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: The fifth case had features of thrombotic microangiopathy related to an antiphospholipid syndrome in a patient with systemic lupus erythematosus .
### Output Text:
The fifth case had features of thrombotic microangiopathy related to an antiphospholipid syndrome in a patient with systemic lupus erythematosus . 