Bone Involvement as a Primary Rare Manifestation of Waldenstrom Macroglobulinemia: A Case Report and Prevalence in a Nationwide Population-Based Cohort Study.

Bone involvement is a rare extranodal manifestation in patients with malignant lymphoproliferative diseases and has also been noted as a rare event in patients with Waldenstrom macroglobulinemia (WM). However, the actual prevalence has not been previously reported. We describe an unusual case of a patient with WM who presented with lower back pain and focal bone lesions at initial diagnosis. Magnetic resonance imaging (MRI) revealed multiple vertebral fractures. Positron emission tomography (PET) detected only nodal changes without pathological skeletal-related metabolic activity. Lymph node and bone marrow biopsies combined with an immunoglobulin M (IgM) M component revealed the diagnosis of WM. A next-generation sequencing (NGS) analysis using a targeted lymphoma panel of 59 recurrently mutated genes in lymphoid neoplasms showed mutations in the MYD88 and CD79B genes. After treatment with rituximab and bendamustine, the patient achieved a partial remission and pain relief. After 3 years of stable disease, a spontaneous subcapital fracture at the base of the femoral neck and new vertebral compression fractures occurred. Whole-body low-dose computed tomography (WB-LDCT) and bone density (dual energy X-ray absorptiometry (DEXA)) scan revealed marked osteopenia. After insertion of a hip prosthesis, examination of the removed hip showed infiltration of clonal lymphoplasmacytic cells. Our case confirms that one must be aware that bone involvement in patients with WM can occur as a rare manifestation. Interestingly, the MYD88/CD79B-mutated (MCD) genotype in diffuse large B-cell lymphoma is characterized by extranodal involvement and may also be involved in the pathogenesis of skeletal-related disease in the present case. As a follow-up to this unusual case, we have carried out an analysis based on the Danish Lymphoma Registry (LYFO) covering the entire national population in the period 2000 - 2020. The registry study included a cohort of 2,459 patients with WM and lymphoplasmacytic lymphoma. Our data revealed that primary bone involvement at diagnosis occurs in 1.75% of adults with WM. To the best of our knowledge, this is the first report of the prevalence of skeletal-related disease in a large nationwide cohort and defines bone involvement as an exceedingly rare event in WM.

Staphylococcus aureus enterotoxins induce FOXP3 in neoplastic T cells in Sézary syndrome.

Sézary syndrome (SS) is a heterogeneous leukemic subtype of cutaneous T-cell lymphoma (CTCL) with generalized erythroderma, lymphadenopathy, and a poor prognosis. Advanced disease is invariably associated with severe immune dysregulation and the majority of patients die from infectious complications caused by microorganisms such as, Staphylococcus aureus, rather than from the lymphoma per se. Here, we examined if staphylococcal enterotoxins (SE) may shape the phenotype of malignant SS cells, including expression of the regulatory T-cell-associated marker FOXP3. Our studies with primary and cultured malignant cells show that SE induce expression of FOXP3 in malignant cells when exposed to nonmalignant cells. Mutations in the MHC class II binding domain of SE-A (SEA) largely block the effect indicating that the response relies at least in part on the MHC class II-mediated antigen presentation. Transwell experiments show that the effect is induced by soluble factors, partly blocked by anti-IL-2 antibody, and depends on STAT5 activation in malignant cells. Collectively, these findings show that SE stimulate nonmalignant cells to induce FOXP3 expression in malignant cells. Thus, differences in exposure to environmental factors, such as bacterial toxins may explain the heterogeneous FOXP3 expression in malignant cells in SS.

Antibiotics inhibit tumor and disease activity in cutaneous T-cell lymphoma.

It has been proposed that CD4 T-cell responses to Staphylococcus aureus (SA) can inadvertently enhance neoplastic progression in models of skin cancer and cutaneous T-cell lymphoma (CTCL). In this prospective study, we explored the effect of transient antibiotic treatment on tumor cells and disease activity in 8 patients with advanced-stage CTCL. All patients experienced significant decrease in clinical symptoms in response to aggressive, transient antibiotic treatment. In some patients, clinical improvements lasted for more than 8 months. In 6 of 8 patients, a malignant T-cell clone could be identified in lesional skin, and a significant decrease in the fraction of malignant T cells was observed following antibiotics but an otherwise unchanged treatment regimen. Immunohistochemistry, global messenger RNA expression, and cell-signaling pathway analysis indicated that transient aggressive antibiotic therapy was associated with decreased expression of interleukin-2 high-affinity receptors (CD25), STAT3 signaling, and cell proliferation in lesional skin. In conclusion, this study provides novel evidence suggesting that aggressive antibiotic treatment inhibits malignant T cells in lesional skin. Thus, we provide a novel rationale for treatment of SA in advanced CTCL.

Prognostic miRNA classifier in early-stage mycosis fungoides: development and validation in a Danish nationwide study.

Mycosis fungoides (MF) is the most frequent form of cutaneous T-cell lymphoma. The disease often takes an indolent course, but in approximately one-third of the patients, the disease progresses to an aggressive malignancy with a poor prognosis. At the time of diagnosis, it is impossible to predict which patients develop severe disease and are in need of aggressive treatment. Accordingly, we investigated the prognostic potential of microRNAs (miRNAs) at the time of diagnosis in MF. Using a quantitative reverse transcription polymerase chain reaction platform, we analyzed miRNA expression in diagnostic skin biopsies from 154 Danish patients with early-stage MF. The patients were subdivided into a discovery cohort (n = 82) and an independent validation cohort (n = 72). The miRNA classifier was built using a LASSO (least absolute shrinkage and selection operator) Cox regression to predict progression-free survival (PFS). We developed a 3-miRNA classifier, based on miR-106b-5p, miR-148a-3p, and miR-338-3p, which successfully separated patients into high-risk and low-risk groups of disease progression. PFS was significantly different between these groups in both the discovery cohort and the validation cohort. The classifier was stronger than existing clinical prognostic factors and remained a strong independent prognostic tool after stratification and adjustment for these factors. Importantly, patients in the high-risk group had a significantly reduced overall survival. The 3-miRNA classifier is an effective tool to predict disease progression of early-stage MF at the time of diagnosis. The classifier adds significant prognostic value to existing clinical prognostic factors and may facilitate more individualized treatment of these patients.

Immunosuppressive Environment in Basal Cell Carcinoma: The Role of Regulatory T Cells.

Interaction between tumour survival tactics and anti-tumour immune response is a major determinant for cancer growth. Regulatory T cells (T-regs) contribute to tumour immune escape, but their role in basal cell carcinoma (BCC) is not understood. The fraction of T-regs among T cells was analysed by immunohistochemistry followed by automated image analysis in facial BCC, peritumoural skin and normal, buttock skin. Quantitative real-time PCR (qRT-PCR) was performed for Foxp3 and cytokines involved in T-reg attraction and T-cell activation. T-regs comprised 45% of CD4-cells surrounding BCC. Foxp3 was highly expressed in BCC, but absent in buttock skin. Unexpectedly, expression of Foxp3 was increased in peritumoural skin, with the FoxP3/CD3 fractions exceeding those of BCC (p = 0.0065). Transforming growth factor (TGF)-ß and T-reg chemokine expression was increased in BCC and peritumoural skin, but not in buttock skin, with expression levels correlating with Foxp3. T-regs are abundantly present both in BCC and in peritumoural skin, mediating an immunosuppressed microenvironment permissive for skin cancer