1. INBORN ERRORS OF METABOLISM Stefano Picca, MD Dept. of Nephrology and Urology, Dialysis Unit “Bambino Gesù” Pediatric Research Hospital ROMA, Italy 5th International Conference on Pediatric Continuous Renal Replacement Therapy Orlando, FLA. 2008, June 19 – 21

2. INCIDENCE Overall: 1:9160 Organic Acidurias: 1:21422 Urea Cycle Defects: 1:41506 Fatty Acids Oxidation Defects: 1:91599 AGE OF ONSET Neonate: 40% Infant: 30% Child: 20% Adult: 5-10% (?) Dionisi-Vici et al, J Pediatrics, 2002. “SMALL MOLECULES” DISEASES INDUCING CONGENITAL HYPERAMMONEMIA

3. hyperammonemia is extremely toxic (per se or through intracellular excess glutamine formation) to the brain causing astrocyte swelling, brain edema, coma, death or severe disability, thus: emergency treatment has to be started even before having a precise diagnosis since prognosis may depend on: coma duration (total and/or before treatment) (Msall, 1984; Picca, 2001; McBryde, 2006) peak ammonium level (Enns, 2007) detoxification rapidity (Schaefer, 1999) KEY POINTS FACING TO A HYPERAMMONEMIC NEWBORN

4. THE USUAL COURSE OF NEONATAL HYPERAMMONEMIA-1 PATIENTDIAGNOSISTREATMENT home Mother: “sleeps too long” (May) Start Pharmacological Treatment peripheral hospital Hyperammonemia 3 rd level hospital Metabolic defect Starts (continues) Pharmacological Treatment DIALYSIS NO RESPONSERESPONSE RE-FEEDING Metabolism expert Biochemistry Lab Neonatologist Nephrologist OUTCOME ANALYSIS

5. Pharmacological “cocktail” NO RESPONSERESPONSE Starts (continues) Pharmacological Treatment DIALYSIS RE-FEEDING OUTCOME ANALYSIS THE USUAL COURSE OF NEONATAL HYPERAMMONEMIA-2

6. Pharmacological treatment before having a diagnosis AIMS  precursors  catabolism  anabolism stop protein caloric intake  100 kcal/kg insulin …and endogenous depuration arginine 250 mg/Kg/2 hrs + 250 - 500 mg/Kg/day carnitine 1g i.v. bolus 250 - 500 mg/Kg/day vitamins (B12 1 mg,biotin 5-15 mg) benzoate/phenylbutyrate 250 mg/Kg/2 hrs + 250 mg/Kg/day (UCD only?) peroral carbamylglutamate 100 – 300 mg/kg Picca et al. Ped Nephrol 2001

7. Pharmacological “cocktail” NO RESPONSERESPONSE Starts (continues) Pharmacological Treatment DIALYSIS RE-FEEDING OUTCOME ANALYSIS THE USUAL COURSE OF NEONATAL HYPERAMMONEMIA-3 Waiting for…

8. 04812162024 0 250 500 750 1000 2000 4000 6000 pNH 4 (  mol/l) HOURS non-responders (dialysis) responders (med. treatment alone) 0-4 HOURS MEDICAL TREATMENT IN NEONATAL HYPERAMMONEMIA Picca, 2002, unpublished

9. Pharmacological “cocktail” NO RESPONSERESPONSE Starts (continues) Pharmacological Treatment DIALYSIS RE-FEEDING OUTCOME ANALYSIS THE USUAL COURSE OF NEONATAL HYPERAMMONEMIA-4 Waiting for… Dialysis

10. VC GKC KDKD Ke PLASMA NH 4 (DIS)EQUILIBRIUM Modified from Sargent JA, Gotch FA, 1996.

11. 0102030405060 0 20 40 60 80 100 CAVHD patients 0102030405060 0 20 40 60 80 100 HD patients TIME (hours) 0102030405060 0 20 40 60 80 100 CVVHD patients NH4p (percent of initial value) Picca et al. Ped Nephrol 2001

