A case of EBV driven haemophagocytic lymphohistiocytosis complicating a teenage Crohn's disease patient on azathioprine, successfully treated with rituximab

Rituximab as a Therapeutic Strategy in Hemophagocytic Lymphohistiocytosis: Efficacy, Outcomes, and Survival-Insights From a Systematic Review

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a severe immunologic disorder that can be fatal if left untreated. The condition is characterized by excessive immune system activation and is often triggered by infections such as Epstein-Barr virus (EBV). Rituximab, an anti-CD20 monoclonal antibody, has been suggested as a treatment, particularly for EBV-associated HLH.

METHODS

A systematic review was conducted using PRISMA guidelines, with a literature search spanning PubMed, Scopus, Web of Science, and the Cochrane Library. The inclusion criteria focused on studies that assessed rituximab's efficacy in treating HLH. Quality assessment was performed using the Joanna Briggs Institute Critical Appraisal Checklist for Case Reports.

RESULTS

Of 783 identified records, 24 studies were included in the final analysis. Rituximab was typically administered at 375 mg/m2, with varying doses and treatment frequency. Clinical response, often seen within 1 month, was assessed by improvements in clinical symptoms and laboratory findings. Survival rates posttreatment displayed a wide range, with instances of complete remission and disease-free periods, as well as reports of relapse and mortality.

CONCLUSION

Rituximab demonstrates the potential for significant clinical benefit in treating HLH, particularly when associated with EBV, showing promise in reducing disease activity and contributing to remission. These findings encourage further research and clinical trials to refine the therapeutic protocols and better understand the long-term effects of rituximab in HLH management.

Case report: Virus-induced hemophagocytic lymphohistiocytosis in a patient with APECED

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), also known as autoimmune polyglandular syndrome type 1 (APS-1) is a rare autosomal recessive inborn error of immunity (IEI), which is accompanied by immune dysregulation. Hypoparathyroidism, adrenocortical failure and candidiasis are its typical manifestations. Here we report about recurrent COVID-19 in a 3-year-old boy with APECED, who developed retinopathy with macular atrophy and autoimmune hepatitis after the first episode of SARS-CoV-2 infection. Primary Epstein-Barr virus infection and a new episode of SARS-CoV-2 infection with COVID pneumonia triggered the development of severe hyperinflammation with signs of hemophagocytic lymphohistiocytosis (HLH): progressive cytopenia (thrombocytopenia, anemia, lymphopenia), hypoproteinemia, hypoalbuminemia, high levels of liver enzymes, hyperferritinemia, increased triglycerides levels; and coagulopathy with a low level of fibrinogen. Treatment with corticosteroids and intravenous immunoglobulins did not lead to a significant improvement. The progression of HLH and COVID-pneumonia resulted in a fatal outcome. The rarity and varied presentation of the HLH symptoms led to diagnostic difficulties and diagnosis delay. HLH should be suspected in a patient with immune dysregulation and impaired viral response. Treatment of infection-HLH is a major challenge due to the difficulties in balancing immunosuppression and management of underlying/triggering infection.

Impact of Epstein-Barr virus infection in patients with inflammatory bowel disease

A high prevalence of Epstein-Barr virus (EBV) infection in patients with inflammatory bowel disease (IBD) has been reported in many case reports and studies; thus, the association between EBV and IBD has gained increasing attention. Patients with IBD are at an increased risk of opportunistic EBV infection owing to the common use of immunomodulators. EBV infection in IBD patients can cause various complications, including superimposed viral colitis, which is associated with chronicity, exacerbation, and poor prognosis of refractory IBD, and can induce progression to lymphoproliferative disorders, such as EBV-positive mucocutaneous ulcer (EBVMCU), lymphomatoid granulomatosis (LYG), hemophagocytic lymphohistiocytosis (HLH) and diffuse large B-cell lymphoma (DLBCL). It has been suggested to screen for EBV before initiating immunosuppressive therapy and monitor the status of EBV infection in patients with IBD, especially those who are EBV-seronegative and have a risk of primary EBV infection. Clinicians should also be careful of misdiagnosing IBD and EBV-associated lymphoproliferative diseases due to similarities in both clinical symptoms and endoscopic manifestations. Withdrawal of immunosuppressants has been shown to be an effective strategy to achieve remission of disease at the time of EBV diagnosis, but antiviral therapy remains controversial. The present review aims to describe the characteristics of the complications caused by EBV infection and generalize the recent research progress on and challenges caused by EBV infection in IBD patients. The literature for writing this review was collected from 'PubMed' research engine. The keywords 'inflammatory bowel disease and Epstein-Barr virus' or 'ulcerative colitis and Epstein-Barr virus' or 'Crohn's disease and Epstein-Barr virus' were used to collect the literature and relevant papers were collected to help writing this review.

