Thiol/Disulfide homeostasis in patients with rheumatoid arthritis

Urinary total superoxide dismutase activity is low in rheumatoid patients, and its low levels are associated with higher DAS28 scores

AIM

Rheumatoid factor and anti-citrullinated peptide antibodies are generally used to diagnose rheumatoid arthritis (RA). However, these antibodies are negative in 15-20 % of RA cases. This study aimed to investigate new biomarkers that can be used in diagnosing RA and evaluating disease activity.

METHODS

This study included 99 RA patients and 94 healthy volunteers. Modified Disease Activity Score28 (DAS28) erythrocyte sedimentation rate (ESR) was used for disease activity score. Thiol/disulfide molecules were measured using an automatic spectrophotometric method, and ischemia-modified albumin was measured using an albumin-cobalt binding test. A spectrophotometer calculated urinary and serum total superoxide dismutase (SOD) activities at 420 nm wavelength.

RESULTS

In the RA group, serum IMA level was higher (unstandardized beta [B]: 5.552, Odds Ratio [OR]: 250.1, CI 95 %: 1.29-48219.1, p: .040), and urinary total SOD activities were significantly lower (B: 2.640 OR: .071, CI 95 %: .027-.192, p < 0.0001) than in the control group. A cut-off value of 5.06 for urinary total SOD was found to have a sensitivity of 97.9 % and a specificity of 97 % in distinguishing RA patients from healthy controls (AUC [95 %Cl] = .986 [.967-1.000], p < 0.001). Urinary total SOD activity was significantly lower in the RA subgroup with high disease activity compared to the groups with moderate disease activity (B: .954, OR: 2.596, CI 95 %: 1.104-6.103, p: .029) and low disease activity (B: 1.251, OR: 3.494, CI 95 %: 1.143-10.678, p: .028).

CONCLUSION

This study showed that urinary total SOD activity has high sensitivity and specificity in distinguishing RA patients from healthy controls and that RA patients with higher DAS28 ESR activity scores have lower urinary total SOD activity.

Evaluation of thiol/disulfide homeostasis in rheumatoid arthritis and disease activity

BACKGROUND

It has been suggested that the deterioration in the antioxidant defense system due to thiols may cause the pro-oxidant/antioxidant imbalance seen in rheumatoid arthritis (RA). This study was conducted to evaluate thiol/disulfide (-SH/-SS) homeostasis in patients with RA compared to healthy controls, and to validate the limited number of studies examining the relationship between Disease Activity Score-28 (DAS28) and thiol parameters.

METHOD

A total of 100 individuals (mean age: 46.3 ± 12.03) consisting of 86 females and 14 males were included in the RA group, and a total of 100 individuals (mean age: 43.3 ± 10.96 years) consisting of 78 females and 22 males were included in the control group. DAS28 was used to assess RA disease activity. -SH/-SS homeostasis parameters were measured using the automated spectrophotometric method described by Erel and Neselioğlu.

RESULTS

While native thiol (-SH) (p:0.001), total thiol (-SH + -SS) (p < 0.0001) levels and -SH\(-SS + -SH) ratio (p: 0.018) were lower in the RA group compared to the healthy controls, disulfide (-SS) level (p: 0.005)), -SS\-SH (p: 0.001) and -SS\(-SS + -SH) (p: 0.002) ratios were found to be higher. In the control group and the group in remission (defined by DAS28 < 2.6), the median values of -SH (p:0.002) and -SS + -SH (p:0.0008) were found to be significantly higher, and the median value of -SS (p: 0.001) was found to be lower compared to the other DAS28 groups. While a negative correlation was found between DAS28 and -SH (r: -0.243, p: 0.007), a positive correlation was found between DAS28 and -SS (r: 0.316, p: 0.0003), -SS\-SH (r:0.229, p: 0.002) and -SS\(-SS + -SH) (r: 0.285, p: 0.0009).

CONCLUSIONS

The plasma thiol antioxidant pool was decreased in RA compared to healthy controls and those with active disease compared to those in remission.

Is there a relationship between dynamic thiol/disulfide homeostasis and osteoarthritis progression?

