Cold agglutinin disease in the setting of pancreatic adenocarcinoma

Autoimmune haemolytic anaemia (AIHA) is caused by antibody-mediated destruction of red blood cells. There are two broad categories of AIHA: warm and cold, both categorized by the thermal reactivity of the autoantibodies. Cold agglutinin disease (CAD) occurs at temperatures below normal body temperature and primarily involves IgM antibodies. CAD typically occurs secondary to other processes: lymphoproliferative disorders or infection, although it can be rarely idiopathic. We present a case of a 65-year-old male with no past medical history who initially presented with haematuria and proteinuria, along with thrombocytopenia and leukopenia. He reported an unintentional weight loss of more than 9 kg, constipation, and pale-greasy coloured stools. Computed tomography (CT) scan of the abdomen and pelvis revealed findings suspicious for primary pancreatic neoplasm with nodal metastases and early carcinomatosis, severe right hydronephrosis, and distended gallbladder. Direct antiglobulin test (DAT) screening was negative, but an antibody screen was positive. The patient had a positive cold agglutin screen and elevated CA 19-9, carcinoembryonic antigen (CEA), and cyclic citrullinated peptide (CCP) levels, tumour markers used typically for diagnosis of pancreatic cancer. The patient presented with symptoms and laboratory findings suggestive of a complex interplay between haemolytic anaemia and a suspected solid organ malignancy, specifically pancreatic cancer. His elevated tumour markers and positive antibody screen and cold agglutinin screen suggested the possibility of paraneoplastic syndrome secondary to his pancreatic cancer. However, his infectious and autoimmune panel findings further complicated the picture and underscored the multifactorial nature of his condition.