Epstein-Barr Virus Status and Subsequent Thiopurine Exposure Within a Paediatric Inflammatory Bowel Disease Population

The use of thiopurine therapy in Epstein-Barr virus (EBV)-naïve inflammatory bowel disease (IBD) patients remains controversial due to a risk of EBV-associated complications. We evaluated EBV status and outcomes within our paediatric IBD population over an 8-year period; finding that 217 of 409 (53%) screened patients were seropositive for EBV at IBD diagnosis; that thiopurines were used in 189 of 217 (87%) seropositive and 159 of 192 (83%) seronegative patients (P = 0.22); and that 7 of 192 (4%) previously seronegative patients subsequently tested positive for EBV with 6 of 7 (86%) patients having concurrently recorded thiopurine use. All six patients continued thiopurine with/without a period of cessation; no EBV-associated lymphoproliferative disorders/serious complications were recorded within our cohort. A significant proportion of our patients would not receive thiopurine therapy should their use be avoided in EBV-negative patients (47%) or seronegative males (30%). The small but significant risks of thiopurine treatment must be balanced against the potential benefits of successful IBD management; further research into this is required.

Hemophagocytic Lymphohistiocytosis and Inflammatory Bowel Disease: Case Report and Systematic Review

Aim

To report a case of a female patient with hemophagocytic lymphohistiocytosis (HLH) and to systematically review the available cases of the association between HLH and inflammatory bowel disease (IBD).

Methods

In accordance to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, retrieval of studies was based on Medical Subject Headings and Health Sciences Descriptors, which were combined using Boolean operators. Searches were run on the electronic databases Scopus, Web of Science, MEDLINE (PubMed), Biblioteca Regional de Medicina, Latin American and Caribbean Health Sciences Literature, Cochrane Library for Systematic Reviews and Opengrey.eu. Languages were restricted to English, Spanish and Portuguese. There was no date of publication restrictions. The reference lists of the studies retrieved were searched manually.

Results

The search strategy retrieved 223 references. In the final analysis, 28 references were included, with the report of 35 cases. The most common clinical finding was fever, 57% of patients had a cytomegalovirus infection and 30 patients were on thiopurines previously to HLH diagnosis. Most patients were treated with steroids and antiviral therapy. All-cause mortality was 22%.

Conclusion

These findings suggest that there might be a connection of HLH to IBD, opportunistic viral infections and the use of thiopurines. Due to the severity of such disease, the clinical suspicion is paramount to early diagnosis and therapy.

Hemophagocytic lymphohistiocytosis: An update on pathogenesis, diagnosis, and therapy

Hemophagocytic lymphohistiocytosis (HLH) is a rare, life-threatening state of immune hyperactivation that arises in the setting of genetic mutations and infectious, inflammatory, or neoplastic triggers. Sustained, aberrant activation of cytotoxic CD8⁺ T cells and resultant inflammatory cytokine release are core pathogenic mechanisms. Key clinical features include high persistent fever, hepatosplenomegaly, blood cytopenia, elevated aminotransferase and ferritin levels, and coagulopathy. HLH is likely under-recognized, and mortality remains high, especially in adults; thus, prompt diagnosis and treatment are essential. Familial forms of HLH are currently treated with chemotherapy as a bridge to hematopoietic stem cell transplantation. HLH occurring in rheumatic disease (macrophage activation syndrome) is treated with glucocorticoids, IL-1 blockade, or cyclosporine A. In other forms of HLH, addressing the underlying trigger is essential. There remains a pressing need for more sensitive, context-specific diagnostic tools. Safer, more effective therapies will arise with improved understanding of the cellular and molecular mechanisms of HLH.

