Eight-cycle rituximab therapy resulted in complete remission in primary cutaneous marginal zone lymphoma

Isolation, Identification, and Characterization of Bacillus cereus Group Bacteria Isolated from the Dairy Farm Environment and Raw Milk in Tunisia

Members of the Bacillus cereus group are well-known opportunistic foodborne pathogens. In this study, the prevalence, hemolytic activity, antimicrobial resistance profile, virulence factor genes, genetic diversity by enterobacterial repetitive intergenic consensus (ERIC)-polymerase chain reaction (PCR) genotyping, and adhesion potential were investigated in isolates from a Tunisian dairy farm environment and raw milk. A total of 200 samples, including bedding, feces, feed, liquid manure, and raw bovine milk, were examined. Based on PCR test targeting sspE gene, 59 isolates were detected. The prevalence of B. cereus group isolates in bedding, feces, liquid manure, feed, and raw milk was 48%, 37.8%, 20%, 17.1%, and 12.5%, respectively. Out of the tested strains, 81.4% showed β-hemolytic on blood agar plates. An antimicrobial resistance test against 11 antibiotics showed that more than 50% of the isolates were resistant to ampicillin and novobiocin, while a high sensitivity to other antibiotics tested was observed in most isolates. The distribution of enterotoxigenic genes showed that 8.5% and 67.8% of isolates carried hblABCD and nheABC, respectively. In addition, the detection rate of cytotoxin K (cytk), enterotoxin T (bceT), and ces genes was 72.9%, 64.4%, and 5.1%, respectively. ERIC-PCR fingerprinting genotype analysis allowed discriminating 40 different profiles. The adhesion potential of B. cereus group on stainless steel showed that all isolates were able to adhere at various levels, from 1.5 ± 0.3 to 5.1 ± 0.1 log colony-forming unit (CFU)/cm2 for vegetative cells and from 2.6 ± 0.4 to 5.7 ± 0.3 log CFU/cm2 for spores. An important finding of the study is useful for updating the knowledge of the contamination status of B. cereus group in Tunisia, at the dairy farm level.

Cutaneous primary B-cell lymphomas: from diagnosis to treatment

Primary cutaneous B-cell lymphomas are a heterogeneous group of mature B-cells neoplasms with tropism for the skin, whose biology and clinical course differ significantly from the equivalent nodal lymphomas. The most indolent forms comprise the primary cutaneous marginal zone and follicle center B-cell lymphomas that despite the excellent prognosis have cutaneous recurrences very commonly. The most aggressive forms include the primary cutaneous large B-cell lymphomas, consisting in two major groups: the leg type, with poor prognosis, and others, the latter representing a heterogeneous group of lymphomas from which specific entities are supposed to be individualized over time, such as intravascular large B-cell lymphomas. Treatment may include surgical excision, radiotherapy, antibiotics, corticosteroids, interferon, monoclonal antibodies and chemotherapy, depending on the type of lymphoma and on the type and location of the skin lesions. In subtypes with good prognosis is contraindicated overtreatment and in those associated with a worse prognosis the recommended therapy relies on CHOP-like regimens associated with rituximab, assisted or not with local radiotherapy. We review the primary cutaneous B-cell lymphomas, remembering the diagnostic criteria, differential diagnosis, classification, and prognostic factors and presenting the available therapies.

Rituximab in the treatment of primary cutaneous B-cell lymphoma: a review

Rituximab is a chimeric mouse-human antibody that targets the CD20 antigen, which is found in both normal and neoplastic B cells. In recent years, it has been increasingly used to treat cutaneous B-cell lymphoma and is now considered an alternative to classic treatment (radiotherapy and surgery) of 2 types of indolent lymphoma, namely, primary cutaneous follicle center lymphoma and primary cutaneous marginal zone B-cell lymphoma. Rituximab is also administered as an alternative to polychemotherapy in the treatment of primary cutaneous large B-cell lymphoma, leg type. Its use as an alternative drug led to it being administered intralesionally, with beneficial effects. In the present article, we review the literature published on the use of rituximab to treat primary cutaneous B-cell lymphoma.

Treatment of cutaneous lymphoid hyperplasia with the monoclonal anti-CD20 antibody rituximab

B-cell lymphoproliferative disorders are a continuum from benign cutaneous lymphoid hyperplasia (CLH) or "pseudolymphoma" to primary cutaneous B-cell lymphoma (PCBCL). Historically, CLH was treated with a combination of antibiotics, topical or intralesional corticosteroids, and/or localized radiotherapy. Rituximab, a monoclonal antibody that targets the CD20 marker on B cells, is an effective and well-reported treatment for PCBCL. We review the pathogenesis and current treatments of B-cell lymphoproliferative disorders and assess the role of rituximab for potential therapy in the setting of refractory CLH. We describe a case of CLH that was treated with intralesional rituximab. The patient had notable clinical improvement over the treatment period with rituximab. Because of some persistent and recurrent erythematous areas, topical tacrolimus was initiated, with significant clinical improvement. There were no reported side effects. Management of CLH with intralesional rituximab has been described. The treatment presented in this report substantiates rituximab as a reasonable therapeutic option for refractory CLH after failure of several other widely accepted treatments. Treatment with intralesional rituximab should be reserved for patients with documented CD20(+) lesions.

Pulmonary BALT lymphoma successfully treated with eight cycles weekly rituximab: report of first case and F-18 FDG PET/CT images

Extra marginal-zone lymphomas of the lung is a very rare tumor and it originates from bronchial-associated lymphoid tissue. A 68-yr-old woman presented with productive cough and dyspnea. A thorax computed tomography scan showed a 9 × 10 cm in size mass in the left lung and pleural effusion in the lower lobe of left lung. Positron emission tomography/computed tomography (PET/CT) revealed intense uptake foci at the upper and middle sites of left lung and slight uptake foci at the mediastinal lymph nodes which showed malignant involvement. After bronchoscopic biopsy, the diagnosis of pulmonary bronchial-associated lymphoid tissue (BALT) lymphoma was confirmed. At the end of the eight cycles weekly rituximab treatment, complete response was obtained by PET/CT findings. It is concluded that extended rituximab schedule is more effective and it would be beneficial to investigate the use of PET/CT in the diagnosis and evaluating of the treatment response of pulmonary BALT lymphoma.