Final answer:
The correct abbreviation for rheumatoid factor is RF, not RHFa; hence, the statement is false. RF antibodies are an important diagnostic marker for rheumatoid arthritis.
Step-by-step explanation:
The abbreviation for rheumatoid factor is RF, not RHFa. Therefore, the statement is false. Rheumatoid factor (RF) is an antibody found in the blood that plays a significant role in diagnosing rheumatoid arthritis (RA), a chronic inflammatory joint disease. The presence of RF is associated with type III hypersensitivity reactions and can be a significant factor in the diagnosis and management of RA.