This invention relates to anti-CD103 antibodies and their use in the diagnosis, prognosis, monitoring, and treatment of diseases. An
imaging agent comprising the anti-CD103
antibody and a detectable
label is also disclosed, wherein the
antibody does not block CD103 binding to E-
cadherin or at least partially blocks CD103 binding to E-
cadherin. Treatment methods involve administering the anti-CD103
antibody, optionally conjugated to a cytotoxic agent. Diseases that need to be treated include, for example, hairy
cell leukemia, HCLv, intestinal and extraintestinal
lymphoma,
enteropathy-associated T-
cell lymphoma (EATL), T-
lymphoblastic leukemia /
lymphoma (T-ALL), T-
cell prolymphocytic
leukemia (T-PLL), adult T-cell
leukemia / lymphoma (ATLL),
mycosis fungoides (ME), anaplastic
large cell lymphoma ALCL, cutaneous T-
cell lymphoma (CTCL), Cezari syndrome (SS), Alzheimer's
disease, Parkinson's
disease, or
multiple sclerosis.