Schönlein-Henoch disease: diagnosis

Laboratory diagnosis of Shenlen-Henoch disease

The laboratory diagnosis of Shenlen-Henoch disease does not find any specific tests.

In most patients with high vasculitis activity there is an increase in ESR. In children, in 30% of cases, an increase in the titer of antistreptolysin-0, a rheumatoid factor, an increase in the content of C-reactive protein is detected.

The main laboratory indicator of purple Shonlein-Genoch - elevated IgA level in 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 is normalized in the absence of recurrence 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 Shenlen-Henoch disease

Any patient with nephropathy, combined with cutaneous hemorrhagic syndrome, abdominal pain and arthralgia, should exclude hemorrhagic vasculitis. However, only when the mesangial deposits of IgA are detected in kidney biopsy can the diagnosis of Shenlaine-Genoch disease can be reliably diagnosed. Without this morphological confirmation, diagnosis can be difficult. Most often it is necessary to differentiate the Shenlaine-Henoch disease from microscopic polyangiitis. Other diseases, which should be differentiated from the Shenlen-Henoch disease, include acute glomerulonephritis, Berger's disease, systemic lupus erythematosus, subacute infective endocarditis with kidney damage, autoimmune hepatitis, tuberculosis with paraspecific reactions.

• Differential diagnosis of Shenlen-Henoch disease and acute poststreptococcal a is difficult, especially if there are symptoms characteristic of the purpura of Schönlein-Henoch syndrome (skin hemorrhages and abdominal pain) in acute glomerulonephritis, since in some cases the streptococcal infection precedes the Schönlein-Henoch purpura and antistreptolysin titers -0 can be increased, which makes it even more difficult to verify the diagnosis. In such situations, the study of the contents of the S3 component of complement in the blood can help, which always remains normal with Schönlein-Henoch purpura and decreases in most patients with acute glomerulonephritis, as well as a kidney biopsy in which IgA deposits are found in mesangium.
• Differential diagnosis of Shenlen-Henoch disease and Berger's disease in adults is necessary if the patient comes under the supervision of a nephrologist for the first time with arterial hypertension and urinary syndrome with a predominance of hematuria. In this case, a key role is assigned to the study of the anamnesis. Indication of the episode of purpura, articular and abdominal syndromes in childhood makes it possible to diagnose hemorrhagic vasculitis.
• For lupus nephritis, unlike nephritis with Schönlein-Henoch purpura, macrohematuria, an increase in IgA concentration in the blood, and abdominal pain syndrome are not characteristic. In systemic lupus erythematosus, kidney damage is combined with polyserositis, erythema of the face in the form of a "butterfly", fever, as well as heart damage, a cytopenic syndrome. Diagnosis of systemic lupus erythematosus confirms the characteristic immunological tests (LE-cells, antinuclear antibodies, antibodies to DNA, hypocomplexemia).
• To exclude secondary hemorrhagic vasculitis in patients with autoimmune hepatitis, subacute infective endocarditis, tuberculosis, it is necessary to investigate the activity of hepatic enzymes in the blood, carry out bacteriological examination of the blood, radiography, echocardiography, liver biopsy.

[1], [2], [3], [4], [5], [6], [7], [8],