Changes in serum hepcidin levels in children with inflammatory bowel disease during anti-inflammatory treatment

Hepcidin and Iron Status in Patients With Inflammatory Bowel Disease Undergoing Induction Therapy With Vedolizumab or Infliximab

BACKGROUND

Hepcidin, the systemic iron regulator, could be critical in differentiating iron deficiency (ID) from functional iron restriction in inflammatory bowel disease (IBD). We assessed hepcidin as a diagnostic ID marker and explored the relationship between hepcidin and its regulators in patients with IBD undergoing induction therapy with infliximab (IFX) or vedolizumab (VEDO).

METHODS

Patients with active IBD receiving induction therapy with IFX or VEDO were included. Serum samples at baseline and after 6 weeks of induction therapy were analyzed for hepcidin, inflammation- and hypoxia-associated cytokines, and oxidative stress. Data were analyzed by stratifying based on the response at week 14. Results were compared with samples from age- and sex-matched healthy control subjects.

RESULTS

Patients receiving induction therapy with IFX (n = 71) or VEDO (n = 51) and healthy control subjects (n = 50) were included. At baseline, hepcidin correlated positively with ferritin and negatively with soluble transferrin receptor/log ferritin index (P < .001). ID was prevalent in 96.7% of patients who had hepcidin levels below the median. Hepcidin accurately identified ID: the area under the curve (hepcidin) was 0.89 (95% confidence interval, 0.82-0.95; P < .001). In total, 75.4% of patients responded to induction therapy; inflammation, hepcidin, and ferritin decreased significantly, while transferrin increased during induction therapy. These changes were observed only in patients who responded to the therapy.

CONCLUSIONS

Hepcidin levels in IBD are primarily determined by ID, even in an inflammatory state. In addition, induction therapy can decrease hepcidin levels, which might lead to better bioavailability of iron supplements. Therefore, hepcidin is a potential diagnostic ID biomarker that could assist therapeutic decision making.

Lactoferrin for iron-deficiency anemia in children with inflammatory bowel disease: a clinical trial

BACKGROUND

Iron-deficiency anemia (IDA) is common in children with inflammatory bowel disease (IBD); however, oral iron supplements are commonly associated with poor compliance due to gastrointestinal side effects. We compared the effect of lactoferrin versus oral ferrous sulfate for the treatment of IDA in children with IBD.

METHODS

Ninety-two IBD children with IDA were included but only 80 children completed the study and they were randomized into two groups: ferrous sulfate group (n = 40) who received ferrous sulfate 6 mg/kg/day for 3 months and lactoferrin group (n = 40) who received lactoferrin 100 mg/day for 3 months. Complete blood count, serum iron, total iron-binding capacity (TIBC), transferrin saturation (TS), serum ferritin, interleukin-6 (IL-6), and hepcidin 25 were measured before and after the treatment.

RESULTS

Hemoglobin (Hb), mean corpuscular volume, serum iron, TS, and serum ferritin significantly increased, while TIBC decreased significantly after the administration of either ferrous sulfate or lactoferrin compared to their baseline data. In addition, lactoferrin significantly increased Hb, serum iron, TS, and serum ferritin compared to ferrous sulfate. Moreover, lactoferrin significantly decreased IL-6 and hepcidin levels.

CONCLUSION

Lactoferrin is a promising effective treatment with fewer side effects than oral elemental iron in children with IBD and IDA.

CLINICAL TRIAL REGISTRATION

The study was registered at www.pactr.org (PACTR202002763901803).

IMPACT

Iron-deficiency anemia (IDA) in children with inflammatory bowel disease (IBD) is treated with oral iron therapy; however, oral iron supplements are commonly associated with poor compliance due to gastrointestinal side effects. To the best of our knowledge, our study was the first in pediatrics that compared the effect of lactoferrin versus oral ferrous sulfate as an iron supplement for the treatment of IDA in children with IBD. We found that lactoferrin is a promising effective treatment with fewer side effects than oral elemental iron in children with IBD and IDA.

Importance of Hepcidin in the Etiopathogenesis of Anemia in Inflammatory Bowel Disease

Anemia is the most common extraintestinal systemic complication of inflammatory bowel disease. Iron deficiency anemia and anemia of chronic disease are among the most frequent types. Intestinal iron absorption is controlled by the activity of ferroportin. Cells with high expression of ferroportin include enterocytes, and also macrophages and hepatocytes. Iron homeostasis is controlled by the hepcidin-ferroportin axis. Hepcidin is a central regulator of iron metabolism and can also serve as a marker of systemic inflammation. During systemic inflammatory response, the synthesis of hepcidin increases, and hepcidin binds to ferroportin and inhibits its activity. Thus, iron is not absorbed from the bowel into the circulation and also remains sequestered in macrophages. Conversely, hepcidin synthesis is suppressed during conditions requiring increased iron intake for enhanced erythropoiesis, such as iron deficiency anemia or hypoxia. Here, ferroportin is not blocked, and iron is actively absorbed into the bloodstream and also released from the stores. Production of hepcidin is influenced by the status of total body iron stores, systemic inflammatory activity and erythropoietic activity. Oral iron therapy is limited in inflammatory bowel diseases due to ongoing gastrointestinal inflammation. It is less effective and may worsen the underlying disease. Therefore, the choice between oral and parenteral iron therapy must be made with caution. Oral iron would be ineffective at high hepcidin levels due to concurrent ferroportin blockage. Contrarily, low levels of hepcidin indicate that oral iron therapy should be successful. An understanding of hepcidin can help in understanding the body's reaction to iron depletion during the inflammatory process.

Anti-TNF-α Monoclonal Antibody Therapy Improves Anemia through Downregulating Hepatocyte Hepcidin Expression in Inflammatory Bowel Disease

Anemia is one of the most common complications in patients with inflammatory bowel disease (IBD). Hepcidin as a key regulator of iron metabolism is pivotal in mediating the occurrence of anemia of chronic disease. Herein, we analyzed the levels of hepcidin in sera from IBD patients by enzyme-linked immunosorbent assay and investigated its potential role in regulating the anemia in IBD. We observed that the levels of serum hepcidin were increased in active IBD patients compared with those in remitted IBD patients and healthy controls and that serum hepcidin was associated with disease activity, CRP, and ESR, respectively. Importantly, we found that the increased levels of serum hepcidin were positively correlated with the severity of anemia and the imbalance of iron metabolism in anemic UC and CD patients. Proinflammatory factors (e.g., IL-6, IL-17, and TNF-α) were positively correlated with the concentrations of serum hepcidin in IBD patients. Interestingly, hepcidin was found to be decreased in patients with Crohn's disease after successful therapy with anti-TNF-α mAb (i.e., infliximab), indicating the underlying association between TNF-α and hepcidin expression. To investigate the specific mechanisms involved, we cultured LO2 and HepG2 cell lines in vitro under stimulation with TNF-α and observed that the levels of hepcidin mRNA were markedly upregulated in caspase-3/8- and NF-κB-dependent manners. Therefore, our data suggest that TNF-α stimulates the expression of hepcidin in IBD patients, resulting in aggravated anemia and that blockage of TNF-α or the caspase-3/8 and NF-κB pathways could downregulate hepcidin expression. This study provides inspiration for the therapy and management of anemia in IBD.