Interleukin-6 and cytochrome-P450, reason for concern?

Interleukin 6 (IL-6) plays a central role in the immunopathogenesis of rheumatoid arthritis (RA) and tocilizumab [TCZ] (an anti-IL-6 receptor antibody) has been shown to be effective in the treatment of the condition. As up-regulation of IL-6 reduces the activity of cytochrome P450 (CYP) enzymes, blockade of this cytokine may enhance CYP function. This may lead to reduced bioavailability of CYP-metabolized drugs. Due to the increasing use of TCZ, we undertook a systematic literature review to explore such interactions. Our search was conducted in MEDLINE, EMBASE, Web of Science, FDA and EMEA websites for in vitro and in vivo studies, clinical trials and reviews mentioning TCZ and CYP on the basis of the title and abstract. Appropriate articles were further screened based on full-text review to select only those reporting IL-6, TCZ and their potential interaction with CYP-metabolized drugs. Two in vitro studies showed that TCZ-reversed IL-6 induced reduction of CYP isozymes. CYP3A4 mRNA expression was most reduced by IL-6 followed by CYP2C9 and CYP2C19. This change was prevented with TCZ. Three clinical studies investigated the interaction showing simvastatin (CYP3A4 substrate) bioavailability reduced by TCZ and omeprazole bioavailability was decreased by TCZ-induced CYP2C19 activity. The bioavailability of dextromethorphan (CYP2D6 and CYP3A4 substrates) was shown to be unaffected by TCZ treatment. The observed increase in CYP isozyme activity by TCZ is of clinical relevance as the bioavailability of the CYP isozyme substrates were decreased in vivo. As CYP3A4 is the isozyme responsible for the largest proportion of drug metabolism, it is probable that the bioavailability of other drugs may be reduced by TCZ. Thus, clinicians should exercise caution when co-prescribing TCZ and CYP-metabolized drugs. More studies are required to investigate this interaction further.     

Interleukin-6-Blockade als potenzielles therapeutisches Target bei entzündlich-rheumatischen Erkrankungen

As a pro-inflammatory cytokine, the 21-kDa glycoprotein interleukin-6 (IL-6) plays a crucial role in the initiation of acute inflammation, as well in the perpetuation of a chronic inflammatory immune response. Thus, IL-6 might be involved in the pathogenesis of various autoimmune diseases. So far, the IL-6-rezeptor-antibody tocilizumab (TCZ, RoActemtra®) is the only approved drug for the treatment of IL-6-mediated disease, including rheumatoid arthritis (RA), systemic juvenile idiopathic (sJIA) and polyarticular juvenile arthritis (pJiA), as well as Castleman’s disease (in Japan only). In recent years, an emerging number of case reports and small uncontrolled case series have reported on the successful treatment of various other chronic inflammatory diseases, which has resulted in the idea of a broad therapeutic potential for IL-6 blockade. Numerous IL-6 targets are currently in phase II/III study programs for RA as well as for other indications. This review focuses on the development of tocilizumab and other IL-6 targets as a therapeutic option for various diseases in rheumatology.     

Interleukin-6-producing dermoid cyst associated with multicentric Castleman’s disease

Dysregulated overproduction of interleukin-6 (IL-6) from activated B cells in affected lymph nodes has been implicated in the pathogenesis of multicentric Castleman’s disease (MCD), a rare lymphoproliferative disorder accompanied by systemic manifestations. We here report the case of a 32-year-old female presenting with MCD associated with a dermoid cyst in the pelvic cavity. The co-occurrence of MCD and dermoid cyst has not been reported before. Immunohistochemical analysis of the tissue sections showed IL-6 production in CD68-positive macrophage cells, which had infiltrated the dermoid cyst. Removal of the cyst resulted in partial improvement in systemic symptoms accompanied by a decrease in serum IL-6, while complete improvement was obtained by treatment with an anti-IL-6 receptor antibody following resection of the dermoid cyst. To the best of our knowledge, this is the first study to provide evidence of IL-6 production by CD68⁺ cells in a dermoid cyst involved in MCD.     

Mechanisms of microRNA 200a in Hepatic Insulin Resistance by Interleukin-6

Aim To explore the mechanisms of microRNA 200a in hepatic insulin resistance induced by interleukin-6(IL-6),specifically to in-vestigate the role of microRNA 200a in hepatic glucogen and insulin signal pathway transduction.Methods The cell model forhepatic insulin resistance was induced by IL-6(10μg/L) for 24 hours in NCTC1469 cell.The level of glucogen was reduced.The expression of microRNA 200a was tested by q-PCR.The level of glucogen was quantified in NCTC 1469 transfected with microRNA200a mimics.The t...     

