AAT Phenotype Research Articles

Presence of Alpha 1 Antitrypsin Risk Variants is Not Associated With Histologic Severity of Pediatric NAFLD.

Among adults with nonalcoholic fatty liver disease (NAFLD), alpha-1-antitrypsin (A1AT) heterozygosity has been linked to advanced liver disease; pediatric data remain unclear. The objective of this study is to determine whether A1AT PiZ or PiS variants are associated with liver disease severity in youth with NAFLD. Retrospective study of youth with confirmed NAFLD. Multivariable logistic regression used to determine independent associations between A1AT risk variants and histologic severity [NAFLD activity score (NAS) ≥5 and/or significant fibrosis (stage ≥2)]. The cohort included 269 patients, mean age 12 [±3] years with NAFLD and A1AT phenotyping (n = 260) and/or A1AT levels (n = 261). The mean NAS of the cohort was 4.2 [±1.5]; 50% had any, and 18% had significant fibrosis. Most (86%) had the MM A1AT phenotype, while 7% had the MS and 3% the MZ phenotype (the rest had other, nonpathogenic variants). Mean A1AT level was 123 mg/dL [±20]. A1AT levels did not differ by low versus high NAS (122 ± 2 vs 126 ± 19 mg/dL, P = 0.12) or by no/mild versus significant fibrosis (123 ± 20 vs 126 ± 20 mg/dL, P = 0.23, respectively). Carriers and noncarriers of the PiS or PiZ variants had similar NAS (mean NAS 3.8 ± 1.6 vs 4.2 ± 1.4; P = 0.25, respectively). Fibrosis severity did not differ by carrier vs noncarrier group: 38% versus 52% had any fibrosis ( P = 0.17) and 14% versus 18% had significant fibrosis ( P = 0.80, respectively). Multivariable modeling showed no association between A1AT risk variants and histologic severity. While not uncommon, carriage of the A1AT PiZ or PiS risk variants was not associated with histologic severity in children with NAFLD.

Molecular characterization of PI * S hangzhou , a SERPINA1 allele from continental China encoding a defective alpha-1-antitrypsin.

Alpha-1-antitrypsin deficiency (AATD) is a heritable condition that predisposes to respiratory and hepatic complications. Screenings in East Asia human populations for the AATD alleles most commonly found among Caucasians have yielded poor outcomes. Serum alpha-1-antitrypsin (AAT) levels, AAT phenotypes, and sequences of SERPINA1 gene were examined in a Chinese child with a moderate deficit of serum AAT, who had suffered several episodes of liver disease, as well as in his first-order relatives. Results allowed the identification of PI*Shangzhou, a novel SERPINA1 defective allele, which has been characterized by a L276R substitution, found in a SERPINA1-M3 genetic background. Moreover, potential effects of PI*Shangzhou mutation over the AAT structure were studied by 3D homology modeling. The presence of an arginine residue at position 276 could destabilize the tertiary structure of AAT, since it occurs at a highly conserved hydrophobic cavity in the protein surface, and very close to two positively-charged lysine residues. Attending to the frequency of R276 variant reported in databases for individuals of East Asian ancestry, the PI*Shangzhou allele may explain the global prevalence of the PiS phenotype observed in China.

The investigation of the frequency of the alpha-1-antitrypsin phenotype in patients with liver cirrhosis

Alpha-1-antitrypsin (AAT) has different phenotypes. Evidence suggests that the abundance of each of these phenotypes may be associated with a disease. The purpose of this study was to evaluate the frequency of AAT phenotypes in patients with liver cirrhosis as well as in healthy individuals. In this study, 42 patients with liver cirrhosis were selected. The results of the previous research done by the researcher on healthy individuals were used to construct the control group. After obtaining informed consent, 5mL of fasting venous blood sample was taken, and phenotypes were analyzed by isoelectric focusing. Data were analyzed using Chi-square and Fisher's exact tests at a significant level of 0.05. The results of this study indicated that all 42 healthy subjects had an MM allele (100%). However, among 42 patients, 35 (83.3%) had an MM allele, 5 (11.9%) had an MS allele, and 2 (4.8%) had MZ allele. The difference between the two groups was significant (p=0.02). There was no difference between men and women in the allele type (p=0.557). This study revealed that MS and MZ alleles were observed only in patients with liver cirrhosis, and none of these alleles were found in healthy subjects. Therefore, MS and MZ alleles can be further investigated as risk factors for liver cirrhosis.

