Common Renal Diseases Dr Mesfn Tassew, Pediatrician, AGHMC. APRIL 2021 Outline Introduction DISEASES PRESENTING PRIMARILY WITH HEMATURIA Nephritic Syndrome Post-streptococcal Glomerulonephritis DISEASES PRESENTING WITH PROTEINURIA Nephrotic syndrome AKI and CKD 5/19/2021 Dr Mesfn on Renal Diseases 2 INTRODUCTION … Kidney Function Excretion of metabolic waste products & foreign chemicals Regulation of water & electrolyte Regulation of arterial pressure Regulation of acid base balance 4 Secretion ,metabolism & excretion of hormones( erythropoetin Gluconeogenesis 5/19/2021 Dr Mesfn on Renal Diseases 3 Anatomy • Anatomy 5/19/2021 Dr Mesfn on Renal Diseases 4 Glomerular disease Abnormalities of glomerular function that can be caused by damage to the major components of the glomerulus: Epithelium (podocytes), Basement membrane, Capillary endothelium, & mesangium. Two chief pathogenesis are recognized: Deposition of antigen-antibody complexes in glomeruli In situ immune complex deposition Circulating immune complex deposition Endogenous or exogeneous antigen[ DNA, Nuclear proteins, IgA, drugs] 5/19/2021 Dr Mesfn on Renal Diseases 5 5/19/2021 Dr Mesfn on Renal Diseases 6 HEMATURIA and PROTEINURIA • Hematuria and proteinuria are manifestation of disease of glomeruli • Hematuria, defined as the persistent presence of more than 5 red blood cells (RBCs)/high power field (HPF) in uncentrifuged urine. • The presence of 10-50 RBCs/µL may suggest underlying pathology, but significant hematuria is generally considered as > 50 RBCs/HPF • Hematuria from within the glomerulus, the tubular system or Lower urinary tract • Proteinuria • Normal urine protein is <150mg/24hr, for albumin 5-10mg/day • 30 to 300mg/day mod albuminuria, >300mg/day is severe • Nephrotic range >3.5gm/24hr 5/19/2021 Dr Mesfn on Renal Diseases 7 Disease Presented by Hematuria Nephritic Syndrome (E.g. APSGN) 5/19/2021 Dr Mesfn on Renal Diseases 8 Acute Glomerulonephritis: Nephritic Syndrome Introduction (APSGN) Acute glomerulonephritis or nephritic syndrome is characterized by sudden-onset hematuria (macroscopic or microscopic), proteinuria, hypertension, edema, and acute kidney injury. E.g. APSGN Acute Post-streptococcal Glomerulonephritis The presence of cola-colored or tea-colored urine without clots and red blood cell casts on urinalysis suggest hematuria of a glomerular origin. The typical patient develops an acute nephritic syndrome 1-2 wk. after an antecedent streptococcal pharyngitis or 3-6 wk after a streptococcal pyoderma Epidemics of nephritis have been described in association with throat (serotypes M1, M4, M25, and some strains of M12) and skin (serotype M49) infections. 5/19/2021 Dr Mesfn on Renal Diseases 9 Etiology − Follows infection with nephrogenic strains of group A betahemolytic streptococci of the throat (mostly in cold weather) or skin (in warm weather) − Diffuse mesangial cell proliferation with an increase in mesangial matrix; lump bumpy deposits of immunoglobulin (Ig) and complement on glomerular basement membrane and in mesangial − Mediated by immune mechanisms but complement activation is mostly through the alternate pathway. 5/19/2021 Dr Mesfn on Renal Diseases 10 Clinical presentation − Most common in 5–12 years old (corresponds with typical age for strep throat) − 1–2 weeks after strep pharyngitis or 3–6 weeks after skin infection (impetigo) − Ranges from asymptomatic microscopic hematuria to acute renal failure – Edema, hypertension, hematuria (classic triad) − Constitutional symptoms—malaise, lethargy, fever, abdominal or flank pain 5/19/2021 Dr Mesfn on Renal Diseases 11 Diagnosis Diagnosis − Urinalysis—RBCs, RBC casts, protein 1–2 +, low C3 (lasts 6mo) − Mild normochromic anemia (hemodilution and low-grade hemolysis) For diagnosis of prior Strep infection Throat culture Use streptozyme (slide agglutination), which detects antibodies to streptolysin O, DNase B, hyaluronidase, streptokinase, and nicotinamide-adenine dinucleotidase. Consider biopsy only in presence of acute renal failure, nephrotic syndrome, absence of streptococcal or normal complement; or if present >2 months after onset 5/19/2021 Dr Mesfn on Renal Diseases 12 Treatment (in-patient, if severe) and Cx − Antibiotics for 10 days (penicillin) − Sodium restriction, -- Diuresis − Fluid and electrolyte management − Control hypertension (calcium channel blocker, vasodilator, or angiotensin-converting enzyme inhibitor) − Complete recovery in >95% 5/19/2021 • . higher risk for HTN At encephalopathy 10% The acute phase generally resolves within 6-8 wk. Urinary protein excretion and hypertension up to 4-6 wk after onset, Microscopic hematuria can persist for 1-2 yrs. CHF, Uremia, Seizure, Acidosis, electrolyte imbalance Dr Mesfn on Renal Diseases 13 Treatment continued • Early systemic antibiotic therapy for streptococcal throat and skin infections does not eliminate the risk of GN. • Family members of patients with acute GN, especially young children, should be considered at risk and be cultured for group A B-hemolytic streptococci and treated if positive 5/19/2021 • A 10 day course of systemic antibiotic therapy with penicillin is recommended to limit the spread of the nephritogenic organisms, antibiotic therapy does not affect the natural history of APSGN, and recurrences are extremely rare • Family pets, particularly dogs, have also been reported as carriers.. Dr Mesfn on Renal Diseases 14 Others • Alport • IgA nephropathy (Berger disease) • Most common cause of chronic glomerular disease worldwide • Hereditary nephritis (X-linked dominant); renal biopsy shows foam cells • Clinical presentation • Asymptomatic hematuria and intermittent gross hematuria 1–2 days after upper respiratory infection • – Most commonly presents with gross hematuria in association URT and GI infection • – Then mild proteinuria, mild to moderate hypertension • – Normal C3 • The synpharyngitic (concomitant with an upper respiratory illness) presentation of IgA nephritis differentiates it from acute PSGN, in which a prior history of sore throat is present. • Hearing deficits (bilateral sensorineural, never congenital); females have subclinical hearing loss • Ocular abnormalities (pathognomonic is extrusion of central part of lens into anterior chamber • Most important primary treatment is blood pressure control 5/19/2021 Dr Mesfn on Renal Diseases 15 Others HUS Henoch-Schönlein purpura Small vessel vasculitis with good prognosis Present with purpuric rash, joint pain, abdominal pain Most common cause of acute renal failure in young children Microangiopathic hemolytic anemia, thrombocytopenia, and uremia == TRAID Most from E. coli O157:H7 (shiga toxin–producing) Most from undercooked meat or unpasteurized milk; spinach Also from Shigella, Salmonella, Campylobacter, viruses, drugs, idiopathic Most resolve spontaneously; antiinflammatory medications, steroids: steroid Treatment is supportive and management of complication 5/19/2021 Dr Mesfn on Renal Diseases 16 Disease of Proteinuria Nephrotic syndrome 5/19/2021 Dr Mesfn on Renal Diseases 17 Nephrotic syndrome Defn: This is a group of signs and symptoms Characterized: − Proteinuria (>40 mg/m2/hour) >3,5 g/24 hrs (> 0,05 g/kg/24hrs), +++ − Hypoalbuminemia (<2.5 g/dL) − Edema − Hyperlipidemia (reactive to loss of protein) and lipiduria Can be primary or secondary Primary Minimal change disease, Membranoproliferative glomerulonephritis, Focal segmental glomerulosclerosis Secondary to Systemic disease Diabetes mellitus, HIV/AIDS, SLE and other connective tissue disorders 5/19/2021 Dr Mesfn on Renal Diseases 18 Minimal change disease • Clinical presentation • − Most common between 2 and 6 years of age • − May follow minor infections • Edema—localized initially around eyes and lower extremities; anasarca with serosal fluid collections less common • − Common—diarrhea, abdominal pain, anorexia • − Uncommon—hypertension, gross hematuria 5/19/2021 Dr Mesfn on Renal Diseases 19 Diagnosis And Treatment • Treatment • Diagnosis • − Mild—outpatient ; if severe—hospitalize • Urinalysis shows proteinuria (3–4 +) • − Some with microscopic hematuria • − • − 24-hour urine protein—40 mg/m2/hour in children but now preferred initial test is a spot urine for protein/creatinine ratio >2 • − Serum creatinine usually normal but may be increased slightly • − Serum albumin <2.5 g/dL • − Elevated serum cholesterol and triglycerides • − C3 and C4 normal 5/19/2021 − Start prednisone for 4–6 weeks, then taper 2–3 months without initial biopsy • − Consider biopsy with hematuria, hypertension, heart failure, or if no response after 8 weeks of prednisone (steroid resistant) • − If severe—fluid restriction, plus intravenous 25% albumin infusion, followed by diuretic to mobilize and eliminate interstitial fluid • − Re-treat relapses (may become steroiddependent or resistant); may use alternate agents (cyclophosphamide, cyclosporine, high-dose