MO802DOES ETELCALCETIDE REVERSE MYELOFIBROTIC BONE CHANGES DUE TO HYPERPARATHYROIDISM? A CASE REPORT

Background and Aims

A 21 year old boy with a diagnosis of Autosomal Recessive Polycystic Kidney Disease and Caroli disease reached a final stage of chronic kidney disease (CKD) and started haemodialysis.

Method

After 3 years in haemodialysis he underwent a kidney transplant from a cadaveric donor. His transplanted kidney worked fairly well until the patients was 31 year old when he developed graft dysfunction (serum creatinine from 2.7 to 5 mg/dL in a very short period). There was a concomitant increase in serum phosphate levels (8.3 mg/dl) and iPTH that progressively increased to 1032 pg/ml despite a traditional therapy.

Results

At age 32, the patient returned to haemodialysis treatment thrice weekly with a concomitant a progressive worsening of hyperparathyroidism with bone pain . Cinacalcet at a dosage of 30 mg daily treatment was initiated, then it was increased to 120 mg daily without any benefit. Two years later, being the clinical situation without any improvement and being the patient scarcely compliant to the therapy and because a further enlargement of parathyroid glands was observed, a Parathyroidectomy (PTX) was advised.

Nevertheless, PTX was not performed because of patient’s refusal. Furthermore, despite Erythropoietic Stimulating Agent (ESA) therapy, he developed severe anemia that required regular and frequent blood transfusions. iPTH increased to 4500 pg/ml [Fig.1] with a parallel rise in alkaline phosphatase >600 UI/L [Fig.2]. A Computed Tomography scan showed multiple bone-thickening lesions. He thus initiated Etelcalcetide 5 mg e.v. 3 times a week, after the HD session but without any benefit. The dosage was then increased to 7.5 mg but the patient gradually became frail and developed pancytopenia and low-grade fever. Hematological evaluation with bone marrow biopsy was performed in December 2019. Bone marrow histology showed severe fibrosis [Myelofibrosis (MF) grade 3] with normal bone marrow cytogenetics. Blood samples for mutations in JAK-2, CALR, and MPL and BCR-ABL rearrangement were negative. There was no evidence for a myeloproliferative neoplasm (MPN) or metastatic lesions.

During the following months, while on a 7,5 mg dose of etalcalcetide, there was a gradual reduction in iPTH [Fig.1] and serum alkaline phosphatase [Fig.2], up to 500 pg/dl and 200 IU/L respectively. The patient developed asymptomatic, often severe, hypocalcemia which was managed with therapy.

The patient’s clinical conditions gradually improved, anemia responded to lower doses of ESAs. A bone marrow biopsy was repeated after one year (December 2020) and it showed a reduction in fibrosis (MF grade varying from 1-2). Then etelcalcetide dosage was reduced while serum calcium and phosphate levels were in the normal limit.

Conclusion

Myelofibrosis secondary to renal osteodystrophy is an uncommon complication. It has been rarely reported and usually is associated with primary hyperparathyroidism. Marrow fibrosis and pancytopenia is related to the excessive iPTH that upregulates production of cytokines and paracrine factors in the bone marrow (IL-1a, IL-6, FNF-a, TGF–b, and platelet-derived growth factor) and it has an important stimulatory effect on fibroblast proliferation. It is known that surgical parathyroidectomy is associated with a reduction of bone marrow fibrosis in primary hyperparathyroidism. To our knowledge, this is probably the first case of tertiary hyperparathyroidism in which the effect of etelcalcetide is comparable to parathyroidectomy as far as on calcium-phosphate balance, and a significant improvement in bone marrow fibrosis and hemoglobin. In conclusion, etelcalcetide at least in this patient seems as effective as PTX on bone balance, bone marrow and anemia.

P1317THE PREVALENCE OF CENTRAL VENOUS CATHETERS AND LOWER ARM ARTERIOVENOUS FISTULAS DEPENDS ON DIFFERENT VASCULAR ACCESS MANAGEMENT POLICIES: A MULTICENTER ITALIAN STUDY

Background and Aims

According to local resources, different vascular access (VA) procedures are employed in every country. In Italy, high variability exists in VA management among different dialysis units. In 2018, the DOPPS 5 study showed a declining prevalence of lower arm arteriovenous fistulas (AVF) in Europe with an increasing tendency of making upper arm AVFs and placing central venous catheters (CVCs). Accordingly, an Italian Survey in 2013 confirmed an increasing trend in CVCs use among different Italian regions.

Hence, we made an epidemiologic, multicenter study to evaluate a possible relation between this trend and the variability of local VA management policies.

Method

VA data from 236 patients of prevalent patients were collected from five dialysis centers in the South of Italy. The prevalence of the various types of VAs was analyzed in relation to the following different VA surgery policies adopted in the participant centers:

Results

Age of patients was comparable among all centers while dialysis vintage was higher in center A (P<0.001). The prevalence of lower arm AVFs was significantly reduced In Center A (50.6%) and the prevalence of CVCs (25.8%) was significantly increased as compared to the Centers D-E. On the contrary the Centers D-E had the highest prevalence of lower arm AVF (70.8%) and the lowest of CVCs (12.3%), with a statistically significant difference as compared to Center A (Table 1 ). Conversely, no differences were noticed when comparing data from Centers B-C vs. Center A and vs. Centers D-E, although the prevalence of lower arm AVFs was slightly higher, but the difference was not significant, and that of CVCs was slightly lower as compared to Center A ,fully supported by the vascular surgeon (Figure 1 ).

