| Abbreviation | Definition |
|---|---|
| AHI | Apnea Hypopnea Index |
| AHRQ | Agency for Healthcare Research and Quality |
| AID | Activation-Induced cytidine Deaminase |
| AIF | Adherence-Inhibiting Factor |
| AIF | Anemia-Inducing Factor |
| AIHA | Auto-Immune Hemolytic Anemia |
| AIL | Advanced Instrumentation Laboratory |
| AIL | Angewandte Innovation Laboratory |
| AIP | Apoptosis-Inducing Protein |
| AIP | Automated ImmunoPrecipitin |
| AISL | Active Intelligent Systems Laboratory |
| AISL | Applied Imaging Science Laboratory |
| AISL | Applied Intelligent Systems Laboratory |
| AK | Activated Killer |
| AKA | AntiKeratin Antibodies |
| AKA | Anti-Keratin Antibodies |
| AL | Absolute Latency |
| AL | After Loading |
| AL | ALbumin |
| AL | Average Lifetime |