Successful Treatment of Hypereosinophilic Syndrome with Cyclosporine

The multidisciplinary approach to eosinophilia

Eosinophilic granulocytes are normally present in low numbers in the bloodstream. Patients with an increased number of eosinophilic granulocytes in the differential count (eosinophilia) are common and can pose a clinical challenge because conditions with eosinophilia occur in all medical specialties. The diagnostic approach must be guided by a thorough medical history, supported by specific tests to guide individualized treatment. Neoplastic (primary) eosinophilia is identified by one of several unique acquired genetic causes. In contrast, reactive (secondary) eosinophilia is associated with a cytokine stimulus in a specific disease, while idiopathic eosinophilia is a diagnosis by exclusion. Rational treatment is disease-directed in secondary cases and has paved the way for targeted treatment against the driver in primary eosinophilia, whereas idiopathic cases are treated as needed by principles in eosinophilia originating from clonal drivers. The vast majority of patients are diagnosed with secondary eosinophilia and are managed by the relevant specialty-e.g., rheumatology, allergy, dermatology, gastroenterology, pulmonary medicine, hematology, or infectious disease. The overlap in symptoms and the risk of irreversible organ involvement in eosinophilia, irrespective of the cause, warrants that patients without a diagnostic clarification or who do not respond to adequate treatment should be referred to a multidisciplinary function anchored in a hematology department for evaluation. This review presents the pathophysiology, manifestations, differential diagnosis, diagnostic workup, and management of (adult) patients with eosinophilia. The purpose is to place eosinophilia in a clinical context, and therefore justify and inspire the establishment of a multidisciplinary team of experts from diagnostic and clinical specialties at the regional level to support the second opinion. The target patient population requires highly specialized laboratory analysis and therapy and occasionally has severe eosinophil-induced organ dysfunction. An added value of a centralized, clinical function is to serve as a platform for education and research to further improve the management of patients with eosinophilia. Primary and idiopathic eosinophilia are key topics in the review, which also address current research and discusses outstanding issues in the field.

Comparison of cyclosporine and systemic corticosteroid for treating drug reaction with eosinophilia and systemic symptoms syndrome: A retrospective 20-year single-centre study in South Korea

BACKGROUND/OBJECTIVES

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a potentially life-threatening hypersensitive disorder. Cyclosporine has been indicated for adverse cutaneous drug eruptions. However, studies evaluating its clinical effectiveness in DRESS syndrome have been rare. This study aimed to evaluate the clinical efficacy of cyclosporine in DRESS syndrome compared to that of systemic corticosteroids.

METHODS

In the cyclosporine group, oral cyclosporine was administered twice a day for a total of 2-3 mg/kg/day for 1 week, and subsequently reduced to 1-1.5 mg/kg/day for extended treatment. In the corticosteroid group, intravenous or oral methylprednisolone was administered at 1-1.5 mg/kg/day for 1 week, with variable tapering plans. Laboratory changes before and after treatment, hospitalized days, treatment periods, and time to normalization from clinical manifestations in each group were statistically evaluated. Adverse effects of these regimens were observed during the entire treatment period.

RESULTS

Eighty patients were enrolled in this retrospective study. The cyclosporine and corticosteroid group had 27 and 53 patients, respectively. Total leucocyte and eosinophil counts, liver enzymes, and C-reactive proteins were significantly decreased after treatment in both groups. There were no statistically significant differences observed in hospitalized days, treatment period, and time to normalization from clinical manifestations between the two groups. The corticosteroid group experienced relatively more adverse effects than the cyclosporine group.

CONCLUSIONS

Cyclosporine was discovered to be clinically effective in DRESS syndrome and this study suggests that cyclosporine could be a feasible primary therapeutic option for DRESS syndrome.

