A recombinant antibody in which at least the constant regions in the heavy chain and the light chain have been converted into human-origin regions and which inhibits the binding of an integrin recognizing the RGD sequence to osteopontin or its fragment and inhibits the binding of an integrin recognizing the SVVYGLR sequence or a sequence corresponding thereto to osteopontin or its fragment. This antibody is useful as a remedy for autoimmune diseases and a remedy for rheumatism or rheumatoid arthritis. Thus, a method of treating autoimmune diseases, rheumatism or rheumatoid arthritis is provided. This osteopontin antibody is useful in a diagnostic for rheumatism and a method of diagnosing rheumatism too.