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.

The Liver Biopsy in Neonatal Cholestasis: Just a Cherry on Top?

Content available: Author Audio Recording.

S2627 A Case of K2-Induced Hyperbilirubinemia

INTRODUCTION: Over the last decade, synthetic cannabinoids (SCB) have been marketed as a natural and safer version of marijuana, leading to an increase in its recreational use. We present a case of isolated hyperbilirubinemia caused by K2 and, to our knowledge, this is the first reported case of K2-induced indirect hyperbilirubinemia. CASE DESCRIPTION/METHODS: An 18-year-old male with no significant medical history presented with behavioral changes. He admitted to using K2 daily. His sibling and paternal uncle had Gilbert's syndrome. On physical exam he was withdrawn and agitated. He had Scleral icterus and jaundice. Slit Lamp exam was equivocal. On labs: Total Bilirubin 11.2 mg/dL, Indirect bilirubin 10.8 mg/dL, Urine toxicology positive for marijuana.Serum ceruloplasmin, serum copper, 24h urinary copper excretion, anti-mitochondrial Ab, anti-Nuclear Ab, anti-LKM, Soluble Liver antigen, ferritin, iron, TIBC, A1AT, A1AT phenotype, IgG, IgM, IgA, hepatitis A, B, C serologies, LDH, haptoglobin, uric acid, Coombs test, and G6PD levels were all within normal limits. His peripheral blood smear was normal. Imaging: MRI brain: unremarkable, Liver biopsy:normal hepatic architecture without severe pathological process (Figures 2a and 2b). He was treated with supportive care and indirect hyperbilirubinemia improved. DISCUSSION: • There is no current literature that correlates indirect hyperbilirubinemia and SCB use. In our otherwise healthy patient, this hyperbilirubinemia was likely a consequence of his K2 ingestion. We hypothesize that K2 may impair hepatic glucuronidation which is the process by which indirect bilirubin is converted to direct bilirubin. • During the time of exacerbation of Gilbert's disease, most often the indirect bilirubin levels remain < 5mg/dL. In the case of our patient, he presented with an indirect bilirubin level of 10.8 mg/dL. His work-up excluded other causes of indirect hyperbilirubinemia. • This leads us to hypothesize that K2 may induce significant isolated indirect hyperbilirubinemia in patients with a predisposition to impaired hepatic glucuronidation. • We believe that removal of the insulting agent is required for resolution of the hyperbilirubinemia. • With the use of SCB increasing recreationally, it is crucial we understand the effects these drugs can have. SCB do not appear on standard hospital drug screens. Therefore, a focused history and exam should be obtained from the patient. Our case serves to increase awareness of SCB use as a cause of indirect hyperbilirubinemia.Figure 1Figure (2a).: Liver biopsy stained with Hematoxylin & Eosin, showing normal hepatic architecture with no periductal or ductular inflammatory infiltration.Figure (2b).: Hepatic tissue stained with Periodid acid-Schiff Diastase and for copper; normal pathology & negative copper staining.

New cis-Acting Variants in PI*S Background Produce Null Phenotypes Causing Alpha-1 Antitrypsin Deficiency.

Alpha-1 antitrypsin deficiency (AATD) is an inherited condition characterized by reduced levels of serum AAT due to mutations in the SERPINA1 (Serpin family A member 1) gene. The Pi*S (Glu264Val) is one of the most frequent deficient alleles of AATD, showing high incidence in the Iberian Peninsula. Herein, we describe two new alleles carrying an S mutation but producing a null phenotype: QOVigo and QOAachen. The new alleles were identified by sequencing the SERPINA1 gene in three patients who had lower AAT serum levels than expected for the initial genotype. These alleles are the result of combined mutations in cis in a PI*S allele. Sequencing detected the S mutation in cis with Tyr138Cys (S+Tyr138Cys) in two patients, whereas a third one had the S mutation in cis with Pro391Thr variant (S+Pro391Thr). When expressed in a cellular model, these variants caused strong AAT polymerization and very low AAT secretion to almost undetectable levels. The isoelectric focusing method for plasma AAT phenotyping did not show AAT protein encoded by the novel mutant alleles, behaving as null. We called these alleles PI*S-plus because the S variant was phased with another variant conferring more aggressive characteristics to the allele. The current data demonstrate that the clinical variability observed in AATD can be explained by additional genetic variation, such as dual cis-acting variants in the SERPINA1 gene. The possible existence of other unrevealed variants combined in the PI*S alleles should be considered to improve the genetic diagnosis of the patients.

