Additional testing
These tests can help with identifying HLH
Genetic testing takes time, and patients with primary HLH often require immediate treatment to control their hyperinflammation.1 There are a range of other tests that can be conducted in the meantime to help identify potential underlying triggers and to help confirm or rule out a primary HLH diagnosis.
Flow cytometry testing
CD=cluster of differentiation; SLAM=signaling lymphocytic activation molecule; XIAP=X-linked inhibitor of apoptosis.
Flow cytometry for perforin expression and CD107a have high specificity for identifying HLH with a genetic basis.3
Ancillary testing2,4
CMV=cytomegalovirus; CT=computed tomography; EBV=Epstein-Barr virus; HSV=herpes simplex virus; MRI=magnetic resonance imaging; PCR=polymerase chain reaction; PET=positron emission tomography.
These tests can help identify an underlying trigger for patients with primary HLH, or to rule out other conditions.2
Other tests2
ALT=alanine aminotransferase; CXCL9=chemokine (C-X-C motif) ligand 9; IL=interleukin.
These tests are useful for identifying the typical features of primary HLH.5 There is evidence suggesting that CXCL9 testing can be helpful for measuring the IFNγ levels in patients with HLH.6
References: 1. Jordan MB, Allen CE, Weitzman S, Filipovich AH, McClain KL. How I treat hemophagocytic lymphohistiocytosis. Blood. 2011;118(15):4041-4052. doi:10.1182/blood-2011-03-278127 2. Cincinnati Children’s Diagnosing HLH. Accessed October 23, 2023. https://www.cincinnatichildrens.org/service/h/hlh/clinical/test 3. Marsh RA, Haddad E. How I treat primary haemophagocytic lymphohistiocytosis. Br J Haematol. 2018;182(2):185-199. doi:10.1111/bjh.15274 4. Jongbloed EM, Hermans MAW, Wabbijn M, van Kampen JJA, van Laar JAM. HLH caused by an HSV-2 infection: a case report and review of the literature. Neth J Med. 2020;78(5):282-285. 5. Jordan MB, Allen CE, Greenberg J, et al. Challenges in the diagnosis of hemophagocytic lymphohistiocytosis: Recommendations from the North American Consortium for Histiocytosis (NACHO). Pediatr Blood Cancer. 2019;66(11):e27929. doi:10.1002/pbc.27929 6. Sylvest S. From the Clinical Laboratories of the Cancer & Blood Diseases Institute. Cincinnati Children’s Hospital. Winter 2019;(15):1-4.