Increased incidence of systemic serious viral infections in patients with inflammatory bowel disease associates with active disease and use of thiopurines

Background

The magnitude and drivers of the risk of serious viral infections in Inflammatory Bowel diseases (IBD) are unclear.

Objective

The objective of this study was to assess the incidence and risk factors for systemic serious viral infections in IBD patients.

Methods

Using MICISTA, a database detailing prospective characteristics and complications of IBD, we identified patients that were followed for IBD in 2005-2014 outside the context of organ transplantation, HIV infection or chronic viral hepatitis. We estimated incidences of systemic serious viral infections, defined by the need for hospitalization or permanent organ damage. Standardized incidence ratios (SIRs) were calculated using the French hospital database. We performed a case-control study nested in MICISTA for assessing the role of exposure to IBD drugs and IBD clinical activity in the risk of developing infection.

Results

We identified 31 patients with serious viral infections among 2645 patients followed for 15,383 person-years. We observed 13 cases of cytomegalovirus, 10 Epstein-Barr virus, 5 varicella zoster virus and 3 herpes simplex virus infections. No deaths occurred. The incidence rate of infections in patients with IBD was 2.02/1000 person-years, and the SIR was 3.09 (95% confidence interval (CI), 1.98-4.20; p = 0.0002) in the study population. By multivariate analysis, increased risk of infection was associated with exposure to thiopurines (odds ratio (OR), 3.48; 95% CI, 1.36-8.90; p = 0.009), and clinically active IBD at onset of infection (OR, 3.35; 95% CI, 1.23-9.23; p = 0.02).

Conclusions

The incidence of systemic serious viral infections in patients with IBD is tripled compared to general population. Clinically active IBD and exposure to thiopurines are the main drivers of the risk.

Challenges in the diagnosis of hemophagocytic lymphohistiocytosis: Recommendations from the North American Consortium for Histiocytosis (NACHO)

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation, often associated with genetic defects of lymphocyte cytotoxicity. Though a distinctive constellation of features has been described for HLH, diagnosis remains challenging as patients have diverse presentations associated with a variety of triggers. We propose two concepts to clarify how HLH is diagnosed and treated: within the broader syndrome of HLH, "HLH disease" should be distinguished from "HLH disease mimics" and HLH subtypes should be categorized by specific etiologic associations, not the ambiguous dichotomy of "primary" and "secondary." We provide expert-based advice regarding the diagnosis and initiation of treatment for patients with HLH, rooted in improved understanding of its pathophysiology.

Infections and malignancies risks related to TNF-α-blocking agents in pediatric inflammatory bowel diseases

Introduction: Tumor necrosis factor-α (TNF-α)-blocking agents are drugs approved for the treatment of inflammatory bowel diseases (IBDs). Infliximab and adalimumab are approved for the treatment of IBD in the pediatric setting with the improvement of therapeutic management. Biological agents, also in the pediatric population, can be administered either alone or in combination with immunomodulators. Their use has raised safety concerns regarding the risk of infections and malignancies.Areas covered: A broad review of the safety concerns for the use of anti-TNF-α drugs in children with IBD was performed, and information regarding the risk of infections and malignancies were updated, also in comparison with the safety of traditional drugs such as steroids and/or immunosuppressants.Expert commentary: Anti-TNF-α drugs have shown favorable safety profiles, and adalimumab treatment is associated with lower immunogenicity compared with infliximab. Heightened awareness and vigilant surveillance leading to prompt diagnosis and treatment are important for optimal management.

A nearly fatal primary Epstein-Barr virus infection associated with low NK-cell counts in a patient receiving azathioprine: a case report and review of literature

Background

Symptomatic primary Epstein-Barr virus infection is a usually self-limiting illness in adolescents. We present a case of an adolescent who had been receiving azathioprine for inflammatory bowel disease for four years and developed a life-threatening primary Epstein-Barr virus infection successfully treated with rituximab.

