Primary glomerulonephritides (GN) II Proliferative GN

1. Primary glomerulonephritides (GN)II Proliferative GN Miroslav Merta Klinika nefrologie 1. LF a VFN

2. Proliferative versus neproliferative GN(glomerular capillary loop – ultrastructural changes) Subendothelial deposits Urinary space Acute GN Epitheliál cells=podocytes Basal membrane Increased number and proliferation of mesangial cells neutrophils Capillary lumen Proliferative GN Subepithelial deposits Endotehelial cells Mesangial cells Subendothelial deposits Increaed number and proliferation of mesangial cells to distal parts of capillary loop Normal glomerulus Increased number and proliferation of mesangial cells neutrophils mesangial deposits of IgA Mesangioproliferative GN Membranoproliferative GN

3. Dysmorphic erythrocytes (of glomerular origine) are typical finding in proliferative GN Urine sediment in phase contrast Electroscanning microscopy

4. Acute (postreptococal) GN Subendotelial deposits neutrophils Increased number and proliferation Subepithelial (hump-like) deposits

5. Acute (postreptococal) GN Light microscopy (LM): picture of diffuse proliferative GN with prominent influx of neutrophils and event. Other cells, (= exsudative GN) Imunofluorescence (IF): coarsely diffusely lightening of C3, event. IgG, rarely other Three charakteristic types: 1) mesangial 2) „star sky 3) „girlands (associated with nephrotic proteinuria) Elektrone microscopy (EM): proof of deposits subendothelially and condensation of cytoskeleton in adjacent epithelial cytoplasma. N = neutrophils

6. Akutní (postreptokoková GN) - basic characteristics • Its frequency is decreasing in Europe, m:f 2:1, common in children. • Acute GN is caused by „nefritogennic“ strains of STREP. pyogenes (infections of higher respiratory airways, event. cutaneous infections). Infection precedes PSGN for several weeks. • Patogenesis: antigens of STREP (např. GADH)  activation of complement  development of circulatory immuno complexes (event. Their deposition), persistation of STREP infection • Clinical picture: acute nephritic syndrome. Always present hematuria, often swlling (90%), hypertension (80%), proteinuria (in 30% NS),  GFR (83%). • Laboratory findings: findings reflecting presence of STREP infection titers of ASO (2x ), positivity of STREPTOZYME panel (involving antibodies against 4 STREP antigenes). Transitory  C3 (in 90%), event. CH50. • Histological picture: difuse endocapillary GN with proliferation of mesangium and endothel, typically exsudation (leukocytes). Rarely complicated by RPGN, cryoglobulinemia and s.o.)

7. Acute (postreptococal GN) –diagnosis, treatment, prognosis • Renal biopsy not routinely warranted; RB indicated: atypical course (NS), long-term  C3, important  GFR • Treatment involves: treatment of persistating STREP infection and treatment of nefritic syndrome: • Treatme of persistating STREP infection: PNC 1.2 M u./7-10 days • Treatment of nephritic syndrome: restriction of fluids and NaCl, diuretics, rarely hemodialysis (in 20-30% adults) • If complicated by RPGN - corticosteroids, (CPA?) • Prognosis: clinical manifestation is short (2 weeks), healing during weeks, mild proteinuria (< 0.5g/l) may persist for weeks and hematuriea even for 1 year. Long-term prognosis excellent.

8. IgA nephropathy – IGANmesangioproliferative glomerulonephritis Increaing number and proliferation of mesangial cells Mesangial deposits of IgA, rarely IgA in capilars (serious forms)

9. IGAN- histological findings Light microscopy (LM): Focal (here) or diffuse mesangial proliferation. Rarely picture of crescentic GN, more frequently picture of sclerotisating GN. Vasculitic lesions occur in HSP. Immunofluorescence (IF): diffuse mesangial deposits of IgA, co-localisation of other Ig less intensive Electrone microscopy (EM): demonstation of deposits in mesangium

10. Patogenesis of IgA nephropathyGómez-Guerrero et al., Kidney Int, 2002, 62: 715 - 717 Impairment of O-glycosylation of IgA1 causes, that exposed domain GalNAc is recognized as antigennic

11. IgA nephropathy - basic characteristics • Commonest GN in Europe (20-40% of all primary GN) • Typical clinical picture – asymptomatic microskopic hematuria či episodes of parainfectious macroskopic hematuria • Natural course of the disease is not benign – at least in 20% patients ESRD develops within 20 years • Histology – mesangial deposits of IgA demonstrated by IF

12. Prognosis of IgAN– negative prognostic factors a. klinical hypertension proteinuria (> 1 g/24 h) decrease of GFR at the time of diagnosis b. histological glomerulosclerosis interstitial fibrosis vascular sclerosis

13. Prognosis of IGAN- dependance on renal function and proteinuria at the time of diagnosis Dependance on protenuria Dependance on renal function (creatininemia) Radford et al., J Am Soc Nephrol, 1997, 8: 199 - 207

14. IgAN - treatment • Strict control of hypertension achieved preferentially with ACE inhibitors (event. ABR) • Fish oil (unsaturated alpha omega acids) in patients with slow progression of renal insufficiency (weak effect) • Cortikosteroids in patients with proteinuria, which do have preserved renal functions • Cytotoxic agents in patients s progressing renal insufficiency

15. Membranoproliferative glomerulonephritis – type I a II Subendothelal deposits Mesangial sferic deposits New formation of BM Increasing number of mesangial cells and their proliferation to distal parts of capillary loop neutrophils Increasing number of mesangial cells and their proliferation to distal parts of capillary loop neutrophils Intramembranus dense deposits MPGN type I MPGN type II

16. Membranoproliferative GN type I Light microscopy (LM): hypercelullarity and proliferation,, lobular appearance, double contour of BM (tram track) – as consequence of interposition of mesangium), Immunofluorescence (IF): diffuse periferal granular deposits of IgG, event.IgM, and C3 (in type II only C3) Electrone microscopy (EM): dense material substitutes BM Electrone microscopy (EM): demonstration of deposits subendothelially and a mesangially, double contour of BM, leucocytes

17. Membranoproliferatie GN (MPGN) Type I • Idiopatic • Secondary – infection (visceral abscesses, endocarditis, infection of atrioventricular shunts, malaria) - systemic diseases ( SLE – LN type III-IV) - paraproteinemias ( LCDD, cryoglobulinemia) - thrombotic microangiopathy ( HUS/TTP, APS) Type II – disease of dense deposits

18. Idiopatic MPGN type I- basic characteristics • Relatively rare disease in developed countries • It is found in less aged subjects • Clinical findings at the time of dg: usually NS and microskopic hematuria • Slowly progressing disease – during 10-y interval 50% patients do progress into ESRD • Treatment in adults is controversial (corticosteroids, CPA, anticoagulation)

19. Membranoproliferative GN type II Electrone microscopy (EM): dense material substitutes BM

20. Idiopatic MPGN type II- basic characteristics • Very rare disease • Clinically: presence of nephritic factor with hypocomplementemia • More pronounced nephritic features and more agressive course of diasease • Efficient treatment unknown