Light chains: heavy burden in kidney transplantation

A therapeutic convection-enhanced macroencapsulation device for enhancing β cell viability and insulin secretion

Islet transplantation for type 1 diabetes treatment has been limited by the need for lifelong immunosuppression regimens. This challenge has prompted the development of macroencapsulation devices (MEDs) to immunoprotect the transplanted islets. While promising, conventional MEDs are faced with insufficient transport of oxygen, glucose, and insulin because of the reliance on passive diffusion. Hence, these devices are constrained to two-dimensional, wafer-like geometries with limited loading capacity to maintain cells within a distance of passive diffusion. We hypothesized that convective nutrient transport could extend the loading capacity while also promoting cell viability, rapid glucose equilibration, and the physiological levels of insulin secretion. Here, we showed that convective transport improves nutrient delivery throughout the device and affords a three-dimensional capsule geometry that encapsulates 9.7-fold-more cells than conventional MEDs. Transplantation of a convection-enhanced MED (ceMED) containing insulin-secreting β cells into immunocompetent, hyperglycemic rats demonstrated a rapid, vascular-independent, and glucose-stimulated insulin response, resulting in early amelioration of hyperglycemia, improved glucose tolerance, and reduced fibrosis. Finally, to address potential translational barriers, we outlined future steps necessary to optimize the ceMED design for long-term efficacy and clinical utility.

Renal Involvement in Multiple Myeloma

Multiple myeloma (MM) is a plasma cell disorder that represents almost 10% of haematologic malignancies. Renal impairment, one of the most common complications of MM that occurs in 20–50% of patients, can present in a variety of forms and is associated with increased mortality. Myeloma cast nephropathy is the most common cause of kidney disease in MM patients, presenting as acute kidney injury in the majority of patients. The recent introduction of new chemotherapy agents, autologous stem cell transplantation, and the development of novel techniques of light chain removal have been associated with improved renal and patient outcomes in MM patients. Nevertheless, dialysis-dependent patients with MM have higher mortality than other dialysis patients and may be considered for kidney transplantation only if sustained remission has been achieved and sustained for at least 3 years, bearing in mind the risk of disease recurrence. The authors review the most frequent renal manifestations associated with MM, namely myeloma cast nephropathy, light-chain amyloidosis, and monoclonal immunoglobulin deposition disease, focussing on the therapeutic options for acute and chronic kidney disease.

Kidney Transplantation in Patients With Active Multiple Myeloma: Case Reports

Kidney disease is a common complication in patients with multiple myeloma. Traditionally, patients with active multiple myeloma and end-stage renal disease have been excluded from kidney transplantation due to the risk of malignancy progression. The introduction of bortezomib-based therapy for patients with multiple myeloma and renal impairment has significantly improved survival in this population. In this report, we present 2 cases of patients with active and controlled multiple myeloma who underwent successful kidney transplantation without progression of their underlying malignancy. In patients with active multiple myeloma controlled with bortezomib, kidney transplantation should be considered a valid option for patients with end-stage kidney disease.

Kidney disease and multiple myeloma

Kidney injury is a common complication of multiple myeloma and other plasma cell dyscrasias, and it is associated with increased mortality. Multiple pathogenic mechanisms can contribute to kidney injury in the patient with myeloma, some of which are the result of nephrotoxic monoclonal Ig and some of which are independent of paraprotein deposition. The pathogenic mechanisms that underlie paraprotein-related kidney disease are increasingly well understood. A novel assay allowing the quantification of free light chains in the serum has aided the diagnosis of new onset disease and allowed for the earlier detection of relapse. Novel myeloma agents have shown considerable promise in reversing renal failure in some patients and improving outcomes. Stem cell transplantation remains a mainstay of management for younger patients with myeloma who are suitable candidates for intensive therapy, whereas the role of new drugs, plasma exchange, and kidney transplantation continues to evolve.

Kidney disease associated with plasma cell dyscrasias

Plasma cell dyscrasias are frequently encountered malignancies often associated with kidney disease through the production of monoclonal immunoglobulin (Ig). Paraproteins can cause a remarkably diverse set of pathologic patterns in the kidney and recent progress has been made in explaining the molecular mechanisms of paraprotein-mediated kidney injury. Other recent advances in the field include the introduction of an assay for free light chains and the use of novel antiplasma cell agents that can reverse renal failure in some cases. The role of stem cell transplantation, plasma exchange, and kidney transplantation in the management of patients with paraprotein-related kidney disease continues to evolve.