Serum Complement C3 Levels Research Articles

Short-term incremental prednisone therapy in patients with serologically active clinically quiescent lupus nephritis: a retrospective observational study

ObjectiveThis study investigated whether short-term incremental prednisone therapy decreases the risk of relapse without increasing adverse events (AEs) in patients with serologically active, clinically quiescent lupus nephritis (LN).MethodsAfter standardized treatment, 153 patients with serologically active, clinically quiescent LN were included. Clinical data were retrospectively reviewed. The patients were divided into two groups: the control group (n = 58) received prednisone or prednisone and immunosuppressant maintenance therapy, the prednisone increment group (n = 95) received additional prednisone doses of up to 10 mg/day as maintenance therapy, which were then gradually reduced back to the original dose at 3 months. Lupus activity, renal involvement, and AEs during follow-up in the two groups were analyzed within 18 months.ResultsNo significant differences in sex, age, disease course, maintenance treatment composition, or laboratory tests between the two groups were observed, except for serum complement C3 levels, which were significantly lower in patients in the prednisone increment group than in controls (P = 0.025). The prednisone increment group had significantly lower recurrence rates than the control group (P = 0.002), with only 3 patients (5.2%) in the prednisone increment group and 24 patients (25.3%) in the control group experiencing relapse. Renal recurrence was significantly lower in the prednisone increase group (P = 0.013). Nine AEs occurred in the prednisone-modulated group and 11 AEs occurred in controls, with infection being the main cause for both groups.ConclusionShort-term incremental prednisone therapy is safe in reducing recurrence rates in serologically active and clinically quiescent patients with LN.Key pointsIncremental prednisone is safe and effective for patients with serologically active clinically quiescent LN.

ELF1 serves as a potential biomarker for the disease activity and renal involvement in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects multiple organs, yet its underlying mechanisms remain unclear, and precise biomarkers are lacking. In this study, we employed Mendelian randomization and HEIDI tools to comprehensively analyze large-scale Genome-Wide Association Study (GWAS) and expression Quantitative Trait Loci (eQTL) data, leading to the identification of seven novel potential functional genes associated with SLE, including BLK, ELF1, STIM1, B3GALT6, APOLD1, INPP5B, and FHL3. Subsequent investigations revealed a significant downregulation of ELF1 gene expression in CD4+ T cells of SLE patients compared to healthy controls. Moreover, within various SLE subgroups, such as those with decreased serum complement C3 levels, positive urinary protein, new-onset skin rashes, and SLE Disease Activity Index (SLEDAI) scores ≥ 5, ELF1 expression displayed a consistent decreasing trend. Notably, ROC curve analysis highlighted the diagnostic potential of ELF1 expression in SLE (AUC = 0.9493), as well as its value in assessing disease activity (AUC = 0.6852) and renal involvement (AUC = 0.7363). In conclusion, this study underscores the potential of ELF1 as a SLE biomarker for diagnosis and evaluation, offering insights into the underlying mechanisms of SLE and paving the way for future therapeutic research.

Serum complement C3 and C4 levels in patients undergoing intramedullary nailing for fracture shaft femur: A prospective study

Serum complement C3 and C4 levels in patients undergoing intramedullary nailing for fracture shaft femur: A prospective study

Effects of microcystin-LR on immune function, lipid metabolism and intestinal microbial structure in Eriocheir sinensis

