High-resolution melting analysis to screen the ST18 gene functional risk variant for pemphigus vulgaris: The occasion to open a debate on its usefulness in clinical setting

Assessing ST18 gene polymorphisms (rs17315309, rs2304365) in Iraqi patients with Pemphigus vulgaris

Pemphigus vulgaris (PV) is a potentially fatal autoimmune disease characterized by blistering of the skin, mucous membranes, and oral cavity. Genetics are implicated in its etiology, with the ST18 gene identified as a potential risk factor for pemphigus in certain populations, suggesting its role as a novel molecular target for therapeutic intervention. This study aimed to detect single nucleotide polymorphisms (SNPs) rs17315309 A/G and rs2304365 C/G in the ST18 gene among Iraqi/Arabic patients with PV. A total of 90 Iraqi subjects participated in this study, including 45 patients diagnosed with PV and 45 healthy controls. SNP analysis was performed using High-Resolution Melt Analysis (HRMA) with Eva Green I Dye. For SNP rs17315309 A/G, the distribution of heterozygous genotypes showed highly significant differences between the patient and healthy groups (P = 0.005), with the mutant G-allele being significantly more prevalent in patients than in the healthy group (P = 0.001). In contrast, for SNP rs2304365 C/G, the distribution of heterozygous and mutant genotypes did not differ significantly between patients and healthy individuals (P = 0.8 and P = 0.3, respectively), with the mutant G-allele also showing no significant difference (P = 0.4). Our data indicate a significant association between PV and the rs17315309 A/G SNP in the ST18 gene among the Iraqi population of Arabic origin. However, no association was found between patients with PV and the rs2304365 C/G SNP in the same gene.

Autoimmune Pemphigus: Latest Advances and Emerging Therapies

Pemphigus represents a group of rare and severe autoimmune intra-epidermal blistering diseases affecting the skin and mucous membranes. These painful and debilitating diseases are driven by the production of autoantibodies that are mainly directed against the desmosomal adhesion proteins, desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1). The search to define underlying triggers for anti-Dsg-antibody production has revealed genetic, environmental, and possible vaccine-driven factors, but our knowledge of the processes underlying disease initiation and pathology remains incomplete. Recent studies point to an important role of T cells in supporting auto-antibody production; yet the involvement of the myeloid compartment remains unexplored. Clinical management of pemphigus is beginning to move away from broad-spectrum immunosuppression and towards B-cell-targeted therapies, which reduce many patients’ symptoms but can have significant side effects. Here, we review the latest developments in our understanding of the predisposing factors/conditions of pemphigus, the underlying pathogenic mechanisms, and new and emerging therapies to treat these devastating diseases.

Duplex high resolution melting analysis (dHRMA) to detect two hot spot CYP24A1 pathogenic variants (PVs) associated to idiopathic infantile hypercalcemia (IIH)

Pathogenic variants (PVs) in CYP24A1 gene are associated with Idiopathic Infantile Hypercalcemia disease (IIH). The identification of CYP24A1 PVs can be a useful tool for the improvement of target therapeutic strategies. Aim of this study is to set up a rapid and inexpensive High Resolution Melting Analysis (HRMA)-based method for the simultaneous genotyping of two hot spot PVs in CYP24A1 gene, involved in IIH. A duplex-HRMA (dHRMA) was designed in order to detect simultaneously CYP24A1 c.428_430delAAG, p.(Glu143del) (rs777676129) and c.1186C > T, p.(Arg396Trp) (rs114368325), in peculiar cases addressed to our Laboratory. dHRMA was able to identify clearly and simultaneously both hot spot CYP24A1 PVs evaluating melting curve shape and melting temperature (T_m). This is the first dHRMA approach to rapidly screen the two most frequent CYP24A1 PVs in peculiar case, providing useful information for diagnosis and patient management in IIH disease.

Pemphigus vulgaris in two pairs of siblings from two unrelated Italian families: Human leukocyte antigen genotypes, ST18 mutation and immunological profile

Pemphigus vulgaris (PV) is an autoimmune intraepithelial bullous disease. Associations with the class II human leukocyte antigen (HLA) alleles and pemphigus vulgaris have been described. Furthermore, an association between the single nucleotide polymorphism of the ST18 gene and pemphigus vulgaris has been reported. We report two pairs of siblings from two unrelated Italian families affected by pemphigus vulgaris, characterizing their genetic and immunological profile. In order to assess the genetic background, HLA-DQA1, HLA-DQB1, HLA-DRB1 and a relevant ST18 polymorphism were investigated. As for the immunological profiles, anti-desmoglein antibodies were analyzed. In family A, the two pemphigus vulgaris patients had the same HLA genetic profile: HLA-DQA1 *01:04/*03:01, HLA-DQB1 *03:02/*05:03 and HLA-DRB1 *04:02/*14:01. The male patient was heterozygous for the ST18 mutation while the female patient had a wild genotype. In family B, the two pemphigus vulgaris patients were both wild type for the ST18 mutation and showed the same HLA genotype: HLA-DQA1 *03:01/*05:08, HLA-DQB1 *03:01/*03:03 and HLA-DRB1 *04:02/*11:01. Our data show a relevant relationship between the HLA profile and pemphigus vulgaris in our Italian families. In family A, all six alleles are frequently associated with pemphigus vulgaris and were expressed only in the two pemphigus patients; and in family B, two of the six alleles are frequently associated with pemphigus vulgaris. No relevant relationship was found between ST18 polymorphism and pemphigus disease.

High resolution melting profiles (HRMPs) obtained by magnetic induction cycler (MIC) have been used to monitor the BRCA2 status highlighted by next generation tumor sequencing (NGTS): a combined approach in a diagnostic environment

Resistance can be the result of secondary tissue variants (STVs), which restore the open reading frame of the germline BRCA allele, producing functional BRCA protein in germline BRCA1/2 (BRCA) pathogenic variant (PV) carriers, treated with platinum-based chemotherapy or poly-(ADP-ribose) polymerase inhibitors (PARP-1). We reported recently a BRCA2 mutant high grade serous ovarian cancer (HGSOC) patient with acquired resistance to the PARP-1 olaparib due to a STV detected by next generation tumor sequencing (NGTS). The aim of this study was to evaluate the versatility of the high-resolution melting analysis (HRMA) obtained by magnetic induction cycler (MIC) to monitor the BRCA2 status in formalin-fixed paraffin-embedded (FFPE) tissue samples of this patient and to compare the results obtained by NGTS. HRMA highlighted the BRCA2 STV previously detected in the IIIrd HGSOC recurrence following the tissue BRCA2 tissue status comparing the high resolution melting profiles (HRMPs). HRMPs differentiate not only BRCA2 alleles, but also their different allele abundance. We underline that (1) the MIC uses a latest generation technology guaranteeing temperature uniformity and maintenance in each well allowing high and accurate performance to obtain reported results and (2) the HRMA maintains a high sensitivity and specificity when it is performed on FFPE samples. Finally, this study represents an additional use of the HRMA, confirming its extreme versatility in the diagnostic environment.