Modulation of the skin microbiome in cutaneous T-cell lymphoma delays tumour growth and increases survival in the murine EL4 model.

Cutaneous T-cell lymphomas (CTCL) are a group of lymphoproliferative disorders of skin-homing T cells causing chronic inflammation. These disorders cause impairment of the immune environment, which leads to severe infections and/or sepsis due to dysbiosis. In this study, we elucidated the host-microbial interaction in CTCL that occurs during the phototherapeutic treatment regime and determined whether modulation of the skin microbiota could beneficially affect the course of CTCL. EL4 T-cell lymphoma cells were intradermally grafted on the back of C57BL/6 mice. Animals were treated with conventional therapeutics such as psoralen + UVA (PUVA) or UVB in the presence or absence of topical antibiotic treatment (neomycin, bacitracin, and polymyxin B sulphate) as an adjuvant. Microbial colonisation of the skin was assessed to correlate with disease severity and tumour growth. Triple antibiotic treatment significantly delayed tumour occurrence (p = 0.026), which prolonged the survival of the mice (p = 0.033). Allocation to phototherapeutic agents PUVA, UVB, or none of these, along with antibiotic intervention, reduced the tumour growth significantly (p = 0.0327, p ≤ 0.0001, p ≤ 0.0001 respectively). The beta diversity indices calculated using the Bray-Curtis model showed that the microbial population significantly differed after antibiotic treatment (p = 0.001). Upon modulating the skin microbiome by antibiotic treatment, we saw an increase in commensal Clostridium species, e.g., Lachnospiraceae sp. (p = 0.0008), Ruminococcaceae sp. (p = 0.0001)., Blautia sp. (p = 0.007) and a significant reduction in facultative pathogens Corynebacterium sp. (p = 0.0009), Pelomonas sp. (p = 0.0306), Streptococcus sp. (p ≥ 0.0001), Pseudomonas sp. (p = 0.0358), and Cutibacterium sp. (p = 0.0237). Intriguingly, we observed a significant decrease in Staphylococcus aureus frequency (p = 0.0001) but an increase in the overall detection frequency of the Staphylococcus genus, indicating that antibiotic treatment helped regain the microbial balance and increased the number of non-pathogenic Staphylococcus populations. These study findings show that modulating microbiota by topical antibiotic treatment helps to restore microbial balance by diminishing the numbers of pathogenic microbes, which, in turn, reduces chronic inflammation, delays tumour growth, and increases survival rates in our CTCL model. These findings support the rationale to modulate the microbial milieu during the disease course of CTCL and indicate its therapeutic potential.

Decolonization of Staphylococcus aureus in Healthcare: A Dermatology Perspective.

The bacterium Staphylococcus aureus is responsible for significant morbidity, mortality, and financial burden in healthcare. It easily colonizes susceptible patients and can cause recurrent infections, especially in populations at risk. In addition to treating sequelae of infections, there is a growing body of literature aimed at decolonizing susceptible patients in order to prevent infection and also to prevent spread. Such strategies are widely employed in surgical, intensive care, and hospitalist fields. Staphylococcus aureus involvement has been implicated in the pathogenesis and persistence of many dermatologic diseases that are treated in the outpatient setting. This review serves to summarize current evidence for the management of Staphylococcus aureus colonized patients, as well as the evidence available for decolonization. We further characterize the role that colonization may play in atopic dermatitis, recurrent infections, hand eczema, cutaneous T-cell lymphoma, and also in surgical infections after Mohs surgery.

Bacterial toxins fuel disease progression in cutaneous T-cell lymphoma.

In patients with cutaneous T-cell lymphoma (CTCL) bacterial infections constitute a major clinical problem caused by compromised skin barrier and a progressive immunodeficiency. Indeed, the majority of patients with advanced disease die from infections with bacteria, e.g., Staphylococcus aureus. Bacterial toxins such as staphylococcal enterotoxins (SE) have long been suspected to be involved in the pathogenesis in CTCL. Here, we review links between bacterial infections and CTCL with focus on earlier studies addressing a direct role of SE on malignant T cells and recent data indicating novel indirect mechanisms involving SE- and cytokine-driven cross-talk between malignant- and non-malignant T cells.

Role of infectious agents in cutaneous T-cell lymphoma: facts and controversies.

The etiology of cutaneous T-cell lymphoma (CTCL) remains unknown, with potential infectious causes having been explored. This contribution evaluates the evidence suggesting an infectious etiology and pathogenesis of the disease, characterizes the relationships between various specific pathogens and CTCL, and discusses some of the difficulties in establishing a causal link between infectious agents and CTCL carcinogenesis. Researchers have evaluated CTCL specimens for evidence of infection with a variety of agents, including human T-lymphotropic virus, Epstein-Barr virus, human herpesvirus-8, and Staphylococcus aureus, although other pathogens also have been detected in CTCL. Although there is significant evidence implicating one or more infectious agents in CTCL, studies to date have not linked definitively any pathogen to disease development, and various studies have yielded conflicting results.

