[Nephropathy associated with hypocomplementemic urticarial vasculitis: A case report and literature review]

Urticarial Vasculitis

Urticarial vasculitis is a rare autoimmune disorder characterized by persistent edematous papules and plaques on the skin that last longer than 24 hours, often accompanied by systemic symptoms such as joint pain and fever. Unlike common urticaria, this condition involves inflammation of small blood vessels, leading to more severe and long-lasting skin lesions with a tendency to leave a bruiselike appearance. Diagnosis is challenging and may require a skin biopsy. Associated with underlying autoimmune diseases, treatment involves managing symptoms with medications such as antihistamines and corticosteroids, addressing the immune system's dysfunction, and treating any concurrent autoimmune conditions.

Urticarial vasculitis: Clinical and laboratory findings with a particular emphasis on differential diagnosis

Urticarial vasculitis (UV) is a rare cutaneous vasculitis of small vessels characterized by recurrent episodes of wheal-like lesions that tend to last more than 24 hours, healing with a residual ecchymotic postinflammatory hyperpigmentation. The histopathologic pattern of UV is that of leukocytoclastic vasculitis, consisting of fibrinoid necrosis of dermal vessels' walls and neutrophil-rich perivascular inflammatory infiltrates. Although its etiopahogenesis remains still undefined, UV is now regarded as an immune complex-driven disease with activation of the complement cascade, leading to exaggerated production of anaphylatoxins that are responsible for neutrophil recruitment and activation. This condition can be categorized into 2 main entities according to serum complement levels: normocomplementemic UV and hypocomplementemic UV, the latter being associated with circulating anti-C1q autoantibodies and possible extracutaneous manifestations. Systemic multiorgan involvement may be seen particularly in syndromic hypocomplementemic UV, also known as McDuffie syndrome. This review summarizes the clinicopathological and laboratory features as well as the underlying pathophysiological mechanisms of UV. A focus on its main differential diagnoses is provided, that is, chronic spontaneous urticaria, bullous pemphigoid, IgA (Henoch-Schönlein purpura) and IgM/IgG immune complex vasculitis, lupus erythematous tumidus, Wells syndrome, erythema multiforme, cutaneous mastocytosis, cryopyrin-associated periodic syndromes, and coronavirus disease 2019-associated and anti-severe acute respiratory syndrome coronavirus 2-vaccine-associated urticarial eruptions.

Urticarial vasculitis

Urticarial vasculitis is a rare clinicopathologic entity that is characterized by chronic or recurrent episodes of urticarial lesions. Skin findings of this disease can be difficult to distinguish visually from those of chronic idiopathic urticaria but are unique in that individual lesions persist for ≥24 hours and can leave behind dusky hyperpigmentation. This disease is most often idiopathic but has been linked to certain drugs, infections, autoimmune connective disease, myelodysplastic disorders, and malignancies. More recently, some authors have reported associations between urticarial vasculitis and COVID-19, as well as influenza A/H1N1 infection. Urticarial vasculitis can extend systemically as well, most often affecting the musculoskeletal, renal, pulmonary, gastrointestinal, and ocular systems. Features of leukocytoclastic vasculitis seen on histopathologic examination are diagnostic of this disease, but not always seen. In practice, antibiotics, dapsone, colchicine, and hydroxychloroquine are popular first-line therapies, especially for mild cutaneous disease. In more severe cases, immunosuppressives, including methotrexate, mycophenolate mofetil, azathioprine, and cyclosporine, as well as corticosteroids, may be necessary for control. More recently, select biologic therapies, including rituximab, omalizumab, and interleukin-1 inhibitors have shown promise for the treatment of recalcitrant or refractory cases.

A case report of hypocomplementemic urticarial vasculitis presenting with membranoproliferative glomerulonephritis

Background

Hypocomplementemic urticarial vasculitis syndrome is an infrequent condition characterized by ocular, renal, gastrointestinal and pulmonary involvement with low serum complement levels and autoantibodies. Renal manifestations vary from microscopic hematuria to nephrotic syndrome and acute kidney injury. Accordingly differing histologic patterns have been reported.

Case presentation

We present the case of a 65 years old woman with a history of chronic uveitis who presented with arthralgias, urticarial rush, nephrotic syndrome, glomerular hematuria and low serum complement. Kidney biopsy revealed an immune-complex membranoproliferative glomerulonephritis. The patient received induction therapy with steroids, cyclophosphamide and hydroxychloroquine followed by rapid clinical improvement and remission of proteinuria. Maintenance treatment consisted of rituximab pulses.

Conclusions

The majority of hypocomplementemic urticarial vasculitis syndrome cases is idiopathic, although an association to drugs, infections or other autoimmune disorders has been recorded. Given the rarity and heterogeneity of the disease, no standard treatment is established.

Kidney Involvement in Hypocomplementemic Urticarial Vasculitis Syndrome-A Case-Based Review

Hypocomplementemic urticarial vasculitis syndrome (HUVS), or McDuffie syndrome, is a rare small vessel vasculitis associated with urticaria, hypocomplementemia and positivity of anti-C1q antibodies. In rare cases, HUVS can manifest as an immune-complex mediated glomerulonephritis with a membranoproliferative pattern of injury. Due to the rarity of this disorder, little is known about the clinical manifestation, pathogenesis, treatment response and outcome of such patients. We describe here three cases of HUVS with severe renal involvement. These patients had a rapidly progressive form of glomerulonephritis with severe nephrotic syndrome against a background of a membranoproliferative pattern of glomerular injury with extensive crescent formation. Therefore, these patients required aggressive induction and maintenance immunosuppressive therapy, with a clinical and renal response in two patients, while the third patient progressed to end-stage renal disease. Because of the rarity of this condition, there are few data regarding the clinical presentation, pathology and outcome of such patients. Accordingly, we provide an extensive literature review of cases reported from 1976 until 2020 and place them in the context of the current knowledge of HUVS pathogenesis. We identified 60 patients with HUVS and renal involvement that had adequate clinical data reported, out of which 52 patients underwent a percutaneous kidney biopsy. The most frequent renal manifestation was hematuria associated with proteinuria (70% of patients), while one third had abnormal kidney function on presentation (estimated glomerular filtration (GFR) below 60 mL/min/1.73 m²). The most frequent glomerular pattern of injury was membranoproliferative (35%), followed by mesangioproliferative (21%) and membranous (19%). Similar to other systemic vasculitis, renal involvement carries a poorer prognosis, but the outcome can be improved by aggressive immunosuppressive treatment.