Page 490 - Concise Pathology for Exam Preparation ( PDFDrive )

16 Diseases of the Kidney and Lower Urinary Tract 475

TABLE 16.4. Differences between nephritic and nephrotic syndrome

Features Nephritic Nephrotic syndrome
Proteinuria Usually ,1.0 g/day .3.5 g/day
Haematuria Present Absent
Oliguria Present Absent
Lipiduria Absent Present
Casts Red cell casts Lipid casts
Colour of urine Cocoa coloured/smoky urine Frothy urine
Azotaemia Present Absent
Hyperlipidaemia Absent Present
Oedema Less marked More marked

Q. Differentiate between membranous glomerulonephritis and
minimal change disease.

Ans. Differences between membranous glomerulonephritis and minimal change disease
are tabulated in Table 16.5.

TABLE 16.5. Differences between membranous glomerulonephritis and minimal change
disease

Features Membranous glomerulonephritis Minimal change disease
Age Adults Children
Light microscopy Thickening of GBM (GBM width in Normal GBM
healthy adults is 300–400 nm)
Electron microscopy Granular subepithelial deposits Foot process effacement and lipid-laden cells in PCT
Immunofluorescence Granular deposits of IgG and C3 No deposition
Hypertension Present Absent
Haematuria Present Absent
Corticosteroid therapy Minimal response Good response

Q. Write briefly on the aetiopathogenesis, clinical features and
pathology of tubulointerstitial nephritis (TIN).

Ans. TIN is defined as inflammation of the tubules and interstitium with sparing of the
glomeruli or their involvement in very late stages. It has two components:
• Pyelonephritis (usually due to bacterial infections) is a term applied to TIN with
prominent involvement of renal pelvis in addition to tubules and interstitium.
• The term interstitial nephritis is reserved for cases of TIN that are nonbacterial in origin
(include tubular injury due to drugs, metabolic disorders, physical and immunologic injury).

Pyelonephritis
Pathogenesis
Principal causative organisms:
Enteric Gram-negative rods, mainly Escherichia coli, Proteus, Klebsiella, Enterobacter,
Pseudomonas, Staphylococcus and Streptococcus faecalis. Rarely mycobacterial, fungal and
viral organisms.
Predisposing conditions:
• Urinary tract manipulations, eg, catheterization, urethral instrumentation and cystoscopy
• Congenital or acquired anomalies of the urinary tract (intrarenal reflux, vesicoureteral
reflux and deranged vesicoureteric junction)
• Outflow obstruction (nodular hyperplasia prostate, uterine prolapse, calculi, strictures,
tumours and neurogenic bladder)
• Immunodeficiency or immunosuppression

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