Cutaneous arteritis with intimal fibrin ring and immature myeloid cell infiltrate: lymphocytic thrombophilic arteritis or histiocytoid polyarteritis nodosa?

The ongoing debate on whether lymphocytic thrombophilic arteritis (LTA) is a separate disease or a type of polyarteritis nodosa (PAN) has yet to be settled. In this study, we analyzed the nature of infiltrating cells in LTA to resolve this controversy. Skin biopsies from five female patients (mean age 29.4 years, age range 16-45 years) diagnosed with LTA were immunostained for CD3, CD20, CD68, lysozyme, myeloid cell nuclear differentiation antigen, myeloperoxidase, and PU.1. Immunohistochemistry revealed that the majority of mononuclear cells in all five cases were not lymphocytes but myelomonocytic cells. Given that the infiltrating cells are of the myelomonocyte lineage including immature myeloid cells, PAN was deemed the more appropriate diagnosis for the five cases rather than LTA. Whether PAN with immature myeloid cells (histiocytoid PAN) is the same disease as conventional PAN with mature neutrophils requires further investigation.

Recent topics related to etiology and clinical manifestations of cutaneous arteritis

Cutaneous polyarteritis nodosa (cPAN) was first reported by Lindberg in 1931. It has been recognized as a skin-limited vasculitis whose cutaneous histopathological features are indistinguishable from those of PAN. Cutaneous arteritis (CA) was defined as a form of single-organ vasculitis in the revised Chapel Hill Classification and was recognized as the same disease as cPAN. It became known that deficiency of adenosine deaminase 2 (DADA2) cases were included in cases that had been diagnosed with CA. Because of their similarity and differences in the treatment methods, DADA2 should be considered in CA cases, especially if they are diagnosed or developed in early childhood. Cutaneous arteritis may be classified as an immune complex-mediated vasculitis. It was reported that the pathogenesis of anti-lysosomal-associated membrane protein-2 (LAMP-2) antibodies and anti-phosphatidylserine-prothrombin complex (PS/PT) antibodies as good parameters in CA. The main skin manifestations include livedo racemosa, subcutaneous nodules, and ulcers. Although CA is recognized to have a benign clinical course, it has become known that it is easy to relapse. The existence of skin ulcers upon diagnosis or sensory neuropathies was suggested to be a predictor of poor prognosis. Cutaneous arteritis with them may need to be treated with more intensive therapies.

Therapeutic options for cutaneous polyarteritis nodosa: a systematic review

OBJECTIVE

Cutaneous polyarteritis nodosa (CPAN) is a necrotizing vasculitis of the middle-size vessels, confined to the skin. We conducted a systematic review in order to identify studies evaluating the different treatment modalities used in CPAN.

METHODS

This systematic review was conducted according to PRISMA guidelines, registered in PROSPERO: CRD42020222195. PubMed/Medline databases were searched from inception to December of 2020 using the terms: (Polyarteritis nodosa[Title/Abstract]) AND ((therapy[Title/Abstract]) OR (management[Title/Abstract]) OR (treatment[Title/Abstract]))' and 'Cutaneous arteritis [Title/Abstract]'. Articles evaluating pertaining to the management of CPAN in adults were eligible for inclusion.

RESULTS

A total of seven eligible case series with 325 unique patients were included. No study included a control population. In general, systemic corticosteroids were widely used as induction treatment. Immunosuppressive agents combined with corticosteroids were AZA, hydroxychloroquine, sulfasalazine, sulphapyridine, CYC, MTX, mycophenolate, tacrolimus, rituxima and thalidomide. Other agents utilized in the studies were dapsone, colchicine, non-steroid anti-inflammatory drugs, salicylates, warfarin and clopidogrel. In some studies, the presence of ulcerations was associated with an increased risk of relapse.

CONCLUSION

The evidence available regarding the management of patients with CPAN is limited at best. Further studies are needed in order to evaluate the effect of treatment on disease remission, relapses and mortality.

Development of a prediction model of treatment response in patients with cutaneous arteritis: Insights from a cohort of 33 patients

Cutaneous arteritis (CA) is necrotizing vasculitis invading the small- to medium-sized arteries of the skin. The majority of patients can be favorably managed by low- to medium-dose systemic corticosteroids (prednisolone, <0.5 mg/kg/day) or other oral medications such as non-steroidal anti-inflammatory drugs, dapsone, and azathioprine. Meanwhile, some patients require more intensive therapy including high-dose systemic corticosteroids (prednisolone, ≥0.5 mg/kg/day), i.v. immunoglobulin, and i.v. cyclophosphamide therapy. Although predicting such treatment response among CA patients is critical in clinical decision-making, prediction rules have not yet been established. Herein, we retrospectively reviewed 33 patients regularly visiting our clinic to reveal predictive factors of their treatment response. Clinical data were collected from electronic medical records. Association between each factor and treatment response was examined by logistic regression analysis. Progression-free time was calculated by Kaplan-Meier's method and analyzed by log-rank test and Cox progression hazard model. Potential predictive factors were selected, given 1 point for each, and integrated into a classification model. Discrimination of the model was examined by the receiver operating characteristic (ROC) curve analysis. In total, 33 CA patients were enrolled in our study. Of these, 11 patients required intensive therapy, classified as treatment non-responders. Logistic analyses revealed that treatment response was significantly associated with male sex, presence of skin ulcers, and elevated serum levels of C-reactive protein at the initial work-up. Kaplan-Meier analyses also demonstrated that those factors are predictive of progression-free time. The area under the ROC curve of our classification model was 0.92 (95% confidence interval, 0.83-1.00), which classified non-responders from the others with a sensitivity of 90.9% and specificity of 81.8% at the cut-off point of 2 or more. Collectively, treatment response of CA could be predictable by a combination of sex, presence of skin ulcers, and serum levels of C-reactive protein.

Cutaneous Polyarteritis Nodosa Sine Nodosa

Background and Objective:

Cutaneous polyarteritis nodosa, a form of vasculitis affecting the small to medium sized arteries, most commonly presents as tender subcutaneous nodules over the lower legs and feet. Other features include livedo reticularis, skin ulcers and tender indurated plaques.

Conclusion:

We report a 51-year old woman with a primarily livedo reticularis presentation of cutaneous polyarteritis nodosa without a nodular component.