The following is a summary of “A case of cold agglutinin syndrome associated with chronic lymphocytic leukaemia harbouring mutations in CARD11 and KMT2D.,” published in the May 2023 issue of Hematology by Fukatsu et al.
Cold agglutinin disease (CAD) is a rare form of autoimmune anemia caused by IgM antibodies targeting red blood cells’ I antigens.
Researchers performed a retrospective study to analyze a case of cold autoimmune hemolytic anemia (cAIHA) without lymphocytosis or lymphadenopathy. Disease was classified into primary CAD and cold agglutinin syndrome (CAS), commonly linked to malignant lymphoma. In many CAD patients, gene mutations in CARD11 and KMT2D have been discovered, indicating CAD as a low-grade lymphoproliferative disorder. Investigators reported a small clonal population (6.8%) of lymphocytes expressing chronic lymphocytic leukemia CLL-related surface markers infiltrated the bone marrow.
Study detected mutations in the CARD11 and KMT2D genes through entire exome sequencing of bone marrow mononuclear cells. Patient exhibited somatic hypermutation with an overrepresentation of IGHV4-34, a common occurrence in CLL cases with the KMT2D mutation.
Their observations suggested that primary CAD may be misdiagnosed when early-stage CLL causes CAS.
Source: link.springer.com/article/10.1007/s12185-023-03608-9