PG-M1: a new monoclonal antibody directed against a fixative-resistant epitope on the macrophage-restricted form of the CD68 molecule.
A new anti-macrophage monoclonal antibody (PG-M1) was produced by immunizing BALB/c mice with fresh spleen cells from a patient with Gaucher's disease. PG-M1 reacts strongly with a fixative-resistant epitope of an intracytoplasmic molecule, selectively expressed by virtually all macrophages of the human body. Although attempts to immunoprecipitate the molecule recognized by PG-M1 have failed so far, the reactivity of the antibody with COS-1 and WOP cells transfected with a human complementary DNA clone encoding for the CD68 antigen suggests that PG-M1 is a new member of the CD68 cluster. However, unlike other CD68 antibodies (KP1, EBM11, etc.), which react with both macrophages and myeloid cells, PG-M1 detects a fixative-resistant epitope on the macrophage-restricted form of the CD68 antigen. In 957 routinely fixed, paraffin-embedded samples, PG-M1 showed a more restricted reactivity with elements of the monocyte/macrophage lineage than the previously described monoclonal antibodies MAC-387 (anti-calgranulins), KP1 (CD68) and Ki-M1P. Among hematological malignancies, PG-M1 only labels acute leukemias of M4 and M5 type and rare examples of malignant histiocytosis/true histiocytic sarcoma. In contrast, acute leukemias of the M1, M2, M3, M6, M7, and L1-L3 types, non-Hodgkin's lymphomas, and Hodgkin and Reed-Sternberg cells of Hodgkin's disease are consistently PG-M1-negative. In the daily diagnostic practice, PG-M1 seems to be particularly valuable for the diagnosis of myelomonocytic or monocytic leukemia and neoplasms of true histiocytic origin in routine paraffin sections.
Falini
B
B
Institute of Hematology, Perugia University, Italy.
Flenghi
L
L
Pileri
S
S
Gambacorta
M
M
Bigerna
B
B
Durkop
H
H
Eitelbach
F
F
Thiele
J
J
Pacini
R
R
Cavaliere
A
A
D000911:Antibodies, Monoclonal / Q000276:immunology*; D000917:Antibody Formation; D015703:Antigens, CD / Q000032:analysis / Q000276:immunology*; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis / Q000276:immunology*; D002460:Cell Line; D004247:DNA / Q000235:genetics; D004351:Drug Resistance; D000939:Epitopes; D005404:Fixatives / Q000494:pharmacology*; D006402:Hematologic Diseases / Q000276:immunology; D006413:Hematopoietic System; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008206:Lymphatic Diseases / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D009369:Neoplasms / Q000276:immunology; D011233:Precipitin Tests; D012016:Reference Values; D014162:Transfection; D000097382:CD68 Molecule
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D004247:DNA; D000939:Epitopes; D005404:Fixatives; C067980:CD68 antigen, human; D000097382:CD68 Molecule