Final Answer:
Three applications of HLA typing in present-day clinical laboratories include organ transplantation matching, blood transfusion compatibility assessment, and disease association studies.
Step-by-step explanation:
Organ Transplantation Matching: HLA typing is crucial in organ transplantation to ensure compatibility between the donor and recipient. Matching human leukocyte antigens (HLAs) reduces the risk of rejection, as the immune system is less likely to recognize the transplanted organ as foreign. This increases the success of organ transplantation and minimizes complications.