To investigate the potential toxic mechanism of Microcystin-LR (MC-LR) on juvenile Eriocheir sinensis (E. sinensis), a toxicity test was conducted by injecting MC-LR into the 3rd pereiopod. Following injection, we evaluated alterations in immune response biomarkers, antioxidant status, lipid metabolism-related genes expression, and intestinal microbiota composition in the hepatopancreas and intestinal tissues of E. sinensis. The results of immune response showed that after injection of MC-LR, the serum complement C3 level in E. sinensis significantly decreased at 48 hours (P < 0.05), whereas complement C4 level increased considerably from 12 to 96 hours (P < 0.01). The phenoloxidase system (PO) showed an increasing trend from 6 to 96 hours (P < 0.05 or P < 0.01). The levels of TNF-α, IL-6 significantly increased at 6 and 12 hours (P < 0.05 or P < 0.01). Gene expression analysis showed that FASN gene in the hepatopancreatic tissue displayed a higher expression at both 6 and 12 hours post-exposure (P < 0.01), while ALDH and ACAA2 gene exhibited a consistent downward trend from 6 to 48 hours (P < 0.05), Additionally, the mRNA levels of MECR and ACSL demonstrated a pattern of initial downregulation, followed by an upregulation, and subsequent downregulation. The antioxidant status results revealed that the levels GSH and CAT increased first and then decreased, while the activity of SOD decreased first and then increased. Meanwhile, the MDA content showed an increasing trend. 16 S rDNA analysis showed that the intestinal microbial diversity in MC-LR treatment group was significantly higher relative to the control group (P < 0.01). Compared with the control group, the MC-LR group had a significantly higher relative abundance of Proteobacteria, Fusobacteria, and Actinobacteria (P < 0.05) and a significantly lower relative abundance of Firmicutes (P < 0.01). At genus level, the relative abundance of Acinnetobacter, Flavobacterium, Acidovorax, Paracoccus, Cloacibacterium, Gemmobacter, Aeromonas, and Dechloromonas in the intestine of MC-LR-treated group was significantly increased relative to the control group (P < 0.05 or P < 0.01), but the relative abundance of Lachnospiraceae_NK4A136_group was significantly decreased (P < 0.01). The results of the study demonstrated that MC-LR could induced oxidative stress, hepatopancreas tissue damage, and intestinal microbial imbalance in E. sinensis.

Risk factors and prognosis of pediatric silent lupus nephritis with class Ⅲ to Ⅴ

To study the risk factors and prognostic characteristics of pediatric silent lupus nephritis (SLN) with class Ⅲ to V. A retrospective study was conducted to collect clinical data from 30 children diagnosed with SLN at the Department of Pediatrics, Second Xiangya Hospital, Central South University, from May 2007 to April 2023. Based on renal pathological classification, the patients were divided into a class Ⅱ group (12 cases) and a class Ⅲ to Ⅴ group (18 cases). The risk factors for the occurrence of class Ⅲ to Ⅴ SLN were analyzed, and the prognostic characteristics were summarized. Among the 30 SLN patients, the median follow-up time was 61.50 months. There were no statistically significant differences in the proportions of patients who discontinued glucocorticoids or achieved low disease activity status, nor in the annual decline rate of estimated glomerular filtration rate (eGFR) between the class Ⅱ and class Ⅲ to V groups (P>0.05). However, three patients in the class Ⅱ group progressed to stage 1 chronic kidney disease (CKD), while eight patients in the class III to V group reached stage 1 CKD, and four patients reached stage 2 CKD. Among the 26 female SLN patients, serum complement C3 levels in the class III to V group were lower than those in the class Ⅱ group (P<0.05). Serum C3 levels in SLN patients, as well as in female SLN patients, were negatively correlated with the fluorescence intensity of IgA, IgG, and C3 immune complexes in the kidneys (P<0.05). Additionally, serum C3 levels in female SLN patients were negatively correlated with the renal pathological activity index (P<0.05). Binary logistic regression analysis indicated that being female and having low serum complement C3 levels were risk factors for the occurrence of class Ⅲ to V SLN in children (P<0.05). Class Ⅲ to V SLN is not uncommon among SLN children, and there remains a risk of long-term renal function progression. Being female and having low serum complement C3 levels are identified as risk factors for class Ⅲ to V SLN in children.

Comparison of efficacy of continuous mycophenolate mofetil with sequential cyclophosphamide and tacrolimus as maintenance therapy for lupus nephritis.