NullCanada: A novel α1-antitrypsin allele with in cis variants Glu366Lys and Ile100Asn

Backgroundα1-Antitrypsin (A1AT) deficiency predisposes patients to pulmonary disease due to inadequate protection against human neutrophil elastase released during inflammatory responses. A1AT deficiency is caused by homozygosity or compound heterozygosity for A1AT variants; individuals with A1AT deficiency most commonly have at least one Z variant allele (c.1096G > A (Glu366Lys)). Null variants that result in complete absence of A1AT in the plasma are much rarer. With one recent exception, all reported A1AT variants are characterized by a single pathogenic variant. CaseAn 8 years old patient from Edmonton, Alberta, Canada, was investigated for A1AT deficiency. His A1AT phenotype was determined to be M (wild type)/Null by isoelectric focusing (IEF) but M/Z by targeted genotyping. Gene sequencing revealed two heterozygous variants: Z and Ile100Asn (c.299 T > A). The Ile100Asn substitution is predicted to disrupt the secondary structure of an α-helix in which it resides and the neighbouring tertiary structure, resulting in intracellular degradation of A1AT prior to hepatocyte secretion. MethodsFamily testing was conducted to verify potential inheritance of an A1AT allele carrying the two mutations in cis, as this arrangement of the mutations would explain “Z” detection by genotyping but not by IEF. Molecular modeling was used to assess the effect of the variants on A1AT structure and stability. DiscussionCarrier status for a novel variant NullCanada with in cis mutations (c.[299 T > A;1096G > A], p.[(Ileu100Asn;Glu366Lys)]) was confirmed. A sibling was identified as having A1AT deficiency on the basis of compound heterozygosity for two alleles: NullCanada and the common Z allele. A separate pedigree from the Maritimes was subsequently recognized as carrying NullCanada. ConclusionIn cis mutations such as NullCanada may be more common than previously described due to failure to detect such mutations using historical testing methods. Combined approaches that include gene sequencing and segregation studies allow recognition of rare A1AT variants, including in cis mutations.

