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

### Input Text: The children share common clinical features including splenomegaly and lymphadenopathy , but only one developed severe autoimmune manifestations .
### Output Text:
The children share common clinical features including <span class="disease">splenomegaly</span> and <span class="disease">lymphadenopathy</span> , but only one developed severe <span class="disease">autoimmune manifestations</span> . 