[Vasculitis: histopathology and differential diagnosis]

Clinical Approach to Diagnosis and Therapy of Polyarteritis Nodosa

PURPOSE OF THE REVIEW

Polyarteritis nodosa is a rare disease characterized by the necrotizing inflammation of medium-sized arteries. Different etiopathogenetic and clinical variants of the disease have been recognized over the past decades. In the present paper, we review the clinical features, diagnosis, and treatment of the different subtypes of the disease.

RECENT FINDINGS

The diagnosis of polyarteritis nodosa is primarily based on clinical findings, imaging, and histopathological investigations. Microbiological and genetic investigations complement the diagnostic work-up. Idiopathic and hereditary variants of polyarteritis nodosa are treated with immunomodulatory medications such as glucocorticoids, conventional immunomodulatory drugs (e.g., cyclophosphamide) and biologic agents (e.g., tumor necrosis factor inhibitors, interleukin 6 inhibitor), while hepatitis B virus-associated polyarteritis nodosa primarily requires antiviral therapy combined with plasma exchange. PAN is a disease with heterogeneous presentations, severity, and therapeutic approaches. The overall prognosis of this disease is improving, mainly due to early diagnosis and more effective treatments. Treatment choices are guided mainly by the disease subtype and severity. In this review, we have presented the current knowledge on PAN clinical variants, their classification, diagnosis, and treatment approaches.

Häufigkeit und Einteilung kutaner Manifestationen bei rheumatoider Arthritis

HINTERGRUND UND FRAGESTELLUNG

Hautveränderungen bei rheumatoider Arthritis (RA) sind nur in wenigen Studien an größeren Patientenkollektiven untersucht. Deshalb sollen hier die aktuelle Prävalenz und das Spektrum an Hautveränderungen bei RA unter Berücksichtigung von Krankheitsaktivitäts-Scores, Anti-CCP-Antikörpern sowie neueren medikamentösen Therapien erfasst werden.

PATIENTEN UND METHODIK

Zwischen November 2006 und Juli 2007 wurden prospektiv 214 Patienten, die im Funktionsbereich Rheumatologie mit RA behandelt wurden, erfasst.

ERGEBNISSE

Bei 27,5 % der Untersuchten wurden RA-assoziierte Hautveränderungen beobachtet, wobei es sich fast ausschließlich um Rheumaknoten handelte. Signifikant gehäuft traten Rheumaknoten bei längerer Erkrankungsdauer, Nachweis von Rheumafaktoren und Anti-CCP-Antikörpern, aber auch unter Gabe von Leflunomid und TNFα-Blockern auf. Vergleichsweise niedrige Prävalenzen wurden hingegen für die "palisadenförmige neutrophile und granulomatöse Dermatitis" und die "rheumatoide Vaskulitis" ermittelt.

SCHLUSSFOLGERUNGEN

Trotz zunehmend frühzeitiger Therapie der RA und dem Einsatz neuerer Medikamente ist die Prävalenz von Rheumaknoten als wichtigste Manifestation der RA am Hautorgan hoch. Deren verstärkte Ausbildung unter Leflunomid und TNFα-Blockern könnte ein Hinweis dafür sein, dass bei der Entstehung von Rheumaknoten eine pathogenetische Wegstrecke eine Rolle spielt, die von den Therapeutika nur unzureichend beeinflusst wird. Hingegen scheinen die palisadenförmige neutrophile und granulomatöse Dermatitis und die "rheumatoide Vaskulitis" durch neuere Medikamente besser beeinflussbar zu sein.

Incidence and classification of cutaneous manifestations in rheumatoid arthritis

BACKGROUND AND OBJECTIVE

There have only been few studies examining rheumatoid arthritis (RA)-related skin manifestations in larger patient populations. Herein, we present current data on the prevalence and spectrum of cutaneous lesions in RA, addressing disease activity scores, anti-CCP antibodies as well as novel pharmacological approaches.

PATIENTS AND METHODS

Between November 2006 and July 2007, 214 patients with RA treated at the Division of Rheumatology, University Hospital Jena, Germany, were prospectively examined.

