| Ia | immune response gene-associated antigen |
|---|---|
| IAHS | infection-associated hemophagocytic syndrome; International Association of Hospital Security |
| IDAV | immunodeficiency-associated virus |
| LAA | left atrial appendage; left atrial area; leukemia-associated antigen; leukocyte ascorbic acid |
| LACI | lipoprotein-associated coagulation inhibitor |