When incompatible blood is given, antibodies and complement in the recipient plasma attack the antigens on the donor RBC. Hemolysis ensues The antigen-antibody complex activate the Hageman factor (factor XII), which acts on the kinin system to produce bradykinin
Still it is not advisable to take it after the expiry date written on the bottle. This is just for your information to let you know that you are safe. Anyway Saline Nasal spray is not going to do any harm even if you used an expired one. So forget about it.
Generally the expiration date is printed on the bottom or back of the package. If there is no expiration date printed on the package, the product is good for three years from the date of manufacture. Sanitizers that have added scents or colors may expire sooner and should have a date printed.