The Association between Inefficient Repair of DNA Double-Strand Breaks and Common Polymorphisms of the HRR and NHEJ Repair Genes in Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation affecting up to 2.0% of adults around the world. The molecular background of RA has not yet been fully elucidated, but RA is classified as a disease in which the genetic background is one of the most significant risk factors. One hallmark of RA is impaired DNA repair observed in patient-derived peripheral blood mononuclear cells (PBMCs). The aim of this study was to correlate the phenotype defined as the efficiency of DNA double-strand break (DSB) repair with the genotype limited to a single-nucleotide polymorphism (SNP) of DSB repair genes. We also analyzed the expression level of key DSB repair genes. The study population contained 45 RA patients and 45 healthy controls. We used a comet assay to study DSB repair after in vitro exposure to bleomycin in PBMCs from patients with rheumatoid arthritis. TaqMan SNP Genotyping Assays were used to determine the distribution of SNPs and the Taq Man gene expression assay was used to assess the RNA expression of DSB repair-related genes. PBMCs from patients with RA had significantly lower bleomycin-induced DNA lesion repair efficiency and we identified more subjects with inefficient DNA repair in RA compared with the control (84.5% vs. 24.4%; OR 41.4, 95% CI, 4.8-355.01). Furthermore, SNPs located within the RAD50 gene (rs1801321 and rs1801320) increased the OR to 53.5 (95% CI, 4.7-613.21) while rs963917 and rs3784099 (RAD51B) to 73.4 (95% CI, 5.3-1011.05). These results were confirmed by decision tree (DT) analysis (accuracy 0.84; precision 0.87, and specificity 0.86). We also found elevated expression of RAD51B, BRCA1, and BRCA2 in PBMCs isolated from RA patients. The findings indicated that impaired DSB repair in RA may be related to genetic variations in DSB repair genes as well as their expression levels. However, the mechanism of this relation, and whether it is direct or indirect, needs to be elucidated.

COVID-19 in pediatric palliative care patients: Multicenter, retrospective cohort study

BACKGROUND

Studies have shown the risk factors for COVID-19 severity in children, including comorbidities, but information on the infection course in children with life-limiting conditions is sparse.

AIM

To describe the effect of COVID-19 on pediatric patients receiving palliative care due to life-limiting conditions.

DESIGN

We conducted retrospective cohort study. The WHO Clinical Progression Scale was used to measure COVID-19 severity.

SETTING/PARTICIPANTS

Seven of the 24 invited pediatric palliative care centers participated in this study. We analyzed the medical records of children under palliative care with confirmed COVID-19 (January 2020-April 2022).

RESULTS

Records of 60 patients with COVID-19 aged 0.24 to 21.6 years (mean (SD); 9.8 (6.6)) were collected. The largest group of patients with COVID-19 was children with congenital malformations and chromosomal abnormalities (42%); the most common manifestation was fever (85%). Bacterial coinfection was confirmed in 17 (28%) children. Fifteen (25%) children required hospitalization, including four admitted to the Intensive Care Unit. Mild COVID-19 was identified in 44 (73%) children, moderate in 11 (18%), severe in 3 (5%), and death in 2 (3%). Six of the 20 eligible children were vaccinated against SARS-CoV-2, followed by 16 mothers and fathers.

CONCLUSION

In the study population initial presentation of COVID-19 was predominantly a mild; however, the small sample size precluded definitive conclusions. For children under palliative care, we should identify if they have an advance care plan for COVID-19, such as desires for intensive care support. Further studies are needed to define the short and long-term effects of COVID-19 in children with life-limiting conditions.

The administration of methotrexate in patients with Still's disease, "real-life" findings from AIDA Network Still Disease Registry

OBJECTIVES

To describe clinical characteristics of patients with Still's disease treated with methotrexate (MTX) and to assess drug effectiveness evaluating change in disease activity, reduction of inflammatory markers, and glucocorticoid (GC)-sparing effect.

METHODS

Patients with Still's disease treated with MTX were assessed among those included in AIDA Network Still Disease Registry.

