| RASS | rheumatoid arthritis and Sjogren syndrome |
|---|---|
| RAST | Radio-Allergo-Sorbent Test ; Specific IgE Test |
| RAST | radioallergosorbent test |
| RAT | repeat action tablet; rheumatoid arthritis test |
| rAT-P | recombinant antitrypsin Pittsburgh |
| RATG | rabbit antithymocyte globulin |
| RATHAS | rat thymus antiserum |
| RATx | radiation therapy |
| RAU | radioactive uptake |
| RAV | Rous-associated virus |