Genetic features of late onset primary hemophagocytic lymphohistiocytosis in adolescence or adulthood. PLoS One. 2014;9:e107386. [PMID: 25233452 PMCID: PMC4169386 DOI: 10.1371/journal.pone.0107386]

Dynamic Changes, Cut-Off Points, Sensitivity, and Specificity of Laboratory Data to Differentiate Macrophage Activation Syndrome from Active Disease

PURPOSE

To compare the laboratory data and changes in these data between patients with MAS and patients with flare-up of the autoimmune diseases.

METHODS

In a prospective study, the static laboratory data and dynamic changes in the selected data in 17 consecutive patients with MAS and 53 patients with active disease of SJIA, PJIA, Kawasaki disease, and SLE were compared. The ROC curve analysis was used to evaluate cut-off points, sensitivity, and specificity of the static and dynamic laboratory data to differentiate between MAS and active disease.

RESULTS

In the MAS group, the mean CRP3, ALT, AST, total bilirubin, ferritin, LDH, PT, PTT, and INR were significantly higher and the mean WBC2, PMN2, Lymph2, Hgb1, 2, 3, ESR2, serum albumin, and sodium were significantly lower than in control group. Some of the important cut-off points were PLT2 < 209000/microliter, AST > 38.5, ALT > 38, WBC < 8200 × 103/UL, ferritin > 5277 ng/mL.

CONCLUSION

The dynamic changes in some laboratory data, especially PLT, can differentiate between MAS and active disease. The changes in WBC, PMN, and ESR and the levels of the liver enzymes may also be helpful in the early differentiation. Very high levels of ferritin may also help the diagnosis along with other clinical and laboratory signs.

The unique aspects of presentation and diagnosis of hemophagocytic lymphohistiocytosis in adults

Hemophagocytic lymphohistiocytosis (HLH) was initially described as an inflammatory condition affecting young children but is increasingly diagnosed in adults. Presenting features such as fever, cytopenias, phagocytosis, elevated ferritin, and increased levels of soluble IL-2 receptor are common in both age groups, but the prevalence of several clinical and biochemical criteria differ between pediatric and adult patients. Specifically, an elevated ferritin level does not have the same specificity for HLH in adults, and many other inflammatory conditions need to be considered in the differential. In contrast to the high incidence of infectious triggers seen in pediatric HLH, HLH in adults is often precipitated by a hematologic malignancy. Malignancy-associated HLH has unique manifestations and a uniformly very poor prognosis. Given these differences, diagnostic scoring systems unique to adult HLH have been proposed, and additional prognostic clinical and immunologic parameters are being explored. Although a genetic predisposition is increasingly found to underlie cases of adult-onset HLH, the mutations are less likely to be bi-allelic and differ slightly from those seen in pediatric cases of familial HLH. The facilitating genetic and environmental factors governing presentation of HLH in adults remain elusive. Understanding the clinical aspects and pathophysiology specific to adults with HLH is necessary to tailor therapies derived in pediatric disease to this under-recognized population.

Treatment of hemophagocytic lymphohistiocytosis in adults

Treatment of hemophagocytic lymphohistiocytosis (HLH) has been developed primarily in pediatric centers, where familial HLH (FHL) is the leading cause of HLH in newborns and toddlers. The Histiocyte Society Study Group for HLH developed the HLH-94 and HLH-2004 treatment protocols, and these are frequently also used by centers treating HLH in adults (aHLH). These protocols contain etoposide, dexamethasone, and cyclosporine A; these agents all have strong activity against proliferation of cytotoxic T/NK-cells and macrophages, as well as inhibitory activity against the cytokine storm that induces, and maintains HLH. In children with predominantly hereditary disease, the HLH-94 protocol can be regarded as a "one size fits all" algorithm. HLH in adults is a much more heterogeneous syndrome requiring a more individualized approach depending on the underlying trigger, disease severity and course, as well as genetic background. Additionally, treatment in adults usually needs to be modified in the face of the preceding disease history and comorbidities. Interdisciplinary patient care with rheumatologists, gastroenterologists, neurologists, pediatricians, the transplant team, and pathologists is a prerequisite to successful treatment. The preferred approach should reflect a disease- and risk-adapted treatment that includes rigorous supportive care with continuous reassessment of sequential therapeutic measures. It should be recognized that the algorithm of HLH treatment in adults is based more on expert opinion than on extensive scientific evidence.

Host genetics of Epstein-Barr virus infection, latency and disease

Epstein–Barr virus (EBV) infects 95% of the adult population and is the cause of infectious mononucleosis. It is also associated with 1% of cancers worldwide, such as nasopharyngeal carcinoma, Hodgkin's lymphoma and Burkitt's lymphoma. Human and cancer genetic studies are now major forces determining gene variants associated with many cancers, including nasopharyngeal carcinoma and Hodgkin's lymphoma. Host genetics is also important in infectious disease; however, there have been no large-scale efforts towards understanding the contribution that human genetic variation plays in primary EBV infection and latency. This review covers 25 years of studies into host genetic susceptibility to EBV infection and disease, from candidate gene studies, to the first genome-wide association study of EBV antibody response, and an EBV-status stratified genome-wide association study of Hodgkin's lymphoma. Although many genes are implicated in EBV-related disease, studies are often small, not replicated or followed up in a different disease. Larger, appropriately powered genomic studies to understand the host response to EBV will be needed to move our understanding of the biology of EBV infection beyond the handful of genes currently identified. Fifty years since the discovery of EBV and its identification as a human oncogenic virus, a glimpse of the future is shown by the first whole-genome and whole-exome studies, revealing new human genes at the heart of the host–EBV interaction. © 2014 The Authors. Reviews in Medical Virology published by John Wiley & Sons Ltd.