Systemic necrotizing vasculitis

Pulmonary Manifestations of Systemic Vasculitis in Children

Vasculitides are defined according to the vessel size involved, and they tend to affect certain organ systems. Pulmonary involvement is rare in the common childhood vasculitides, such as Kawasaki disease, IgA vasculitis (Henoch Schonlein purpura). On the other hand, lung involvement is common in a rare pediatric vasculitis, granulomatosis with polyangiitis (GPA) (Wegener granulomatosis), where respiratory system findings are common. A criterion in the Ankara 2008 classification criteria for GPA is the presence of nodules, cavities, or fixed infiltrates. The adult data suggest that rituximab may be an alternative to cyclophosphamide in induction treatment.

Contrast-enhanced ultrasound and computed tomography findings of granulomatosis with polyangiitis presenting with multiple intrarenal microaneurysms: A case report

Granulomatosis with polyangiitis (GPA) is a systemic disorder that affects small- and medium- sized vessels in many organs. Although the kidneys are the second most commonly involved organ in patients with GPA, its manifestation as multiple intrarenal aneurysms is rare. We report an unusual manifestation of GPA with multiple intrarenal microaneurysms, as demonstrated by contrast-enhanced ultrasound and computed tomography.

The Clinical Spectrum of Primary Renal Vasculitis

BACKGROUND AND OBJECTIVES

The vasculitides are potentially severe and often difficult to diagnose syndromes. Many forms of vasculitis may involve the kidneys. This review will focus on the clinical and histopathological aspects of renal involvement in the systemic vasculitides.

METHODS

We searched the MEDLINE database using as key terms the MeSH terms and textwords for different forms of vasculitis and for renal involvement, creating a database of more than 2200 relevant references.

RESULTS

The frequency of renal involvement in vasculitis varies among different syndromes. It is more frequent in Wegener's granulomatosis and microscopic polyarteritis, while it is uncommon to rare in other forms of vasculitis such as Behçet's disease and relapsing polychondritis. The vessels affected include the renal artery in Takayasu arteritis, medium-size renal parenchymal artery in classic polyarteritis nodosa, and glomerular involvement in Wegener's granulomatosis and microscopic polyarteritis. The clinical expression of renal vasculitis depends on the size of the affected vessels and includes renovascular hypertension, isolated nonnephrotic proteinuria, interstitial nephritis, and glomerulonephritis, which can be rapidly progressive. Diagnosis is established by a combination of history, clinical manifestations, laboratory findings (eg, urine sediment, urine protein, antineutrophil cytoplasmic antibodies), imaging techniques (renal angiography, especially when there is a suspicion of medium-to-large vessel disease, and chest radiograph), and finally, renal biopsy. Prognosis varies from unfavorable in the rapidly progressive glomerulonephritis of microscopic polyarteritis, which can lead to renal failure, chronic dialysis, and renal transplantation, to benign, as in the case of Henoch Schonlein purpura, in which the majority of patients recover.

CONCLUSIONS

The manifestations and prognosis of renal vasculitis range widely. Renal involvement greatly influences prognosis and dictates the need for early and prompt immunosuppressive therapy. Thus, the clinician should be alert for the timely diagnosis and treatment of renal vasculitis.

Vasculitic peripheral ulcerative keratitis

The onset of peripheral ulcerative keratitis in the course of a connective tissue disorder, such as rheumatoid arthritis, relapsing polychondritis, or systemic lupus erythematosus, may reflect the presence of potentially lethal systemic vasculitis. Moreover, peripheral ulcerative keratitis may be the first sign of systemic necrotizing vasculitis in patients with Wegener's granulomatosis, polyarteritis nodosa, microscopic polyangiitis, or Churg-Strauss syndrome. Although the exact pathogenesis of this severe corneal inflammation and destruction is not well understood, evidence points to a dysfunction in immunoregulation with immune complexes formed in response to autoantigens or to some unknown microbial antigen depositing in scleral and limbal vessels. These events lead to changes that are mainly responsible for the resulting tissue damage. In pauci-immune vasculitides positive for antineutrophil cytoplasmic antibodies, cell-mediated cytotoxicity may play an important role in the pathogenesis of peripheral ulcerative keratitis. Untreated systemic conditions such as those mentioned above may carry a grave prognosis for the eye and may also be life-threatening. Immunosuppressive therapy with corticosteroids and cytotoxic agents is, we believe, mandatory in the treatment of these multisystem disorders associated with vasculitic peripheral ulcerative keratitis.

Molecular approaches for identification of infectious agents in Wegener's granulomatosis and other vasculitides

The primary symptoms of many vasculitides resemble those of infectious diseases. Patients with Wegener's granulomatosis usually seek medical care for respiratory tract symptoms resembling those caused by infection or allergy. In addition, vasculitis is a well-documented manifestation of infection by some known microbial agents. There have been relatively few controlled studies, however, seeking to identify infectious agents as the triggering factors in systemic vasculitides. Molecular methods offer powerful approaches for the identification of infectious agents in diseases of previously unknown origin. These methods include broad-range amplification of microbial nucleic acid sequences and comparative or subtractive methods, such as differential display and representational difference analysis. Host gene expression profiles (using DNA-chip technology) may also provide clues as to the possible infectious cause of an idiopathic disease. Furthermore, the application of molecular methods may reveal pathologic mechanisms and novel therapeutic strategies for the vasculitides.