functional deficit correlates with HRCT scan evidence of progression of interstitial lung disease.

Use of a highly purified alpha 1-antitrypsin standard to establish ranges for the common normal and deficient alpha 1-antitrypsin phenotypes.

Diagnosis of the hereditary disorder alpha 1-antitrypsin (alpha 1AT) deficiency is critically dependent on quantification of serum levels of alpha 1AT, a 52-kDa antiprotease that serves to protect the lung from destruction by neutrophil elastase. Although the measurement of serum alpha 1AT levels is not difficult, there is no international standard for alpha 1AT, and investigators in the field recognize that widely used commercially available standards vary by as much as 50 percent. To establish accurate ranges for the common normal and deficient alpha 1AT phenotypes, the present study uses a purified alpha 1AT standard to quantify the alpha 1AT serum levels of 443 individuals with common normal and deficient alpha 1AT phenotypes, including MM, ZZ, SS, MZ, MS, and SZ. Based on the observed values, a statistical model was developed to generate predicted frequency distributions of alpha 1AT serum levels for each of these phenotypes. Based on these studies, the ranges (5th to 95th percentile) for alpha 1AT serum levels of the common phenotypes are: MM, 20 to 53 mumol/L; SS, 20 to 48 mumol/L; ZZ, 3.4 to 7.0 mumol/L; MZ, 15 to 42 mumol/L; MS, 18 to 52 mumol/L; and SZ, 10 to 23 mumol/L. This alpha 1AT standard and these ranges are being used for the National alpha 1-Antitrypsin Deficiency Registry organized under the auspices of the National Heart, Lung, and Blood Institute.

Baseline characteristics of enrollees in the National Heart, Lung and Blood Institute Registry of alpha 1-antitrypsin deficiency. Alpha 1-Antitrypsin Deficiency Registry Study Group.

OBJECTIVE: alpha 1-Antitrypsin (alpha 1-AT) deficiency is a hereditary disorder characterized by a high risk for the development of emphysema at an early age. In 1988, the National Heart, Lung and Blood Institute, National Institutes of Health, initiated a registry of individuals with alpha 1-AT deficiency to help define the natural history and clinical course of this disorder. This article describes demographic and clinical characteristics of subjects enrolled in the Registry at baseline. DESIGN: Prospective longitudinal natural history study. SETTING: Thirty-seven clinical centers in the United States (36 centers) and Canada (one center). PATIENTS: There were 1,129 subjects 18 years of age or older with severe deficiency of alpha 1-AT, defined as having serum alpha 1-AT levels < or = 11 mumol/L confirmed by a Central Phenotyping Laboratory, or a ZZ or ZNull genotype identified by genomic DNA analysis. RESULTS: Most enrollees were symptomatic white subjects in their fourth to sixth decade, with a ZZ phenotype, a history of having smoked cigarettes, and pulmonary function tests demonstrating a pattern consistent with emphysema. Interestingly, only a small percentage were current smokers on enrollment, suggesting that this population is amenable to smoking cessation. A subgroup of individuals in the Registry with relatively normal lung function were younger, more likely to have never smoked and more likely to have come to medical attention owing to a family history of alpha 1-AT deficiency rather than symptomatic involvement. CONCLUSIONS: These results emphasize the need for increased awareness and early detection of alpha 1-AT deficiency. In this endeavor, dissemination of the information contained in the Registry to health-care professionals and the general population, along with initiation of appropriate preventative measures before significant lung damage has occurred, could have considerable benefits for individuals with this condition.

Pulmonary dysfunction in adults with nephropathic cystinosis.

OBJECTIVE: To characterize the pulmonary dysfunction in patients with nephropathic cystinosis after renal transplantation. DESIGN: Cross-sectional analysis of consecutive adult patients. PATIENTS: Twelve adult, nephropathic cystinosis patients and 3 adult, ocular, nonnephropathic cystinosis patients admitted to the National Institutes of Health Clinical Center. RESULTS: The 12 nephropathic cystinosis patients (age range, 21 to 40 years) showed an extraparenchymal pattern of restrictive lung disease, with inspiratory and expiratory dysfunction. Specifically, the mean FVC was 58% of predicted, the mean FEV(1) was 57% of predicted, and the mean total lung capacity was 66% of predicted, while the mean residual volume was normal. Furthermore, the mean maximal inspiratory pressure for the eight patients tested was 40% of predicted, and the mean maximal expiratory pressure was 26% of predicted. Two patients died of respiratory insufficiency. All the patients had lived at least 17 years, while lacking compliant cystine-depleting therapy with oral cysteamine. Seven patients had a conical chest, restricting excursion, and 10 of the 12 patients had evidence of the myopathy that typifies late cystinosis. In fact, the severity of pulmonary disease correlated directly with the severity of myopathy in our group of 12 patients. In contrast, the lung parenchyma was essentially normal, as gauged by chest radiographs and CT scans of the lung. The three patients with nonnephropathic cystinosis displayed entirely normal pulmonary function. CONCLUSION: The distal myopathy characteristic of nephropathic cystinosis results in an extraparenchymal pattern of restrictive lung disease in adults who have not received long-term cystine depletion. Whether or not oral cysteamine therapy can prevent this complication remains to be determined.

Molecular mechanisms of alpha1-antitrypsin null alleles.

Alpha1-antitrypsin (alpha1-AT) is the most abundant circulating inhibitor of serine proteases and therefore is essential to normal protease-anti-protease homeostasis. Inheritance of two parental alpha1-AT deficiency alleles is associated with a substantially increased risk for development of emphysema and liver disease. In very rare circumstances individuals may inherit alpha1-AT null alleles. Null alpha1-AT alleles are characterized by the total absence of serum alpha1-AT. These alleles represent the extreme end in a continuum of alleles associated with alpha1-AT deficiency. The molecular mechanisms responsible for absence of serum alpha1-AT include splicing abnormalities, deletion of alpha1-AT coding exons and premature stop codons. While these alleles comprise only a small proportion of alpha1-AT alleles associated with profound alpha1-AT deficiency, studies of their molecular mechanisms provide valuable insights into the structure, gene expression and intracellular transport of alpha1-AT.