Extensive Pyoderma Gangrenosum Associated With Granulomatosis With Polyangiitis With Both Responsive to Rituximab

Efficacy of Rituximab on Refractory Organ Involvements in Granulomatosis with Polyangiitis: A Systematic Review of Case Reports

INTRODUCTION

Granulomatosis with polyangiitis (GPA) is a type of Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) characterized by necrotizing vasculitis affecting small and medium-sized blood vessels. GPA affects various organs, with respiratory tract, vasculitis and glomerulonephritis being the most common triad. Remission induction and maintenance therapy for GPA traditionally involves corticosteroids and cyclophosphamide. However, treatment with rituximab, a monoclonal antibody that depletes B-cells involved in autoimmune disease, has been successful in inducing remission in several studies. The purpose of this systematic review was to investigate the efficacy of rituximab in treating various clinical manifestations of GPA.

METHODS

In adherence to PRISMA guidelines for systematic reviews and meta-analyses, we carried out a comprehensive review to investigate the effectiveness of rituximab on particular organ involvement in GPA. We searched three databases (PubMed, Scopus, and Embase) up until November 6, 2022, for case reports on the topic. To ensure all relevant studies were included, we manually screened the first 50 pages of Google Scholar's search results.

RESULTS

The review identified a total of 64 case reports and a case series of 113 cases, highlighting the effectiveness of rituximab in treating refractory organ involvement in GPA. The review also analyzed the effectiveness of rituximab in treating ocular, CNS, cardiac, pulmonary, cutaneous, gastrointestinal, renal, and other organ involvements in GPA.

CONCLUSIONS

Our results indicated that rituximab can be a promising therapy for treating specific clinical manifestations of several organ involvements. However, more research is needed to determine the long-term efficacy of rituximab in treating GPA.

The Efficacy and Safety of Rituximab in ANCA-Associated Vasculitis: A Systematic Review

Background and aim: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare multisystem autoimmune disease developed by autoantibody production against human neutrophilic granulocytes, including proteinase-3 (PR3) and myeloperoxidase (MPO). The management of AAV patients is difficult due to the multiorgan involvement, high rate of relapse, and complications of immunosuppressive agents that make it challenging. This study aims to investigate the efficacy and safety of rituximab (RTX) therapy in patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) subtypes. Method: The PubMed/Medline database was searched for any studies related to RTX therapy in ANCA-associated vasculitis (GPA and MPA subtypes), from inception to 1 August 2022, and proceeded in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results: Our search resulted in 1082 initial records. After the elimination of review papers, irrelevant studies, and non-English records, 223 articles were included, and the data related to the efficacy and safety of RTX therapy were extracted. Several randomized and non-randomized studies showed that RTX is an effective treatment option for patients with AAV. Most of the studies showed the very effective effect of RTX in controlling disease in AAV patients, including pediatrics, adults, and elderlies, although RTX cannot completely prevent relapse. However, maintenance therapy helps delay the disease's relapse and causes sustained remission. Not only the licensed dose (375 mg/m² intravenous per week for 4 weeks) could induce disease remission, but studies also showed that a single infusion of RTX could be effective. Although RTX could resolve many rare manifestations in AAV patients, there are few reports showing treatment failure. Additionally, few sudies have reported the unexpeted worsening of the disease after RTX administration. Generally, RTX is relatively safe compared to conventional therapies, but some serious adverse effects, mainly infections, cytopenia, hypogammaglobinemia, malignancy, and hypersensitivity have been reported. Conclusions: RTX is an effective and relatively safe therapeutic option for AAV. Studies on the evaluation of the safety profiles of RTX and the prevention of severe RTX-related side effects in AAV patients are required.

Pyoderma Gangrenosum: An Updated Literature Review on Established and Emerging Pharmacological Treatments

Pyoderma gangrenosum is a rare inflammatory skin disease classified within the group of neutrophilic dermatoses and clinically characterized by painful, rapidly evolving cutaneous ulcers with undermined, irregular, erythematous-violaceous edges. Pyoderma gangrenosum pathogenesis is complex and involves a profound dysregulation of components of both innate and adaptive immunity in genetically predisposed individuals, with the follicular unit increasingly recognized as the putative initial target. T helper 17/T helper 1-skewed inflammation and exaggerated inflammasome activation lead to a dysregulated neutrophil-dominant milieu with high levels of tumor necrosis factor-α, interleukin (IL)-1β, IL-1α, IL-8, IL-12, IL-15, IL-17, IL-23, and IL-36. Low-evidence studies and a lack of validated diagnostic and response criteria have hindered the discovery and validation of new effective treatments for pyoderma gangrenosum. We review established and emerging treatments for pyoderma gangrenosum. A therapeutic algorithm based on available evidence is also provided. For emerging treatments, we review target molecules and their role in the pathogenesis of pyoderma gangrenosum.

Pyoderma gangrenosum adverse event with Rituximab use: A postmarketing pharmacovigilance analysis

Rituximab is a monoclonal antibody that is used for the treatment of certain malignancies and autoimmune conditions. Pyoderma gangrenosum is a rare painful ulcer that can be fatal in some cases and can also reoccur after treatment. The objective of this paper was to analyze whether a statistically significant signal exists between Rituximab and pyoderma gangrenosum in the Food and Drug Administration Adverse Event Reporting System (FAERS). A disproportionality analysis was carried out on cases from January 1, 2004 to March 31, 2019 in the FAERS. Frequentist methods of relative reporting ratio, reporting odds ratio (ROR), and proportional reporting ratio (PRR) and the Bayesian-based IC₀₂₅ metric were used in order to assess the adverse event signal. Thirty-two cases were found in FAERS in which the drug Rituximab was administered and pyoderma gangrenosum was reported as an adverse event. The lower 95% CI of the information component was 0.97, the lower 95% CI of ROR was 2.18, the PRR was 3.09 and Chi-squared was 42.16, which indicates a statistically significant signal. The signal is supported by six case reports in the literature that describe a total of 14 patients who developed pyoderma gangrenosum after Rituximab administration. When administering Rituximab, clinicians should monitor for the occurrence of symptoms representing pyoderma gangrenosum.

Pyoderma gangrenosum-like ulcerations in granulomatosis with polyangiitis: two cases and literature review

Granulomatosis with polyangiitis (GPA) is a systemic necrotizing small vessel vasculitis associated with circulating anti-neutrophil cytoplasmic antibodies (ANCAs). Skin manifestations, mostly represented by palpable purpura, papulonodular lesions and livedo reticularis, are present in up to 50% of the cases. Ulcerations with undermined, raised erythematous-violaceous border resembling pyoderma gangrenosum (PG) have rarely been reported as skin involvement in GPA. The presence of circulating ANCAs with a cytoplasmic labelling pattern, the involvement of internal organs, particularly of the lung, and the absence on histology of a mainly neutrophilic infiltrate in early phases of the cutaneous lesions may be regarded as clues to rule out true PG and confirm the diagnosis of GPA skin ulcerations simulating PG. Herein, we describe two paradigmatic cases of such a unique presentation of GPA and a literature review focusing on clinicopathological features of GPA presenting with PG-like ulcerations in the skin has been provided. Moreover, referring to the scenario observed in these two cases, an easy-to-use working approach for the differential diagnosis between the two conditions has also been proposed.