To evaluate the renal response to mycophenolate mofetil (MMF) as maintenance therapy for lupus nephritis (LN) in Japanese patients, we compared the efficacy of MMF and the sequential use of monthly intravenous cyclophosphamide (IVCY) followed by tacrolimus (TAC). We examined 14 patients with LN who were treated with continuous MMF as induction and maintenance therapies (MMF group) and 10 patients with LN who received monthly IVCY as induction therapy followed by maintenance therapy with TAC (IVCY-TAC group). We assessed the therapeutic effects of each treatment regimen on renal manifestations and serological findings over a 36-month period after treatment initiation. Mean urine protein-to-creatinine ratios in the MMF and IVCY-TAC groups significantly decreased from 2.75 to 0.11g/gCr and from 3.26 to 0.22g/gCr, respectively. Significant improvements in serum immunological variables (serum complement C3 or C4 levels and the anti-double-stranded DNA antibody titer) and reductions in the SLE disease activity index and daily prednisolone dosages were observed in both groups during induction therapy and were maintained during maintenance therapy. Efficacy was similar between the MMF and IVCY-TAC groups. MMF has potential as an effective treatment for renal manifestations in Japanese patients throughout induction and maintenance therapies for LN, as an alternative to conventional IVCY-TAC therapy, and as a glucocorticoid-sparing agent.

Serum Uric Acid Associates with Systemic Complement C3 Activation in Severe ANCA-Associated Renal Vasculitides.

Involvement of the complement system is key to the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis, but immunometabolic implications, especially on serum uric acid (UA) levels, still need to be elucidated. A total of 34 patients with biopsy-proven ANCA-associated renal vasculitis between 2015 and 2020 were retrospectively enrolled. Serum UA levels were correlated with clinical and histopathological characteristics, separated for critically ill (CI, n = 19), myeloperoxidase (MPO)-ANCA (n = 21) and proteinase 3 (PR3)-ANCA (n = 13) subgroups. We here identified inverse correlations of serum UA levels and complement C3 levels in the total cohort (p = 0.005) and the CI subgroup (p < 0.001). Intrarenal complement C4d deposition in venules correlated with serum UA levels in the total cohort (p = 0.007) and in the CI subgroup (p = 0.016). Significant associations of serum UA levels and tubulitis in areas of scarred cortex (t-IFTA) were identified in the total cohort (p = 0.008), and both subgroups of CI (p = 0.034) and MPO-ANCA (p = 0.029). In PR3-ANCA, interstitial fibrosis (ci) was observed as the strongest association with serum UA levels (p = 0.022). Our observations broaden our current understanding of contributory metabolic factors that influence the initial disease course in ANCA-associated renal vasculitis.

The phenotypic characteristics and course of chronic obstructive pulmonary disease (COPD) and their association with serum complement C3 levels

The phenotypic characteristics and course of chronic obstructive pulmonary disease (COPD) and their association with serum complement C3 levels

Use of cardiac troponin I, lactic acid, procalcitonin, and serum complement C3 as prognostic indicators in patients with sepsis

Sepsis is a heterogeneous syndrome caused by the immune response to severe infection. This study aimed to investigate the value of cardiac troponin I, lactic acid, procalcitonin, and serum complement C3 levels for predicting death in patients with sepsis. Patients with sepsis who were hospitalized in the Department of Critical Care Medicine at our hospital between June 2017 and October 2022 were included in this retrospective study and divided into a survival group and a death group according to their survival status after 28 days. The Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores, and levels of cardiac troponin I, lactic acid, procalcitonin, and serum complement C3 were measured. A total of 516 patients were included in the analysis. Multivariable analysis showed that the APACHE II score (P &lt; .001), SOFA score (P &lt; .001), and cardiac troponin I (P &lt; .001), lactic acid (P = .002), procalcitonin (P &lt; .001), and serum complement C3 (P = .01) levels were independent predictors of sepsis death. The area under the receiver operating characteristic curve (AUC) was 0.882 (95% CI: 0.794–0.941) in patients with sepsis predicted using a combination of cardiac troponin I, lactic acid, procalcitonin, and serum complement C3 levels, which was better than the predictive value of cardiac troponin I (AUC: 0.734, 95% CI: 0.628–0.824), lactic acid (AUC: 0.686, 95% CI: 0.576–0.781), procalcitonin (AUC: 0.727, 95% CI: 0.620–0.817), or serum complement C3 (AUC: 0.684, 95% CI: 0.575–0.780) alone. Cardiac troponin I, lactic acid, and procalcitonin levels are independent predictors of death, whereas serum complement C3 protects against death in patients with sepsis. The combination of cardiac troponin I, lactic acid, procalcitonin, and serum complement C3 levels has a better predictive value for death than any single measure alone in patients with sepsis.

