Outcomes of patients with Goodpasture syndrome: A nationwide cohort-based study from the French Society of Hemapheresis.

The overall and renal outcomes of patients with Goodpasture syndrome (GS), a rare autoimmune disorder characterized by circulating anti-GBM antibodies and rapidly progressive glomerulonephritis and/or pulmonary hemorrhage, have mostly been reported in small-sized cohorts or by aggregating patients receiving a variety of therapies that include aggressive (i.e., combined plasma exchanges, corticosteroids, and cyclophosphamide) and less aggressive (i.e., either plasma exchanges or immunosuppressive drugs, or no treatment). To address the prognosis of GS patients with relatively homogeneous management including plasma exchanges, we conducted a multicenter retrospective study on GS patients included in the registry of the French Society of Hemapheresis. 122 patients were included (kidney alone (n = 28), lung alone (n = 5), or combined involvement (n = 89)). All 122 patients received plasma exchanges (median number of sessions: 13 [9-17]), either alone (n = 8) or associated with combined corticosteroids and oral or IV cyclophosphamide (n = 101) or with corticosteroids alone (n = 12) or cyclophosphamide alone (n = 2). One-year survival was 86.9%. 7/16 patients died from severe infection. In multivariate analyses (Cox's regression model), being aged <60 years, and number of plasma exchanges were correlated to overall survival. The use of alternative immunosuppressive drugs (because of refractory or relapsing GS) was correlated to mortality at one year. Superiority of oral cyclophosphamide compared to intravenous intake was close to significant. Using a logistic regression model, renal survival in patients alive at 1 year was only predicted by serum creatinine <500 µmol/L at presentation. This large series describes the predictive factors for overall and renal survival of GS patients treated by plasma exchanges. Interventional studies that compare oral and intravenous cyclophosphamide, as well as testing new immunosuppressive therapies, are warranted.

Falsely elevated whole-blood tacrolimus concentrations in a kidney-transplant patient: potential hazards.

SUMMARY: Tacrolimus-based immunosuppression is the most frequently prescribed immunosuppression for kidney-transplant (KT) patients. Because tacrolimus has a narrow therapeutic window, drug monitoring is mandatory. Of the many methods used to assess whole-blood trough levels, antibody-conjugated magnetic immunoassay (ACMIA) is popular because, compared with microparticle enzyme-linked immunoassays (MEIA), there is no need to pretreat samples, thus reducing time taken by the laboratory technician. Herein, we report on a KT tacrolimus-treated patient who experienced falsely elevated whole-blood tacrolimus concentrations after using the ACMIA method. ACMIA gave trough levels of 24 ng/ml, whereas the actual trough level, when measured by enzyme-multiplied immunoassay technique (EMIT) and high-performance liquid chromatography coupled with mass spectrometry (LC-MS/MS), was nil. After a workup we only found one factor that might have caused the elevated concentration: positive anti-double stranded DNA autoantibodies. We conclude that, when ACMIA produces surprisingly high tacrolimus concentrations in organ-transplant patients, these should be reassessed immediately using either LC-MS/MS or another immunoassay in order to eliminate falsely elevated results.