AA amyloidosis is a rare renal complication of Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL). A 66-year-old man with WM/LPL presented with nephrotic syndrome. A renal biopsy show Show more
AA amyloidosis is a rare renal complication of Waldenström's macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL). A 66-year-old man with WM/LPL presented with nephrotic syndrome. A renal biopsy showed AA amyloidosis. Chemotherapy resulted in the remission of hematologic and nephrotic syndromes. Two years into follow-up, he became infected with coronavirus disease 2019 and had massive proteinuria, despite no relapse of WM/LPL. A second renal biopsy confirmed a diagnosis of AA amyloidosis. However, increased prednisolone did not improve proteinuria. The patient ultimately died of cryptococcal meningitis. This case highlights the diverse spectrum of renal involvement in monoclonal IgM-secreting diseases and difficulty in managing fatal complications. Show less
Controversy exists regarding the proper mining of the human serum proteome. Because of the analytical challenges of accurately measuring samples containing a very large dynamic range of protein concen Show more
Controversy exists regarding the proper mining of the human serum proteome. Because of the analytical challenges of accurately measuring samples containing a very large dynamic range of protein concentrations, current practices have employed depletion of the highly abundant housekeeping serum proteins, such as albumin and immunoglobins. There is question as to the selectivity of depletion, namely, is there loss of other non abundant serum proteins along with albumin, haptoglobin and other commonly depleted proteins. In this study, human serum was analyzed with and without immunoaffinity depletion of the six most abundant proteins by multidimensional liquid chromatography tandem mass spectrometry. Two replicates of each experiment were conducted and compared against one another. In both depleted and nondepleted replicates there was a 73% and 72% overlap of identified peptides and a 64% and 78% overlap of identified proteins, respectively. Of 262 unique proteins identified in the four experiments, 82 were found in common to all four experiments, 142 unique to the depleted serum, and 38 unique to the nondepleted serum. Although serum depletion of highly abundant proteins significantly increased the number of proteins identified, both the degree of sample complexity and this depletion method resulted in a nonselective loss of other proteins. Show less