Treatment of lymphocyte-variant hypereosinophilic syndrome (L-HES): what to consider after confirming the elusive diagnosis

Lymphocyte-variant hypereosinophilic syndrome (L-HES) is a rare disease driven by immunophenotypically aberrant T cells producing eosinophilopoetic cytokines such as interleukin-5 (IL-5). Treatment is challenging because L-HES is relatively steroid resistant and not amenable to tyrosine kinase inhibitors. We searched the literature for clinical trials and observational studies, including case reports, of patients treated for L-HES. In all, 25 studies were selected; two were randomised controlled trials of IL-5 blockade, which included some patients with L-HES, and the rest were observational studies. Corticosteroids are often used as first-line therapy, but patients with L-HES have lower response rates than other types of HES. Treatments that reduce symptoms and steroid dependence in some patients include interferon-alpha (IFN-α), anti-IL-5 monoclonal antibodies, cyclosporine and mycophenolate. These drugs target T-cell activation and proliferation, or IL-5 directly. Although effective, IFN-α and cyclosporine were commonly reported to cause side-effects resulting in discontinuation. Alemtuzumab can induce remissions, but these are generally short lived. The anti-IL-5 monoclonal antibodies mepolizumab and benralizumab are effective and well tolerated, but with a high rate of relapse once withdrawn. Hydroxyurea, methotrexate, imatinib were unsuccessful in most patients studied. More prospective clinical trials are needed for patients with L-HES.

NIK prevents the development of hypereosinophilic syndrome-like disease in mice independent of IKKα activation

Immune cell-mediated tissue injury is a common feature of different inflammatory diseases, yet the pathogenetic mechanisms and cell types involved vary significantly. Hypereosinophilic syndrome (HES) represents a group of inflammatory diseases that is characterized by increased numbers of pathogenic eosinophilic granulocytes in the peripheral blood and diverse organs. On the basis of clinical and laboratory findings, various forms of HES have been defined, yet the molecular mechanism and potential signaling pathways that drive eosinophil expansion remain largely unknown. In this study, we show that mice deficient of the serine/threonine-specific protein kinase NF-κB-inducing kinase (NIK) develop a HES-like disease, reflected by progressive blood and tissue eosinophilia, tissue injury, and premature death at around 25-30 wk of age. Similar to the lymphocytic form of HES, CD4(+) T cells from NIK-deficient mice express increased levels of Th2-associated cytokines, and eosinophilia and survival of NIK-deficient mice could be prevented completely by genetic ablation of CD4(+) T cells. Experiments based on bone marrow chimeric mice, however, demonstrated that inflammation in NIK-deficient mice depended on radiation-resistant tissues, implicating that NIK-deficient immune cells mediate inflammation in a nonautonomous manner. Surprisingly, disease development was independent of NIK's known function as an IκB kinase α (IKKα) kinase, because mice carrying a mutation in the activation loop of IKKα, which is phosphorylated by NIK, did not develop inflammatory disease. Our data show that NIK activity in nonhematopoietic cells controls Th2 cell development and prevents eosinophil-driven inflammatory disease, most likely using a signaling pathway that operates independent of the known NIK substrate IKKα.

Purtscher-like retinopathy and primary hypereosinophilic syndrome association

PURPOSE

The purpose of this study was to describe a patient who presented with a Purtscherlike retinopathy and subsequent diagnosis of primary hypereosinophilic syndrome.

METHODS

Observational case report.

PATIENT

A 39-year-old woman presented with a 10-day history of blurry vision and urticarial skin rash. Retinoscopic examination demonstrated bilateral cotton wool spots in the posterior pole, Purtscher flecken, and intraretinal hemorrhages. Workup included a complete history and systemic physical examination, fluorescein angiography, serum laboratory evaluation, magnetic resonance imaging of brain and orbits, pathologic analysis of skin and bone marrow biopsies, flow cytometry, and cytogenetic testing.

RESULTS

The diagnosis given to this patient was primary hypereosinophilic syndrome. Review of the literature reveals one previous report of this association.

CONCLUSION

The differential diagnosis of Purtscher retinopathy should include hypereosinophilic syndrome.