Acute Renal Colic Due to Immunoglobulin Free Light Chain Kidney Stones: A Case Report of an Unusual Complication of Multiple Myeloma

Kidney disease in multiple myeloma

Renal disease is a frequent complication of symptomatic multiple myeloma, that increases morbidity and reduces quality of life and overall survival. It may result from various lesions, the most frequent being light chain cast nephropathy (LCCN), related to precipitation of monoclonal free light chains (FLC) with uromodulin in distal tubules. Rapid identification of the type of kidney disease with appropriate management is key. LCCN typically reveals the underlying myeloma and manifests with severe acute kidney injury, high serum FLC level (>500 mg/l) and predominant light chain proteinuria (urine albumin/creatinine ratio <10 %). Urgent therapy is required, based on vigorous fluid expansion, correction of precipitating factors and introduction of efficient anti-myeloma therapy which choice should consider renal elimination of each agent and patient frailty. Early and deep reduction in serum FLC level conditions renal recovery, warranting assessment of efficacy by serial serum FLC level monitoring. In newly diagnosed patients, the combination of bortezomib, high-dose dexamethasone and an anti-CD38 monoclonal antibody is commonly used. The benefit to risk balance of quadruplets incorporating cyclophosphamide or an immunodulatory agent requires to be evaluated in prospective studies. In patients with severe acute kidney injury, reinforcing chemotherapy with FLC removal through plasma exchange or high-cutoff hemodialysis may increase the probability of renal response, despite controversial data from randomized trials. Histological assessment of the extent of cast formation and interstitial fibrosis/tubular atrophy may help evaluating renal prognosis and refining therapy. Thanks to improved overall survival, renal transplantation may be considered in selected candidates with end-stage kidney disease.

Revisiting the case of Sarah Newbury's death from Mollities Ossium

Multiple myeloma and its precursor and variant types represent some of the most common hematologic malignancies in adults. These plasma cell dyscrasias are well-known to modern medicine. There are well-established clinical, laboratory and pathologic criteria for diagnosis and staging. There is debate about the diagnosis of some of the earliest cases of myeloma described in the literature. We present a critical review of one such case.

A guide to crystal-related and nano- or microparticle-related tissue responses

Crystals and nano- and microparticles form inside the human body from intrinsic proteins, minerals, or metabolites or enter the body as particulate matter from occupational and environmental sources. Associated tissue injuries and diseases mostly develop from cellular responses to such crystal deposits and include inflammation, cell necrosis, granuloma formation, tissue fibrosis, and stone-related obstruction of excretory organs. But how do crystals and nano- and microparticles trigger these biological processes? Which pathomechanisms are identical across different particle types, sizes, and shapes? In addition, which mechanisms are specific to the atomic or molecular structure of crystals or to specific sizes or shapes? Do specific cellular or molecular mechanisms qualify as target for therapeutic interventions? Here, we provide a guide to approach this diverse and multidisciplinary research domain. We give an overview about the clinical spectrum of crystallopathies, about shared and specific pathomechanisms as a conceptual overview before digging deeper into the specialty field of interest.