Infectious agents in cutaneous T-cell lymphoma.

Infectious agents have long been suspected as potential causative agents in cutaneous T-cell lymphoma (CTCL). Tissues of patients with CTCL have been evaluated for evidence of infection with a number of agents, including Staphylococcus aureus, retroviruses, and herpesviruses. These studies have failed to reveal a consistent association of CTCL with investigated agents. However, there is substantial evidence suggesting a potential role of a yet unidentified virus in CTCL. This article will review the findings of studies exploring potential roles of infectious agents in CTCL. In addition, we investigated CTCL tissues for evidence of infection with Merkel cell polyomavirus, a novel polyomavirus that was recently discovered as a probable carcinogenic agent in Merkel cell carcinoma. Cutaneous lesions demonstrating mycosis fungoides were stained with a monoclonal antibody against the Merkel cell polyomavirus T antigen, along with appropriate positive and negative controls. Immunohistochemical stains produced negative results in all examined mycosis fungoides specimens. These findings, which suggest a lack of association of CTCL with Merkel cell polyomavirus, add to the current body of knowledge regarding infectious agents and CTCL.

Corynebacterium striatum infecting a malignant cutaneous lesion: the emergence of an opportunistic pathogen.

We described a case of a 27-year old male patient with skin and soft tissue infection of a neoplastic lesion caused by Corynebacterium striatum, an organism which has been rarely described as a human pathogen. Identification was confirmed by DNA sequencing. Successful treatment with penicillin was achieved. The role of the C. striatum as an emerging opportunistic pathogen is discussed.

Corynebacterium striatum infecting a malignant cutaneous lesion: the emergence of an opportunistic pathogen / Corynebacterium striatum infectando lesão cutânea maligna: a emergência de um patógeno oportunista

We described a case of a 27-year old male patient with skin and soft tissue infection of a neoplastic lesion caused by Corynebacterium striatum, an organism which has been rarely described as a human pathogen. Identification was confirmed by DNA sequencing. Successful treatment with penicillin was achieved. The role of the C. striatum as an emerging opportunistic pathogen is discussed.

Descrevemos infecção de lesão neoplásica em paciente masculino de 27 anos, envolvendo pele e partes moles, causada por Corynebacterium striatum, um microrganismo raramente descrito como patógeno humano. A identificação foi confirmada por seqüenciamento de DNA. O paciente foi tratado com penicilina, com sucesso. O papel do C. striatum como patógeno oportunista é discutido.

Cutaneous T-cell lymphoma and Staphylococcus aureus colonization.

BACKGROUND: Bacterial infections are a common complication of cutaneous T-cell lymphoma (CTCL). The most common pathogen of cutaneous infections in CTCL patients is Staphylococcus aureus. OBJECTIVE: The purpose of this study was to assess S aureus colonization rates among CTCL subjects compared to control subjects. METHODS: Fifty subjects with CTCL, 25 psoriasis control subjects, and 25 healthy control subjects were included in this study. Culture swabs were obtained from nares and lesional skin or normal skin in the healthy controls. RESULTS: S aureus colonization rates were 44% in CTCL subjects, 48% in psoriasis subjects, and 28% in healthy control subjects (P = .29). LIMITATIONS: The sample size was small, and the exclusion criteria resulted in an underestimation of the colonization rate. CONCLUSION: There was a trend for higher methicillin-sensitive S aureus colonization in the CTCL group compared with healthy control subjects. S aureus colonization may be directly related to body surface area of CTCL.

Prevalence and treatment of Staphylococcus aureus colonization in patients with mycosis fungoides and Sézary syndrome.

BACKGROUND: Mycosis fungoides (MF) and Sézary syndrome (SS), variants of cutaneous T-cell lymphoma, may arise from antigen-driven clonal expansion and accumulation of helper-memory T cells. Superantigens from Staphylococcus aureus can stimulate T cells. OBJECTIVES: (i) To determine the prevalence of S. aureus carriage in nares and skin in patients with MF/SS compared with historical rates in other conditions. (ii) To determine whether eradication of S. aureus carriage is associated with clinical improvement. Methods Skin and nares cultures were performed prospectively. Patients with positive nares and skin cultures were treated with oral antibiotics and intranasal mupirocin 2% and samples were taken for reculturing at 3 days, 4 weeks and 8 weeks. An exact binomial test was used to compare the carriage rates among different groups. RESULTS: Among 106 patients with MF/SS, 67 (63%) had skin colonization and 57 (54%) had nasal colonization. Staphylococcus aureus was isolated from 44 patients, 33 (31%) each from skin and nares. Colonization was highest in erythrodermic SS (48%), similar to atopic dermatitis (64%), and lowest in MF without erythroderma (26%), psoriasis (21%), and the general population (10%). Oral and topical antibiotics eradicated S. aureus colonization in nares in 28 of 33 (85%) patients and in MF skin lesions in 30 of 33 (91%) patients at 4-8 weeks, with rapid clinical improvement seen in 58% of S. aureus-colonized patients. CONCLUSIONS: Staphylococcal carriage in nares and skin lesions of patients with MF is similar to that in atopic dermatitis. Eradication of staphylococci from the skin is possible with treatment and was associated with clinical improvement.