RESULTS

27.5 % of patients exhibited RA-related skin manifestations, almost all of which were rheumatoid nodules. These lesions occurred significantly more frequently in patients with longstanding disease, those testing positive for rheumatoid factor and anti-CCP-antibodies, as well as individuals on leflunomide and TNF-alpha antagonists. Comparatively lower prevalence rates were observed for palisading neutrophilic and granulomatous dermatitis and rheumatoid vasculitis.

CONCLUSIONS

Despite increasingly early treatment of RA and use of novel pharmacological agents, there is a high prevalence of rheumatoid nodules, which represent the most common cutaneous manifestation in RA. The higher prevalence of rheumatoid nodules in patients on leflunomide and TNF-alpha antagonists might be an indication that pharmacological treatment has only limited effects on their formation, possibly due to pathogenetic pathways that are only inadequately affected by drug therapies. By contrast, palisading neutrophilic and granulomatous dermatitis and rheumatoid vasculitis appear to respond better to novel pharmacological agents.

[Polyarteritis nodosa: differential diagnostics and therapy]

Polyarteritis nodosa (PAN) is a necrotizing vasculitis of medium size arteries that may affect various organs. The clinical appearance is very variable. The most common manifestations are of the skin, the peripheral nervous system presenting as mononeuritis multiplex and the mesenteric and renal blood vessels due to the development of stenoses and small aneurysms. Of the cases one third are estimated to be associated with hepatitis B virus (HBV). The therapy depends on the pathogenesis of the disease: primary PAN is treated with immunosuppressants, whereas patients with HBV-related PAN should receive antiviral therapy and plasmapheresis. Differentiating PAN from other forms of vasculitis can be difficult and requires complex differential diagnostics.

[Is bioptic assurance reasonable in patients with Sjögren's syndrome? From focus score to diagnosing vasculitides]

Sjögren's syndrome is an autoimmune disease which targets the salivary and lacrimal glands in particular, causing sicca syndrome. Extraglandular manifestations are often seen. Chronic sialadenitis of the parotid gland is the most common symptom to be assessed for differential diagnosis. Common HE and Giemsa slices are histopathologically examined and graduated for lymphocyte infiltration (focus): grade 0: absent, grade 1: slight, grade 2: moderate non-focal infiltration, grade 3: 1 focus (> or =50 lymphocytes) per 4 mm2, grade 4: >1 focus. Grade 3 infiltrates correspond to a focus score of 1, which is one of four disease-classifying criteria acknowledged for diagnosis. Bioptic examination is also performed to rule out different (non-) immunologic sialadenitises, such as the necrotizing or epithelioid-like form (in sarcoidosis), and the extranodal marginal-zone lymphoma. Extraglandular manifestations of Sjögren's syndrome can also be safely diagnosed by histopathological examination. Emphases lie on vasculitides and myositides. Bioptic work-up, therefore, is not only reasonable but also an essential tool for diagnostics in Sjögren's syndrome.

[Histomorphology of interstitial lung disease and pulmonary vasculitis]

Rheumatic diseases or collagen vascular diseases represent a heterogeneous group of immunologically mediated inflammatory disorders. The respiratory system is often affected,the causes being manifold: infection, medication toxicity and specific manifestations of immunological processes due to the underlying disease. The lung can be involved in all its components. Due to their extremely broad differential diagnosis, pulmonary vasculitic syndromes still constitute a major challenge for the pathologist. Pulmonary involvement is frequent in primary systemic vasculitis (PSV) associated with anti-neutrophil-cytoplasmic antibodies (ANCA); other PSV only rarely affect the lungs. Histomorphologically, small vessel vasculitis with neutrophil alveolitis and diffuse alveolar hemorrhage, as well as extravascular intraparenchymal or peribronchial granulomas, can point to PSV. A single biopsy is often insufficient to identify all diagnostic criteria. Therefore, the selection of suitable biopsy material and correlation with clinical, serological and radiological parameters is indispensable. Almost all forms of interstitial lung disease may be present in collagen vascular disease; however, several parallel morphological types, rather than one in isolation, are frequently found.