Diagnostic difficulties of the hemophagocytic lymphohistiocytosis (HLH) associated with the Epstein-Barr virus

Hemophagocytic lymphohistiocytosis: a case series analysis in a pediatric hospital

INTRODUCTION

Hemophagocytic lymphohistiocytosis (HLH) is a rare clinical laboratory condition with high mortality rates, resulting from ineffective overactivation of the immune system. Data in the Brazilian literature is scarce, contributing to the challenge in standardizing conducts and performing an early diagnosis of HLH.

OBJECTIVE

To describe the clinical, laboratory, and evolutionary findings on HLH patients treated at a pediatric hospital.

METHODS

This is an observational, cross-sectional and retrospective study on children diagnosed with HLH, hospitalized between 2009 and 2019. The diagnostic criteria were those described in the Histiocyte Society protocol. The authors evaluated HLH patient laboratory tests, myelograms and bone marrow biopsies, clinical characteristics and therapy.

RESULTS

Twenty-three patients were included, 52.2% of whom were males. The age at diagnosis ranged from one to one hundred and eighty months. Four cases were classified as Primary HLH and nineteen, as Secondary HLH. The main triggers were infections and rheumatological diseases. All children had bicytopenia, and 95.4% had hyperferritinemia. Nineteen patients had liver dysfunction, sixteen had neurological disorders and fourteen had kidney injury. Pulmonary involvement was seen in 61.9%, acting as a worse prognosis for death (p = 0.01). Nine patients underwent the immuno-chemotherapy protocol proposed in the HLH 2004. The time to confirm the diagnosis varied from five to eighty days. The lethality found was 56.3%.

CONCLUSIONS

The present study is the most extensive retrospective exclusively pediatric study published in Brazil to date. Despite the limitations, it was possible to demonstrate the importance of discussing HLH as a pediatric emergency.

Ruxolitinib treatment permits lower cumulative glucocorticoid dosing in children with secondary hemophagocytic lymphohistiocytosis

BACKGROUND

This study aimed to analyze the effects of ruxolitinib on children with secondary hemophagocytic lymphohistiocytosis (HLH).

METHODS

Eleven pediatric patients diagnosed with HLH and treated with ruxolitinib (ruxolitinib group: group R) between November 2017 and August 2018 were retrospectively analyzed. Eleven age-matched pediatric patients with HLH undergoing conventional treatment (control group: group C) during the same period were also analyzed.

RESULTS

In group R, three patients who did not respond to methylprednisolone (MP) pulse and intravenous immunoglobulin (IVIG) therapies were treated with Ruxolitinib and their temperature decreased to normal levels. Four patients had normal temperature after conventional treatment (dexamethasone and etoposide, with or without cyclosporine A), but they had severe organ involvement, including obvious yellowing of the skin, increased liver enzyme levels and neuropsychiatric symptoms, and they were all ameliorated with ruxolitinib treatment. Four patients were relieved with ruxolitinib therapy alone. In group C, the body temperatures of eleven patients decreased to normal levels after conventional treatment. The body temperature of group R patients decreased to normal levels more rapidly than that of group C patients. The glucocorticoid dosage in group R was significantly lower than that in group C. Both groups were followed-up for 2-2.5 years. No obvious adverse drug reactions to ruxolitinib were observed during treatment and follow-up.

CONCLUSION

Ruxolitinib might be an effective drug in controlling body temperature and reducing inflammation indicators. It might be a potential replacement for glucocorticoid therapy for HLH treatment in children, thereby reducing or avoiding glucocorticoid-related adverse reactions.

Downregulation of CD5 and dysregulated CD8+ T-cell activation

CD5 is a cell surface molecule that is expressed on most circulating T cells and a small population of B cells, and is involved in modulation of antigen-specific receptor-mediated activation. Downregulation of CD5 on CD8⁺ T cells is a poorly understood but increasingly recognized phenomenon that may be associated with dysregulated T-cell activation. An increased subpopulation of activated CD8⁺ T cells with downregulation of CD5 has recently been described in patients with Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (HLH) and familial HLH caused by perforin deficiency and Munc 13-4 deficiency. These cells were detectable only in the acute phase of HLH, in which patients exhibited hypercytokinemia, and declined progressively after successful treatment in parallel with improvement of systemic inflammation. It is unknown whether CD8⁺ T cells from HLH with other causes have similar profiles. Assessment of CD5 expression on T cells has the potential to assist in the understanding of the diagnosis and pathogenesis of human inflammatory diseases such as HLH.

Clinically Mild Encephalitis/Encephalopathy With a Reversible Splenial Lesion Accompanied by Epstein-Barr Virus Hemophagocytic Lymphohistiocytosis: A Case Report and Review of the Literature

Central nervous system involvement in hemophagocytic lymphohistiocytosis (HLH) is associated with a poor outcome. For such patients, it is unknown whether more aggressive therapies, such as intrathecal methotrexate or hydrocortisone, are inevitably required. We present a very rare case of 3-year-old Japanese girl who developed mild encephalitis/encephalopathy with a reversible splenial lesion, accompanied by Epstein-Barr virus-associated HLH, and review previous similar reports. Our case and previous reports suggest that mild encephalitis/encephalopathy with a reversible splenial lesion accompanied by Epstein-Barr virus-associated HLH has a relatively good prognosis, even in the absence of intrathecal treatments.

Hemophagocytic lymphohistiocytosis: review of etiologies and management

Hemophagocytic lymphohistiocytosis (HLH) covers a wide array of related life-threatening conditions featuring ineffective immunity characterized by an uncontrolled hyperinflammatory response. HLH is often triggered by infection. Familial forms result from genetic defects in natural killer cells and cytotoxic T-cells, typically affecting perforin and intracellular vesicles. HLH is likely under-recognized, which contributes to its high morbidity and mortality. Early recognition is crucial for any reasonable attempt at curative therapy to be made. Current treatment regimens include immunosuppression, immune modulation, chemotherapy, and biological response modification, followed by hematopoietic stem-cell transplant (bone marrow transplant). A number of recent studies have contributed to the understanding of HLH pathophysiology, leading to alternate treatment options; however, much work remains to raise awareness and improve the high morbidity and mortality of these complex conditions.