Presentation from the Nephrology Quiz and Questionnaire (NQQ) has become an annual tradition at the meetings of the American Society of Nephrology. incorrect answers were then briefly discussed after the audience responses and the results of the questionnaire were displayed. This article recapitulates the session and reproduces its educational value for a larger audiencethat of the readers of the has been suggested as more appropriately describing this condition (6). In contrast to children, adults are more likely to Rabbit Polyclonal to SENP5. have infection-related GN secondary to nonstreptococcal infections, particularly staphylococcal infection, and the overall prognosis in terms of renal and patient survival is poor. The pathogenesis of acute postinfectious GN has been the subject of recent reviews (7,8). It is important to recognize that no animal model can reproduce the classic findings of abundant neutrophil infiltration and subepithelial humps characteristic of human postinfectious GN (8). Nevertheless, it has been proposed that the initial phase of the process is characterized by deposition of bacterial antigens (with the planted antigens (2,9). Antigens that enter the circulation after the antibody response is fully underway form immune complexes in circulation. Most of these immune complexes are cleared from the circulation by the DAPT liver and spleen, but the ones that escape the phagocytic system may deposit in the glomeruli and DAPT thus induce immune complexCmediated GN (7). Reduction in serum C3 complement levels is a constant feature during the initial phase of postinfectious GN (10,11). The hypocomplementemia is due to activation of the alternative pathway (AP) of complement while C1q, C2, and C4 complement levels (classic pathway) are usually normal. In some patients with poststreptococcal GN, low C3 levels have been associated with the transient expression of circulating autoantibodies against the C3 convertase complex (and 1 patient with a mutation in is also used for this entity because it results in a sclerosing lesion of multiple organs, including the kidney, with formation of pseudotumors (41,42). Patients with renal involvement are often elderly men presenting with progressive renal failure. There are several other characteristics. Patients often have elevated serum total IgG and/or IgG4 levels or hypergammaglobulinemia. Kidney biopsy usually shows a tubulointerstitial nephritis (TIN) with moderate to marked increase in IgG4-positive plasma cells, with or without tubular basement DAPT membrane deposits. The term has been proposed to describe this entity (39). A paucity of cases of IgG4-related TIN with MN has also been described (option B) (43,44). The absence of systemic organ involvement and TIN in this case make the diagnosis of an IgG4-related MN unlikely. Renal ultrasonography with Doppler examination of renal veins (option D) is indicated to rule out renal vein thrombosis. Acute renal vein thrombosis is usually characterized by a recent DAPT episode of acute flank pain, macroscopic hematuria, flank tenderness at percussion, worsening proteinuria, and deterioration of renal function (45). Hypoalbuminemia, particularly a serum albumin concentration <2.8 g/dl, is the most significant independent predictor of venous thrombotic risk in patients with MN (46). In view of the above, it is unlikely that our patient had developed acute renal vein thrombosis, although asymptomatic chronic renal vein thrombosis cannot be ruled out. However, there is no convincing evidence that chronic renal vein thrombosis is associated with worsening renal function or proteinuria (45). Anti-PLA2R antibodies (option C) are present in 70%C82% of patients with idiopathic MN but are not present in the serum of healthy controls or patients with other glomerular and autoimmune diseases (47,48). Levels of anti-PLA2R correlate strongly correlated with disease activity and response to therapy: Disappearance of the antibody is associated with remission of proteinuria, and reappearance of the antibody heralds a relapse of nephrotic syndrome (47C50). Taken together, these observations suggest that detection and quantification of circulating anti-PLA2R levels may provide a tool for monitoring disease activity and treatment efficacy in patients with MN (51). On the other hand, low titers of anti-PLA2R have been detected in patients in remission (48), whereas the presence of high titers of anti-PLA2R antibodies did not preclude development of spontaneous remission (52). Similarly, discrepancies between circulating anti-PLA2R antibodies and detectable PLA2R in glomerular deposits have been reported in a.