We aim to determine serum dynamic thiol/disulphide homeostasis with novel methods in early-stage osteoarthritis and late-stage osteoarthritis patients and investigated whether it was associated with the progression of osteoarthritis risk or not. One hundred eighteen patients were included in this prospective study. Osteoarthritis patients were divided into five stages, according to the Kellgren-Lawrence scale. Dynamic thiol/disulphide homeostasis was determined with a novel spectrophotometric method. Late-stage osteoarthritis patients had significantly lower levels of native and total thiol than the patients of early-stage osteoarthritis. Disulphide, index-1, index-2 levels, and WOMAC score of late-stage osteoarthritis patients were significantly higher than the ones belonging to patients of early-stage osteoarthritis. Decreased native thiol and total thiol levels and increased WOMAC score and disulphide levels were independently associated with increased risk of late-stage osteoarthritis. We suggest that both WOMAC score and dynamic thiol/disulphide homeostasis may be implicated in the pathogenesis and progression of osteoarthritis. We also recommend that dynamic thiol/disulphide homeostasis may have clinical utility as possible markers of differential diagnosis of early-stage and late-stage osteoarthritis.

Erythrocyte reduced/oxidized glutathione and serum thiol/disulfide homeostasis in patients with rheumatoid arthritis

BACKGROUND

Chronic inflammation and oxidative stress are the most known mechanisms in Rheumatoid Arthritis (RA) pathophysiology, which is still not fully elucidated. In this study, we evaluated oxidative status by determining intracellular reduced/oxidized glutathione (GSH/GSSG) homeostasis and serum thiol/disulfide (SH/SS) homeostasis in RA patients.

METHODS

A total of 152 RA patient and 89 healthy controls were included in the study. RA patients were subdivided according to disease activity score-28 (DAS-28) as active RA and remission RA. Intracellular GSH/GSSG and serum SH/SS homeostasis parameters were analyzed.

RESULTS

Median (1st-3rd quartile values) SS/SH and GSSG/GSH percent ratio levels were significantly higher in RA patients (6.94 (6.02-8.54) and 69.8 (44.05-85.29); respectively) compared to controls (4.62 (4.15-5.46) and 34.9 (22.43-62.2); respectively) (p < 0.05 for all). SS/SH and GSSG/GSH percent ratio levels were significantly higher in active RA patients when compared to remission RA patients and controls (p < 0.05 for all). SS/SH and GSSG/GSH percent ratios were significantly increased in remission RA group compared to controls (p < 0.05 for all). DAS28 scores were positively correlated with SS/SH and GSSG/GSH percent ratios (rho = 0.259 and 0.296; respectively).

CONCLUSIONS

These findings suggest that active intracellular and extracellular thiol group oxidation process might play a role in RA pathogenesis and further work in these areas may be warranted to show potential value of evaluating intracellular GSSG/GSH and serum SH/SS balances together in disease monitoring.

Thiol/disulphide homeostasis in intensive care unit patients with sepsis and septic shock

Background/aim

Sepsis is a condition caused by infection followed by unregulated inflammatory response which may lead to organ dysfunction. The aim of this study is to be the first in the literature and it has been designed to show the thiol/disulphide changes in patients with sepsis and septic shock and their correlation with acute phase reactants.

Material and methods

A total of 113 patients (septic shock 53 and sepsis 60) and 60 healthy control subjects have been enrolled in this study from the period February 2018 to 2019. The patients were divided in 2 groups: nonsurvivors (74) and survivors (39). The investigation includes measurements of native thiol, total thiol, dynamic disulphide bond, oxidized thiol ratio, reduced thiol ratio and thiol oxidation reduction ratio, erythrocyte sedimentation rate, C-reactive protein, and procalcitonin.

Results

The findings of this study suggest that changes in thiol levels play a role in the pathogenesis of patients with sepsis and septic shock.

Conclusions

Thiol/disulphide homeostasis is impaired in patients with sepsis and septic shock. Understanding the role of thiol/ disulphide homeostasis in sepsis and septic shock may provide different therapeutic intervention strategies for patients.