MO1028EFFECTIVENESS AND KIDNEY PROGNOSIS IN THE TREATMENT OF CORTICORRESISTANT NEPHROTIC SYNDROME IN PEDIATRICS

Background and Aims

To report the response to different treatments and the renal prognosis in a cohort of patients with corticosteroid-resistant nephrotic syndrome (CRNS).

Method

Retrospective observational study in patients with CRNS. For this, the results of the histology, the different treatment guidelines used in each case and the evolution of renal function were collected, determining the results in terms of remission and renal survival in the different groups.

Results

Of the initial cohort of 37 patients, 33 were included, excluding 4 patients with Finnish-type genetic CRNS. The mean age at diagnosis was 6.1 years. 54.5% were women. Regarding the initial biopsy, 45.5% corresponded to minimal changes (15 patients), 27.3% (9) focal and segmental glomerulosclerosis, 15.1% (5) diffuse mesangial proliferation and 12.1% (4) others. The mean follow-up was 53 months (3-115 months). 27 patients (84.4%) received cyclosporine (CyA), 66.7% (18) of them presented complete remission and 22.2% (6) partial response. Of the patients in complete remission, 33% had at least one relapse after 17 months of treatment (7–27 months). Rituximab was administered in 12 patients (37.5%), of which 7 had not previously responded to immunosuppressants. 100% of frequent relapsers presented complete remission after administration of Rituximab, although 3 had subsequent relapses (60%) after 21 months of treatment (12-34 months). 57% of the patients who did not respond to immunosuppressants did not respond to Rituximab either, with Ofatumumab allowing complete remission in one of them. When relating the results with the histology, we saw how the remission in minimal changes and diffuse mesangial proliferation was 100% and 80%, respectively, although it was 33.3% in focal and segmental glomerulosclerosis. Similarly, renal failure was more frequent in patients with focal segmental glomerulosclerosis (77.7%). Of the remissions (24; 72.7%), 3 were partial (9.1%) and 6 (18.2%) did not respond to any immunosuppressive treatment, with the need for kidney transplantation in 2 of them (6%) and with 1 deceased due to an infectious cause (3%).

Conclusion

Histology and, especially, focal and segmental glomerulosclerosis, play a prognostic role in the CRNS with a lower remission rate and a greater deterioration in renal function and the need for associated kidney transplantation.

MO1014PROSPECTIVE STUDY OF SAFETY AND EFFECTIVENESS OF OFATUMUMAB AS A TREATMENT IN REFRACTORY NEPHROTIC SYNDROME (CORTICODEPENDENT AND CORTICORRESISTANT)

Background and Aims

Ofatumumab (OFA) is an anti-CD-20 monoclonal antibody useful in nephrotic syndrome refractory to conventional treatments and rituximab (RTX). Our objective is to evaluate the response and safety in patients with nephrotic syndrome (NS) treated with Ofatumumab.

Method

A prospective descriptive study of 2 years duration (2017-2019) in children with NS refractory to first-line therapies who received treatment with anti-CD20 monoclonal antibodies. To do this, we divided the cohort into 3 groups: Patients with corticodependent NS (CDNS) without response or with adverse effects associated with first-line treatment that preclude its use (Group 1); Corticosteroid-resistant SN (CRNS) (Group 2) and SN with post-transplant recurrence (Group 3). In them, the results of safety and remission rate were evaluated.

Results

Thirty-three patients (21 with SNCD, 11 with SNCR, and 1 with SN recurrence in transplantation) were included and administered anti-CD20. The male / female ratio was 2: 1 and the mean age at diagnosis was 5.2 years. 100% of the children (33) received RTX and 18.2% (6) OFA. The RTX achieved complete remission in 87.9% (29) and 48.3% of these did not present new relapses after 70 months of follow-up. 100% of Group 1 presented complete remission after RTX, although 52.4% (11) presented at least 1 relapse after 22.9 months (mean 2.5 relapses). In group 2, 72.72% (8) complete remission and 27.2% (3) partial, with persistent proteinuria. 36.4% (4) presented relapse after 17 months of treatment (mean 1 relapse). Of the 6 who received OFA, 83.3% presented complete remission (1 SNCR and 4 SNCD) and 1 patient (SNCD) presented relapse at 24 months (mean follow-up 1 year). The other case, a 13-year-old girl with recurrence of focal segmental glomerulosclerosis (FSGS) in kidney transplantation, presented partial remission after one year of treatment in association with immunoadsorption sessions. Regarding safety, adverse reactions occurred in 6% (2): allergic reaction with 2nd dose of RTX and cytokine release syndrome with 1st dose of OFA.