A retrospective study of myelin oligodendrocyte glycoprotein antibody-associated disease from a clinical laboratory perspective.

To analyze the differences in laboratory data between patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). The study included 26 MOGAD patients who visited Beijing Tiantan Hospital from 2018 to 2021. MS and NMOSD patients who visited the clinic during the same period were selected as controls. Relevant indicators were compared between the MOGAD group and the MS/NMOSD groups, and the diagnostic performance of meaningful markers was assessed. The MOGAD group showed a slight female preponderance of 57.7%, with an average onset age of 29.8 years. The absolute and relative counts of neutrophils were higher in the MOGAD group than in the MS group, while the proportion of lymphocytes was lower. The cerebrospinal fluid (CSF) IgG level, IgG index, 24-h IgG synthesis rate, and positive rate of oligoclonal bands (OCB) were lower in MOGAD patients than in the MS group. The area under ROC curve (AUC) was 0.939 when combining the relative lymphocyte count and IgG index. Compared to the NMOSD group, the MOGAD group had higher levels of serum complement C4 and lower levels of serum IgG. The AUC of serum C4 combined with FT4 was 0.783. Statistically significant markers were observed in the laboratory data of MOGAD patients compared to MS/NMOSD patients. The relative lymphocyte count combined with IgG index had excellent diagnostic efficacy for MOGAD and MS, while serum C4 combined with FT4 had better diagnostic efficacy for MOGAD and NMOSD.

Renal C4d is a potential biomarker of disease activity and severity in pediatric lupus nephritis patients.

Systemic lupus erythematosus (SLE), a multisystemic autoimmune disease, is very aggressive in pediatric-onset patients as they are prone to develop lupus nephritis (LN). Although renal C4d positivity is correlated with the activity of renal disease and SLE in adult-onset LN patients, available information for pediatric-onset patients is limited. To evaluate the potential diagnostic significance of renal C4d staining in pediatric LN patients, we retrospectively detected C4d staining by immunohistochemistry on renal biopsy specimens from 58 pediatric LN patients. The clinical and laboratory data at the time of the kidney biopsy and the renal disease activity of histological injury were analyzed according to the C4d staining status. Glomerular C4d (G-C4d)-positive staining was detected in all 58 cases of LN. Patients with a G-C4d score of 2 displayed more severe proteinuria than those with a G-C4d score of 1 (24-h urinary protein: 3.40 ± 3.55 g vs. 1.36 ± 1.24 g, P < 0.05). Peritubular capillary C4d (PTC-C4d) positivity was found in 34 of 58 LN patients (58.62%). The PTC-C4d-positive patient groups (patients with a PTC-C4d score of 1 or 2) had higher serum creatinine and blood urea nitrogen levels as well as renal pathological activity index (AI) and SLE disease activity index (SLEDAI) scores; however, they had lower serum complement C3 and C4 levels compared to PTC-C4d-negative patients (P < 0.05). In addition, there was positive tubular basement membrane C4d (TBM-C4d) staining in 11 of 58 LN patients (18.96%), and a higher proportion of TBM-C4d-positive patients than TBM-C4d-negative patients (63.63% vs. 21.27%) had hypertension. Our study revealed that G-C4d, PTC-C4d, and TMB-C4d were positively correlated with proteinuria, disease activity and severity, and hypertension, respectively, in pediatric LN patients. These data suggest that renal C4d is a potential biomarker for disease activity and severity in pediatric LN patients, providing insights into the development of novel identification and therapeutic approaches for pediatric-onset SLE with LN.

