GLA-modified RNA treatment lowers GB3 levels in iPSC-derived cardiomyocytes from Fabry-affected individuals.

Recent studies in non-human model systems have shown therapeutic potential of nucleoside-modified messenger RNA (modRNA) treatments for lysosomal storage diseases. Here, we assessed the efficacy of a modRNA treatment to restore the expression of the galactosidase alpha (GLA), which codes for α-Galactosidase A (α-GAL) enzyme, in a human cardiac model generated from induced pluripotent stem cells (iPSCs) derived from two individuals with Fabry disease. Consistent with the clinical phenotype, cardiomyocytes from iPSCs derived from Fabry-affected individuals showed accumulation of the glycosphingolipid Globotriaosylceramide (GB3), which is an α-galactosidase substrate. Furthermore, the Fabry cardiomyocytes displayed significant upregulation of lysosomal-associated proteins. Upon GLA modRNA treatment, a subset of lysosomal proteins were partially restored to wild-type levels, implying the rescue of the molecular phenotype associated with the Fabry genotype. Importantly, a significant reduction of GB3 levels was observed in GLA modRNA-treated cardiomyocytes, demonstrating that α-GAL enzymatic activity was restored. Together, our results validate the utility of iPSC-derived cardiomyocytes from affected individuals as a model to study disease processes in Fabry disease and the therapeutic potential of GLA modRNA treatment to reduce GB3 accumulation in the heart.

Cardiovascular outcomes in Fabry disease are linked to severity of chronic kidney disease.

OBJECTIVES: Assess the impact of end-stage renal disease (chronic kidney disease stage 5 (CKD5)) on cardiovascular outcomes in patients with Fabry disease on enzyme replacement therapy. BACKGROUND: Fabry disease, an X-linked lysosomal storage disease, causes hypertrophic cardiomyopathy and cardiovascular dysfunction. METHODS: Cardiac and renal function of 25 male patients with Fabry disease were analysed at 0, 1, 2, 5, 7 and 10 years after initiation of treatment. Patients were grouped at baseline into those with CKD5 (n=10) and those without (n=15). ECG and echocardiography were performed 6 and 12 monthly, respectively, while renal function was measured yearly. RESULTS: After 10 years of treatment, cardiac and renal function in non-CKD5 patients remained unchanged. In contrast, CKD5 was associated with worse baseline cardiac parameters and progressive LV hypertrophy. LV mass index grew by 35.4±31.8 g/m(2.7) in CKD5 versus 5.7±7.9 g/m(2.7), p=0.044 in non-CKD5, predominantly due to increased interventricular septal wall thickness (7.7±5.5 mm vs 1.3±1.7 mm, p=0.003). Cardiovascular events, including sudden death, arrhythmia and pacing device insertion, occurred in 100% patients with CKD5 (21 events) and 26% non-CKD5 patients (7 events), p<0.0001. Additionally, estimated LV filling pressure (E/Ea) was significantly higher in patients having cardiovascular events (21.1±7.7 vs 12.5±4.5, p=0.008) irrespective of renal function. CONCLUSIONS: End-stage renal disease was the strongest indicator of cardiovascular disease progression in Fabry disease. Enzyme replacement initiated prior to CKD5 was associated with stability in cardiac and renal disease while patients with CKD5 showed ongoing deterioration. Additionally, E/Ea ≥15 may predict risk of cardiac events.

Conversion of cyclosporine to tacrolimus in stable renal allograft recipients: quantification of effects on the severity of gingival enlargement and hirsutism and patient-reported outcomes.

