CRP genotype and haplotype associations with serum C-reactive protein level and DAS28 in untreated early rheumatoid arthritis patients

Correlation of CRP genotypes with serum CRP levels and the risk of rheumatoid arthritis in Chinese Han population

OBJECTIVE

C-reactive protein (CRP) is an important index for evaluating the disease activity of rheumatoid arthritis (RA). CRP may play a direct role in bone destruction in RA. Studies have demonstrated that serum CRP levels had a close correlation with tissue inflammation scores in patients with RA. In addition, genetic factors play a crucial role in the development of RA. In this study, we aimed to investigate the relationship between the CRP gene variants (rs1205 polymorphism) and the risk of RA in Chinese Han population.

METHODS

502 RA patients and 581 controls were included in this study. The associations between CRP gene variants and CRP levels and RA risk were investigated.

RESULTS

We found that TT/ TT + CT genotype was significantly related with an increased risk of RA (TT vs CC: OR, 1.56, 95%CI, 1.01-2.40, P = 0.045; TT + CT vs CC: OR, 1.30, 95%CI, 1.02-1.65, P = 0.032). In addition, T allele was shown to associate with an elevated risk of RA. After subgroup analysis, we found that rs1205 polymorphism was significantly related with an enhanced risk of RA among females, individuals lower than 60 years, and subjects with a BMI > 25 kg/m². Furthermore, data showed that the CRP gene rs1205 polymorphism correlated with CRP and ESR levels. Furthermore, the TT genotype was significantly associated with a reduction of CRP levels compared with CT or CC genotype.

CONCLUSIONS

To sum up, this study reveals that rs1205 polymorphism of the CRP gene is related with an increased risk of RA and CRP levels in Chinese Han population. Key Points • The CRP gene rs1205 polymorphism is related with a higher risk of RA. • The CRP gene rs1205 polymorphism correlates with CRP and ESR levels. • The TT genotype of rs1205 polymorphism is linked with a reduction of CRP levels.

Quantile-dependent expressivity of serum C-reactive protein concentrations in family sets

BACKGROUND

"Quantile-dependent expressivity" occurs when the effect size of a genetic variant depends upon whether the phenotype (e.g., C-reactive protein, CRP) is high or low relative to its distribution. We have previously shown that the heritabilities (h 2) of coffee and alcohol consumption, postprandial lipemia, lipoproteins, leptin, adiponectin, adiposity, and pulmonary function are quantile-specific. Whether CRP heritability is quantile-specific is currently unknown.

METHODS

Serum CRP concentrations from 2,036 sibships and 6,144 offspring-parent pairs were analyzed from the Framingham Heart Study. Quantile-specific heritability from full-sib (βFS, h 2 ={(1 + 8rspouseβFS)0.5 - 1}/(2rspouse)) and offspring-parent regression slopes (βOP, h 2 = 2βOP/(1 + rspouse)) were estimated robustly by quantile regression with nonparametric significance determined from 1,000 bootstrap samples.

RESULTS

Quantile-specific h 2 (±SE) increased with increasing percentiles of the offspring's age- and sex-adjusted CRP distribution when estimated from βOP (P trend = 0.0004): 0.02 ± 0.01 at the 10th, 0.04 ± 0.01 at the 25th, 0.10 ± 0.02 at the 50th, 0.20 ± 0.05 at the 75th, and 0.33 ± 0.10 at the 90th percentile, and when estimated from βFS (P trend = 0.0008): 0.03±0.01 at the 10th, 0.06 ± 0.02 at the 25th, 0.14 ± 0.03 at the 50th, 0.24 ± 0.05 at the 75th, and 0.53 ± 0.21 at the 90th percentile.

CONCLUSION

Heritability of serum CRP concentration is quantile-specific, which may explain or contribute to the inflated CRP differences between CRP (rs1130864, rs1205, rs1800947, rs2794521, rs3091244), FGB (rs1800787), IL-6 (rs1800795, rs1800796), IL6R (rs8192284), TNF-α (rs1800629) and APOE genotypes following CABG surgery, stroke, TIA, curative esophagectomy, intensive periodontal therapy, or acute exercise; during acute coronary syndrome or Staphylococcus aureus bacteremia; or in patients with chronic rheumatoid arthritis, diabetes, peripheral arterial disease, ankylosing spondylitis, obesity or inflammatory bowel disease or who smoke.

C-reactive protein and implications in rheumatoid arthritis and associated comorbidities

C-reactive protein (CRP) is routinely assessed as a marker of systemic inflammation in rheumatoid arthritis (RA). However, it is also an immune regulator that plays an important role in inflammatory pathways associated with RA and promotes atherogenic effects. Comorbidities linked to systemic inflammation are common in RA, and CRP has been associated with the risk for cardiovascular disease, diabetes, metabolic syndrome, pulmonary diseases, and depression. The relationship between systemic inflammation, CRP, and comorbidities in RA is complex, and it is challenging to determine how changing CRP levels may affect the risk or progression of these comorbidities. We review the biological role of CRP in RA and its implications for disease activity and treatment response. We also discuss the impact of treatment on CRP levels and whether reducing systemic inflammation and inhibiting CRP-mediated inflammatory pathways may have an impact on conditions commonly comorbid with RA.