Effect of tonsillotomy on the inflammation and immune function in children with chronic tonsillitis

Objective:To investigate the changes of inflammation and immune function in children with chronic tonsillitis after tonsillotomy. Methods:Prospectively collected 60 children with obstructive sleep apnea （OSA） diagnosed as chronic tonsillitis with adenoids and tonsillar hypertrophy from January to June 2021. Two groups were divided, the experimental group （n=30） underwent bilateral partial tonsillectomy + adenoidectomy by hypothermia plasma ablation, and the control group （n=30） underwent adenoidectomy by using the same hypothermia plasma ablation method. The number of tonsillitis attacks before surgery and within one year after surgery was recorded, and the serum immunoglobulin IgM, IgG, IgA, complement C3 and complement C4 levels before operation, one month and three months after operation were measured. Results:The number of tonsillitis attacks in the experimental group and the control group at one year after surgery was lower than that before surgery（P<0.05）; The number of inflammatory attacks in the experimental group was （0.50±0.63） times/year, which was lower than that of （1.33±0.80） times/year in the control group. There was no significant difference in the five immunization results of the two groups at one month and three months after operation compared with before operation, and there was also no significant difference between the experimental and the control groups. Conclusion:Partial tonsillectomy can be applied to children with chronic tonsillitis, which can effectively reduce the number of tonsillitis attacks and has no effect on the immune function of children.

A Cross-Sectional Study to Correlate Serum Complement C3 and C4 Levels With Clinical and Pathological Severity in Cutaneous Small-Vessel Vasculitis.

IntroductionThe role of serum C3 and C4 levels as a marker of disease activity in cutaneous small-vessel vasculitis (CSVV) has been sparsely studied, especially in India. The primary objective was to determine the correlation between clinico-histopathological severity and serum C3 and C4 levels in CSVV. The secondary objective was to determine the association between direct immunofluorescence (DIF) findings and serum C3 and C4 levels and clinico-histopathological findings.MethodThis prospective cross-sectional study included all the clinically diagnosed cases of CSVV that satisfied the pathological criteria for CSVV. A clinical disease activity grade and a histopathological severity grade were calculated in all patients (N=50).ResultsSerum C3 and C4 levels (n=44) were diminished in 4.5% of cases. There was no significant correlation between the serum C3 and C4 levels and the clinical and histopathological severity. DIF was positive in 60.0% of cases (n=45), and IgA was the predominant immune deposit (46.7%). No significant association was detected between the DIF findings and the serum C3 and C4 levels, histopathological severity, and clinical disease activity grade. Positive DIF findings were significantly associated with palpable purpura and cutaneous necrosis. A significant association was detected between gastrointestinal involvement and IgA positivity.ConclusionIn CSVV, serum C3 and C4 may not be used as markers of disease severity, and a positive DIF finding may indicate an underlying gastrointestinal involvement.

Natural antibody IgG levels are associated with HBeAg-positivity and seroconversion in chronic hepatitis B patients treated with entecavir

B1 cell-derived natural antibodies are non-specific polyreactive antibodies and can activate the complement pathway leading to lysis of enveloped virus particles before activation of the adaptive immune response. We investigated the relationship between natural antibody levels and treatment outcomes of 126 treatment-naïve chronic hepatitis B (CHB) patients, who underwent entecavir (ETV) treatment. Serum IgG1-3 and complement C3 levels were significantly higher in HBeAg-positive patients. In pre-treatment, IgG1 (odd ratios [OR] 2.3, p < 0.0001), IgG2 (OR 9.8, p < 0.0001), IgG3 (OR 7.4, p < 0.0001), and C3 (OR 7.2, p < 0.0001) were associated with HBeAg-positive patients. At baseline, IgG2 (OR 10.2, p = 0.025), IgG4, (OR 3.4, p = 0.026), and complement C1q (OR 5.0, p = 0.0068) were associated with seroconverters. Post-treatment levels of IgG1-4 and C3/C1q were also associated with HBeAg-positive patients and seroconverters. High levels of IgG2-4 and C1q were observed in seroconverters but not in virological responders. Thus, high pretreatment and post-treatment levels of natural antibody IgG1-4, complement C3, and/or C1q were significantly associated with HBeAg-positivity and HBeAg seroconverters in CHB patients with ETV treatment. These results suggest that the presence of preexisting host immunity against chronic hepatitis B is closely related to outcome of ETV treatment.

Association of Complement C3 with Clinical Deterioration Among Hospitalized Patients with COVID-19.

