Case description: Two patients, 68 and 72 years old, were admitted with fever whilst under treatment with ruxolitinib for myelofibrosis. They had not been screened for latent tuberculosis infection (LTBI) and extensive tuberculosis was found in both patients. They died within weeks from complications of fulminant disease.
Conclusion: Doctors who prescribe ruxolitinib should be aware of the increased risk of infectious diseases like tuberculosis. Under immune suppression, tuberculosis often runs a disseminated course. The constitutional symptoms of myelofibrosis strongly resemble those of tuberculosis and the latter diagnosis should always be considered. Active and latent tuberculosis should be excluded and treated, if necessary, before giving ruxolitinib.