Minimal change nephropathy: an update (for adults) Dr. CC Szeto Department of Medicine & Therapeutics The Chinese University of Hong Kong

Minimal change nephropathy: an update (for adults) Dr. CC Szeto Department of Medicine & Therapeutics The Chinese University of Hong Kong

First, it is not uncommon Cameron JS. Am J Kidney Dis 10: 157 171, 1987

How about Hong Kong? overall prevalence: 33.2% Ng JK, et al. Nephrology (in press).

Possible even in non-nephrotic proteinuria overall prevalence: 3.5% Ng JK, et al. Nephrology (in press).

Secondary causes are increasingly recongized allergens: pollen, bee sting, food allergens malignancies, e.g. Hodgkin disease, solid tumor drugs NSAID tyrosine kinase inhibitors salazopyrin, penicillamine, lithium mercury?, gold? infections, e.g. viral autoimmune SLE others, e.g. myasthenia gravis, celiac disease Waldman M, et al. Clin J Am Soc Nephrol 2: 445 453, 2007 Vivarelli M, et al. Clin J Am Soc Nephrol 12: 332 345, 2017.

Time to response is much longer Vivarelli M, et al. Clin J Am Soc Nephrol 12: 332 345, 2017.

Some patients never respond 125 patients from 10 centers onset in adulthood or late adolescence Rutger J. Maas, et al. Am J Kidney Dis. 2017;69(5):637-646.

AKI is not uncommon at presentation no AKI AKI P value no. of case 75 (60%) 50 (40%) age 41 (28-52) 55 (42-72) p < 0.001 HT 19 (25%) 27 (54%) p = 0.001 serum albumin (g/l) 21 (17-25) 18 (15-23) p = 0.06 proteinuria (g/day) 7.5 (5.1-11.6) 12.4 (9.6-18.5) p < 0.001 Rutger J. Maas, et al. Am J Kidney Dis. 2017;69(5):637-646.

Risk of relapse is high Rutger J. Maas, et al. Am J Kidney Dis. 2017;69(5):637-646.

KDIGO treatment recommendation first episode prednisolone 1 mg/kg per d or 2 mg/kg every other d (max 80 mg/d or 120 mg every other d) for 4 16 wk (level 2C) taper slowly over a total period of up to 6 mo after achieving remission (level 2D) infrequent relapses 1 mg/kg per d or 2 mg/kg every other d (max 80 mg/d or 120 mg every other d) for 4 16 wk (level 2C) taper slowly over a total period of up to 6 mo after achieving remission (level 2D) KDIGO glomerulonephritis workgroup. Kidney Int 2[Suppl. 2]: 139 274, 2012

Second line agents frequent relapses and steroid dependency CP 2 2.5 mg/kg per d for 8 wk (single course) (level 2C) if relapse occurs despite CP or to preserve fertility: CyA 3 5 mg/kg per d in two doses for 1 2 yr (level 2C), or TAC 0.05 0.1 mg/kg per d in two doses until 3 mo after remission, then tapered to the min efficient dose for 1 2 yr (level 2C) if intolerant to all of the above: MMF 500 1000 mg twice daily for 1 2 yr (level 2D) KDIGO glomerulonephritis workgroup. Kidney Int 2[Suppl. 2]: 139 274, 2012

MMF: may not be quite as good 60 children with steroid resistant nephrotic syndrome RCT: tacrolimus vs MMF MMF FK P value no. of case favorable outcome treatment failure 29 31 13 28 p = 0.0002 16 3 p = 0.0002 Sinha A, et al. Kidney International (2017) 92, 248 257.

Rituximab 10 children and 20 adults MCD/MesGN (n = 22) or FSGS (n = 8) 1 dose (n = 28) or 2 doses of rituximab (375 mg/m2) Ruggenenti P, et al. J Am Soc Nephrol. 2014 Apr;25(4):850-63.

Effect on B cell or podocyte? after rituximab, some patients maintain prolonged remission despite reconstitution of B cells rituximab binds directly to podocyte SMPDL3b and antiproteinuric effect may be independent of B cell depletion Fornoni A, et al. Sci Transl Med. 2011 Jun 1;3(85):85ra46.

