Multidisciplinary Teamwork Needed to Improve HLH Prognosis in Adults, Study Says

Multidisciplinary Teamwork Needed to Improve HLH Prognosis in Adults, Study Says

A highly cooperative multidisciplinary approach is crucial to improve the prognosis of adults with hemophagocytic lymphohistiocytosis (HLH), a study says.

The study, “Hemophagocytic lymphohistiocytosis in adults: collaborative analysis of 137 cases of a nationwide German registry,” was published in the Journal of Cancer Research and Clinical Oncology.

HLH is characterized by excessive inflammation and organ damage due to an overactivation of the immune system. The disease is considered primary when it is caused by mutations in specific genes that control the activity of the immune system, or secondary when it is associated with medical conditions that act as triggers, such as autoimmune diseases or cancer.

The primary form of the disease usually manifests during childhood. Pediatric data was used to determine the current diagnostic criteria (HLH-2004) defined by the Histiocyte Society. Due to its rarity, detailed systematic data about HLH in adults is limited.

“In adults, systematic data are sparse, which is why recommendations on diagnosis and management have been adopted from pediatric guidelines,” the researchers wrote.

To better characterize the disease in adults, a group of HLH experts in Germany, including pediatricians and hematologists, joined efforts to create a nationwide clinical registry for HLH.

In the study, investigators reported the findings from the first analysis performed based on data gathered from this registry.

The analysis was based on data from 137 adults (87 male and 50 female, with a median age at diagnosis of 50 years), with a proven or suspected diagnosis of HLH, whose information was gathered and added to the registry.

The HLH-2004 diagnostic criteria and the Hscore diagnostic algorithm were both used to confirm the diagnosis of HLH. Additional data about underlying disorders, treatment, clinical presentation, and laboratory findings were also recorded and analyzed.

Infections were found to be the most common triggers for HLH (44.5%) in this patient group, followed by different types of cancer (35%). The most common infections associated with HLH included those caused by viruses (28.5%), such as Epstein-Barr virus (15.3%) or cytomegalovirus (2.9%). B-cell lymphoma was the most common type of cancer associated with HLH, accounting for 21.9% of cases.

Although symptoms varied, nearly all patients had fever (98%), and a significant proportion (86%) had an abnormally large spleen (splenomegaly). More than half (61%) of the patients also had an abnormally enlarged liver (hepatomegaly), nearly half (47%) had kidney failure, and approximately a third had respiratory insufficiency (33%), and neurological symptoms (31%).

Nearly all patients (99%) had abnormally high levels of ferritin, a protein that is responsible for storing iron in the body, and 73% had cytopenia (low blood cell counts).

As for treatment, most patients taking anti-inflammatory medications were using glucocorticosteroids (90.5%), either alone or in combination with immunosuppressants, or as part of a chemotherapy regimen in the case of those with cancer-associated HLH.

At the time of the analysis (June 30, 2017), 51% of the patients in the registry had died. The most common cause of death was multi-organ failure. Those with HLH-associated cancer had the shortest median survival (160 days), followed by those with idiopathic HLH (248 days), and infection-associated HLH (641 days).

Statistical analyses revealed platelet counts under 20×109/L, and albumin levels below 20 g/L were both independent predictors of poor 30-day survival following HLH diagnosis.

Overall, “HLH in adults is clinically highly heterogeneous,” wrote the researchers, who suggested that “close multidisciplinary case consultation and cooperation is mandatory when treating adult HLH patients.”

“Further cooperative research is necessary to systematically study this rare syndrome and to define optimal treatment algorithms, including novel targeted therapies,” they added.