IDIOPATHIC LARYNOTRACHEAL STENOSIS AND LOW ALPHA-ONE ANTITRYPSIN LEVELS

SESSION TITLE: Tuesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/22/2019 01:00 PM - 02:00 PM INTRODUCTION: Idiopathic laryngotracheal stenosis (ILS) is an inflammatory condition resulting in the narrowing of the airway. (1) To date, in the literature, there has been no clear association between ILS and low alpha-one antitrypsin (A1AT) levels. We report a case in which a patient had both abnormalities and we postulate mechanisms through which low A1AT levels could cause airway stenosis. CASE PRESENTATION: A 57-year-old lady with a past medical history of Parkinson's disease was sent for a second opinion for shortness of breath and wheezing. She had been erroneously diagnosed with A1AT deficiency and was started on augmentation therapy. Physical examination demonstrated a hoarse voice and diffuse expiratory wheeze, but no stridor, emanating from the upper airway. Her A1AT level was 79 mg/dl (normal 80-220 mg/dl) and her A1AT phenotype was PI*MZ. Pulmonary function testing showed the following: FVC: 87%, FEV1: 82%, FEV1/FVC: 93% and DLCO: 91%. The flow-volume loop suggested a fixed airway obstruction. Chest and neck tomography showed a scant amount of secretions involving the superior aspect of the trachea inferior to the vocal cord. She underwent bronchoscopy, which revealed tracheal narrowing to 5mm in diameter approximately 3 cm below the vocal cords. There was a thick fibrous band on the left side and a few smaller webs tethering the trachea. There was also a tracheal diverticulum present on the left side of the thick fibrous band. The rest of the tracheobronchial tree was normal. Initially, endobronchial scissors and a YAG laser were used to cut the webs and the trachea partially unfolded. The trachea was then dilated from 10 to 15 mm in diameter. Complete tracheal patency was achieved. DISCUSSION: ILS is rare and is most commonly seen in post-menopausal women. Proposed mechanisms are related to estrogen, disruption of blood supply, gastroesophageal reflux, and unremitting cough. (2) Secondary causes of laryngotracheal stenosis include prolonged endotracheal intubation and autoimmune diseases such as granulomatosis with polyangiitis and sarcoidosis. (1) There is no clear evidence showing an association between low A1AT levels and ILS. A1AT is a potent inhibitor of proteases and is crucial in conserving the integrity of connective tissue. In patients with low A1AT levels, these proteolytic enzymes can lead to fibrosis and scarring. Though most commonly associated with emphysema, low levels of A1AT have also been associated with arterial fibromuscular dysplasia with evidence of altered extracellular matrix and connective tissue abnormalities. (3) Although causation is impossible to establish in this case, we speculate that low A1AT levels may have led to connective tissue dysregulation and stenotic lesions of the trachea. CONCLUSIONS: This case is the first report of ILS occurring in the setting of low levels of A1AT. We speculate that there may be a pathobiologic link between the two entities. Reference #1: Gelbard A, Francis DO, Sandulache VC, Simmons JC, Donovan DT, Ongkasuwan J. Causes and consequences of adult laryngotracheal stenosis.Laryngoscope.2015 May;125(5):1137-43. https://doi.org/10.1002/lary.24956. Epub 2014 Oct 7. Reference #2: Damrose EJ. On the development of idiopathic subglottic stenosis. Med Hypotheses. 2008;71(1):122-5. https://doi.org/10.1016/j.mehy.2007.12.017. Epub 2008 Mar 4. Reference #3: Schievink WI, Björnsson J, Parisi JE, Prakash UB. Arterial fibromuscular dysplasia associated with severe alpha 1-antitrypsin deficiency. Mayo Clin Proc. 1994 Nov;69(11):1040-3. DISCLOSURES: No relevant relationships by Hamzah Alfahel, source=Web Response No relevant relationships by Anthony Cucci, source=Web Response No relevant relationships by Ahmad JABRI, source=Web Response No relevant relationships by Sanjiv Tewari, source=Web Response No relevant relationships by Elizabeth Verghese, source=Web Response

Alpha-1 antitrypsin deficiency panniculitis: clinical and pathologic characteristics of 10 cases.

Alpha-1 antitrypsin deficiency (AATD) may be associated with liver and lung disease and rarely causes panniculitis. We evaluated the clinicopathologic and laboratory findings of AATD panniculitis in 10 patients. We conducted a retrospective review of all cases of AATD panniculitis at Mayo Clinic, Rochester, MN, from 1989 to 2016. Ten patients with AATD panniculitis were included. Seven of ten were women. Clinical lesions were most commonly nodular (100%), erythematous (90%), ulcerated (90%), and painful (90%) subcutaneous nodules and plaques. Extracutaneous associations were rare. PiZZ phenotype was most commonly identified (50%). Histopathologically, lobular panniculitis (80%) with associated septal involvement (60%) and a predominant neutrophilic infiltrate (100%) were most common. Treatments varied; dapsone and alpha-1 proteinase inhibitor infusions were each used in five (50%) patients, respectively. In patients with greater than 6-month follow-up (n = 4), one patient continued to have disease activity despite treatment. AATD panniculitis should be considered in the differential for a painful, ulcerative panniculitis with a predominantly neutrophilic histopathologic infiltrate. Diagnosis can be made with clinicopathologic correlation and genetic and laboratory evaluations. Serum AAT level and phenotype assists in diagnosing patients with suspected AATD panniculitis.