Case presentation

An 11-year-old girl presented with chronic, bloody diarrhea. Endoscopic biopsies confirmed a diagnosis of chronic ulcerative colitis with features of Crohn’s disease. Azathioprine was initiated after one year due to active colitis. She responded well and remission was achieved. At the age of 16 years she developed a life-threatening Epstein-Barr virus infection including severe multiple organ failure and was critically ill for 4 weeks in the intensive care unit. Natural killer cells were virtually absent in the lymphocyte subset analysis. Azathioprine was stopped on admission. She was initially treated with corticosteroids, acyclovir and intravenous immunoglobulin. Approximately 30 days after admission, she developed signs of severe hepatitis and pneumonitis and received weekly rituximab infusions for 8 weeks. Primary immunodeficiency was excluded by whole exome sequencing in two independent laboratories. Persistent viremia stopped when the natural killer cell count started to rise, approximately 90 days after the cessation of azathioprine.

Conclusions

We found 17 comparable cases in the literature. None of the previous cases reported in the literature, who had been treated with azathioprine and developed either a severe or a fatal Epstein-Barr virus infection, underwent full genetic and prospective immunological workup to rule out known primary immunodeficiencies. Recently, azathioprine has been shown to cause rather specific immunosuppression, resulting in natural killer cell depletion. Our case demonstrates that slow recovery from azathioprine-induced natural killer cell depletion, 3 months after the stopping of azathioprine, coincided with the clearance of viremia and clinical recovery. Finally, our choice of treating the patient with rituximab, as previously used for patients with a severe immunosuppression and Epstein-Barr virus viremia, appeared to be successful in this case. We suggest testing for Epstein-Barr virus serology before starting azathioprine and measuring natural killer cell counts during the treatment to identify patients at risk of developing an unusually severe primary Epstein-Barr virus infection.

An Elusive Diagnosis: Case Reports of Secondary Hemophagocytic Lymphohistiocytosis and Review of Current Literature

Hemophagocytic lymphohistiocytosis (HLH) is a rare and serious hematologic disorder characterized by severe immune system dysregulation with a cytokine storm and histologic evidence of hemophagocytosis. It can be inherited or develop secondary to other diseases. We present three cases of secondary HLH in patients with distinct backgrounds. Our objective is to characterize the unique features of the disease, its underlying associations, treatment, and potential prognostic variables.

The first case was a 20-year-old male with a history of intravenous (IV) drug abuse who presented with multi-organ failure and septic shock. A diagnosis of HLH was suspected after finding a ferritin of >100,000 ng/mL and confirmed with bone marrow biopsy. Furthermore, the patient was found to have significant Epstein-Barr virus (EBV) viremia. He responded well to the HLH-94 protocol with the addition of rituximab and ganciclovir. The second case was a 50-year-old female with a history of human immunodeficiency virus (HIV) who presented with multi-organ failure and severe anemia. Ferritin was also significantly elevated and a bone marrow biopsy confirmed the diagnosis of HLH. She was started on HLH-94 protocol. Despite treatment, the patient expired due to worsening renal failure and shock. Her autopsy report also showed evidence of Hodgkin’s lymphoma. The third case was a 57-year-old male with a history of Crohn’s disease treated with infliximab and adalimumab, who presented with multi-organ failure and pancytopenia. A diagnosis of HLH was made based on clinical findings and later confirmed on bone marrow biopsy. He responded to HLH-94 protocol but experienced fatal gastrointestinal bleeding.

Patients presenting with HLH are often critically ill and deteriorate rapidly. The diagnosis is often challenging to establish due to its variable presentation and association with other pathologies. A moderate index of suspicion should be present for patients who have febrile illness with pancytopenia, multi-organ failure, high ferritin, and low fibrinogen levels. We discuss associations with viral infections, hematologic malignancies and immunosuppressive therapy. Treatment is directed at suppressing the immune response and for secondary HLH, addressing the underlying conditions, such as use of rituximab for EBV viremia and treatment of lymphoma.

Impact of Epstein-Barr virus serological status on clinical outcomes in adult patients with inflammatory bowel disease

BACKGROUND

Little is known about the impact of Epstein-Barr virus (EBV) infection on clinical outcomes in adults with inflammatory bowel disease (IBD).

AIM

To evaluate seroprevalence, seroconversion rate and complications associated with EBV infection in an adult IBD cohort attending a tertiary care hospital in Spain between 2006 and 2016.

METHODS

EBV serological status was determined. In seronegative patients, the seroconversion rate was evaluated. The complications associated with primary and latent EBV infection are described.

