Clinical efficacy of TNF-α inhibitors: an update

Effect of NLRP3 inflammasome genes polymorphism on disease susceptibility and response to TNF-α inhibitors in Iraqi patients with rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a genetically predisposed, systemic, chronic, inflammatory disease. Immune system dysregulation and inherited susceptibility polymorphisms suggest that this type of variation is functional and may help predict disease susceptibility and develop new therapeutic strategies. Anti-TNF-alpha (TNF-α) drugs are highly effective RA treatments, but not all patients respond the same way. It's important to figure out whether RA risk alleles can identify and predict anti-TNF-α-responsiveness in RA patients.

Aims of the study

Examine the function of the NLR family pyrin domain containing 3 (NLRP3) and caspase recruitment domain family member 8 (CARD8) genes polymorphisms and their morbid genotypes and alleles in RA patients and apparently healthy controls. In addition, their role in disease susceptibility, severity, and response to anti-TNF-α therapy. Also, examine how single nucleotide polymorphisms (SNPs) affect serum levels of pro-inflammatory cytokines like TNF-α and interleukin (IL)-1β.

Materials and methods

100 RA patients (88 females, 12 males) and 100 apparently healthy people (86 females, 14 males) were examined. To measure serum TNF-α and IL-1β, Elabscience sandwich ELISA kits were used. Iraq Biotech, Turkey DNA extraction kit was used to extract genomic DNA from whole blood. CARD8 (rs2043211) and NLRP3 (rs4612666) were genotyped using Agilent, AriaMx, USA, through Tri-Plex SYBR Green-based real-time PCR allelic discrimination assays. Geneious software, version 2019.2.2, used to design primers from published sequences (GenBank accession no. GCA 009914755.1). Primer specificity was determined by NCBI's BLAST.

Results

Study found that there is association between cytokines serum level and 28-joints disease activity score (DAS-28). The level of TNF-α increases with the higher DAS-28 (r² = 0.45, P < 0.0001). Also, IL- 1β level increases with higher DAS-28 (r² = 0.51, P < 0.0001). There were no statistically significant variations between patients with RA and the control group in the distribution of CARD8 SNP rs2043211 and NLRP3 SNP rs4612666 genotypes (P = 0.17 and 0.08 respectively) as well their alleles (P = 0.059 and 0.879 respectively). CARD8 (rs2043211) TT genotype was more frequent in patients with higher DAS-28 (P < 0.0001) and higher TNF-α and IL-1β serum levels (P < 0.0001 for both). Also, NLRP3 (rs4612666) TT genotype was more frequent in patients with higher DAS-28 (P < 0.0001) and higher TNF-α and IL- 1β serum levels (P < 0.0001 for both). Interestingly, this study revealed that CARD8 (rs2043211) and NLRP3 (rs4612666) variant genotypes are associated with lower response to anti-TNF-α drugs.

Conclusions

Serum TNF-α and IL-1β correlate with DAS-28 and disease activity. Non-responders have elevated TNF-α and IL-1β. CARD8 rs2043211 and NLRP3 rs4612666 variant polymorphisms are associated with high serum TNF-α and IL-1β, active disease course, poor disease outcomes, and low response to anti-TNF-α therapy.

Serum Markers in Rheumatoid Arthritis: A Longitudinal Study of Patients Undergoing Infliximab Treatment

Objective. The aim of this study was to investigate the clinical effect and serum markers in a cohort of rheumatoid arthritis patients with moderate to high disease activity, participating in an open clinical phase IV study conducted in Norway between 2001 and 2003 receiving infliximab treatment. Method. A total of 39 patients were studied, with a mean age of 54 years and 12-year disease duration. The analyses were performed using serum from patients at four assessment time points: baseline and 3, 6, and 12 months after starting treatment with infliximab. A wide variety of clinical data was collected and disease activity of 28 joints and Simple Disease Activity Index were calculated. The joint erosion was determined by X-ray imaging and the Sharp/van der Heijde score was determined. Serum analysis included multiplex immunoassays for 12 cytokines, 5 matrix metalloproteases, and 2 VEGFs. Results. The majority of the RA patients in this study had initially moderate to high disease activity and the infliximab treatment reduced the disease activity significantly and also reduced any further joint destruction and improved disease status. Most of the serum levels of cytokines and metalloproteases remained unchanged during the course of the study, and we were unable to detect changes in TNF-α in serum. Serum levels of IL-6 and VEGF-A decreased significantly after initiation of infliximab treatment. Conclusion. The serum levels of IL-6 and VEGF-A may be promising disease markers as they vary with disease progression. The clinical significance of these findings is yet to be determined and has to be confirmed in future clinical trials before being applied in the clinics.

Lack of adverse effect of anti-tumor necrosis factor-α biologics in treatment of rheumatoid arthritis: 5 years follow-up

BACKGROUND

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder affecting synovial joints and many other organs. Most patients seen in clinical settings have a progressive chronic disease, with radiographic damage, frequent work disability, incremental functional declines and increased mortality rates. The introduction of the biological drugs in treatment of RA has played an important role in prevention of destructive effects of the disease but may have serious adverse effects due to their powerful inhibition of the immune system.

OBJECTIVES

To study the adverse effects (ADEs) of three different tumor necrosis factor α inhibitor (TNFi) drugs (infliximab, adalimumab and etanercept) in RA patients for 5 years in the south-west area of Saudi Arabia.

METHODS

Two groups of RA patients were included in this study: The first group included 112 patients, representing the biologics group. These patients received biological therapy plus disease modifying anti-rheumatic drugs (DMARDs): 56 patients received infliximab (IFX), 36 patients received adalimumab (ADL) and 20 patients received etanercept (ETN). The second group also included 112 patients, representing the control group: RA patients treated only with the traditional DMARDs. ADEs were classified into mild and severe.

RESULTS

The mild ADEs which had been recorded during 5 years of follow-up in patients receiving TNFi, were onycholysis (1.8%), positive tuberculin test (1.8%) and small vessel vasculitis (1.8%). Statistically, there were insignificant differences in the mild ADEs except for upper respiratory tract infection that was significantly higher in the control group. Severe ADEs included pneumonia (1.8%) and solid tumor (1.8%) and there were no significant differences between the biologics and control groups. Also there were no significant statistical differences for the ADEs, mild or severe, between the three biologics, infliximab, adalimumab and etanercept. Occurrence of ADEs did not correlate to methotrexate dose, steroid dose or rheumatoid factor positivity.

CONCLUSIONS

Our results indicate that the use of TNFi therapy appeared to be as safe as traditional DMARDs in treatment of rheumatoid arthritis patients and long-term follow-up with careful examination is essential to pick up any abnormal ADEs.