Conclusion

The reduced tendency of lower arm fistulas and the increasing prevalence of CVCs showed by the DOPPS 5 study might not be applicable to all Italian regions. In our study of 5 dialysis units in the South of Italy, the stability of the nephrologist’s surgical activity probably played a crucial role in explaining the observed decreased use of CVCs with a steadily high prevalence (over 70%) of the lower arm fistulas, regardless of aging.

Association of Higher Advanced Oxidation Protein Products (AOPPs) Levels in Patients with Diabetic and Hypertensive Nephropathy

Background and Objectives: Diabetes mellitus (DM) and hypertension (HT) are characterized by cell damage caused by inflammatory and metabolic mechanisms induced by alteration in reduction-oxidative status. Serum advanced oxidation protein products (AOPP) are new markers of protein damage induced by oxidative stress. We evaluated serum levels of AOPP in a cohort of patients with DM and HT, with or without renal complications, compared with a control healthy population. Materials and Methods: The study group comprised of 62 patients with type 2 DM and 56 with HT. The 62 patients affected by DM were further distinguished in 24 subjects without renal impairment, 18 with diabetic nephropathy (DN), 20 with chronic kidney disease (CKD) stage 2–3 secondary to DN. The subgroup of 56 patients with primary HT comprised 26 subjects without renal complications and 30 with CKD (stage 2–3) secondary to HT. Thirty healthy controls, matched for age and sex, were recruited among blood donors. Results: Increased AOPP levels were found in DM patients compared with healthy subjects, although not significantly. This index was higher and more significant in patients with DN and CKD secondary to DN than in DM patients without nephropathy (p < 0.05) or controls (p < 0.0001). Patients with HT and with kidney impairment secondary to HT also had significantly higher AOPP serum levels than controls (p < 0.01 and p < 0.0001, respectively). There were no significant differences in mean AOPP levels among DM and HT patients. Conclusion: Our study showed that oxidative stress was higher in diabetic or hypertensive subjects than in healthy controls and, in particular, it appeared to be more severe in patients with renal complications. We suggest that the assessment of AOPP in diabetic and hypertensive patients may be important to predict the onset of renal failure and to open a new perspective on the adoption of antioxidant molecules to prevent CKD in those settings.

Carotid artery diameter and wall stiffness in proteinuric renal disease without severely reduced kidney function

PURPOSE

To evaluate the carotid artery diameter, and wall thickness and stiffness in patients with glomerulopathy and proteinuria without severely reduced kidney function.

METHODS

We compared 30 control subjects to 30 patients with glomerular disease, proteinuria, and glomerular filtration rate > 30 ml/min/1.73 m(2) : membranous glomerulonephritis (n = 13), minimal change disease (n = 2), focal and segmental glomerulosclerosis (n = 3), IgA nephropathy (n = 5), lupus nephritis (n = 5), antiphospholipid antibody nephropathy (n = 1), cryoglobulinemic glomerulonephritis (n = 1). The laboratory evaluations included carotid artery diameter, intima-media thickness, and stiffness measurements.

RESULTS

Carotid cross-sectional area of intima-media complex was thicker in patients (18.6 ± 1.4 [x ± SEM]) than in controls (14.8 ± 0.6 mm(2) , p = 0.014), as was carotid artery wall stiffness (8.96 ± 0.86 versus 5.65 ± 0.38, [x ± SEM], p < 0.01). This difference remained significant after adjustment for age, sex, and metabolic cardiovascular risk factors: carotid stiffness was 9.19 ± 0.67 (99% confidence interval [CI] 7.40-10.98)] in patients and 4.80 ± 0.75 (99% CI 2.79-7.11) in controls; adjusted mean difference 4.40 (99% CI 1.46-7.34); p <0.001.

CONCLUSIONS

This study showed, for the first time, signs of altered structural and elastic properties of the arterial wall in patients with proteinuria and glomerular disease without severely reduced kidney function.

Comparison of chondrogensis in static and perfused bioreactor culture

As a result of the low yield of cartilage from primary patient harvests and a high demand for autologous cartilage for reconstructive surgery and structural repair, primary explant cartilage must be augmented by tissue engineering techniques. In this study, chondrocytes seeded on PLLA/PGA scaffolds in static culture and a direct perfusion bioreactor were biochemically and histologically analyzed to determine the effects of fluid flow and media pH on matrix assembly. A gradual media pH change was maintained in the bioreactor within 7.4-6.96 over 2 weeks compared to a more rapid decrease from 7.4 to 6.58 in static culture over 3 days. Seeded scaffolds subjected to 1 microm/s flow demonstrated a 118% increase (p < 0.05) in DNA content, a 184% increase (p < 0.05) in GAG content, and a 155% (p < 0.05) increase in hydroxyproline content compared to static culture. Distinct differences were noted in tissue morphology, including more intense staining for proteoglycans by safranin-O and alignment of cells in the direction of media flow. Culture of chondrocyte seeded matrices thus offers the possibility of rapid in vitro expansion of donor cartilage for the repair of structural defects, tracheal injury, and vascularized tissue damage.