Does treatment affect the levels of serum Interleukin-6, Interleukin-8 and procalcitonin in diabetic foot infection? A pilot study

AimsTo investigate about serum PCT, IL-6 and IL-8 levels and how they are affected by the treatment in diabetic foot patients.MethodsFifty patients’ blood samples were taken to study ESR and CRP, IL-6, IL-8 and PCT before and at the 14th day of the treatment.ResultsThe pretreatment results of the 50 patients showed positive correlations between PCT and either ESH (r = 0.49, p < 0.001), or CRP (r = 0.56, p < 0.001). Similarly, there was a positive correlation between IL-6 and ESH (r = 0.46, p = 0.001), just like as it was between IL-6 and CRP (r = 0.54, p < 0.001). At the 14th day, the levels of ESR (70 ± 30.2 and 58.4 ± 26.2, p = 0.02), CRP (63.8 ± 73.1 and 18.1 ± 19.7, p < 0.001) and PCT (0.6 ± 2.1 and 0.05 ± 0.02, p = 0.007) were significantly decreased while IL-6 was decreased at a close range to statistical significancy at healing patients (97.5 ± 147.2 and 47.1 ± 77.6; p = 0.05), but they did not at nonhealing patients. IL-8 levels were not changed anyhow.ConclusionsPCT was significantly decreased such as ESR and CRP were in the early phase of healing; IL-6 and IL-8 levels were also decreased by the treatment, but not statistically significantly. IL-6 and PCT were affected in correlation with the other inflammatory parameters in the beginning, but IL-8 was not. PCT and IL-6 may be useful like CRP and ESR in the diagnosis and follow up of diabetic foot infection, but IL-8 is not. Further investigation is needed.     

Interleukin-10 and Interleukin-10–Receptor Defects in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease characterized by abdominal pain, bloody diarrhoea, and malabsorption leading to weight loss. It is considered the result of inadequate control of an excessive reaction of the immune system to the resident flora of the gut. Like other primary immunodeficiencies, IL-10 and IL-10 receptor (IL10R) deficiency present with IBD and demonstrate the sensitivity of the intestine to any changes of the immune system. Both IL-10 and IL10R deficiency cause severe early-onset enterocolitis and can be successfully treated by hematopoietic stem cell transplantation (HSCT).     

Biliary Interleukin-6 and Tumor Necrosis Factor-α in Patients Undergoing Endoscopic Retrograde Cholangiopancreatography

Cytokines are low-molecular-weight proteinmediators that possess a wide spectrum of inflammatory,metabolic, and immunomodulatory properties. Cytokineshave been shown to be produced by monocytes/macrophages, lymphocytes, fibroblasts, endothelial cells,and more recently, hepatocytes and biliary epithelium.The aim of this study was to define biliary levels ofinterleukin-6 (IL-6) and tumor necrosis factor- (TNF-) in patients undergoing endoscopicretrograde cholangiopancreatography (ERCP) in variousdisease states. Fifty-four patients undergoing ERCPcomprised the study group. IL-6 and TNF- were measured in aspirated bile using an ELISAtechnique. Levels of both TNF- and IL-6 weresignificantly higher in patients with cholangitis (P< 0.00001). Moreover, IL-6 was 100% specific forcholangitis since none of the patients without bacterialcholangitis — including patients with biliaryobstruction secondary to cholangiocarcinoma orpancreatic carcinoma — had measurable IL-6 intheir bile. Low levels of biliary TNF- were detectable in fivepatients without cholangitis; the sensitivity andspecificity of TNF- for cholangitis were 100% and82%, respectively. There was a strong statisticalcorrelation between biliary IL-6 and TNF- levels (r= 0.819, P < 0.0001). In contrast, the correlationsbetween biliary cytokines and serum biochemicalparameters were weak. These results suggest that IL-6and TNF- are sensitive markers for cholangitis and maydifferentiate it from other types of biliary tractdisease.     

Associations of the −174 G/C Interleukin-6 Gene Promoter Polymorphism with Serum Interleukin 6 and Mortality in the Elderly

Serum interleukin-6 (sIL6) is an acknowledged predictor of all-cause mortality in older age. A common G/C polymorphism has been identified at position −174 of the IL6 gene promoter (IL6−174G>C), but its associations with sIL6 and mortality are still unclear. Data from a population-based elderly cohort (n = 824) were used to study the associations of baseline sIL6 with the IL6−174 C-allele (C+) carrier status and all-cause mortality at 4 years, in the presence and absence of preexisting major diseases (PMD). Analyses were adjusted for socio-demographic factors and body-mass-index. Three-hundred-eighty-eight participants (47.1%) had PMD. Compared to the bottom sIL6 quartile, mortality increased both in presence [Hazard Ratio (HR) = 3.04; 95% confidence interval (CI): 1.48–6.25] and absence of PMD [HR = 3.91; 95%CI: 1.42–10.72] for the third higher sIL6 quartile, but only in presence of PMD for the top sIL6 quartile [HR = 2.30; 95%CI: 1.09–4.83]. In absence of PMD, C+ carrier status did not affect both sIL6 and mortality. In presence of PMD, C+ carrier status was associated with increased baseline sIL6 [odds ratio 2.01; 95%CI: 1.25–3.22, for all sIL6 quartiles above the bottom] but not with increased mortality risk. A survival advantage was even found for C+ carriers with PMD and sIL6 in the top quartile [HR = 0.31, 95%CI: 0.13–0.76]. In conclusion, although associated with increased sIL6 levels in presence of major diseases, the IL6−174 C-allele does not seem to have direct detrimental effects on survival in older age.     