BackgroundThe role of the complement system in coronavirus disease 2019 (COVID-19) remains controversial. This study aimed to evaluate the relationship between serum complement C3 levels, clinical worsening, and risk of death in hospitalized patients with COVID-19.MethodsData were collected from 216 adults with COVID-19 admitted to a designated clinical center in Wuhan Union Hospital (China) between February 13, 2020, and February 29, 2020. Their complement C3 levels were measured within 24 h of admission. The primary outcome was a clinical worsening of 2 points on a 6-point ordinal scale. The secondary outcome was all-causes of death. Inverse probability of treatment weighting (IPTW) analysis was conducted to adjust for the baseline confounders.ResultsThe median value of C3 was 0.89 (interquartile range, 0.78–1.01) g/L. Clinical worsening occurred in 12.3% (7/57) and 2.5% (4/159) of patients with baseline C3 levels < and ≥0.79 g/L, respectively (hazard ratio [HR], 5.22; 95% confidence interval [CI], 1.53–17.86). After IPTW adjustment, the risk for clinical worsening was 4-fold greater (weighted HR, 4.61; 95% CI, 1.16–18.4) in patients with C3 levels less than 0.79 g/L comparatively. The sensitivity analyses revealed the robustness of the results. No significant associations between C3 levels and death were observed on unadjusted (HR, 2.92; 95% CI, 0.73–11.69) and IPTW analyses (weighted HR, 3.78; 95% CI, 0.84–17.04).ConclusionLow complement C3 levels are associated with a higher risk for clinical worsening among inpatients with COVID-19. The serum C3 levels may contribute to the identification of patient populations that could benefit from therapeutic complement inhibition.

Association of Serum Complement C1q and C3 Level with Age-Related Macular Degeneration in Women

PurposeTo investigate the association between serum complement components and age-related macular degeneration (AMD).Patients and MethodsA total of 118 AMD patients and age- and sex-matched 106 control subjects were included. Demographic data and the level of serum complement component (C)1q, C3 and C4 were evaluated. Based on sex, the subjects were stratified into male and female subgroups.ResultsThe level of C1q (226.31±45.33mg/dL) was significantly higher and C3 (121.14±15.76mg/dL) was significantly lower than that in control group (200.03±38.54mg/dL) (128.42±19.81mg/dL) in the female AMD patients (p = 0.005, p = 0.045). Logistic regression showed that increased C1q (OR = 1.132, p = 0.016) and decreased C3 (OR = 0.960, p = 0.048) were independent risk factors for female AMD patients. No statistical significance was observed in the male.ConclusionIncreased C1q and decreased C3 were associated with increased risk of AMD, suggesting that the complement classical pathway probably be involved in AMD, especially in female.

Effect of dietary Ficus carica polysaccharides on the growth performance, innate immune response and survival of crucian carp against Aeromonas hydrophila infection

Ficus carica polysaccharides (FCPS), one of the most effective and important compo-nents in Ficus carica L., had been considered to be a beneficial immunostimulant and may be used in immunotherapy for animals and human. However, studies were little about the effect of FCPS used as immunomodulatory and the suitable dosage in fish. The present study investigated the effect of four different dietary levels of FCPS (0.1%, 0.2%, 0.4%, 0.8%) on the growth performance, innate immune responses and survival of crucian carp against Aeromonas hydrophila infection. The results showed that compared with control group, dietary FCPS had positive effects the growth performance (final weight, feed conversion ratio and survival rate) of crucian carp. FCPS induced significant higher (p < 0.05) leukocyte phagocytosis activity, serum bactericidal activity, lysozyme activity, com-plement C3, SOD activity and total protein level in the serum of crucian carp. Moreover, innate immune response of fish in FCPS groups increased first and then decreased with increasing dietary FCPS from 0.1% to 0.8%, and reached up to the peak in 0.4% dietary FCPS groups. Besides, the cumulative mortalities in FCPS groups were remarkably lower than that of control group when challenged with A. hydrophila, the relative percent survivals were 22.67%, 55.56%, 62.22% and 17.78% in 0.1% group, 0.2% group, 0.4% group and 0.8% group, respectively. These results suggested that dietary FCPS could improve the growth performance, innate immune response and disease resistance against A. hydrophila in fish, and the suitable dietary dose of FCPS was 0.4% in crucian carp.

