In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: In both cases , discontinuation of FK506 and treatment with plasma exchange , fresh frozen plasma replacement , corticosteroids , aspirin , and dipyridamole led to resolution of MAHA .
### Output Text:
In both cases , discontinuation of <span class="chemical">FK506</span> and treatment with plasma exchange , fresh frozen plasma replacement , <span class="chemical">corticosteroids</span> , <span class="chemical">aspirin</span> , and <span class="chemical">dipyridamole</span> led to resolution of MAHA . 