The Effects of Inflammation on Alpha 1 Antitrypsin Levels in a National Screening Cohort

ABSTRACTAlpha 1 Antitrypsin (AAT) is a highly polymorphic serum protein. Several genetic variants are associated with varying degrees of decreased serum levels; however, these levels can rise in response to infection, inflammation, injury and estrogen levels. Although the effect of inflammation is well established, it has never been studied quantitatively with respect to specific genotypes in a large representative sample. Using data from a national AAT deficiency-targeted screening cohort, we evaluated AAT levels of patients with normal and deficiency genotypes in response to inflammation, indicated by elevated serum C-reactive protein (CRP). Additionally, we utilized a regression analysis to adjust for the effect of inflammation for each genotype. Across all stratified genotype groups, increased AAT levels were observed in patients with CRP ≥5 mg/L. Different AAT phenotypes reacted differently in the acute phase; M showed a strong response and Z a reduced reaction. Nevertheless, we discovered that inflammation significantly masked clinically relevant base AAT levels in some PI*MZ individuals; approximately a quarter of PI*MZ samples showed signs of inflammation. Median AAT levels (mg/dL) in the presence of inflammation are given for several genotypes; numbers in parentheses are levels from the cohort without inflammation/adjusted levels from the cohort with inflammation using the newly devised algorithm: PI*MM: 162 (142/140); PI*MS: 136 (117/115); PI*MZ: 104 (85/89); PI*MF: 161 (132/141); PI*SS: 115 (96/91); PI*SZ: 66 (54/50). We conclude that simultaneous determinations of CRP and AAT levels, and genotyping are clinically valuable in defining AAT variants and that the effect of inflammation can be adjusted for.

Brief Report: Genetic Variation of the α1 -Antitrypsin Gene Is Associated With Increased Autoantibody Production in Rheumatoid Arthritis.

To examine the prevalence of α1 -antitrypsin deficiency (AATD) in rheumatoid arthritis (RA), and to determine whether AATD is associated with higher levels of rheumatoid factor (RF), antinuclear antibodies (ANAs), and anti-citrullinated peptide autoantibodies (ACPAs). RF, ANAs, and ACPAs were measured by standard immunoturbidimetry, immunofluorescence assay, and enzyme-linked immunosorbent assay, respectively. Characterization of AAT phenotypes was performed by isoelectric focusing and immunofixation. The chi-square test with Yates' correction and the Mann-Whitney U test were used to assess the prevalence of alleles associated with AATD in RA and to compare mean antibody titers, respectively. Of 246 patients with RA, 24 who were heterozygous for AATD were identified, with no statistically significant difference in the prevalence of AATD between RA patients and the general population (P = 0.39). A positive association between heterozygosity for AATD and the production of ACPAs was observed (P < 0.0001), with increased ACPA titers recorded in the AATD RA cohort compared with the general population (P = 0.01). AAT heterozygous status in RA is strongly associated with positive ACPAs and may define a distinct subset of patients with increased disease severity.

A role of endothelial dysfunction for development of microcirculation and cardiopulmonary blood flow abnormalities in patients with COPD and different alpha-1-antitrypsin phenotypes

The aim of this study was to investigate structural and functional changes of pulmonary vessels and cardiopulmonary blood flow in COPD patients with different alpha-1-antitrypsin (A1AT) phenotypes and endothelial dysfunction. Methods. Patients with COPD stage 2 to 3 (n = 113) with different A1AT phenotypes underwent clinical and radiological examination; endothelial dysfunction markers were measured. Results. More severe COPD was associated with more severe pulmonary microcirculation disorders and more significant perfusion defects. Patients with ZZ phenotype had worse pulmonary blood flow abnormalities compared to patients with MM phenotype. Pulmonary blood flow abnormalities were closely related to endothelial dysfunction (r = 0.75) and were more significant than structural abnormalities diagnosed on multi spiral computed tomography. Severe disorders of pulmonary blood flow were not accompanied by severe pulmonary hypertension. Conclusions: Blood levels of main endothelial dysfunction markers were directly related to COPD severity. Angiotensin-converting enzyme concentration was significantly below the normal level and was related to pulmonary artery pressure. The pulmonary blood flow differed in patients with different A1AT phenotypes and COPD stage 3 or higher. Perfusion defects were more severe in patients with ZZ phenotype.

