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Monoclonal gammopathy of renal significance (MGRS) is a new concept with evolving evidence for treatment. MGRS in the transplant kidney is a rare cause of renal transplant dysfunction that can lead to graft loss. Most cases of post-transplant MGRS are due to recurrent disease. Clone-specific chemotherapy is required to target the underlying clone, and this may improve graft survival; however, this can be challenging, as most patients are elderly with age-related comorbidities and may have complications associated with increasing immunosuppression. Here, we report 3 cases of renal allograft MGRS, and each case highlights different challenges in the diagnosis and management of this condition.

Background Optimal upfront therapy for posttransplant lymphoproliferative disease (PTLD) arising after solid organ transplant remains contentious. Rituximab monotherapy (R-Mono) in unselected patients has shown a lack of durable remissions. Cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP)-based chemotherapy confers improved response rates, although concerns exist about toxicity. Methods This multicenter retrospective study reports outcomes for adults with biopsy-proven B-cell PTLD treated initially with R-Mono or Rituximab plus CHOP (R-CHOP). Selection of therapy was made according to physician preference. Results Among 101 patients, 41 received R-Mono and 60 had R-CHOP. Most (93%) had undergone renal or liver transplantation. R-CHOP showed a trend toward improved complete (53% versus 71%; P = 0.066) and overall (75% versus 90%; P = 0.054) response rates. In the R-Mono group, 13 of 41 (32%) subsequently received chemotherapy, while 25 of 41 (61%) remained progression-free without further therapy. With median follow-up of 47 months, overall survival (OS) was similar for R-Mono and R-CHOP, with 3-year OS of 71% and 63%, respectively (P = 0.722). Non-PTLD mortality was 3 of 41 (7%) and 4 of 60 (7%) within 12 months of R-Mono or R-CHOP, respectively. The International Prognostic Index was statistically significant, with low- (0-2 points) and high-risk (≥3 points) groups exhibiting 3-year OS of 78% and 54%, respectively (P = 0.0003). In low-risk PTLD, outcomes were similar between therapies. However, in high-risk disease R-Mono conferred an inferior complete response rate (21% versus 68%; P = 0.006), albeit with no impact on survival. Conclusions Our data support R-Mono as initial therapy for PTLD arising after renal or liver transplantation. However, upfront R-CHOP may benefit selected high-risk cases in whom rapid attainment of response is desirable.

Membranoproliferative glomerulonephritis (MPGN) secondary to a monoclonal gammopathy is a rare glomerular disease and is defined as a monoclonal gammopathy of renal significance. The disease is characterized by glomerular monotypic immunoglobulin deposits and specific changes on light microscopy and electron microscopy. Immunochemistry is required to establish monoclonality, and electron microscopy helps to characterize the deposits ultrastructurally. Investigation for the underlying monoclonal protein should be done. We report a case of MPGN secondary to monoclonal gammopathy of renal significance that responded to treatment of the underlying clone with chemotherapy, resulting in improvement in renal function. Patients with MPGN and immunoglobulin deposition should be evaluated for a monoclonal protein to guide the management strategy.

Pruritic papular eruption of HIV (PPE) represents an intensely pruritic papular rash with greatest severity on the extensor surfaces of extremities. It is one of the most common cutaneous manifestations in HIV-infected individuals, in whom prevalence ranges between 11% and 46% depending on geographic location.1, 2, 3, 4, 5 Persistent or recurrent PPE despite effective antiretroviral therapy (ART) may be associated with higher viral load at ART initiation.6 Although pathogenesis is uncertain, an exaggerated immunologic reaction to arthropod bites has been suggested because of geographical restriction to the tropics, localization to the extremities, similarity in histology, and increased peripheral eosinophil counts.1 The optimum treatment pathway is poorly defined because of lack of evidence for different treatment modalities. We report a case of recurrent PPE responding well to oral thalidomide during a 3-month treatment period.