Detecting T-cell receptor clonality in patients with severe atopic dermatitis refractory to dupilumab.

BACKGROUND: Trials and real-life studies demonstrated clinically meaningful improvements of disease activity in the majority of patients with moderate to severe atopic dermatitis (AD) treated with the anti-IL-4RA-antibody dupilumab. However, misdiagnosis or confounding skin diseases in particular cutaneous T-cell lymphoma (CTCL) may lead to inadequate response. OBJECTIVE: To investigate the clinical and pathological features of patients with AD who showed insufficient response to dupilumab. METHODS: We reviewed the medical records of 371 patients treated with dupilumab for severe AD. Insufficient response was defined as failure to achieve an improvement of the eczema area severity index (EASI) of at least 50% (EASI-50) at Week 16 and of 75% (EASI-75) at Week 52. Among 46 patients with insufficient response, 35 patients consented to a re-evaluation including a full physical exam, biopsies and laboratory assessments including immunohistochemistry and T-cell receptor gene rearrangement analysis to differentiate CTCL. RESULTS: Of the 371 patients treated with dupilumab, 46 (12.3%) patients showed insufficient response to dupilumab. Of these, 35 underwent further evaluation, and 19 (54.2% of inadequate responders) were finally diagnosed with mycosis fungoides (MF). In these patients, transition to or addition of conventional MF treatment led to clinical improvements. CONCLUSION: Insufficient response to dupilumab treatment may help uncover early MF on an existing AD background.

Tuberculous Lymphadenitis in a Patient Treated with Dupilumab: A Case Report.

Tuberculous lymphadenitis is among the most frequent presentations of extrapulmonary tuberculosis; the most common presentation is isolated chronic non-tender lymphadenopathy in young adults without systemic symptoms. Dupilumab is a fully human monoclonal antibody directed against interleukin-4 receptor-α that blocks the synergistic effects of interleukin-4 and interleukin-13 on allergic inflammation. Its well-known adverse events are allergic conjunctivitis, injection site reaction, and dupilumab facial redness. A 32-year-old female with severe atopic dermatitis was treated with dupilumab for 2 months at our clinic. She complained of multiple enlarged palpable lymph nodes on the right side of the neck and inguinal area for 2 months. Laboratory tests showed an increased total eosinophil count and immunoglobulin E level, as well as positive interferon-γ release assays. Radiological examination showed multiple low echoic and heterogeneous well-enhancing lymph nodes in level II, III, IV, and V of the neck. Histological examination revealed caseous necrosis and tuberculoid granuloma. The lymph node enlargements were completely relieved after antituberculosis treatment. The mechanism for the development of tuberculous lymphadenitis in a patient receiving dupilumab is not fully understood yet. In some previous studies, treatment with dupilumab suppressed the expression of genes related not only to T helper 2 and eosinophil response but also to proinflammatory responses. It could not inhibit the intracellular growth of Mycobacterium tuberculosis in macrophages, predisposing them to the development of tuberculous infection. To the best of our knowledge, this is the first report on the development of tuberculosis lymphadenitis in a patient treated with dupilumab.

Very Early Patch Stage of AIDS-related Kaposi Sarcoma: A Case Report.

Kaposi sarcoma (KS) is a vascular and lymphatic neoplasm caused by human herpesvirus 8 (HHV-8). AIDS-related KS has variable clinical courses ranging from mild disease presenting as an incidental finding to severe disease presenting as an aggressively progressing neoplasm that can lead to poor prognosis or even death. Typical clinical manifestation of KS is known as multiple cutaneous lesions on the extremities, trunk, and face with mucosal involvement. A 46-year-old male with AIDS complained of an erythematous patch on the right forearm which appeared 5 months ago. For a year, he was treated with antiretroviral drugs for AIDS. Physical examination revealed a 2.5-cm solitary erythematous patch only on the right forearm. Laboratory data revealed human immunodeficiency virus (HIV)-1 RNA of less than 40 copies/ml and a CD4 cell count of 264 cells/mm3. Histological examination revealed numerous slit-like spaces and vascular proliferation with primitive blood vessels dissecting between the collagen bundles and the dermis. Immunohistochemical staining showed positive HHV-8 nuclear staining of spindle cells. The histological features and positive HHV-8 immunohistochemical stain were consistent with the diagnosis of early patch stage of AIDS-related KS. KS can readily be misdiagnosed in early patch stage even by experienced clinicians, which leads to requirement of pathologic determination. On close inspection, it can be distinguished from other mimickers by its distinctive histologic features and immunohistochemical staining for HHV-8. Therefore, in cases of HIV-positive patients with clinically or histologically vascular-appearing mucocutaneous lesions, KS should be considered as a possible differential diagnosis.