12. AMMONIUM CLEARANCE AND FILTRATION FRACTION USING DIFFERENT DIALYSIS MODALITIES. Picca et al., 2001

13. Dialysis in hyperammonemia: the “beyond ammonium removal” effects DIALYSIS NH 4 removal GOOD BAD Protein loss in the dialysate: 10-12 g/1.73m 2 /day (Maxvold, 2000) Dialysis-induced catabolism (Schulman, 2004) NH 4 scavengers (NaBz+NaPh) removal (Bunchman, 2007) Correction of AKI Citrulline removal (McBryde, 2004) Glutamine removal (McBryde, 2004)

14. Starts (continues) Pharmacological Treatment DIALYSIS NO RESPONSERESPONSE RE-FEEDING Pharmacological “cocktail” OUTCOME ANALYSIS Waiting for… Dialysis THE USUAL COURSE OF NEONATAL HYPERAMMONEMIA-5 Have we been successful?

15. PROGNOSTIC INDICATORS: SURVIVAL McBryde, 2006 pNH 4 at admission<180  mol/L Time to RRT<24 hrs Medical treatment<24 hrs BP> 5%ile at RRT initiation HD initial RRT (trend) Bachman, 2003 pNH 4 at admission<300  mol/L Peak pNH 4 <480  mol/L Uchino, 1998 pNH 4 at admission<180  mol/L Schaefer, 1999 50% pNH 4 decay time < 7 hrs (catheter > 5F) Picca, 2001 pre-treatment coma duration < 33 hrs (no influence of post-treatment duration) responsiveness to pharmacological therapy Pela, 2008 pre-treatment coma duration < 10 hrs

16. SINP ITALIAN SOCIETY OF PEDIATRIC NEPHROLOGY Italian Study Group “Dialysis Treatment of Neonatal hyperammonemia” (Coord.: S. Picca, MD)

17. 19861988199019921994199619982000200220042006 0 1 2 3 4 5 6 patients years n= 48

18. DESCRIPTIVE (1) Continuous VariablenMeanSEM Year of treatment (yrs after 1985)4714.00.6 GA3939.00.28 Birth BW (g)43324067.6 Apgar (1 min)318.450.18 Apgar (5 min)319.60.11 Creatinine (mg/dl)361.130.09 Age at admission (hrs)46120.818.5 BW at admission (g)46298569.6 BE at admission29-9.101.7 pNH 4 pre-medical treatment (  mol/L) 46685103 pNH 4 pre-dialysis (  mol/L) 4783984 pNH 4 peak (  mol/L) 391124141 pNH 4 dialysis 50% decay time (hrs)3711.41.8 Dialysis duration (hrs)4550.97.2 Coma total duration (hrs)3975.57.8 Predialysis coma duration (hrs)4418.32.4

19. DESCRIPTIVE (2) Non continuous variablen CAVHD6 CVVHD16 HD3 PD25 GenderM 32/46 Intubation31/ 42 Survival at discharge35/46 (76%) Survival at 2 years * (*follow up N/A in 6 pts) 23/39 (59%) Normal development at 2 years12/ 27 (44%)

20. DEP. VARIABLE 1: SURVIVAL AT DISCHARGE Year of treatment Birth BW (g) Age at admission (hrs) BW at admission (g) BE at admission Creatinine (mg/dl) pNH 4 pre-medical treatment (  mol/L) pNH 4 pre-dialysis (  mol/L) pNH 4 peak (  mol/L) pNH 4 dialysis 50% decay time (hrs) Dialysis duration (hrs) Coma total duration (hrs) Predialysis coma duration (hrs) CAVHD CVVHD HD DP Gender Intubation NS 0.056 0.62 0.25 0.93 0.075 NS 0.08 NS

