Background Membranoproliferative glomerulonephritis types I (MPGN-I) and II (MPGN-II) are rare diseases that in limited case series have been reported to recur frequently in kidney transplants and ...have a negative impact on allograft survival. Study Design Retrospective database review. Setting & Participants 189,211 primary kidney transplants in the United Network for Organ Sharing (UNOS) database from September 1987 to May 2007. Predictor or Factor MPGN-I (811 patients; 0.4%), MPGN-II (179 patients; 0.1%), other GN (58,129 patients; 30.7%), and all other diagnoses (130,092 patients; 68.7%). Outcomes Death-censored and non–death-censored allograft survival. Results Compared with controls, patients with MPGN-I and MPGN-II were significantly younger at the time of transplant, with a median age of 36 and 27 years compared with 44 years in the GN group and 46 years in all other disease groups, respectively (all P < 0.001). Mortality in patients with MPGN-I (8.8%) was significantly lower compared with the GN (11.3%; P = 0.02) and other disease (16.6%; P < 0.001) populations and lower in those with MPGN-II (9.5%) compared with the other disease (16.6%; P = 0.01) population. Graft failure rates were significantly higher in the MPGN-I (44.5%) cohort, but not in the MPGN-II (45.3%) cohort compared with the GN (38.0%) population ( P < 0.001 and P = 0.05, respectively); neither MPGN cohort differed from the other disease (43.0%) population ( P = 0.4 and P = 0.5). Overall, 10-year death-censored graft survival was similar for MPGN-I (56.2%) and MPGN-II (57.5%); both were significantly worse than for GN (65.2%; P < 0.001 and P = 0.003, respectively), and only MPGN-I was significantly worse than the other disease (60.0%) population ( P = 0.004). Of allograft failures with a reported cause, disease recurrence was the primary cause in 36 (14.5%) MPGN-I and 18 (29.5%) MPGN-II transplant recipients and was significantly higher compared with 879 (6.6%) GN and 1,319 (4.4%) all-other-disease recurrence failures ( P < 0.001). Limitations Limited pretransplant clinical and biopsy data. Conclusions A diagnosis of MPGN-I or MPGN-II has a significant negative impact on overall primary allograft survival compared with other forms of glomerulonephritis, whereas only MPGN-I has a significant, but modest, negative effect compared with other causes of end-stage renal disease.
VEGF-D is a lymphangiogenic growth factor that has a key role in tumour metastasis. Serum VEGF-D concentrations are increased in most patients with lymphangioleiomyomatosis, a rare neoplasm ...associated with mTOR-activating tuberous sclerosis gene mutations, lymphadenopathy, metastatic spread, and pulmonary cyst formation. We used data from the Multicenter International Lymphangioleiomyomatosis Efficacy of Sirolimus (MILES) trial to assess the usefulness of serum VEGF-D concentration as a marker of severity and therapeutic response to sirolimus in patients with lymphangioleiomyomatosis.
In the MILES trial, patients with lymphangioleiomyomatosis who had forced expiratory volume in 1 second (FEV1) of 70% or less of predicted were randomly assigned (1:1) to 12 months masked treatment with sirolimus or placebo. Serum VEGF-D concentrations were measured at baseline, 6 months, and 12 months. We used a linear regression model to assess associations of baseline VEGF-D concentrations with markers of disease severity, and a linear mixed effects model to assess the associations of VEGF-D concentrations with between-group differences in clinical, physiological, and patient-reported outcomes.
We included 42 patients from the placebo group and 45 from the sirolimus group in our analysis. Baseline VEGF-D concentrations in individual patients varied from 0·34 ng/mL to 16·7 ng/mL. Baseline VEGF-D concentrations were higher in patients who needed supplemental oxygen than in those who did not need supplemental oxygen (1·7 ng/mL IQR 0·99–3·36 vs 0·84 ng/mL 0·52–1·39; p<0·0001) and in those who had a bronchodilator response than in those who did not (2·01 ng/mL 0·99–2·86 vs 1·00 ng/mL 0·61–2·15; 0·0273). Median serum VEGF-D concentrations were similar at baseline in the sirolimus and placebo groups, and fell from baseline at 6 and 12 months in the sirolimus group but remained roughly stable in the placebo group. Each one-unit increase in baseline log(VEGF-D) was associated with a between-group difference in baseline-to-12-month FEV1 change of 134 mL (p=0·0007). In the sirolimus group, improvement in baseline-to-12-month FEV1 occurred in 15 of 23 (65%) VEGF-D responders (ie, those in whom baseline-to-12-month VEGF-D concentrations decreased by more than they did in any patients in the placebo group) and four of 15 (27%) VEGF-D non-responders (p=0·0448).
Serum VEGF-D is a biologically plausible and useful biomarker in lymphangioleiomyomatosis that correlates with disease severity and treatment response. Measurement of serum VEGF-D concentrations could inform the risk–benefit analysis of sirolimus therapy in patients with lymphangioleiomyomatosis and reduce the numbers of patients needed for clinical trials.
National Institutes of Health, US Department of Defense.
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