Mycosis on mycosis fungoides: zoophilic dermatophytosis selectively superimposed on pre-existing cutaneous T-cell lymphoma (mycosis fungoides) plaques.

We report a case of tinea corporis caused by a cattle-derived strain of Trichophyton mentagrophytes in a 44-year-old male affected by cutaneous T-cell lymphoma (CTCL, so-called mycosis fungoides). Fungal colonization of glabrous skin was strictly confined within pre-existing lymphomatous plaques. Either oral itraconazole or griseofulvin, or topical terbinafine were ineffective until the patient, who was treated with systemic retinoids and interferon-alpha for his CTCL, was shifted from leucocyte to lymphoblastoid interferon. The hypothesis that a local immunodisturbance could be responsible for the selective superimposition of tinea on CTCL lesions ('mycosis on mycosis'), and that such an immunodisturbance could be partially corrected by the interferon switch is discussed.

Association between Sézary T cell-activating factor, Chlamydia pneumoniae, and cutaneous T cell lymphoma.

Sézary T cell-activating factor (SAF) was originally defined as an inducer of functional interleukin-2 (IL-2) receptors on normal and malignant T cells in patients suffering from Sézary syndrome. In fact, a combination of SAF and IL-2 stimulated the propagation of T cell lines from the peripheral blood mononuclear cells (PBMC) of those patients, with approximately one third of those cell lines containing the predominant malignant clone as determined via cytogenetic and/or T cell receptor gene rearrangement analysis. Although the primary source of SAF was mitogen-stimulated PBMC of a patient with Sézary syndrome, we were unable to isolate the gene encoding SAF from eukaryotic libraries. However, we observed SAF activity in the cytoplasm of one of the malignant cell lines in a complex containing RNA and DNA. This observation led us to consider the possibility that SAF is not of eukaryotic origin. Intracellular pathogens replicate in the cytoplasm of host cells and contain proteins, DNA, and RNA. Using a panel of antichlamydial antibodies with confirmation from polymerase chain reaction primers, we found that most patients with mycosis fungoides were positive for these determinants. Immunoelectron microscopy and protein blotting further confirmed antibody reactivity. We showed that Chlamydia pneumoniae were capable of infecting normal human keratinocytes in culture. We also demonstrated that C. pneumoniae antigen expression was associated with active disease because these determinants were not expressed after psoralen and ultraviolet A therapy. We hypothesize that chronic infection by C. pneumoniae leads to expansion of C. pneumoniae-specific T cells, thereby potentiating the development of cutaneous T cell lymphoma.

Enterococcal eschars in cutaneous T-cell lymphoma tumors: a distinct clinical entity.

Cutaneous T-cell lymphomas (CTCL) are extranodal non-Hodgkin's T-cell lymphomas that present in the skin, the most common form being mycosis fungoides. The progression of disease is associated with acquired immunodeficiency and increased susceptibility to infections. Ten CTCL patients presented with dark brown to black eschars overlying ulcerated tumors that cultured positive for Enterococcus and healed with appropriate antibiotic therapy. Enterococcal infections in CTCL tumors may be recognized as a distinct clinical entity requiring specific intervention.

Sézary T-cell activating factor is a Chlamydia pneumoniae-associated protein.

We previously identified a protein that was stimulatory for malignant Sézary T cells, termed Sézary T-cell activating factor (SAF). However, the identity of this protein has not been fully elucidated, nor has it's role been determined in the pathogenesis of cutaneous T-cell lymphoma (CTCL). The basis for epidermotropism and proliferation of malignant cells in the skin of patients with CTCL is unknown. Using a monoclonal antibody inhibitory for SAF activity, we demonstrated that SAF is present in the skin of 16 of 27 samples from patients with mycosis fungoides, the predominant form of CTCL. In this report, the SAF determinant is demonstrated to be associated with Chlamydia pneumoniae bacteria by immunohistochemistry, immunoelectron microscopy, and culture analysis. Reactivity of antibodies against an outer membrane protein of C. pneumoniae or against the lipopolysaccharide of Chlamydiae spp. demonstrated that these determinants are coexpressed in 90% of the SAF-positive samples. We confirmed the presence of C. pneumoniae DNA and RNA in the skin by PCR and reverse transcription-PCR and by sequence analysis of the PCR products. The expression of the C. pneumoniae antigens and SAF appears to be associated with active disease in that C. pneumoniae antigens were absent or greatly diminished in the skin of three patients examined after Psoralen and long-wave UVA radiation treatment. Our results suggest that SAF is a Chlamydia-associated protein and that further investigation is warranted to determine whether SAF and C. pneumoniae play a role in the pathogenesis of CTCL.