#2897 Kidney disease spectrum in patients with haematological malignancies

Abstract Background and Aims Haematological malignancies can present with kidney manifestations of various types. At first presentation kidney biopsy can help to diagnose the malignancy, whereas during follow-up a biopsy can differentiate between malignancy-related and unrelated findings. The aim of our study was to investigate the spectrum of kidney diseases associated with haematological malignancies. Method In this single-center retrospective study we analyzed patients with native kidney biopsies and a diagnosis of a haematological malignancies over a 10-year period (2015–2024) at our University hospital. Results We identified 79 patients (male n = 41, female = 38) with 82 native kidney biopsies. The diagnosis of the haematological malignancy (other than MGUS) was known in 50% at time of biopsy, mean age of the patients was 63 years. 11 patients presented after bone marrow transplantation. Impaired kidney function (65/82 with creatinine >1.2 mg/dl) and proteinuria were the main biopsy indications. Proteinuria >3g/g were present in one third (28/82 patients). The spectrum of kidney disease included AL-amyloidosis (n = 21), cast nephropathy (n = 10), lymphoma infiltration (n = 11), glomerulonephritis (n = 8) including cryoglobulinemia (n = 5), interstitial nephritis (n = 8), thrombotic microangiopathy (n = 11) and others manifestations (including podocytopathies) (Table 1). Lymphoma infiltration occurred in different malignancy types (DLBC, B-ALL, marginal zone lymphoma, immunocytoma, CLL, CMML, multiple myeloma). In biopsies after bone marrow transplantation thrombotic microangiopathy (n = 8) and interstitial nephritis (n = 2) were the main findings. Among the 41 patients with the diagnosis of a haematological malignancy based on kidney biopsy the main findings were AL-amyloidosis (32%), cast nephropathy (20%), cryoglobulinemia (12%), lymphoma infiltration (12%) and others. Conclusion Our study confirms the broad spectrum of kidney lesions with haematological malignancies. While kidney biopsy can reveal the diagnosis of haematological malignancy in so far undiagnosed patients, it is helpful in differentiation of unrelated kidney disease versus kidney involvement in patients with known haematological disease.