RESULTS

In this registry, 171 patients with Still's disease were treated with MTX (males 43.3%, age 37.1 ± 16.0 years). They were mainly characterised by joint features and fever without a prominent multiorgan involvement. MTX was administered with GCs in 68.4% of patients, with other conventional synthetic DMARDs in 6.4%, and with biologic DMARDs in 25.1%. A significant reduction of the modified systemic score was observed, and 38.6% patients were codified as being in clinical remission at the end of follow-up. The concomitant administration of a biologic DMARD resulted a predictor of the clinical remission. Furthermore, a reduction of inflammatory markers and ferritin levels was observed following the administration of MTX. Additionally, a marked reduction of the dosage of concomitant GCs was identified, while 36.7% discontinued such drugs. Male gender appeared as a predictor of GC discontinuation. MTX was discontinued in 12.3% of patients because of adverse effects, and in 12.3% for lack of efficacy.

CONCLUSIONS

Clinical characteristics of patients with Still's disease treated with MTX were described, mainly joint features and fever without a prominent multiorgan involvement. The clinical usefulness of MTX was reported in reducing the disease activity, decreasing the inflammatory markers, and as GC-sparing agent.

Polymorphisms in DNA Repair Genes and Association with Rheumatoid Arthritis in a Pilot Study on a Central European Population

Rheumatoid arthritis (RA) is a chronic, multifactorial autoimmune disease characterized by chronic arthritis, a tendency to develop joint deformities, and involvement of extra-articular tissues. The risk of malignant neoplasms among patients with RA is the subject of ongoing research due to the autoimmune pathogenesis that underlies RA, the common etiology of rheumatic disease and malignancies, and the use of immunomodulatory therapy, which can alter immune system function and thus increase the risk of malignant neoplasms. This risk can also be increased by impaired DNA repair efficiency in individuals with RA, as reported in our recent study. Impaired DNA repair may reflect the variability in the genes that encode DNA repair proteins. The aim of our study was to evaluate the genetic variation in RA within the genes of the DNA damage repair system through base excision repair (BER), nucleotide excision repair (NER), and the double strand break repair system by homologous recombination (HR) and non-homologous end joining (NHEJ). We genotyped a total of 28 polymorphisms in 19 genes encoding DNA repair-related proteins in 100 age- and sex-matched RA patients and healthy subjects from Central Europe (Poland). Polymorphism genotypes were determined using the Taq-man SNP Genotyping Assay. We found an association between the RA occurrence and rs25487/XRCC1, rs7180135/RAD51, rs1801321/RAD51, rs963917/RAD51B, rs963918/RAD51B, rs2735383/NBS1, rs132774/XRCC6, rs207906/XRCC5, and rs861539/XRCC3 polymorphisms. Our results suggest that polymorphisms of DNA damage repair genes may play a role in RA pathogenesis and may be considered as potential markers of RA.

Circulating cell free DNA response to exhaustive exercise in average trained men with type I diabetes mellitus

It is believed that neutrophils extracellular traps (NETs) formation is responsible for the increase in cf DNA after exercise. Since T1DM is accompanied by enhanced NETs generation, we compared exercise-induced increase in cf DNA in 14 men with T1DM and 11 healthy controls and analyzed its association with exercise load. Subjects performed a treadmill run to exhaustion at speed corresponding to 70% of their personal VO2max. Blood was collected before and just after exercise for determination of plasma cf nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, blood cell count and metabolic markers. Exercise resulted in the increase in median cf n-DNA from 3.9 ng/mL to 21.0 ng/mL in T1DM group and from 3.3 ng/mL to 28.9 ng/mL in controls. Median exercise-induced increment (∆) in cf n-DNA did not differ significantly in both groups (17.8 ng/mL vs. 22.1 ng/mL, p = 0.23), but this variable correlated with run distance (r = 0.66), Δ neutrophils (r = 0.86), Δ creatinine (r = 0.65) and Δ creatine kinase (r = 0.77) only in controls. Pre- and post-exercise cf mt-DNA were not significantly different within and between groups. These suggest low usefulness of Δ cf n-DNA as a marker of exercise intensity in T1DM men.