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➲ Rapidly progressive nephritic syndrome: relentlessly progressive glomerulonephritis resulting in ESRF within weeks
➲ Recurrent gross haematuria
GLOMERULOPATHYclinical categories
➲ Asymptomatic glomerulopathy: proteinuria, haematuria, or both – without clinical symptoms
➲ Chronic nephritic (glomerular) syndrome: glomerular disease that progress in chronic renal failure
➲ Nephrotic syndrome
GLOMERULOPATHYstructural characteristics
➲Acute damage (diffuse or segmental): - proliferation of epithelial, endothelial and mesangial cells; - exudation of polymorphonuclear leukocytes in the glomerulus; - necrosis of glomerular capillaries
GLOMERULOPATHYstructural characteristics
➲ Chronic damage: - proliferation of cellular elements (epithelium, endothelium, mesangium); - membranous involvement with thickening of glomerular basement membrane (GBM); - sclerosis of the glomerulus; - tubular atrophy, nephrosclerosis, interstitial scarring (in ESRF)
➲ Microalbuminuria●Urine [albumin] > 30mg/day but not detectable
by urine dipstick➲ Nephrotic syndrome
●Urine protein excretion > 3.5g/day (with hypoalbuminaemia, oedema and hyperlipidaemia)
Nephrotic Syndrome (NS)
Is not a disease but a group of signs and symptoms seen in patients with heavy proteinuria
presents with oedema proteinuria usually > 3.5g / 24hrs (>0.05g / kg /
24hrs in children) serum albumin < 30g/l other features: hyperlipidaemia, and
hypercoaguable state
NS pathophysiology proteinuria: due to an increase in glomerular
permeability hypoalbuminuria: occurs when liver synthesis cannot
keep up with urine losses oedema mechanism is complex and still in dispute:
primary salt and water retention associated with reduced renal function as well as reduced plasma oncotic pressure are primary factors (overfill and underfill)
hyperlipidaemia: increased liver synthesis hypercoagulation: increased fibrinogen and loss of
antithrombin III
Clinical Features in NS - Thrombosis
➲ Serious risk of thrombosis➲ Increased fibrinogen concentration➲ Antithrombin III concentration reduced➲ NS patients resistant to heparin➲ Platelets hyperaggregable➲ Increased blood viscosity
NS - laboratory Features
➲Hct may be elevated➲Hyponatremia is common➲Plasma creatinine is elevated in
33% of patients
NS laboratory- Plasma Protein
➲ Albumin● Hypoalbuminemia due to loss via the kidney
Primary glomerulonephritides as a cause of nephrotic syndrome Korbet et al., Am. J. Kidney Dis., 1996, 27: 647 - 651
Indications for Biopsy
➲ Pretreatment● Recommended
●Onset age < 6 months●Macroscopic hematuria●Microscopic hematuria and HTN●Low C3●Renal failure
● Discretionary●Onset between 6-12 months or > 12 years●Persistent HTN of hematuria
Indications for Biopsy
➲ Post treatment●Steroid resistance●Frequent relapsers
Minimal change disease
Minimal change disease
Pathogenesis of minimal change disease
1. circulating permeability factor(hemopexin?)
1. decreased synthesis of glomerular polyanions (heparan sulfate) by podocytes
2. impaired adhesion of podocytes to GBM( -dystroglycan, 1-integrins?)