Correlation Between Alpha-1-Antitrypsin Levels and Bronchiectasis in Humoral Immunodeficiency Patients Receiving Gammaglobulin Infusions

When Alpha-1-antitrypsin (AAT) is low or deficient, it can be associated with bronchiectasis, a chronic inflammatory lung disease. Bronchiectasis is also seen in humoral immunodeficiency states such as Common Variable Immunodeficiency (CVID) and hypogammagloblinemia (Hypogam). In patients with CVID/Hypogam, the progression of bronchiectasis has been known to occur even in the absence of recurrent infections and while the patient is receiving adequate treatment. Both the AAT levels as well as AAT phenotypic (P) variation and their potential correlation between CVID/Hypogam patients with or without bronchiectasis has not been studied. Our hypothesis is: Patients with humoral immunodeficiencies and bronchiectasis have lower levels of AAT compared to those without bronchiectasis. 154 Patients with CVID/Hypogam, both with and without bronchiectasis, requiring IVIG were screened for their AAT levels and phenotype during their routine IgG nadir levels. High Resolution chest CT scans of patients were obtained and compared with AAT levels and phenotype. Patients without bronchiectasis were found to have higher levels of AAT (PM) than those with bronchiectasis (32.66 vs. 31.62, P0.02). Furthermore patients with improved/resolved bronchiectasis since initiating IVIG had higher levels of AAT (PM) than those with worsening bronchiectasis (33.21 vs. 31.36, P0.005). The prevalence of AAT mutation phenotypes was 1:11 vs. 1:17 reported in the general public. Higher levels of AAT (PM) correlate with CVID/Hypogam patients requiring IVIG who are without or improving bronchiectasis, than those that have lower levels and stable or worsening bronchiectasis. The prevalence of AAT mutations is higher in these patients then in the general public.

Alpha-1 antitrypsin Pi*Z gene frequency and Pi*ZZ genotype numbers worldwide: an update.

In alpha-1 antitrypsin deficiency (AATD), the Z allele is present in 98% of cases with severe disease, and knowledge of the frequency of this allele is essential from a public health perspective. However, there is a remarkable lack of epidemiological data on AATD worldwide, and many of the data currently used are outdated. Therefore, the objective of this study was to update the knowledge of the frequency of the Z allele to achieve accurate estimates of the prevalence and number of Pi*ZZ genotypes worldwide based on studies performed according to the following criteria: 1) samples representative of the general population, 2) AAT phenotyping characterized by adequate methods, and 3) measurements performed using a coefficient of variation calculated from the sample size and 95% confidence intervals. Studies fulfilling these criteria were used to develop maps with an inverse distance weighted (IDW)-interpolation method, providing numerical and graphical information of Pi*Z distribution worldwide. A total of 224 cohorts from 65 countries were included in the study. With the data provided by these cohorts, a total of 253,404 Pi*ZZ were estimated worldwide: 119,594 in Europe, 91,490 in America and Caribbean, 3,824 in Africa, 32,154 in Asia, 4,126 in Australia, and 2,216 in New Zealand. In addition, the IDW-interpolation maps predicted Pi*Z frequencies throughout the world even in some areas that lack real data. In conclusion, the inclusion of new well-designed studies and the exclusion of the low-quality ones have significantly improved the reliability of results, which may be useful to plan strategies for future research and diagnosis and to rationalize the therapeutic resources available.

AAT Phenotype Identification by Isoelectric Focusing.

Isoelectric focusing (IEF) electrophoresis is considered to be the gold standard test for determining an individual's AAT phenotype. IEF electrophoresis is a technique used to separate proteins by differences in their isoelectric point (pI). Testing is performed on serum that is applied to an agarose gel containing ampholytes which create a pH gradient ranging from 4.2 to 4.9. Variants of AAT are therefore separated from each other and, after visualization of the focused protein bands using immunochemical techniques, can be identified and an AAT phenotype determined.In this chapter we elaborate on IEF electrophoresis as it relates to AAT phenotyping, describe practical approaches to AAT variant identification, and discuss circumstances in which phenotype testing may be inaccurate.

Is severe progressive liver disease caused by alpha-1-antitrypsin deficiency more common in children or adults?

