Abstract: The invention relates to specific peptides derived from hsp70, and to pharmaceutical compositions comprising the same. The peptides and compositions of the invention are particularly suitable for the prevention or treatment of an autoimmune disease such as Type 1 Diabetes, Systemic Lupus Erithematosus, Multiple Sclerosis or Rheumatoid Arthritis. The invention further relates to a method for diagnosing the occurrence or incipience of an autoimmune disease in a patient by use of the peptides of the invention, by testing a blood or urine sample of a patient for the presence of antibodies or T-cells which are immunologically reactive to human hsp70. The invention also relates to a kit for the diagnosis of an autoimmune disease by testing for the presence of anti-hsp70 antibodies by aid of the peptides of the invention.