pathology of kidneys and lower UTI Flashcards
Pathogenesis of a descending infectious disease of the kidney
Haematogenous
Pathogenesis of an ascending infectious disease of the kidney
Urinary
Viral kidney diseases
Canine herpesvirus 1
Canine Adenovirus 1
Ovine Herpesvirus 2
Bacterial Kidney Disease
Leptospira interrogans,
Actinobacillus equuli,
Escherichia coli- causes white spotted kidney
Corynebacterium renale.
Parasitic Kidney Disease
Toxocara canis,
Halicephalobus gingivalis,
Encephalitozoon cuniculi,
Leishmania spp.
What is a non-suppurative tubulointerstitial nephritis
Nonsuppurative interstitial nephritis can be either acute, subacute or chronic.
Gross pathology
In acute cases, the kidneys are often enlarged and have pale cortices with a streaked appearance.
In chronic cases, shrinkage of the kidney as well as extensive fibrosis and capsular adhesions occurs.
Histopathology
Presence of inflammatory cells in the interstitium.
Degenerative changes of the tubular epithelium.
Presences of fibrous tissue due to repair attempts by the kidney.
Examples
‘White spot’ kidney of calves and Leptospira canicola infection are both examples of nonsuppurative interstitial nephritis.
White spot kidney is common and usually an incidental finding. Kidneys have multiple small, white, slightly raised nodules throughout the cortex. The cause is likely a sequel to previous bacteraemia.
Leptospira canicola in the dog is also another good example. It localises in the renal capillaries then migrates to the tubules via the interstitium. Necrosis of the tubular epithelium occurs as well as a pronounced interstitial inflammatory reaction. In chronic cases, fibrosis and widespread degenerative changes are seen. The liver, csf and placenta can also be affected.
If the condition is chronic, marked interstitial fibrosis can be seen as well as degenerative changes in the tubules.
What is suppurative interstitial nephritis?
Suppurative interstitial nephritis follows bacteraemia or embolic septicaemia.
Can be haematogenous or urogenous in origin.
If large thrombi lodge in the afferent vessels, infarction may occur.
Bacteria lodge within the glomeruli and peritubular capillaries.
Abscesses may occur in the glomeruli or interstitium.
Examples include Actinobacillus equuli in foals, Erysipelothrix rhusiopathiae in pigs,
Most common bacteria causing cystitis
Escherichia coli
Proteus vulgaris
streptococci
staphylococci
enterococci.
Common causes of cystitis in cattle
Corynebacterium renale
C. pilosum
C. cystitidis
Common causes of cystitis in pigs
Actinobaculum (Eubacterium) suis
Common causes of cystitis in dog
Aspergillus, Candida, Nocardia
Common causes of cystitis in cat
Enterococcus faecalis, Aspergillus, Candida, Nocardia
Common causes of cystitis in horses
Klebsiella sp.
Predisposing factors to cystitis
stagnation of urine because of obstruction or incomplete bladder emptying
urothelial trauma (uroliths),
catheterization,
vaginoscopy,
Urinary incontinence
Vaginitis
diabetes mellitus
administration of antibiotics or corticosteroids
Hyperoestrogenism
Immunodepression
gender (shorter urethra in females)
malformations,
comorbidities (E.g.: pyometra, prostatitis).
Defense mechanisms against cystitis
Urothelial barrier
pH
urine osmolality,
IgA,
IgG
Tamm-Horsfall mucoprotein
hedding of urothelium.
Gross pathology of acute cystitis
haemorrhagic,
catarrhal (build-up of mucous)
fibrinopurulent
necrotizing
ulcerative
Gross pathology of chronic cystits
Associated to chronic bacterial infection and/or urolithiasis: diffuse, follicular, polypoid.
Associated to glycosuria: emphysematous (shortness of breath)
What is tamm-Horfsal Mucoprotein
Glycoprotein synthesized in kidneys and secreted in urine
Maintains osmotic balance in kidneys and protects against urinary tract infections
Most abundant protein in normal urine
Synthesized by epithelial cells lining the thick ascending limb of Henle’s loop in the kidney
Glycosylation pattern varies depending on individual, can be used as a biomarker for kidney function
Implicated in inflammation and regulation of blood pressure
Abnormalities in THP expression or function associated with various kidney diseases, including autosomal dominant tubulointerstitial kidney disease, medullary cystic kidney disease, and familial juvenile hyperuricemic nephropathy