The classical form of alpha-1-antitrypsin deficiency (A1ATD) is known to cause liver disease in children and adults, but there is relatively little information about the risk of severe, progressive liver disease and the need for liver transplantation. To better understand how newly evolving pharmacological, genetic, and cellular therapies may be targeted according to risk for progressive liver disease, we sought to determine the age distribution of A1ATD as a cause of severe liver disease, as defined by the need for liver transplantation. Using 3 US liver transplantation databases for the period 1991-2012, we found 77.2% of 1677 liver transplants with a reported diagnosis of A1ATD were adults. The peak age range was 50-64 years. Using 2 of the databases which included specific A1AT phenotypes, we found that many of these adults who undergo liver transplantation with A1ATD as the diagnosis are heterozygotes and have other potential causes of liver disease, most notably obesity and ethanol abuse. However, even when these cases are excluded and only ZZ and SZ phenotypes are considered, severe liver disease requiring transplantation is more than 2.5 times as likely in adults. The analysis also showed a markedly increased risk for males. In the pediatric group, almost all of the transplants are done in children less than 5 years of age. In conclusion, A1ATD causes progressive liver disease most commonly in adults with males in the highest risk category. In the pediatric group, children less than 5 years of age are highest in risk. These results suggest that A1ATD most commonly causes liver disease by mechanisms similar to age-dependent degenerative diseases and more rarely in children by powerful modifiers. Liver Transplantation 22 886-894 2016 AASLD.

Neutrophilic panniculitis associated with alpha-1-antitrypsin deficiency: an update.

Neutrophilic panniculitis associated with alpha-1-antitrypsin deficiency (AATD) is a very rare disease. Its estimated prevalence is 1 in 1000 subjects with severe AATD (usually white individuals with a Pi*ZZ genotype). It is manifested clinically by painful recurrent ulcerating subcutaneous nodules, and characterized histologically by dense infiltrates of neutrophils in the deep dermis and connective-tissue septae, with secondary lobular panniculitis. It may be the only clinical manifestation of AATD, although it can also occur together with the classical pulmonary or hepatic manifestations of the disease. AATD-associated panniculitis is not only very rare but may also be significantly underdiagnosed. The physician managing a case of panniculitis with a clinical presentation suggestive of AATD and a compatible skin biopsy should measure serum AAT concentration and, if low, determine the AAT phenotype by isoelectric focusing. If uncertainty remains, the SERPINA1 gene should be sequenced to identify the genotype. If AATD is diagnosed, AATD testing of first-degree family members should be performed in order to take appropriate preventive and therapeutic measures, including genetic counselling, education on inheritance, risk arising from tobacco smoke, occupational exposure to pollutants and hepatotoxic substances, and the provision of information on clinical management. Cases of panniculitis in which conventional therapy with dapsone has failed may be managed with intravenous augmentative therapy using human AAT. The current manuscript addresses the fundamental concepts of the pathogenesis of AATD-associated panniculitis and describes the clinical presentation and management of cases in order to reduce underdiagnosis and improve outcomes.

The Diagnostic Value of Alpha-1-Antitrypsin Phenotype in Patients with Granulomatosis with Polyangiitis.

The deficiency of alpha-1 protease inhibitor, or alpha-1-antitrypsin (A1AT), predisposes to chronic lung diseases and extrapulmonary pathology. Besides classical manifestations, such as pulmonary emphysema and liver disease, alpha-1-antitrypsin deficiency (A1ATD) is also known to be associated with granulomatosis with polyangiitis (GPA or Wegener's granulomatosis). The aim of our study was to evaluate the frequency of allelic isoforms of A1AT and their clinical significance among GPA patients. Detailed clinical information, including Birmingham Vasculitis Activity Score (BVAS), incidence of lung involvement, anti-proteinase 3 (PR3) antibodies concentrations, and other laboratory data were collected in 38 GPA patients. We also studied serum samples obtained from 46 healthy donors. In all collected samples A1AT phenotyping by isoelectrofocusing (IEF) and turbidimetric A1AT measurement were performed. Abnormal A1AT variants were found in 18.4% (7/38) of cases: 1 ZZ, 4 MZ, 2 MF, and only 1 MZ in control group (2%). The mean A1AT concentration in samples with atypical A1AT phenotypes was significantly lower (P = 0.0038) than in normal A1AT phenotype. We found that patients with abnormal A1AT phenotypes had significantly higher vasculitis activity (BVAS) as well as anti-PR3 antibodies concentration. We conclude that A1AT deficiency should be considered in all patients with GPA.

P121 Cost-Effectiveness of Alpha-1 Antitrypsin (A1AT) Deficiency Case-Finding in Secondary Care

BackgroundScreening for A1AT-deficiency at our institution involves serum protein assay, then phenotyping where A1AT≤1.1g/L. RT-PCR genotyping for S/Z variants is available for clarification. We recently established a multi-disciplinary respiratory/hepatology London...