Microscopic polyangiitis
| Classification according to ICD-10 | |
|---|---|
| M31.7 | Microscopic polyangiitis |
| ICD-10 online (WHO version 2019) | |
The microscopic polyangiitis (MPA) is a vasculitis (inflammation of blood vessels), to the group of autoimmune diseases belongs. It is similar to the granulomatosis with polyangiitis (formerly Wegener's granulomatosis.), With ANCA - autoantibodies associated.
Name and nomenclature
For a long time MPA was regarded as a subtype of polyarteritis nodosa (PAN). The abbreviation "mPAN" comes from this time to distinguish it from the classic PAN (cPAN). According to the Chapel Hill Consensus Conference of 1994, however, MPA is to be viewed as an independent disease.
Epidemiology
MPA is a rare disease with an annual incidence of 4 cases per 1 million population.
root cause
An exact cause of the MPA as with almost all autoimmune diseases is not known, a causal role of p ANCA - autoantibodies but discussed. In contrast to polyarteritis nodosa the MPA is not with chronic hepatitis B associated.
Symptoms
- Kidney involvement (70%): glomerulonephritis up to rapid progressive glomerulonephritis with crescent formation; Development of renal hypertension and renal insufficiency . In the urine, microhematuria , proteinuria .
- Lungs: pulmonary vasculitis, possibly with alveolar hemorrhage and blood in the sputum, pneumonitis, rarely fibrosing alveolitis.
- Skin changes (40%): subcutaneous nodules, palpable purpura, especially on the lower extremities, possibly with necrosis, leukocytoclastic vasculitis.
- Further symptoms: polyneuritis, sinusitis, episcleritis, myalgia, arthralgia, chronic bronchitis, double vision, bloody runny nose.
Differential diagnosis
- Collagenoses , especially systemic lupus erythematosus
- granulomatous polyangiitis
- Polyarteritis nodosa
- other vasculitis
Clinically, MPA can be compared to granulomatous polyangiitis, but histologically there is no granulomatous inflammation. ANCA (antineutrophil cytoplasmic antibodies) are also found in MPA, in 60% of cases these are associated with the target antigen MPO (myeloperoxidase).
therapy
There are no independent studies on the therapy of MPA. Therapy adapted to the severity is recommended, as is the case with granulomatous polyangiitis. Induction therapy - usually with corticosteroids and cyclophosphamide - is followed by maintenance therapy - with azathioprine or methotrexate, the latter not in the case of kidney involvement.
Individual evidence
- ↑ JC Jennette et al.: Nomenclature of systemic vasculitides. Proposal of an international consensus conference. In: Arthritis Rheum . (1994); 37, p. 187 PMID 8129773
- ^ M. Classen, V. Diehl, K. Kochsiek (eds.): Internal medicine. 5th edition. Urban & Fischer, Munich 2004, ISBN 3-437-42830-6 .
- ↑ Gerd Herold (Ed.): Internal Medicine. Self-published, Cologne 2008.