RESULTS

One thousand four hundred and eighty-three patients over the age of 17 were included in the study (mean age at EBV serological status determination was 48.3). Overall seroprevalence of EBV was 97.4% (95% CI: 96.6%-98.2%). The seroconversion rate was 29.7% (95% CI: 16.2-45.9) after a mean of 47.5 months. There were no differences in seroconversion rates between patients 35 years or younger and patients older than 35 years. A 66-year-old man, on treatment with thiopurines, developed lymphoma and a hemophagocytic syndrome during a primary EBV infection. Overall, six patients (one with primary infection and five with prior EBV infection) developed lymphoma. In three of five patients with lymphoma and thiopurine use, EBV was associated to the development of lymphoma.

CONCLUSIONS

There is a small percentage of adults with IBD at risk of primary EBV infection. The risks of seroconversion and its complications remain through adulthood. Our results suggest that, when considering the use of thiopurines in IBD, the information on EBV serological status should be taken into account at any age.

Update on the Use of Thiopurines and Methotrexate in Inflammatory Bowel Disease

PURPOSE OF REVIEW

The increased use of biologic agents over the past two decades has led to a reappraisal of the role of the immunomodulators (thiopurines and methotrexate) in the treatment of inflammatory bowel disease. The purpose of this review is to summarize recent data on the use of thiopurines and methotrexate either as monotherapy or as part of combination therapy with biologic agents.

RECENT FINDINGS

Recent studies have addressed the need for concomitant immunomodulatory therapy in treatment-naïve patients starting anti-TNF-α therapy, the appropriate dose of the immunomodulator in this setting, the minimum duration of combination therapy, and the possible mechanisms by which immunomodulators enhance the effectiveness of anti-TNF-α agents. Little is known about the role of immunomodulators in combination with agents belonging to other classes of biologic therapies. Recent studies have shown that methotrexate is not effective in inducing or maintaining remission in ulcerative colitis. Finally, several studies have broadened our understanding of the infection and malignancy risks of the immunomodulators. Immunomodulators continue to have a place in the treatment of inflammatory bowel disease. However, with the ever-increasing list of biologic agents, properly positioning the immunomodulators within the overall therapeutic scheme is a complicated task. In order to optimize outcomes, each patient requires an individualized approach, which takes into account risks, benefits, cost, alternatives, and patient preferences.

Pharmacological treatments and infectious diseases in pediatric inflammatory bowel disease

The incidence of pediatric inflammatory bowel disease (IBD) is rising, as is the employment of immunosuppressive and biological drugs. Most patients with IBD receive immunosuppressive therapies during the course of the disease. These molecules are a double-edged sword; while they can help control disease activity, they also increase the risk of infections. Therefore, it is important that pediatricians involved in primary care, pediatric gastroenterologists, and infectious disease physicians have a thorough knowledge of the infections that can affect patients with IBD. Areas covered: A broad review of the major infectious diseases that have been reported in children and adolescents with IBD was performed, and information regarding surveillance, diagnosis and management were updated. The possible correlations with IBD pharmacological tools are discussed. Expert commentary: Opportunistic infections are possible in pediatric IBD, and immunosuppressive and immunomodulator therapy seems to play a causative role. Heightened awareness and vigilant surveillance leading to prompt diagnosis and treatment are important for optimal management.

Crohn's disease complicated by Epstein-Barr virus-driven haemophagocytic lymphohistiocytosis successfully treated with rituximab

We report a case of Epstein-Barr virus (EBV)-driven haemophagocytic lymphohistiocytosis (HLH) in a man with Crohn's disease treated with 6-mercaptopurine and adalimumab therapy who was successfully treated with rituximab therapy alone. This is the first published case in an adult patient with EBV-driven HLH in the setting of thiopurine use and inflammatory bowel disease to be successfully treated with rituximab therapy alone. Here, we will discuss putative immunological mechanisms which may contribute to this potentially life-threatening complication.

Health Care Maintenance for the Pediatric Patient With Inflammatory Bowel Disease

Nearly one-quarter of patients with inflammatory bowel disease (IBD) are younger than 20 years of age at diagnosis. Furthermore, the incidence of IBD in children continues to increase. Nevertheless, variation in management exists within the care of patients with IBD with regards to disease screening and preventive care. A multidisciplinary approach that involves the general practitioner and pediatric gastroenterologist is needed to routinely monitor growth, bone health, vitamin and mineral deficiencies, vaccination status, and endoscopic surveillance. It is also important to monitor for extraintestinal manifestations of IBD that may affect the liver, joints, skin, and eyes. The purpose of this article is to provide an updated overview of comprehensive care for pediatric patients with IBD.

