Clinical & laboratory indications of secondary causes of GN

Known extra renal diseases that causes GN

• Infections– Post-streptococcal

glomerulonephritis.– Bacterial endocarditis– Viral infections

• Immune diseases– Systemic Lupus

erythematosus– Goodpasture's syndrome.– IgA nephropathy.

• Vasculitis– Polyarteritis– Wegener's granulomatosis

Post-streptococcal glomerulonephritis

• Definition: The patient suffers a strep infection 1-3 weeks before onset of GN

• organism: Group A beta-hemolytic Streptococcus

• More common in children

Group A streps

Conditions Ex findings Investigations

Septicaemia Fever, GI symp, Abdo pain, SOB, Tachy

FBE, U&E, LP, swab, sputum sample

Wound/ skin infections

blisters Swab

Tonsillitis red swollen tonsils, purulent exudate

FBESwab

Scarlet fever rash on chest, neck, skin folds & inner thigh

Throat culture, Rapid antigen test, Rapid DNA test

Necrotising fasciitis Fever, severe pain, swelling, heat, redness

?

Late complications

• Rheumatic fever, post-streptococcal glomerulonephritis

Condition Ex findings Investigations

Endocarditis abnormal heart rhythm, murmur (may indicate inflammation)

ECGECHO

UTI dysuria, urgency, frequency (↓vol), suprapubic pain

+/- haematuria, loin pain, vomiting

FBEU&EMSU

Toxic shock fever, dizziness, confusion -no specific test-FBEU&EMSUSwabs – throat, vagina

Viral Infections

• HIV– Seroconversion/primary illness: 6-8wks after inf.

Lasts 3 weeks, full recovery

– Symp: fever, arthralgia, myalgia, lethargy, lymphadenopathy, sore throat, mucosal ulcers, & faint pink maculopapular rash

– Neuro: headache, photophobia, myelopathy, neuropathy, rarer: encephalopathy

– Lymphopenia w atypical reactive lymphocytes

• Hep B/ C– Investigations: LFT, Bloods

LFT• Prodromal stage: Bilirubin is normal

– Bilirubinuria

– ↑ Urinary urobilinogen

– ↑ ↑ AST/ ALT

• Icteric stage: Bilirubin reflects the level of jaundice– AST reaches a maximum >500 IU/L– ALP <300 IU/L

• Haematological test– Leucopenia– Lymphocytosis– Rare: Coombs’ – positive haemolytic anaemia w.

ass. Aplastic anaemia– Severe: PT time prolonged– ↑ESR