4. expression of TGF1 detectable almost only in steroid resistant MCD and FSGS
Minimal change disease
1. full-blown nephrotic syndrome with selective proteinuria
2. hematuria, hypertension and reduced renal function uncommon
3. absence of glomerular abnormalities on LM and IF
4. fusion of epithelial cells foot processes on electron microscopy
Minimal change disease-prevalence among nephrotic patients
Children - 85 – 95%
Young adults - 50%
Adults > 40 years - 20 – 25%
Classification of patients with minimal change disease based on response to corticosteroids
1. Steroid responsive (sensitive)develop complete remission of proteinuria
within 8 – 12 weeks of treatment (in adults remission should develop within
16 weeks)2. Steroid dependent
develop relapse during tapering of steroids or within 2 weeks after cessation of therapy
3. Steroid resistant fail to respond to steroid treatment at all
Definitions
➲ Steroid Dependence- Two consecutive relapses occurring during corticosteroid treatment or within 14 days of its cessation
➲ Steroid Resistance- Failure to achieve response in spite of 4 weeks of prednisone 60 mg/m2*day
Clinical course of MCD in children
1. Remission - 90%a. no relapses - 20%
b. infrequent relapses - 40%c. frequent relapses and
steroid dependent - 30%2. Resistance to steroids - 10%
a. response to alternative treatment - 8%
b. refractory to any kind of treatment - 2%
In adults, initial response rate is lower, relapses and steroid dependence are less frequent
Therapy of MCD in children – current recommendations
1. Initially course of prednisone 60 mg/m2 for 4-6 weeks with 40 mg/m2 every alternate day for another 4-6 weeks
2. Relapses treated in a similar way, but tapering of prednisone starts when urine becomes protein free
3. Frequent relapsers and steroid dependent patients treated either by cyclophosphamide 2 mg/kg/day for 8 weeks or by cyclosporine 5 mg/kg/day for 6-12 months
4. Treatment of steroid resistant patients is usually unsatisfactory
Therapy of MCD – modifications in adults
1. Initially course of prednisone 1mg/kg for 8-16 weeks or for one week after remission is achieved, then several weeks (one month) 1 mg/kg on alternate days, thereafter corticosteroids are slowly tapered during several months
2. Relapses treated in a similar way3. Frequent relapsers and steroid dependent
patients treated either by CPH 2 mg/kg/day for 8 weeks or by CyA 5 mg/kg/day for 6-12 months
4. Treatment of steroid resistant patients is usually unsatisfactory
Mild FSGS
Moderate FSGS
Tip lesion in early FSGS
Collapsing FSGS
Etiology of FSGS
1. Primary FSGSa. glomerular tip lesionb. collapsing glomerulopathy
- agenesis of one kidney- vesicoureteral reflux- morbid obesity
c. damage to epithelial cells- HIV nephropathy- heroin nephropathy
Classification of FSGS
1. Genetic FSGSa. podocinb. -actinin
2. Immunologicmechanisms not yet identified
3. Viral FSGSa. HIVb. hepatitis C
4. Toxic FSGSa. heroinb. pamidronate
Pathogenesis of primary FSGS
1. Late onset congenital FSGSdeficiency of podocyte proteins (podocin, -actinin, CD2AP, et al.)
2. Circulating permeability factorsa. imunoglobulin, or Ig-like moleculeb. protein of MW about 30-50 kDa
c. factor inhibiting inducible NO synthase in mesangial cells (hemopexin)
3. Deficient inhibitors of permeability factors lost in urineapolipoproteins of HDL complex (e.g. apo J, apo E2 and apo E4)
Permeability factors in MCD and FSGSGlassock, J Am Soc Nephrol, 2003, 14: 541 - 543
1. Permeability factors in MCD and FSGS may be different2. Among PF described in MCD (e.g. heparanase, VEGF)
hemopexin is best characterized (Cheung et al., Kidney Int, 2000, 57: 1512 – 1520)
3. In FSGS 30-50 kD weakly anionic, heat labile, protease-sensitive factor inhibiting NO production in mesangial cells was identified with the Palb assay (Sharma et al., Kidney Int, 2000, 58: 1073 - 1079).