Conclusion

Ofatumumab in our series has proven to be an effective and safe drug in difficult-to-manage NS, achieving complete remission in 5 patients who had not previously responded to Rituximab

P1803EFFICACY, SAFETY AND IMPACT ON RENAL FUNCTIONALITY OF ACETAZOLAMIDE TREATMENT IN PATIENTS WITH PMM2-CDG (AZATAX CLINICAL TRIAL)

Background and Aims

Deficit of phosphomanomutase-(PMM2-CDG) is the most frequent congenital N-glycosylation defect, producing cerebellar syndrome with intellectual deficit and “stroke-like” episodes. It has been associated with renal alterations such as proteinuria, diffuse cortical hyperechogenicity and malformations. We evaluated efficacy, safety and renal repercussion of acetazolamide as a new therapeutic tool.

Method

First clinical trial in phase II including PMM2-CDG patients (5-21-years). First phase: 6 months treatment group with acetazolamide. Second phase: 5 weeks randomized withdrawal in responders (acetazolamide vs placebo), assessing renal functionality and effects of this medication. Dosing acetazolamide by 8 to 30mg/kg/day in 2-3 doses. Controls were performed at 3, 6, 14, 25 and 30 weeks determining acid-base balance, ionogram, renal function (creatinine) and Pr/Cr, Ca/Cr index and B2-microglobulin in first morning urine. All patients underwent in a bone densitometry study and renal ultrasound.

Results

24 patients were included (mean age 12.3 ± 4.5 years). Bicarbonate levels and plasma pH were significantly lower at week 25(p <0.001). 13 patient needs to reduce acetazolamide dose due to excessive metabolic acidosis or asthenia. They showed a decrease in sodium (p=0.06), potassium (p<0.001) and serum calcium(p=0.030), although maintained in low normality limit with a decrease in protein loss(p=0.019) and increase in calcium/creatinine index(p=0.025) without B2-microglobulin alterations. The previously ultrasound renal described findings; the cortical hyperechogenicity was observed in 8.4% without renal dysfunction or associated nephrocalcinosis. One patient presented microlithiasis and another, symptomatic renal lithiasis. Densitometric study 69% of patients presented values in the range of osteopenia at the end of trial (-0.9 to -4.9SD, average of -2.36SD).

Conclusion

The efficacy of acetazolamide in the neurological symptoms of PMM2-CDG, due to an enzymatic stimulation mechanism mediated by acidosis, generates the possibility of chronic treatment with the drug in this group of patients, with possible renal adverse effects associated with long-term, overshadowing the skeletal and renal prognosis.

MO079SECURITY OF THERAPEUTIC APHERESIS IN PEDIATRICS. PROSPECTIVE STUDY DURING 2018 IN 171 APHERESIS SESSSIONS

Background and Aims

Identify hypocalcemia and hemodynamic disorders related to apheresis in pediatrics either complications in vascular access or related to anticoagulation and adverse reactions with replacement fluid.

Method

Prospective and descriptive study of 171 sessions for therapeutic apheresis in pediatrics during 2018. Inclusion criteria was based on the 2016 Clinical-Practice-of-Therapeutic-Apheresis-guidelines(ASFA). The apheresis technique was selected also based on the 2016 ASFA Guidelines and the expertise in our center.

Results

The 171 sessions were distributed as follows: 73% were immunoadsorption(IA), 12% were cytoapheresis, 10.5% were LDL-apheresis and 4.5% therapeutic plasma exchange(TPE). The average age was 9 years and 58% were women. 50, 33 and 17% were due to Nephrological, Neurological and Digestive pathology respectively. 83% of the nephrological indications correspond to a category I of the ASFA Guidelines, as well as 25% of the neurological indications and all indications of Digestive pathology correspond to a category II. 58, 25 and 17% used temporary catheter, permanent catheter and needles respectively. Only one patient is accidentally removed from the temporary jugular catheter and it has not been related to vascular access or by the apheresis technique itself. Sixty-six percent had individual anticoagulation with citrate/calcium plus heparin and the remaining 33%, only once. Any case of bleeding related to catheter or others. Only 3 sessions of IA in the hypocalcemia objective, being symptomatic in only one of them. Of all 8 sessions of TPE, we performed 6 with frozen fresh plasma as replacement fluid with no adverse reactions.

Conclusion

The apheresis techniques in pediatrics had been presented with few complications in our center, none derived from vascular access, anticoagulation, infections or adverse effects due to use of replacement fluid. The training of medical and nursing staff is essential to identify risk situations. The use of protocols and international guidelines ensure safety in pediatrics.