Case Report: A case of type II cryoglobulinemia secondary to diffuse large B-cell lymphoma

Background: Diffuse Large B-Cell Lymphoma (DLBCL) represents the most prevalent subtype of Non-Hodgkin Lymphoma (NHL). Cryoglobulinemia results from reversible precipitation of serum immunoglobulin complexes at low temperatures, with Type II (mixed) cryoglobulinemia commonly associated with hepatitis C virus (HCV) infection, autoimmune diseases, and B-cell lymphoproliferative disorders. However, its occurrence secondary to DLBCL is exceedingly rare. This report presents a rare case of DLBCL complicated by Type II cryoglobulinemia, acute liver injury, acute kidney injury, and severe infection. Case report: A female patient in her 40s presented to an external hospital with unexplained high fever, dry cough, and chest tightness. She was diagnosed with DLBCL based on bone marrow cytology and histopathological findings. The patient received chemotherapy with the zuberitamab plus CHOP regimen. However, anaphylactic shock occurred during zuberitamab infusion, leading to temporary discontinuation of chemotherapy. Upon transfer to our hospital, laboratory tests indicated renal insufficiency and severe hepatic injury. Combined with clinical manifestations such as extensive skin and mucosal ecchymoses, bilateral lower limb edema, arthralgia, reversible serum cryoprecipitation, positive mixed type II cryoglobulin, and decreased C4 complement levels, a diagnosis of type II cryoglobulinemia was confirmed. Following fluid resuscitation, diuresis, and continuous renal replacement therapy, her condition temporarily improved. Unfortunately, the patient succumbed due to disease progression of lymphoma. Conclusion: This case illustrates the diagnostic and therapeutic management of type II cryoglobulinemia secondary to DLBCL. It highlights the importance of closely monitoring clinical manifestations and implementing early intervention for related complications during the treatment of B-cell lymphoproliferative disorders, aiming to reduce the high mortality rate and improve patient outcomes.