(CNN) When ESPN reporter Edward Aschoff died, he had been diagnosed with multifocal pneumonia and a rare disease known as HLH, his fiancée tweeted.

Aschoff was first admitted to the hospital and diagnosed with pneumonia in many parts of his lungs but was brought back to the emergency room when antibiotic treatment failed and he got worse, Katy Berteau said.

"After many tests - bone marrow and lung biopsies - treatment was started for a presumed diagnosis of HLH," she tweeted. "Within 3 days of being moved into the ICU, he passed."

HLH, hemophagocytic lymphohistiocytosis, is a rare disease that affects the immune system.

She did not provide any further details about the manner of Aschoff's death, which occurred on his 34th birthday.

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