Tests
1st tests to order
blood pressure
Test
Required at diagnosis and if there are concerns about nephritis.[31]
Result
may be normal or elevated
urinalysis
Test
Regular checks of early morning urinalysis are indicated to assess for renal involvement.
Determines presence of hematuria or proteinuria and should be quantified using the urine protein:creatinine ratio.
Monitor for at least 6 months in all patients after diagnosis.[31]
Result
may show RBCs, proteinuria, or casts
serum creatinine and electrolyte levels
Test
To determine renal function using estimated glomerular filtration rate (eGFR) in patients with suspected nephritis.
Result
elevated creatinine indicates renal impairment or renal failure
Tests to consider
serum IgA levels
Test
May be elevated, but this is not a specific test for IgAV.
Result
normal or elevated
CBC and coagulation studies
Test
Can be considered to help exclude other causes (e.g., abnormal coagulation studies and low platelet counts are seen in septicemia or immune thrombocytopenia).
Result
normal in IgAV
skin biopsy
Test
Performed in cases of atypical rash (such as extensive lesions or diffusely distributed lesions).
Skin biopsy excludes alternative diagnoses including other forms of vasculitis, such as ANCA-associated vasculitis, particularly in older children.[29]
Result
leukocytoclastic vasculitis with IgA deposition
renal biopsy
Test
A renal biopsy should be performed if a patient with IgAV has severe proteinuria (>250 mg/mmol at least 4 weeks after diagnosis; shorter duration of severe proteinuria is a relative indication for biopsy), persistent moderate proteinuria, or persistent impaired GFR.[29]
Additional indications for renal biopsy include: acute kidney injury with worsening renal function; patients who are nephrotic (e.g., heavy proteinuria, hypoalbuminemia, and edema) or nephritic (e.g., impaired eGFR, hypertension, hematuria/proteinuria) at any time point.[29]
The UK Kidney Association guideline on IgAV in children and young people recommends classifying kidney histology using the International Study of Kidney Disease in Children (ISKDC) classification criteria.[33] Additional renal activity and chronicity indices may help predict prognosis.[5]
Result
IgA deposition in the mesangial region; ISKD histologic class I-VI
ultrasound, abdomen
Test
Indicated for severe abdominal pain to evaluate for intussusception or perforation.
Result
may show intussusception or perforation
ultrasound, testicles
Test
Can be used to evaluate testicular pain and swelling.
Result
may show testicular swelling
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