pulsed methylprednisolone); • renal biopsy with evidence of steroid dependency Dr Mesfn on Renal Diseases 20 Complication and prognosis • Complications • − Infection is the major complication; make sure immunized against Pneumococcus and Varicella and check PPD • − Most frequent is spontaneous bacterial peritonitis (S. pneumoniae most common) • − Increased risk of thromboembolism (increased prothrombotic factors and decreased fibrinolytic factors) but really with aggressive diuresis • Prognosis • − Majority of children have repeated relapses; decrease in number with age • − Those with steroid resistance and who have focal segmental glomerulosclerosis have much poorer prognosis (progressive renal insufficiency). 5/19/2021 Dr Mesfn on Renal Diseases 21 5/19/2021 Dr Mesfn on Renal Diseases 22 AKI-Definition Defined as the abrupt loss of kidney function that results in; Retention of urea and other nitrogenous waste products Dysregulation of extracellular volume and electrolytes. Loss of acid base regulation. These loss of kidney function is detected by Serum creatinine which is used to estimate GFR. The term Acute Kidney Injury (AKI) has largely replaced acute renal failure (ARF) as it more clearly defines renal dysfunction; As a continuum rather than a discrete finding of failed kidney This term also highlights that injury to kidney that does not results in “failure” The Acute Dialysis Quality initiatives (ADQI) group proposed a consensus graded definition, called the RIFLE criteria 5/19/2021 Dr Mesfn on Renal Diseases 23 Epidemiology and risks • Approximately 13 – 18% of all people admitted to hospital have AKI, the mortality depends on the severity, setting (i.e. ITU or not) and other patient factors but is estimated to be 25 – 30%. • Patients should be investigated for AKI under the following conditions; hypovolaemic, limited access to fluids, recent use of nephrotoxic drugs (NSAIDs, aminoglycosides, ACE inhibitors, Ang- II antagonists and diuretics), heart failure, liver disease, history of AKI, current CKD, sepsis, urological obstruction, diabetes and also aged over 65 if adult. For children, the same conditions apply but also; diarrhoea, symptoms of nephritis, hypotension or haematological malignancy. • Investigation is done via measurement of serum creatinine. 5/19/2021 Dr Mesfn on Renal Diseases 24 5/19/2021 Dr Mesfn on Renal Diseases 25 5/19/2021 Dr Mesfn on Renal Diseases 26 Causes of AKI Pre-renal, Intrinsic to the kidneys, or Post-renal. • Pre-renal 55% causes include heart failure, dehydration, sepsis and liver damage which can all affect the flow of blood to the kidneys, which in turn affects GFR and renal function. Anything causing hypovolaemia, hypoxia, massive systemic inflammatory responses and dramatic changes in RBF can potentially cause pre-renal AKI, which accounts for 65% of all cases. • Intrinsic renal injury 45% originates from the kidneys themselves, i.e. glomerular nephritis (haematuria and proteinuria) or nephrotic syndrome (proteinuria without haematuria). It can also be caused by drugs with nephrotoxic potential, like NSAIDs, aminoglycosides, Ang-II antagonists, ACE inhibitors and more. • Post-renal causes of AKI 5% are those which block the flow of urine along the ureters, or urethra. Origins include benign prostatic hyperplasia, tumours which impact on the aforementioned tubes and kidney stones. • One of the commonest causes of AKI is sepsis,. 5/19/2021 Dr Mesfn on Renal Diseases 27 5/19/2021 Dr Mesfn on Renal Diseases 28 Investigations • Renal function test • Serum electrolyte; Na, K, Ca, Po4, Cl, HCO3 • Renal ultrasound, VCUG • Vit D, PTH • CBC, iron studies • Echo, ECG • Others to diagnose eatiology 5/19/2021 Dr Mesfn on Renal Diseases 29 Monitoring AKI Risk • The best way to monitor AKI causes is via urine output. A reduced output (oliguria) can indicate AKI from any of the three aforementioned causes, i.e. dehydration (pre-renal), kidney damage (intrinsic) or kidney stones (post-renal). • • • • • • • Temperature should be 36 – 38°C, Systolic pressure should be 101 – 179mmHg, Pulse should be 51 – 101 BPM, Oxygen saturation should be above 96%, respiration rate is anywhere from 9 – 20 BPM and urine output should be greater than 0.5mL/Kg/hour. Weight monitored twice daily for fluid retention, as well as creatinine,. • The first step in managing AKI is to identify and treat the underlying causes, and not the presenting symptoms in isolation. Then