HLA-B27 detection - comparison of genetic sequence-based method and flow cytometry assay

Human leucocyte antigen-B27 testing in clinical practice: a global perspective

PURPOSE OF REVIEW

The association between human leucocyte antigen (HLA)-B27 and spondyloarthritis (SpA) was described half a century ago. New insights about pathophysiologic pathways and their role in bone formation were reported in recent years and will be discussed in this review.

RECENT FINDINGS

There is a considerable variation in the association between HLA-B27 and SpA across the globe, with the strongest association reported in populations of Northern European and Asian descent and the lowest in the Middle East and Africa. Other genes are also involved in disease susceptibility, highlighting the importance of newly proposed weighted genetic scores to support the diagnosis. On the global level, the interaction between genetic background and gut dysbiosis seems critical for disease predisposition. As for the individual patient, the presence of HLA-B27 can have a significant influence on SpA diagnosis and disease phenotype. More importantly, new studies suggested a role for HLA-B27 in radiographic damage in the sacroiliac joints and the progression of bone formation in the spine.

SUMMARY

Findings in recent years have enhanced our understanding of the role of HLA-B27 in the pathophysiology and in disease-related bone formation in SpA, which may pave the way for new therapeutic targets.

High-Throughput and Automated Detection of HLA-B*27 Using the LabTurboTM AIO System

The adoption of an automated system can decrease the hands-on time requirements in a clinical laboratory setting. For the detection of HLA-B*27, implementing a high-throughput and fully automated system has several advantages over using manual methods. Therefore, this study aimed to evaluate automation efficiency for the detection of HLA-B*27. Peripheral blood samples were obtained from 50 participants, and DNA was isolated from these samples. A Pharmigene PG27 detection kit was used for the qualitative detection of HLA-B*27. The performances of the semi-automated and fully automated LabTurbo^TM AIO systems in the detection of HLA-B*27 were compared. The mean absorbance (optical density) values for the Maelstrom^TM 8 and LabTurbo^TM AIO systems were found to be 1.88 and 1.9, respectively. The housekeeping gene was amplified and quantified using a real-time PCR assay across all DNA extracts to check the quality of the extracted human DNA. The results were expressed as the cycle threshold (Ct) values for all DNA extracts from both platforms. The mean Ct values for the Roche Cobas z480 and LabTurbo^TM AIO systems were found to be 22.7 and 20.4, respectively. This study demonstrated that the semi-automated method and the LabTurbo^TM AIO system yield consistent results for the detection of HLA-B*27. However, compared to the semi-automated method, the LabTurbo^TM AIO system provides standardized procedures, avoids manual handling, and improves turnaround time.

The potential implication of MDR1 and NAC1 genetic polymorphisms on resistance to antiepileptic drugs among a Jordanian epileptic population: a cross-sectional study

BACKGROUND

Resistance to antiepileptic drugs (AEDs) remains one of the main challenges to neurologists. Polymorphisms of drug efflux transporters such as multidrug resistance (MDR1) gene and target sites such as the nucleus accumbens-associated 1 (NAC1) gene have been suggested to influence the responsiveness to treatment.

AIM

Evaluation of the association of MDR1 and NAC1 polymorphisms with AEDs resistance among Jordanian epileptic patients.

SUBJECTS AND METHODS

86 Jordanian epileptics were included in the study. DNA was extracted and genotyping was conducted by polymerase chain reaction followed by sequencing. Nine single nucleotide polymorphisms (SNPs) on the MDR1 gene and six SNPs on the NAC1 gene were investigated.

RESULTS

MDR1 and NAC1 polymorphisms don't seem to influence the resistance to AEDs at the genotype or allele level. However, a strong association was found between MDR1 rs2032588 (OR = 5; 95%CI = [1.3-18.8], p = 0.01) and AEDs resistance among males at the allele level. Also, data revealed an association between MDR1 rs1128503 and AEDs resistance among females at the allele level.

CONCLUSION

The data suggest that MDR1 and NAC1 polymorphisms do not influence the AEDs resistance among Jordanian epileptics. However, there is a gender-dependent association between MDR1 polymorphisms and resistance to AEDs at two SNPs (rs2032588 and rs1128503).

Association between ABCB1 polymorphisms and response to antiepileptic drugs among Jordanian epileptic patients

BACKGROUND

Genetic polymorphisms of drug efflux transporters as ATP-binding cassette subfamily B, member 1 (ABCB1) have been suggested to modulate antiepileptic drugs (AEDs) response. We aimed to explore the association of ABCB1 polymorphisms and AEDs resistance among epileptic patients.

METHODS

A total of 86 Jordanian epileptic patients treated with AEDs was included in the study. DNA was extracted from blood samples and genotyping and haplotypes analyses were conducted for Nine single nucleotide polymorphisms (SNPs) on the ABCB1 gene.

RESULTS

Data revealed that none of the examined SNPs were associated with resistance to AEDs neither on the level of alleles nor genotypes. However, strong association was found between rs2235048 (OR = 10.6; 95%CI = [1.89-59.8], p= 0.01), rs1045642 (OR = 14; 95%CI = [1.3-156.7], p= 0.02), rs2032582 (OR = 9.1; 95%CI = [1.4-57.3], p= 0.04) and rs1128503 (OR = 18.7; 95%CI = [1.6-222.9], p= 0.02), ABCB1 polymorphisms and resistance to AEDs among females but not males. Haplotype analysis revealed statistically significant associations. The strongest significant associations were for haplotypes containing 2677G_1236 T in two-SNPshaplotypes (OR = 4.2; 95%CI = [1.2-14.9], p = 0.024); three-SNPs-haplotypes (OR = 4.2; 95% CI = [1.2-14.9], p = 0.02); four-SNPs-haplotypes (OR = 4.1; 95%CI = [1.2-14.3], p = 0.026).