Haemophagocytic lymphohistiocytosis in inflammatory bowel disease with virus infection

Patients with inflammatory bowel disease (IBD) are at risk of developing haemophagocytic lymphohistiocytosis (HLH) because of chronic systemic inflammation as well as exposure to immunosuppressive medications. The two main causes of HLH in IBD patients are infection with cytomegalovirus and Epstein-Barr virus. Patients with Crohn's disease are more susceptible to HLH than those with ulcerative colitis. The majority of cases are seen in people receiving an immunosuppressive regimen that included thiopurines.

Alternative therapy for epstein-barr virus related hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly fatal condition characterized by excessive immune activation. HLH can occur as a familial or sporadic acquired disorder. Acquired HLH is more frequently found in adults and is commonly secondary to infections, malignancies, or autoimmune diseases. Diagnosing HLH is challenging because of the rare occurrence, variable presentation, and nonspecific findings of this disorder. Diagnosis of HLH can be based on the diagnostic criteria which were used in the HLH-2004 trial. Given the rarity of this disease, protocols for its treatment have developed slowly, and obtaining adequate short-term and long-term control of the disease continues to be a challenge. Conventional induction therapy for HLH is dexamethasone and etoposide (VP-16), followed by or with cyclosporine. Intrathecal methotrexate ± hydrocortisone is given to those with central nervous system disease. We are reporting a patient who was diagnosed with Epstein-Barr virus (EBV) related HLH. He achieved complete remission with rituximab alone. To our knowledge, this is the first case of an adult patient with EBV related HLH who went into remission with rituximab therapy alone, without using the conventional chemotherapy.

Prevention of infection caused by immunosuppressive drugs in gastroenterology

Immunosuppressive therapy is frequently used to treat gastrointestinal diseases such as inflammatory bowel disease, autoimmune hepatitis, IgG4-related disease (autoimmune pancreatitis and sclerosing cholangitis) and in the post-transplantation setting. These drugs interfere with the immune system. The main safety concern with their use is the risk of infections. Certain infections can be prevented or their impact minimized. Physicians must adopt preventative strategies and should have a high degree of suspicion to recognize infections early and treat appropriately. This article reviews the risk factors for infections, the mechanism of action of immunosuppressive therapy and proposes preventive strategies.

Systematic review: macrophage activation syndrome in inflammatory bowel disease

BACKGROUND

Recently, there have been increasingly frequent reports on the occurrence of macrophage activation syndrome (MAS) in patients with inflammatory bowel disease (IBD). Clinically, MAS is characterized mainly by fever, hepatosplenomegaly, cytopenia, and elevated circulating ferritin and CD25. Mortality, even if diagnosed rapidly, is high.

AIM

To identify all reports on MAS in IBD and to establish data on triggering agents, immunosuppression leading to MAS, and mortality.

METHODS

A language unrestricted search on Pubmed and Scopus relating to the past 30 years was carried out by matching the following search-terms: h(a)emophagocytic lymphohistiocytosis OR h(a)emophagocytic lymphohistiocytic syndrome OR macrophage activation syndrome OR opportunistic infections OR cytomegalovirus OR Epstein-Barr virus AND Crohn's disease OR ulcerative colitis OR inflammatory bowel disease(s).

RESULTS

Fifty cases were identified with an overall mortality of 30%. Virus-related MAS associated with cytomegalovirus or Epstein-Barr virus infections represents the main type of MAS, but in isolated cases bacterial infections precipitated the syndrome. In four cases (8%), a lymphoma was present at the time of MAS diagnosis or developed shortly thereafter. Thiopurine monotherapy was given before MAS onset in 56% of the patients, whereas multiple immunosuppression, including biologics, was administered to 24%.

CONCLUSIONS

In IBD patients, the syndrome appears to be triggered by infections, but genetic susceptibility may contribute to its development. Since immunosuppressive therapy represents the backbone of therapeutic interventions in IBD, with the risk of new, or the reactivation of latent infections, even more frequent cases of macrophage activation syndrome may be expected.