BACKGROUND: Cyclosporine-induced side-effects such as gum enlargement and hirsutism potentially limit its effectiveness as a calcineurin-antagonist if these effects contribute to a lack of compliance. Although the differences in incidence of these effects are widely recognized, few studies are available to show the extent of reduced gum enlargement and hirsutism in patients converted from cyclosporine to tacrolimus. This study aimed to determine the efficacy and safety and patient-reported outcomes of such conversions. METHODS: Twenty-one consecutive cyclosporine-treated renal-transplant recipients with evidence of gingival enlargement were randomized into two arms: 10 continued to receive cyclosporine, 11 were converted to tacrolimus. Mean differences (0-3, 0-6, 0-9 and 0-12 months) in periodontal indices (gingival inflammation, plaque, pocket depth, gingival enlargement), hirsutism, serum creatinine and glucose and subjective differences in the patient's rating of disfigurement due to hirsutism and gingival enlargement were recorded. RESULTS: There were no differences in baseline periodontal scores between the two groups. Tacrolimus-treated subjects had significantly reduced pocket depth and gingival enlargement measures (Pocket Depths: -0.40 +/- 0.58 vs 0.30 +/- 0.35, P < 0.01; Gingival Enlargement Index: -1.12 +/- 0.83 vs-0.10 +/- 0.89, P < 0.05; tacrolimus vs cyclosporine, respectively), and decreased subjective disfigurement compared with the cyclosporine-treated group over the 12 months. While there was no difference in objective hirsutism scores between the two groups, tacrolimus-treated patients reported a significant improvement and cyclosporine-treated patients a significant worsening in their degree of disfigurement at the end of 12 months. There were no differences in creatinine or glucose levels. CONCLUSION: Conversion from cyclosporine to tacrolimus in stable renal-transplant recipients with cyclosporine-induced gingival enlargement can be achieved safely and with measurably good effect.

Glomerular size and global glomerulosclerosis in normal Caucasian donor kidneys: effects of aging and gender.

BACKGROUND: To assess the effects of aging and gender on glomerular size and global glomerulosclerosis (GS) and evaluate the relationship between glomerular size and GS in normal Caucasian donor kidneys. METHODS: All baseline graft biopsies between 1990 and 1998 were reviewed and sections with tissues containing at least 15 glomeruli were selected for morphometric analyses using a Digital Imaging Analyzer. Glomerular volumes (GV) were measured using the maximal profile area (MPA) method. The frequency of glomeruli with totally sclerotic lesions representing degree of global GS was expressed as a percentage of total number of glomeruli counted. RESULTS: 102 donor specimens (M/F, 46/56; mean age, 37.4 +/- 17.3 yrs) were analyzed showing mean MPA of 27.8 +/- 6.6 (x 10(-3)mm2), mean GV of 3.6 +/- 1.2 (x 10(6)microm3) and mean GS% of 6 +/- 10%. GV was increased with increasing age (r2 = 0.32, p < 0.0001). There was a progressive increase in glomerular size between infancy and adolescence (2-18 years old). The rate of MPA growth over childhood appeared to be linear (n = 13, r2 = 0.66, p = 0.0004). However, MPA increased with age at a slower rate (n = 99, r2 = 0.66, p = 0.0004) in adults (excluding data for patients < 18 years) than in infancy and adolescence. There wasn't significant gender difference in GV. Age (r = 0.47, p < 0.0001) and MPA (r = 0.31, p < 0.05) were both positively correlated with global GS. CONCLUSIONS: 1. Aging contributes to enlargement of glomerular size and global GS. 2. Gender had no significant effect on glomerular size. 3. Enlargement of glomerular size was associated with global GS in normal Caucasians.

Risk factors for late renal allograft dysfunction: effects of baseline glomerular size.

BACKGROUND: Both alloantigen dependent and alloantigen independent factors contribute to late allograft dysfunction. Among the latter, the importance of the mass of the donor kidney is an issue of interest. We hypothesized that glomerular hypertrophy is a risk factor for deterioration of allograft function. The goal of this study was to examine the role of glomerular size in predicting late allograft dysfunction. METHODS: All baseline graft biopsies between 1990 and 1998 were reviewed and sections containing at least 15 glomeruli were selected for morphometric analyses. Glomerular size was measured using the maximal profile area (MPA) method. Linear correlations between creatinine clearance (Ccr) and variables were evaluated. Covariates that tended to correlate with Ccr on univariate analysis (p < 0.2) were examined using multivariate analysis to determine the covariates associated with Ccr at 6 months (M) and 1, 2, 3, 4 years (yrs) after transplantation. RESULTS: Eighty-six patients were enrolled. Donor age, MPA, baseline Ccr, percent of global glomerulosclerosis (GS%), cyclosporin nephrotoxicity, cold ischemic time(CIT) and episodes of rejection were significantly correlated with interval Ccr in univariate analyses. MPA was a significant covariate at 6M, 1 yr, 3 yrs and 4 yrs. Other covariates significantly associated with interval Ccr included GS%, baseline Ccr, CIT and number of acute rejection episodes. CONCLUSIONS: Glomerular size in baseline biopsies is predictive of late allograft function, and the presence of hypertrophied glomeruli combined with other factors contributes to chronic renal allograft dysfunction.