CONCLUSION

Data suggests that there is a gender dependent association between ABCB1 genetic polymorphisms and response to AEDs. Additionally, ABCB1 haplotypes influence the response to AEDs. Further investigation is needed to confirm the results of this study.

Cervus and cucumis peptides combined umbilical cord mesenchymal stem cells therapy for rheumatoid arthritis

Cervus and cucumis peptides (Lugua polypeptides, LG) are traditional Chinese medicine, which are active components of polypeptide extracted from Sika deer bone and melon seed, and they contain bone induced polypeptide biological factors. Umbilical cord mesenchymal stem cell, (UC-MSC) have tissue repair multiple effects, anti-inflammatory, and immune regulation function, which become a very promising start in rheumatoid arthritis (RA) treatment. Hence, LG combined UC-MSC can significantly enhance the UC-MSC treatment of rheumatoid arthritis (RA).To explore the clinical curative effect and therapeutic mechanism of LG combined UC-MSC for treating RA.119 patients were divided into control and treatment groups, and both groups were treated with methotrexate tablets, leflunomide, and UC-MSC. But, LG were added to the treatment group. In vitro, the effects of LG on UC-MSC cell secretion of anti-inflammatory factors were also performed.The Health Assessment Questionnaire; the 28 joint disease activity score; C reactive protein; the erythrocyte sedimentation rate; rheumatoid factor; and anti-cyclic citrullinated peptide antibody were significantly reduced in treatment group 1 year after treatment (P < .05). In vitro, compared with the control group, the number of hepatocyte growth factor (HGF), the secretion of prostaglandin E2 (PGE2) and tumor necrosis factor-inducible gene 6 protein (TSG6) increased significantly (P < .05).LG combined UC-MSCs can significantly improve the curative effect of RA patients, while LG may reduce inflammatory cytokines, regulate immunity, improve microcirculation, and are conducive to UC-MSCs migration and the repair of damaged tissue.

What Does Human Leukocyte Antigen B27 Have to Do with Spondyloarthritis?

Human leukocyte antigen (HLA) B27 is the key laboratory parameter for axial spondyloarthritis (axSpA). Its prevalence is variable across different geographic zones and ethnicities, and often mirrors the prevalence of axSpA. HLA-B27 plays a role in axSpA physiopathology. It is correlated with spondyloarthritis phenotype with a consistent positive association with family history, early disease onset, shorter diagnostic delay, hip involvement, and acute anterior uveitis. HLA-B27 has a pivotal role in many referral strategies. However, these strategies were developed in European populations and need to be evaluated in populations with lower HLA-B27 background prevalence, and where additional parameters might be needed.

Advances in nanomedicine for the treatment of ankylosing spondylitis

Ankylosing spondylitis (AS) is a complex disease characterized by inflammation and ankylosis primarily at the cartilage–bone interface. The disease is more common in young males and risk factors include both genetic and environmental. While the pathogenesis of AS is not completely understood, it is thought to be an immune-mediated disease involving inflammatory cellular infiltrates, and human leukocyte antigen-B27. Currently, there is no specific diagnostic technique available for this disease; therefore conventional diagnostic approaches such as clinical symptoms, laboratory tests and imaging techniques are used. There are various review papers that have been published on conventional treatment approaches, and in this review work, we focus on the more promising nanomedicine-based treatment modalities to move this field forward.

Optimization of an in-house PCR method for the detection of HLA-B*27 alleles

The association of spondyloarthropathies with different alleles of human leukocyte antigen (HLA) B*27 is well established. Different subtypes of HLA-B*27 may be linked with different ethnic groups, distinct clinical manifestations, specific age of onset and different prognoses. Polymerase chain reaction with sequence specific primers (PCR-SSP) is the most frequently adapted molecular method used for the recognition of HLA-B*27-specific DNA sequences. The aim of the present study was to standarise an in-house protocol of PCR-SSP for HLA-B*27 allele detection for use in the Armed Forces Institute of Pathology (AFIP), Pakistan, with consideration of its cost effectiveness. A total of 49 individual samples were included, comprising 10 transplant samples determined to be HLA-B*27-negative by PCR-SSP and 39 HLA-B*27-positive samples determined by flow cytometry, obtained from patients who were symptomatic and referred for HLA-B*27 testing. By altering each variable individually, an in-house PCR-SSP protocol was optimized to amplify common HLA-B*27 alleles (2701-2721, 2723-2730). To discriminate B*27 from all other HLA-B alleles, a low-resolution HLA-B typing set with a 96 PCR-SSP primer mixture was used in conjunction. Among the 39 HLA-B*27-positive specimens, 31 (79%) were detected as positive by PCR-SSP, with the remaining samples failing due to a sub-optimized protocol and/or low DNA concentration. Additionally, there was complete concordance between flow cytometry and in-house PCR, and the sensitivity and specificity of the PCR-SSP were determined to be 100%. In conclusion, in-house SSP-PCR is, standard method for the detection of HLA-B*27 alleles. The determination of associations between specific HLA-B*27 alleles and AS may aid to identify individuals at higher risk of developing the disease. Furthermore, the identification of individuals at risk may aid to adapt preventive strategies.