Local data 340 consecutive adult patients with nephrotic syndrome and biopsy-proven MCN treated from 1984 to 2004 treatment response groups: primary steroid resistance frequent relapse ( 4 relapses within 1 year) infrequent relapse ( 1 relapse but not frequent relapse) no relapse (reference group) outcome measures medical problems after diagnosis patient survival renal survival Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Clinical characteristics no relapse infreq relapse freq relapse resistant no. of patients 179 42 86 33 sex (M:F) 90:89 23:19 64:22 13:20 age at diagnosis (years) 39.1 ± 17.0 33.2 ± 12.8 34.4 ± 14.1 50.5 ± 15.5 range 18 82 18 67 19 69 22 81 feature at presentation proteinuria (g/day) 4.9 (3.2 9.0) 4.0 (2.4 7.3) 5.3 (3.0 10.7) 4.2 (2.8 7.4) estimated GFR 93 (74 110) 99 (83 136) 101 (82 132) 34 (16 51) microscopic hematuria 43 (24.0%) 8 (19.0%) 20 (23.3%) 6 (18.2%) high blood pressure 28 (15.6%) 8 (19.0%) 14 (16.3%) 20 (60.6%) acute kidney injury 18 (10.1%) 0 7 (8.1%) 23 (69.7%) Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Clinical characteristics no relapse infreq relapse freq relapse resistant no. of patients 179 42 86 33 time to remission ( weeks) 10 (8 12) 11 (8 14) 12 (10 12) - second line treatment cyclophosphamide 0 0 53 (61.6%) 5 (15.2%) cyclosporine 2 (1.1%) 0 36 (41.9%) 8 (24.2%) levamisole 0 0 9 (10.5%) 0 second kidney biopsy total 29 (16.2%) 12 (28.6%) 31 (36.1%) 12 (36.3%) MCN 24 10 25 5 FGS 5 2 5 6 Szeto QI CC, et al. Am J Kidney Dis. 2015;65:710-8. 0 0 1 1

Overall outcome Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Renal function loss? Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Patient survival Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Long term complications all patients no relapse infreq relapse frequent resistant no. of cases 340 179 42 86 33 any problem 185 (54.4%) 82 (45.8%) 21 (50.0%) 53 (61.6%) 29 (87.9%) diabetes b 60 (17.6%) 30 (16.8%) 3 (7.1%) 16 (18.6%) 11 (33.3%) hypertension b 139 (40.9%) 57 (31.8%) 17 (40.5%) 37 (43.0%) 28 (84.8%) CVD 37 (10.9%) 13 (7.3%) 2 (4.8%) 8 (9.3%) 14 (42.4%) CVA 23 (6.8%) 10 (5.6%) 3 (7.1%) 4 (4.7%) 6 (18.2%) persistent UP 44 (12.9%) 14 (7.8%) 8 (19.0%) 19 (22.1%) 3 (9.1%) Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Non-cardiovascular complicaitons all patients no relapse infreq relapse frequent resistant no. of cases 340 179 42 86 33 AVN 6 (1.8%) 2 (1.1%) 1 (2.4%) 3 (3.5%) 0 any fracture 24 (7.1%) 9 (5.0%) 2 (4.8%) 13 (15.1%) 0 peptic ulcer 13 (3.8%) 9 (5.0%) 1 (2.4%) 2 (2.3%) 1 (3.0%) DVT / PE 10 (2.9%) 5 (2.8%) 1 (2.4%) 3 (3.5%) 1 (3.0%) any cancer 35 (10.3%) 15 (8.4%) 2 (4.8%) 7 (8.1%) 11 (33.3%) major infections 17 (5.0%) 5 (2.8%) 2 (4.8%) 5 (5.8%) 5 (15.2%) hepatitis B flare c 15 (4.4%) 5 (2.8%) 0 7 (8.1%) 3 (9.1%) Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Complication: another recent series 125 cases Rutger J. Maas, et al. Am J Kidney Dis. 2017;69(5):637-646.

Other published literature feature at presentation first episode relapse author no. mic HU HT AKI remission at 8 weeks steroid resistance never infreq freq Nolasco et al 89 60% 19% 24% 56% 21% Korbet et al 40 21% 21% 18% 52.5% 9% 32.3% Mak et al 51 33% 47% 55% 70% 8% Huang et al 46 13% 13% 35% 80% 6% 56% Nakayama et al 62 69.4% 1.6% 24.2% 53.2% 21.0% Tse et al 50 90% 4% 46% Waldman et al 95 25.3% 25% 20% 33.8% 21% present study 340 22.6% 20.6% 14.1% 30.9% 9.7% 52.7% 12.4% 25.3% Szeto CC, et al. Am J Kidney Dis. 2015;65:710-8.

Paediatric cases going into adulthood 55 paediatric patients with biopsy-proved MCN 35 were followed after age 18 years 13 (37%) had relapses during adulthood 20 (57%) had treatment-related complications none had persistent abnormal kidney function Kwong VW, et al. Hong Kong J Nephrol 2013; 15: 22-27.

All kinds of complication are possible Kwong VW, et al. Hong Kong J Nephrol 2013; 15: 22-27.

Conclusion MCN in adult should not be taken lightheartedly many have secondary causes takes longer to respond to steroid AKI is common at presentation rate of complication, including delayed ones, is high some, esp. those resistant to steroid, may progress to dialysis-dependent renal failure

Acknowledgement Dr. Terry Ma Dr. Jack Ng Dr. Vickie Kwong Prof. Fernand Lai Ms. Phyllis Cheng Ms. Cathy Luk Division of Nephrology, Department of Medicine & Therapeutics, Prince of Wales Hospital, CUHK