Association between complement C3 and the prevalence of metabolic-associated fatty liver disease in a Chinese population: a cross-sectional study

ObjectivesRecently studies demonstrated that adipose tissue can produce and release complement C3 and serum complement C3 levels were associated with diabetes mellitus, metabolic syndrome and non-alcoholic fatty liver disease (NAFLD)....

Effects of Simulated Heat Wave on Oxidative Physiology and Immunity in Asian Yellow Pond Turtle (Mauremys mutica)

Global warming has led to an increase in the frequency, duration, and intensity of heat waves in the summer, which can cause frequent and acute heat stress on ectotherms. Thus, determining how ectothermic animals respond to heat waves has been attracting growing interest among ecologists. However, the physiological and biochemical responses to heat waves in reptiles, especially aquatic reptiles, are still poorly understood. The current study investigated the oxidant physiology, immunity, and expression levels of heat shock proteins (HSP) mRNA after exposure to a simulated heat wave (1 week, 35 ± 4°C), followed by a recovery period (1 week, 28 ± 4°C) in juvenile Asian yellow pond turtle (Mauremys mutica), a widely farmed aquatic turtle in East Asia. The contents of malondialdehyde (MDA) in the liver and muscle were not significantly affected by the heat wave or recovery. Of all antioxidant enzymes, only the activity of glutathione peroxidase (GSH-Px) in muscles increased after heat wave, while the total superoxide dismutase (T-SOD), catalase activity (CAT), and total antioxidant capacity (T-AOC) did not change during the study. The organo-somatic index for the liver and spleen of M. mutica decreased after the heat wave but increased to the initial level after recovery. In contrast, plasma lysozyme activity and serum complement C4 levels increased after the heat wave, returning to the control level after recovery. In addition, heat waves did not alter the relative expression of HSP60, HSP70, and HSP90 mRNA in the liver. Eventually, heat wave slightly increased the IBR/n index. Therefore, our results suggested that heat waves did not lead to oxidative damage to lipids in M. mutica, but deleteriously affected the turtles’ immune organs. Meanwhile, the constitutive levels of most antioxidative enzyme activities, HSPs and enhanced blood immune functions might protect the turtles from the threat of heat waves under the current climate scenarios.

Dose-effect relationship between serum polycyclic aromatic hydrocarbon adducts and serum complements among children in a city of East China

Objective: To investigate the dose-response relationship between serum polycyclic aromatic hydrocarbon adducts and serum complement C3 and C4 levels among children from a city in East China. Methods: In September 2016, two boarding schools in the air pollution exposure area and the control area (beyond the upwind of 30 km in the air pollution exposure area) in a city in East China were selected as the research site, and the eligible school-age children were recruited as the research objects. A total of 273 children were included, including 163 in the exposure group and 110 in the control group. The annual air pollutant data (PM2.5, PM10 and NO2) of the two regions during the study period were collected. The exposure level of tobacco was evaluated by cotinine in urine. The levels of serum complement C3 and C4 were determined by automatic biochemical analyzer. The serum anti-7, 8, -dihydrodiol-9, 10-epoxide benzo[a]pyrene (BPDE)-albumin adduct levels were detected by ELISA. Linear regression model was used to explore the dose-response relationship between BPDE-albumin adducts and serum complement C3 and C4. Results: The age of 273 subjects was (13.67±0.37) years old, including 165 boys (60.4%). The average annual exposure levels of PM2.5, PM10 and NO2 and the level of serum BPDE-albumin adducts in the exposure group were higher than those in the control group (P<0.05). The results of linear regression model analysis showed that after adjusting age, sex, BMI z-score and urinary cotinine level, when the serum BPDE-albumin adduct level increased by 10%, the serum complement C4 level decreased by 1.2% (P=0.017). After adjusting age, BMI z-score and urinary cotinine level, for every 10% increase in serum BPDE-albumin adduct level in boys, the serum complement C4 level decreased by 1.68% (P=0.024). After adjusting age, sex and BMI z-score, the levels of serum complement C3 and C4 decreased by 1.31% and 3.57% respectively for every 10% increase in serum BPDE-albumin adducts among children in the urinary cotinine detection group (P<0.05). Conclusion: There is a significant dose-response relationship between serum BPDE-albumin adducts and the complement C4 among children.