Treatment of Epstein-Barr virus-related hemophagocytic lymphohistiocytosis: Study protocol of a prospective pilot study

Clinical utility of plasma Epstein-Barr virus DNA monitoring in pediatric Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis: a Chinese retrospective observational study

BACKGROUND

Epstein-Barr virus DNA (EBV-DNA) is closely related to the pathogenesis and prognosis of EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). The quantitative measurement of blood EBV-DNA is widely used in EBV-HLH, but there remains a lack of evidence to guide clinicians.

METHODS

A retrospective analysis was conducted on clinical manifestations, laboratory tests, 310 blood EBV-DNA loads, and prognosis of 51 pediatric patients diagnosed with EBV-HLH. Receiver operating characteristic (ROC) curves were utilized to determine the optimal cutoff values of EBV-DNA for predicting mortality and evaluating the active status of EBV-HLH.

RESULTS

EBV-positive- lymphoma-HLH had higher initial plasma EBV-DNA load(1.10 × 106copies/ml) compared to the EBV-HLH group (1.98 × 104 copies/ml) (P = 0.006), and experienced recurrently elevated plasma EBV-DNA levels during treatment. The optimal cut-off value of initial plasma EBV-DNA load in predicting mortality was 2.68 × 105 copies/ml, with a sensitivity of 88.57% and a specificity of 56.25%. For determining the active status of HLH, the optimal cutoff value of PBMC EBV-DNA load during treatment was 2.95 × 105 copies/ml, with a sensitivity of 69.14% and a specificity of 64.71%. The cut-off value of plasma EBV-DNA for determining active status was 1.32 × 103 copies/ml, with a sensitivity of 84.34%, and a specificity of 87.67%. Patients with higher PBMC and plasma EBV-DNA at initial and those with repeated elevated plasma EBV-DNA during treatment had worse prognoses (P < 0.05).

CONCLUSION

Dynamic monitoring of EBV-DNA is a valuable tool for assessing disease status and predicting the prognosis of EBV-HLH, with plasma EBV-DNA being more effective than PBMC EBV-DNA. Patients with high levels of PBMC and plasma EBV-DNA at initial and those with repeated elevated plasma EBV-DNA during treatment had worse prognoses.

Virus-triggered secondary hemophagocytic lymphohistiocytosis

Primary (familial/hereditary) and secondary (non-familial/hereditary) hemophagocytic lymphohistiocytosis (HLH) are hyperinflammatory and hypercytokinemic syndromes. Secondary HLH includes infection- (eg viral/bacterial/fungal/parasitic) and non-infection- (eg collagen disease or malignancy) related diseases. Viral HLH is the major type among all age groups. Secondary viral HLH and primary HLH must be differentiated carefully because primary HLH can be associated with viral infection(s), and the outcome is dismal without a timely diagnosis and hematopoietic stem cell transplantation (HSCT). Epstein-Barr virus (EBV)-related HLH (EBV-HLH) is the most common type of viral HLH in childhood. For non-EBV-HLH, appropriate treatment of viral infection, followed by immunomodulatory agent(s) such as corticosteroids, intravenous immunoglobulin or cyclosporine A, is usually successful; however, recent SARS-CoV-2-related HLH may become life-threatening. EBV-HLH may occur heterogeneously associated with the primary infection, with chronic active EBV infection or with underlying primary HLH. Although immunomodulatory agent(s) are effective in the majority of EBV-HLH cases, management differs from that of non-EBV-HLH because severe and refractory cases may require etoposide-containing HLH-1994/2004 regimens or other experimental agents. The novel agent, emapalumab (an anti-IFN-γ monoclonal antibody) can be used to treat EBV-HLH cases to avoid the risk of secondary malignancy due to etoposide. Finally, HSCT is required for refractory EBV-HLH cases and can also be curative in some other cases.