potential nephrotoxic drugs should be addressed, IV fluids administered if necessary, and the patient monitored with observations of urine output, serum creatinine, U’s and E’s. 5/19/2021 Dr Mesfn on Renal Diseases 30 Principle of management • Maintenance of fluid and electrolyte • Monitor input and output, diuretics, fluids Indication for dialysis in ARF Anuria/oliguria Severe fluid overload unresponsive to management • Management of complications • Hyperkalemia, hyponatremia, CHF, HTN, Acidosis, Anemia Persistent hyperkalemia K+ > 6.5 meq/l, K+ 5.5-6.5 meq/l with ECG changes Hyponatremia: Na+ < 120 meq/l if symptomatic • Supportive management • Nutritional support, trearting infection • Dialysis • Peritoneal or Hemodialysis • Intermittent or continuous 5/19/2021 Severe metabolic acidosis unresponsive to management. Neurologic symptoms (altered mental status, seizures) BUN >100-150 mg/dL (or lower if rapidly rising) Ca:PO4 imbalance, with hypocalcemic tetany. Dr Mesfn on Renal Diseases 31 Chronic Renal Failure 5/19/2021 Dr Mesfn on Renal Diseases 32 Chronic Kidney Disease • Chronic kidney disease (CKD) is defined as renal injury (proteinuria) and/or a glomerular filtration rate <60 mL/min/1.73 m2 for >3 mo. 5/19/2021 Dr Mesfn on Renal Diseases 33 Pathogenesis • Hyperfiltration injury may be an important pathway of glomerular destruction, independent of the underlying cause of renal injury. • As nephrons are lost, the remaining nephrons undergo structural and functional hypertrophy (increase in GBF). • The driving force for glomerular filtration is thereby increased in the surviving nephrons. • Although this compensatory hyperfiltration temporarily preserves total renal function, it can cause progressive damage to the surviving glomeruli, possibly by a direct effect of the elevated hydrostatic pressure on the integrity of the capillary wall and/or the toxic effect of increased protein traffic across the capillary wall. 5/19/2021 Dr Mesfn on Renal Diseases 34 Pathogenesis • In addition to progressive injury with ongoing structural or metabolic genetic diseases, renal injury can progress despite removal of the original insult. • Progressively, as the population of sclerosed nephrons increases, the surviving nephrons suffer an increased excretory burden, resulting in a vicious cycle of increasing glomerular blood flow and hyperfiltration injury • Unclted hypertension can exacerbate disease progression by causing arteriolar nephrosclerosis and by increasing the hyperfiltration injury. 5/19/2021 Dr Mesfn on Renal Diseases 35 Proteinuria • Proteins that traverse the glomerular capillary wall can exert a direct toxic effect on tubular cells and recruit monocytes and macrophages, enhancing the process of glomerular sclerosis and tubulointerstitial fibrosis. • Hyperphosphatemia can increase progression of disease by leading to calcium phosphate deposition in the renal interstitium and blood vessels. • Hyperlipidemia, a common condition in CKD patients, can adversely affect glomerular function through oxidant-mediated injury. 5/19/2021 Dr Mesfn on Renal Diseases 36 5/19/2021 Dr Mesfn on Renal Diseases 37 5/19/2021 Dr Mesfn on Renal Diseases 38 Clinical presentation • Varied and depends on the underlying renal disease • Children and adolescents with CKD from chronic glomerulonephritis can present with edema, hypertension, hematuria, and proteinuria. • Infants and children with congenital disorders (renal dysplasia and obstructive uropathy) can present in the neonatal period with FTT, polyuria dehydration, UTI, or overt renal insufficiency. • Congenital kidney disease is diagnosed with prenatal USG in many infants, allowing early diagnostic and therapeutic intervention. • Children with familial juvenile nephronophthisis can have a very subtle presentation with nonspecific complaints such as headache, fatigue, lethargy, anorexia, vomiting, polydipsia, 5/19/2021 Dr Mesfn on Renal Diseases 39 polyuria, and growth failure over a number of years. Investigation AND • Renal function test • Serum electrolyte; Na, K, Ca, Po4, Cl, HCO3 • Renal ultrasound • VCUG • Vit D, PTH • CBC, iron studies • Echo, ECG • Others to diagnose eatiology 5/19/2021 Treatment • • • • • • • • • • Dr Mesfn on Renal Diseases Fluid and electrolyte management Correction of acidosis Nutrition Growth MBD Anaemia Hypertension Immunization Drug dose adjustment RRT; HD, PD, kidney transplant 40 GRACIAS 5/19/2021 Dr Mesfn on Renal Diseases 41