Schoenlein-Genoch disease - Diagnosis

Laboratory diagnostics of Henoch-Schonlein disease

Laboratory diagnostics of Henoch-Schonlein disease does not reveal any specific tests.

Most patients with high vasculitis activity have an increase in ESR. In children, 30% of cases show an increase in antistreptolysin-O titers, rheumatoid factor, and an increase in C-reactive protein.

The main laboratory sign of Henoch-Schonlein purpura - an elevated level of IgA in the blood plasma - is detected in the acute stage of the disease in 50-70% of patients. A year after the acute episode, the IgA content in most cases normalizes in the absence of a relapse of purpura, even if the urinary syndrome persists. In a third of patients, IgA-containing immune complexes are detected at the time of high vasculitis activity.

Differential diagnosis of Henoch-Schonlein disease

In any patient with nephropathy associated with cutaneous hemorrhagic syndrome, abdominal pain and arthralgia, hemorrhagic vasculitis should be excluded. However, only if mesangial IgA deposits are detected during kidney biopsy can Henoch-Schonlein disease be reliably diagnosed. Without this morphological confirmation, diagnosis may be difficult. Henoch-Schonlein disease must most often be differentiated from microscopic polyangiitis. Other diseases from which Henoch-Schonlein disease must be differentiated include acute glomerulonephritis, Berger's disease, systemic lupus erythematosus, subacute infective endocarditis with renal involvement, autoimmune hepatitis, and tuberculosis with paraspecific reactions.

• Differential diagnosis of Henoch-Schonlein disease and acute poststreptococcal a can be difficult, especially if acute glomerulonephritis is accompanied by symptoms characteristic of Henoch-Schonlein purpura (skin hemorrhages and abdominal pain), since in some cases streptococcal infection precedes Henoch-Schonlein purpura, and antistreptolysin-0 titers can be elevated, which further complicates diagnosis verification. In such situations, a study of the content of the complement component C3 in the blood can be helpful, which always remains normal in Henoch-Schonlein purpura and decreases in most patients with acute glomerulonephritis, as well as a kidney biopsy, which reveals IgA deposits in the mesangium.
• Differential diagnostics of Henoch-Schonlein disease and Berger's disease in adults is necessary if the patient is admitted to a nephrologist for the first time with arterial hypertension and urinary syndrome with a predominance of hematuria. In this case, the key role is given to studying the anamnesis. An indication of an episode of purpura, articular and abdominal syndromes in childhood allows diagnosing hemorrhagic vasculitis.
• Unlike nephritis in Henoch-Schonlein purpura, lupus nephritis is not characterized by macrohematuria, increased IgA concentration in the blood, or abdominal pain syndrome. In systemic lupus erythematosus, kidney damage is combined with polyserositis, butterfly-shaped facial erythema, fever, as well as heart damage and cytopenic syndrome. The diagnosis of systemic lupus erythematosus is confirmed by characteristic immunological tests (LE cells, antinuclear antibodies, DNA antibodies, hypocomplementemia).
• To exclude secondary hemorrhagic vasculitis in patients with autoimmune hepatitis, subacute infective endocarditis, tuberculosis, it is necessary to examine the activity of liver enzymes in the blood, conduct a bacteriological blood test, radiography, echocardiography, and liver biopsy.

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