21. 081624324048 0 20 40 60 80 100 Ammonia Decay (%) Time (h) PD CVVH, HD, CAVH

22. PD n=25 No PD n=21 p pNH 4 pre-medical treatment (  mol/L) 546±82850±2020.146 pNH 4 pre-dialysis (  mol/L) 848±112829±1280.914 pNH 4 increase (  mol/L) 302±80-8±1540.061 Dialysis duration (hrs)75 ± 1122 ± 3.9<0.001 Predialysis coma duration (hrs)13.2± 2.324.3± 18.20.017 PD vs. EXTRACORPOREAL

23. DEP. VARIABLE 2: DEVELOPMENT AT 2 YEARS Year of treatment Birth BW (g) Age at admission (hrs) BW at admission (g) BE at admission Creatinine (mg/dl) pNH 4 pre-medical treatment (  mol/L) pNH 4 pre-dialysis (  mol/L) pNH 4 peak (  mol/L) pNH 4 dialysis 50% decay time (hrs) Dialysis duration (hrs) Coma total duration (hrs) Predialysis coma duration (hrs) CAVHD CVVHD HD DP Gender Intubation 0.017 (M-W); 0.056 (Regr. analysis) 0.15 0.073 NS

24. 3126±91 vs 2765±88 p 0.018 -6.3±0.8 vs -12.2±1.0 p 0.018 -5.7±2 vs -14.6±1.9 p 0.023 997±124 vs 606 ±69 p 0.034 NS 779±121 vs 550±183 p 0.041 DEP. VARIABLE 3: UCD vs OA Year of treatment Birth BW (g) Age at admission (hrs) BW at admission (g) BW loss from birth BW at admission (%) BE at admission pNH 4 pre-medical treatment (  mol/L) pNH 4 pre-dialysis (  mol/L) pNH 4 peak (  mol/L) pNH 4 dialysis 50% decay time (hrs) Creatinine (mg/dl) Dialysis duration (hrs) Coma total duration (hrs) Predialysis coma duration (hrs) CAVHD CVVHD HD DP Gender Intubation

25. CONCLUSIONS-DIALYSIS PD provides NH 4 clearance lower than HD and CRRT However, in this series and in that of Schaefer (1999) detoxification rapidity was not significantly different from that of extracorporeal dialysis and patients treated with PD showed a trend toward a better survival This may have been the consequence of a shorter coma duration and of a lower intoxication level before dialysis initiation Extracorporeal should be the first-line dialysis modality in neonatal hyperammonemia When HD and/or CRRT facilities are not available, PD should be considered. However, results are likely similar to those obtained with extracorporeal dialysis only in less intoxicated patients.

26. In our and in other series, dialysis modality did not affect the outcome in the presence of a long mean pre-treatment duration In fact, plasma ammonium level before every treatment and predialysis coma duration resulted to be the main determinants of survival both at short and long term It is thus likely that the influence of detoxification rapidity on the outcome becomes evident when pre-treatment duration is shorter than that reported in our series, as reported by others (Schaefer 1999, Pela 2008) However, as high intoxication level and long pre-treatment duration are the consequence of a delayed intervention, the need for an early diagnosis and treatment remains the crucial issue of neonatal hyperammonemia. CONCLUSIONS-OUTCOME

27. Short-term <2 nd year of life Mortality 27.5% Cognitive development Normal 71% Mild MR 4.7% Severe MR 23% Outcome Neonatal Onset pts Long-term >2 nd year of life (2-18 yrs) 48% 28.5% 9.5% 57% No significant difference between UCDs and OAs Deodato F et al, 2004

28. ACKNOWLEDGEMENTS Bambino Gesù Children Hospital: Metabolic Unit: Carlo Dionisi-Vici, MD; Andrea Bartuli, MD; Gaetano Sabetta, MD Clinical Biochemistry Lab: Cristiano Rizzo BSc, PhD; Anna Pastore BSc, PhD NICU: all doctors and nurses Dialysis Unit: Francesco Emma, MD, all doctors and nurses (thanks!) In Italy: SINP (Italian Society of Pediatric Nephrology) All doctors from Pediatric Nephrology and NICUs of Genova, Milan, Turin, Padua, Florence, Naples, Bari.