The relationship between CRP gene polymorphism (rs2794521, rs3091244), ASDAS-CRP and ASDAS-ESR in ankylosing spondylitis

Background: We aimed to investigate the haplotypes and alleles of two variants (rs2794521 and rs3091244) in AS patients and to examine their relationship with ASDAS-CRP and ASDAS-ESR values.Methods: We evaluated 160 AS patients diagnosed according to the ASAS criteria. ASDAS-CRP and ASDAS-ESR values were calculated. ESR and CRP were examined. The restriction fragment length polymorphism (RFLP) method was used for detecting the rs2794521 and rs3091244 regions on the CRP gene.Results: As a result of the evaluation of rs2794521 gene polymorphism using PCR, TT, TC and CC genotypes were observed in 90, 81 and 9 individuals, respectively. As a result of the evaluation of rs3091244 gene polymorphism, CC, AC and TT genotypes were observed in 104, 51 and 5 individuals, respectively. T allele and C allele were found in rs2794521 gene by 75% and 25%, respectively. In addition, T allele, C allele and A allele were found in rs3091244 gene by 80%, 17% and 3%, respectively. With the help of regression equation, ASDAS-CRP level was 0.34 units higher in cases with rs3091244 C allele than cases without rs3091244 C alleles.Conclusion: CRP rs3091244 C allele may be associated with the increased relative risk for ASDAS-CRP.

Synergistic enhancement and hepatoprotective effect of combination of total phenolic extracts of Citrus aurantium L. and methotrexate for treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune inflammatory disorder characterized by joint destruction and bone damage. Methotrexate (MTX) is recommended as the first-line disease-modifying agent for the treatment of RA. However, the clinical efficacy of MTX is limited due to its low response and side effects, especially hepatotoxicity. Total phenolic extracts of Citrus aurantium L. (TPE-CA) are rich in dietary bioactive flavonoids, which show beneficial effects on liver health and are regarded as therapeutic tools against inflammatory diseases. In this study, the efficacy of MTX, alone or in combination with TPE-CA, for the treatment of collagen-induced arthritis and protection against hepatic injury in rats was investigated. TPE-CA and MTX combination effectively reduced the inflammatory symptoms and joint damage by inhibiting the NF-κB pathway. Moreover, TPE-CA significantly ameliorated MTX-induced chronic hepatic injury by enhancing antioxidant enzymes activities, suppressing hepatic cytochrome P450 2E1 expression, and modulating the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway. This combination regimen not only provided synergistic enhancement but also exhibited hepatoprotective effect against chemically induced chronic hepatotoxicity. This could be an alternative strategy to improve the low response of MTX in RA treatment.

Real-time CRP detection from whole blood using micropost-embedded microfluidic chip incorporated with label-free biosensor

We demonstrate the detection of C-creative protein (CRP) from whole blood samples without sample pretreatment by using a lab-on-a-chip system consisting of a microfluidic chip and a label-free biosensor.

Impact of the size and number of swollen joints on serum C-reactive protein level and erythrocyte sedimentation rate in rheumatoid arthritis: a cross-sectional study in Japan

No studies have yet reported the influence of swelling in individual joints on serum C-reactive protein and erythrocyte sedimentation rate. To examine this association, we used data from the NinJa registry, the largest registry of rheumatoid arthritis patients in Japan. Sixty-six palpable joints were categorized by size into three groups (small, medium-sized, and knees) with surface area cutoffs of 10 and 100 cm². Of 10,720 cases registered in NinJa in 2012, 8444 cases with either no swollen joints or swelling limited to one joint-size category were analyzed. Groups with larger numbers of swollen joints showed higher levels of both markers in each joint-size category. Groups with larger swollen joints had higher levels of both markers compared with groups with the same number of (smaller) swollen joints. Linear regression revealed that the increments of C-reactive protein (mg/dL/joint) and erythrocyte sedimentation rate (mm/1 h/joint) were 0.056 and 0.89, 0.24 and 5.0, and 0.46 and 8.9 for small and medium-sized joints and knee joints, respectively. The levels of systemic inflammation markers increased with the involvement of larger and/or more joints. These results were successfully illustrated by the use of large-scale data, which eliminated wide intragroup scattering of the marker values.

Multibiomarker disease activity score and C-reactive protein in a cross-sectional observational study of patients with rheumatoid arthritis with and without concomitant fibromyalgia

OBJECTIVES

To examine the association between a multibiomarker disease activity (MBDA) score, CRP and clinical disease activity measures among RA patients with and without concomitant FM.

METHODS

In an observational cohort of patients with established RA, we performed a cross-sectional analysis comparing MBDA scores with CRP by rank correlation and cross-classification. MBDA scores, CRP and clinical measures of disease activity were compared between patients with RA alone and RA with concomitant FM (RA and FM) by univariate and multivariate analyses.

RESULTS

CRP was ⩽1.0 mg/dl for 184 of 198 patients (93%). MBDA scores correlated with CRP (r = 0.755, P < 0.001), but were often discordant, being moderate or high for 19%, 55% and 87% of patients with CRP ⩽0.1, 0.1 to ⩽0.3, or 0.3 to ⩽1.0 mg/dl, respectively. Among patients with CRP ⩽1.0 mg/dl, swollen joint count (SJC) increased linearly across levels of MBDA score, both with (P = 0.021) and without (P = 0.004) adjustment for CRP, whereas CRP was not associated with SJC. The 28-joint-DAS-CRP, other composite measures, and their non-joint-count component measures were significantly greater for patients with RA and FM (n = 25) versus RA alone (n = 173) (all P ⩽ 0.005). MBDA scores and CRP were similar between groups.

CONCLUSION

MBDA scores frequently indicated RA disease activity when CRP did not. Neither one was significantly greater among patients with RA and FM versus RA alone. Thus, MBDA score may be a useful objective measure for identifying RA patients with active inflammation when CRP is low (⩽1.0 mg/dl), including RA patients with concomitant FM.