Clinical Features, Serum Interleukin-6, and Interferon-γ Levels of 34 Turkish Patients With Hepatoportal Sclerosis

Hepatoportal sclerosis (HPS) is a clinical disorder of obscure pathogenesis with a variable clinical profile. The aim of the study was to summarize the clinical features of Turkish patients with HPS and to measure the serum levels of interleukin (IL)-6 and interferon (IFN)-γ to determine the T helper cell profile in the pathogenesis. The study was conducted on 34 HPS patients (17 men, 17 women; mean age at diagnosis, 27±10 years) and 15 healthy controls. The clinical features of HPS patients including demographics, clinical history, laboratory, and ultrasonography findings were summarized. Serum IL-6 and IFN-γ levels were measured by using commercially available enzyme-linked immunosorbent assay kits. Gastrointestinal bleeding was the most common dominant presenting symptom. Majority of the patients had preserved liver function tests. Serum triglyceride levels were decreased in 30%. Abdominal ultrasonography revealed well-demarcated bands of increased echogenicity surrounding the portal vein wall and sudden narrowing of the intrahepatic second-degree portal vein branches in all cases. Spontaneous shunts and/or collaterals were seen in 13 cases (37%). Extrahepatic portal vein thrombosis were seen in 7 (20%) patients after at least 5 years of disease duration. Serum levels of both IL-6 (median, 3.2 pg/mL) and IFN-γ (median, 7.8 pg/mL) were significantly higher in HPS patients compared with the control group (median, 1 pg/mL). HPS has variable clinical profile in different geographic areas of the world. Both Th1 and 2 cells may have a role in the regulation of immune response and pathogenesis of the disease.     

Interleukin-6 serum concentration in ankylosing spondylitis: a reliable predictor of disease progression in the subsequent year?

The aim of the present study was to evaluate whether in ankylosing spondylitis (AS), interleukin-6 (IL-6) is a reliable predictor of changes in mobility in the subsequent year. Of 261 AS patients who had been enrolled in a previous study, 128 returned for treatment at our health centre after 1 year (±3 months). The variables for mobility after 1 year (II) were compared with the findings of the previous year (I). Differences in parameters for mobility were related to the serum concentration of IL-6 in the previous year. Relation between serum concentration of IL-6 and difference (II–I) in occiput-to-wall distance (Spearman's rank correlation coefficient r _s, P value) was 0.02, 0.82; chin–chest distance −0.09, 0.31; cervical rotation −0.08, 0.39; chest expansion 0.05, 0.54; finger–floor distance −0.02, 0.84; Ott sign (flexibility of the thoracic spine) −0.11, 0.22; Schober sign 0.01, 0.94. After 1 year there was a significant improvement in cervical rotation in patients with low IL-6 serum concentration (lower quartile), but not in those with high levels of IL-6 (upper quartile). No further difference was seen between patients with high or low levels of IL-6. The present data suggest that the serum concentration of IL-6 does not allow a prediction of disease progression in the subsequent year. Received: 15 September 1999 / Accepted: 20 January 2000     

Expression of Interleukin-11 and Interleukin-11 receptor a in human colorectal adenocarcinoma; Immunohistochemical analyses and correlation with clinicopathological factors

AIM: There is strong evidence that interleukin-11 (IL-11) is involved in the regulation of tumor progression, cellular growth and differentiation. Recently, interleukin-11 receptor (IL-11R) has been detected on some cancer cells. In this study, we investigated the expression of IL-11 and IL-11R in colorectal adenocarcinoma. METHODS: To elucidate the involvement of IL-11 and IL-11Ra in human intestinal adenocarcinomas, we examined 115 cases of surgically resected human colonic adenocarcinoma and 11 cases of adenoma by immuno-histochemistry and Western blotting. RESULTS: Among 115 cases of adenocarcinoma, 100 cases (87.0%) showed positive staining in the cytoplasm of carcinoma cells for the IL-11, and 87 cases (75.6%) were positive for the IL-11Ra. Six cases (54.5%) and four cases (36.4%) of 11 adenomas were positive for IL-11 and IL-11Ra, respectively. The expression of IL-11Ra correlated with the histological differentiation (P=0.033503), the depth of tumor invasion (P=0.006395), Dukes' classification (P= 0.015648) and lymphatic invasion (P=0.003865). However, the expression of IL-11Ra was not correlated with the venous invasion and the presence of lymph node metastasis. The expression of IL-11 was not correlated with any clinicopathological factors. In Western blot analysis, two human colorectal carcinoma cell lines and four tissues of surgically resected human carcinoma expressed both IL-11 and IL-11Ra proteins. CONCLUSION: IL-11 and IL-11Ra are highly expressed in human colorectal adenocarcinoma and the IL-11Ra expression is correlated with clinicopathological factors. These findings suggest that the expression of IL-11Ra is an important factor for the invasion of human colorectal adenocarcinoma.