4. This PF is increased also in pts with genetic mutation of podocin (Carraro et al., JASN, 2002, 13: 1946 - 1952).
Serial estimates of permeability factors in FSGSCattran et al., J Am Soc Nephrol, 2003, 14: 448 - 453
1. Serum permeability activity assessed in 27 pts with FSGS treated either by cyclosporine or placebo before and after 26 weeks of treatment (Cattran et al., Kidney Int., 1999, 56: 2220 – 2226)
2. Proteinuria decreased in cyclosporine treated patients from 7.2 to 3.1 g/day and did not change in pts on placebo (from 9.5 to 7.4 g/day)
3. Serum permeability activity changed neither in cyclosporine (from 0.31 to 0.46), nor in placebo (from 0.41 to 0.36) treated pts
4. Antiproteinuric effect of cyclosporine seemed to be independent on changes of Palb
Focal segmental glomerulosclerosis
1. Asymptomatic proteinuria or full blown nephrotic syndrome
2. Hypertension, microscopic hematuria and decreased renal function common
Treatment of primary FSGS – current recommendations
1. Response to corticosteroids may increase from only 10-30% up to 60% with longer treatment with higher dose (60 mg/m2 at least 3 months, patients should be considered steroid resistant after 6 months)
2. Cyclosporine may reduce proteinuria and lower the risk of progression to ESRD even in steroid resistant patients, treatment should be long (at least 6 months), relapses after cyclosporine withdrawal common
3. Cytotoxics remain only second-line therapy, the evidence for their effect in steroid resistant patients is not conclusive
Membranous nephropathy
Membranous nephropathy
Membranous nephropathy
Membranous nephropathy
1. Secondary- infections
(hepatitis B, syphilis, malaria)- drugs
(organic gold, penicillamine, NSAID)
- neoplasms(carcinomas, e.g. Colon, lung, or
stomach, and lymphomas)- systemic lupus erythematosus
2. Idiopathic
Idiopathic membranous nephropathy
1. Membranous nephropathy represents 15-25% of adult nephrotic syndrome
2. Nephrotic proteinuria is present in about 80% of patients, remaining patients have asymptomatic proteinuria
3. Microscopic hematuria is common4. Hypertension and chronic renal failure are
uncommon at presentation, but may develop during follow-up
5. Histology – subepithelial deposits along often thickened GBM
Natural course of idiopathic membranous nephropathy
1. Spontaneous remission may develop in about one third of patients
2. Nephrotic syndrome persists in another third of patients
3. Only 20-30% of patients progress to ESRD during 20-30 years of follow up
Cyclosporine in steroid-resistant MNCattran et al., Kidney Int., 2001, 59: 1484 - 1490
complete or partial remission developed after 26 weeks in 75% of pts treated by CyA vs. in 22% of pts treated by placebo
during 52 weeks relapse developed in 43% of pts treated by CyA and 40% of pts treated by placebo
at the end of follow-up in remission was 39% of pts treated by CyA and 13% of pts treated by placebo
Treatment of idiopathic membranous nephropathy – current
recommendations
1. Corticosteroids should not be used a sole therapy
2. Azathioprine is not effective in reversing or stabilizing progressive renal insufficiency
3. Cytotoxics induce prolonged remission of nephrotic syndrome and improve renal survival, their use should be reserved for patients with progressive disease
4. Cyclosporine seems to be effective in progressive renal insufficiency
Guidelines for the treatment of IMN Cattran, Kidney Int., 2001, 59: 1983 - 1994
2. Microscopic hematuria with proteinuria - mesangial proliferation with peripheral
expansion of mesangium (membranoproliferative GN)
Ultrastructural changes in glomerular capillaries in mesangio- and membranoproliferative GN
IgA nephropathy –mesangioproliferative glomerulonephritis
IgA nephropathy
Pathogenesis of IgA nephropathyGómez-Guerrero et al., Kidney Int, 2002, 62: 715 - 717
1. Aberrantly O-glycosylated IgA1 with exposed GalNAc may be recognized as antigens by IgG
2. Circulating immune complexes of IgA1 and IgG and/or IgA1 and soluble FcRI (CD89) were identified in pts with IgA nephropathy
3. Except from ASGP-R, CD89, Fc/R and TfR mesangial cells may express further, not yet described IgA receptors
4. Patients with IgA nephropathy have increased expression of megsin (serine protease inhibitor – serpin). Overexpression of megsin leads to progressive mesangial matrix expansion
IgA nephropathy
1. Commonest glomerulonephritis in Europe (20-40% of primary glomerulonephritides)
2. Typical clinical presentation – asymptomatic microscopic hematuria or episodes of parainfectious macroscopic hematuria
3. Natural history is not benign – at least 20% of patients develop ESRD during 20 years
IgA nephropathy –negative prognostic factors
a. clinicalhypertension
proteinuria (> 1 g/24 hrs)decreased renal function at presentation
b. histologic glomerulosclerosisinterstitial fibrosis vascular sclerosis
IgA nephropathy - treatment
1. Strict control of hypertension with ACE inhibitors
2. Fish oil in patients with slowly progressive course of renal insufficiency
3. Corticosteroids in proteinuric patients with preserved renal function
4. Cytotoxics in patients with progressive renal insufficiency
Corticosteroids in IgA nephropathy: long-term results
Pozzi et al., J Am Soc Nephrol, 2004, 15: 157 - 163
1. Secondary analysis of a multicenter, randomized, controlled trial of 86 adult IgAN treated for 6 months either with intravenous methylprednisolone followed by oral steroids of supportive therapy
2. Ten-year renal survival was significantly better in the steroid than in the control group (97% vs. 53%, p=0.0003)
3. Proteinuria decreased in patients who did not double baseline serum creatinine and increased in progressive patients
Evidence-based recommendations for IST in IgAN: handle with caution