Utility of the Serum Protein Electrophoresis in the Opportunistic Screening for the Deficiency of Alpha-1 Antitrypsin

BACKGROUND

A deficiency in alpha-1 antitrypsin (AAT1) is a rare disorder that represents a significant health threat and early diagnostic priority issue. We investigated the usefulness of the serum protein electrophoresis (SPE) as an opportunistic screening tool for AAT1 deficiency.

METHODS

For 6 months, all SPE carried out for any reasons were evaluated in our center. In those with less than 3% of alpha-1 globulins, AAT1 concentrations were studied. The SERPINA1 gene was subsequently sequenced in those patients displaying concentrations below 100 mg/dL.

RESULTS

Out of the total, 14 patients (0.3%) were identified with low AAT1 concentrations, with 11 of them agreeing to enter the study. Of those, mutations in the SERPINA1 gene were discovered in 10 patients (91%). Heterozygous mutations were detected in seven patients; three had the c.1096G>A mutation (p.Glu366Lys; Pi*Z), two had the c.863A>T mutation (p.Glu288Val; Pi*S), one had the c.221_223delTCT mutation (p.Phe76del; Pi*Malton), and the last one had the c.1066G>A (p.Ala356Thr) mutation, which was not previously described. Finally, one patient had the c.863A>T mutation in homozygosis, whereas two double heterozygous patients c.863A>T/c.1096G>A were detected.

CONCLUSIONS

An altered result in the concentration of AAT1 anticipates a mutation in the SERPINA1 gene in a manner close to 91%. The relationship between a decrease in the alpha-1 globulin band of the SPE and an alteration in the AAT1 concentration is direct in basal states of health. The SPE is presented as a highly sensitive test for opportunistic screening of AAT1 deficiency.

Optimizing the screening of alpha-1 antitrypsin deficiency using serum protein electrophoresis

OBJECTIVES

Alpha-1 antitrypsin (A1AT) deficiency was first identified in patients with emphysema by the absence of the α₁ band on serum protein electrophoresis (SPE). Today, capillary zone electrophoresis is widely performed in laboratories. Here, we compared two SPE systems to detect decreased A1AT concentrations to optimize their use as a screening tool for A1AT deficiency.

METHODS

Serum protein electrophoresis was performed on 200 samples on the Capillarys 2 and the V8 Nexus. The latter presents two α₁ bands (α₁ band 1 and 2) while the Capillarys 2 has only one (Capillarys 2 total α₁). The measures of A1AT and α₁ acid glycoprotein (AAG) were performed as well as the phenotyping of M, S and Z alleles.

RESULTS

At a A1AT cutoff of 0.80 g/L, a cutoff of 1.21 g/L using the V8 Nexus α₁ band 2 corresponded to a 100% sensitivity and a 92.4% specificity while a 1.69% cutoff corresponded to a 100% sensitivity and a 92.4% specificity. The performance of the α₁ band 1 was suboptimal and rather corresponded to AAG. On the Capillarys 2, a cutoff of 2.0 g/L corresponded to a 75.0% sensitivity and a 86.6% specificity, while a 3.2% cutoff showed a 96.4% sensitivity and a 67.4% specificity. The V8 Nexus α₁ band 2 was the method the most correlated with A1AT (r=0.90-0.94).

CONCLUSIONS

The V8 Nexus α₁ band 2 was the best predictor of A1AT deficiency, probably owing to a better resolution. The use of SPE was however unable to predict each phenotype. Phenotype or genotype studies are therefore still advisable in case of A1AT deficiency.

An Italian expert consensus on the management of alpha1-antitrypsin deficiency: a comprehensive set of algorithms

BACKGROUND

Alpha1-antitrypin deficiency (AATD) is a genetic-based risk condition, mainly affecting the lungs and liver. Despite its wide distribution, it is largely underdiagnosed, thus being considered a rare disease, and is consequently managed in ad hoc reference centers. Unfortunately, an easy-to-use algorithm for managing such a complex disease is still lacking.

METHODS

An expert consensus meeting was conducted among experts in the management of AATD to build a comprehensive algorithm, including diagnosis, monitoring, AAT therapy, rehabilitation and lung transplantation, and liver disease, that could serve as a guide for physicians and treating centers. A panel of AATD specialists evaluated the results of their work.

RESULTS

Diagnosis is the most delicate phase, and awareness about this condition should be raised among GPs. A set of recommendations has been written about the most suitable follow-up visits. Augmentation therapy with AAT may be useful to reduce the progression of emphysema and lung function decline in selected patients. Exercise capacity may be improved by pulmonary rehabilitation and, in selected cases, by lung volume reduction or lung transplantation. Support therapies are needed for those who develop liver disease, and, in selected cases, liver transplantation may be considered. Patients should be carefully educated about their lifestyle, including smoking cessation, body weight control, and reduced alcohol intake.

CONCLUSIONS

The proposed algorithm obtained the endorsement of the Italian Society of Pneumology (SIP). However, further studies and additional clinical data are required to confirm the validity of these recommendations.

Evaluation of a Capillary Electrophoresis System for the Separation of Proteins

BACKGROUND

Serum protein electrophoresis is one of the core investigations for screening for monoclonal proteins. Among the available capillary systems, the Helena V8 system has been evaluated in a limited number of studies.

METHODS

In total, 310 sera samples were assessed on the Helena V8 system and compared with the Sebia Capillarys instrument. Abnormalities suggestive of monoclonal proteins were confirmed by immunofixation. Imprecision studies and reference intervals were determined.

RESULTS

The imprecision of the Helena V8 was inferior or equal to 5.8%. The mean bias of Helena V8 vs Sebia Capillarys was about -0.9 g/L for albumin; -0.2 g/L foralpha-1; 1.1 g/L for alpha-2; -0.2 g/L for beta; 0.3 g/L for gamma; -0.5 g/L for monoclonal protein in beta; and 0.3 g/L for monoclonal protein in gamma. Among the 56 samples with monoclonal proteins confirmed by immunofixation, all were seen on both methods, with only 1 discordant result at a cutoff of 5.0 g/L. Reference intervals were statistically different between the 2 analyzers, except for the beta fraction.

CONCLUSIONS

Our evaluation confirms the good analytical performance of the Helena V8 analyzer as a suitable alternative to the Sebia Capillarys instrument.

Obstacles to Early Diagnosis and Treatment of Alpha-1 Antitrypsin Deficiency: Current Perspectives

This review summarizes the current research and outlooks regarding the obstacles to diagnosing and treating early alpha-1-antitrypsin deficiency (AATD). It draws on prior systematic reviews and expert surveys to discover precisely what difficulties exist in early diagnosis and treatment of AATD and elucidate potential solutions to ease these difficulties. The perceived rarity of AATD may translate to a condition poorly understood by primary care physicians, and even many respiratory physicians, which results in opportunities for diagnosis being missed, especially in mild or asymptomatic patients. There are diagnostic techniques involving biomarkers and home testing methods which could improve the rate of early diagnosis. With respect to treatment, AATD involves treating two separate pathologies, lung disease and liver disease. The only specific AATD treatment, augmentation therapy, has proven ability in treating lung disease but not liver disease. Alpha-1-antitrypsin (AAT) synthesized in the liver can form damaging polymers that also result in reduced circulating AAT levels and, whilst liver transplantation is used to effectively treat AATD, it is inappropriate in early disease. Novel therapeutic areas such as gene editing and increasing autophagy are therefore being researched as future treatments. Ultimately, diagnosis and treatment are intrinsically linked in AATD, with earlier diagnosis leading to better treatment options and thus better patient outcomes.