Two cases demonstrate an association between Tropheryma whipplei and pulmonary marginal zone lymphoma

BACKGROUND

Marginal zone lymphomas of mucosa-associated lymphatic tissues (MZL of MALT) are a group of indolent B-cell neoplasms, which are thought to arise from chronic antigenic stimulation of B-cells either due to underlying chronic infection or autoimmune disease. Little is known about potential causative pathogens in pulmonary MZL (PMZL), although some data suggests a potential role of Achromobacter (A.) xylosoxidans.

METHODS

An index case of chronic pulmonary colonisation with Tropheryma (T.) whipplei and subsequent development of PMZL was identified by T. whipplei specific PCR and metagenomic next genome sequencing (mNGS). This case prompted a retrospectively conducted analysis of T. whipplei-specific PCRs in lung tissue from PMZL patients (n = 22), other pulmonary lymphomas, and normal controls. Positive results were confirmed by mNGS. A systematic search for T. whipplei and A. xylosoxidans in our in-house mNGS dataset comprising autopsy lungs, lung biopsies and lung resection specimens (n = 181) was subsequently performed.

RESULTS

A 69-year-old patient presented with weight loss and persistent pulmonary consolidation. Subsequent mNGS analysis detected T. whipplei in the resected lung specimen. An antibiotic regimen eventually eliminated the bacterium. However, the consolidation persisted, and the diagnosis of PMZL was made in a second lung resection specimen. A second case of T. whipplei-associated PMZL was subsequently detected in the retrospectively analysed PMZL cohort. Both cases showed comparatively few mutations and no mutations in genes encoding for NF-κB pathway components, suggesting that T. whipplei infection may substitute for mutations in these PMZL. None of the samples in our in-house dataset tested positive for T. whipplei. In contrast, A. xylosoxidans was frequently found in both autopsy lungs and lung biopsy / resection specimens that were not affected by PMZL (> 50%).

CONCLUSIONS

Our data suggests that T. whipplei colonisation of lungs may trigger PMZL as a potential driver. Systematic analyses with larger cohorts should be conducted to further support this hypothesis. The frequent detection of A. xylosoxidans in lung tissue suggests that it is a common component of the pulmonary microbiome and therefore less likely to trigger lymphomas.

First-line antibiotic treatment in patients with localized extragastric mucosa-associated lymphoid tissue lymphoma

Between January 2010 and December 2015, we enrolled 28 patients with stage IEI/IIE1 extragastric mucosa-associated lymphoid tissue (MALT) lymphoma who received first-line antibiotic treatment, after informing them about the pros and cons of alternative therapies. In addition, during the same period, 64 patients with stage IE/IIE1 disease who received conventional treatment were selected as the control group. The most common primary sites were the ocular adnexal area (17 cases), followed by the salivary glands (four cases), pulmonary (three cases), and thyroid, trachea, larynx, and colon region (one case each). First-line antibiotic treatment resulted in an overall response rate of 57.1%: 12 patients achieved complete remission (CR), while four achieved partial remission (antibiotic-responsive tumors). Monoclonal gammopathy was significantly prevalent in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (50.0% [6/12] vs. 12.5% [2/16], p = 0.044). After a median follow-up of 7 years, all patients with CR remained lymphoma-free, with 7-year event-free survival (EFS) and overall survival (OS) rates of 62.7% and 96.4%, respectively. The 7-year EFS and OS rates of patients who received conventional treatments were 73.1% and 91.1%, respectively. Compared with that noted in patients who received conventional treatment, antibiotic treatment was effective in some patients with localized extragastric MALT lymphoma.

Bacterial Infection and Non-Hodgkin B-Cell Lymphoma: Interactions between Pathogen, Host and the Tumor Environment

Non-Hodgkin B-cell lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms with complex etiopathology, rich symptomatology, and a variety of clinical courses, therefore requiring different therapeutic approaches. The hypothesis that an infectious agent may initiate chronic inflammation and facilitate B lymphocyte transformation and lymphogenesis has been raised in recent years. Viruses, like EBV, HTLV-1, HIV, HCV and parasites, like Plasmodium falciparum, have been linked to the development of lymphomas. The association of chronic Helicobacter pylori (H. pylori) infection with mucosa-associated lymphoid tissue (MALT) lymphoma, Borrelia burgdorferi with cutaneous MALT lymphoma and Chlamydophila psittaci with ocular adnexal MALT lymphoma is well documented. Recent studies have indicated that other infectious agents may also be relevant in B-cell lymphogenesis such as Coxiella burnettii, Campylobacter jejuni, Achromobacter xylosoxidans, and Escherichia coli. The aim of the present review is to provide a summary of the current literature on infectious bacterial agents associated with B-cell NHL and to discuss its role in lymphogenesis, taking into account the interaction between infectious agents, host factors, and the tumor environment.

Drug Repositioning for the Treatment of Hematologic Disease: Limits, Challenges and Future Perspectives

Drug repositioning is a strategy to identify new uses for approved or investigational drugs that are used off-label outside the scope of the original medical indication. In this review, we report the most relevant studies about drug repositioning in hematology, reporting the signalling pathways and molecular targets of these drugs, and describing the biological mechanisms which are responsible for their anticancer effects. Although the majority of studies on drug repositioning in hematology concern acute myeloid leukemia and multiple myeloma, numerous studies are present in the literature on the possibility of using these drugs also in other hematological diseases, such as acute lymphoblastic leukemia, chronic myeloid leukemia, and lymphomas. Numerous anti-infectious drugs and chemical entities used for the therapy of neurological or endocrine diseases, oral antidiabetics, statins and medications used to treat high blood pressure and heart failure, bisphosphonate and natural substance such as artemisin and curcumin, have found a place in the treatment of hematological diseases. Moreover, several molecules drastically reversed the resistance of the tumor cells to the chemotherapeutic drugs both in vitro and in vivo.

Maltoma veiled in the lung-a rare case of pulmonary and gastric maltoma

Mucosa associated lymphoid tissue (MALT) is a type of B-cell lymphoma that is commonly observed in the gastrointestinal site, most frequently occurring in the stomach. However, the incidence of this type of lymphoma in the respiratory tract is very uncommon. We report a case of this rare clinical entity in a patient who presented with non-symptomatology and was diagnosed with pulmonary MALT lymphoma (pMALToma).

Possible mechanisms of action of clarithromycin and its clinical application as a repurposing drug for treating multiple myeloma

Clarithromycin (CAM), a semisynthetic macrolide antibiotic, is a widely used antibacterial drug. Recently, the efficacy of CAM as an add-on drug for treating multiple myeloma (MM) has been noted. Its effect on treating MM has been confirmed in combination chemotherapies that include CAM. However, a single treatment of CAM has no efficacy for treating MM. Many myeloma growth factors (MGFs) including interleukin (IL)-6 are known to be closely involved in the development of MM. CAM has been shown to suppress many MGFs, particularly IL-6. The possible mechanisms of action of CAM in treating MM have been suggested to include its immunomodulatory effect, autophagy inhibition, reversibility of drug resistance, steroid-sparing/enhancing effect and suppression of MGFs. In addition, MM is characterised by uncontrolled cell growth of monoclonal immunoglobulin (Ig)-producing neoplastic plasma cells. Large quantities of unfolded or misfolded Ig production may trigger considerable endoplasmic reticulum stress. Thus, MM is originally a fragile neoplasm particularly susceptible to autophagy-, proteasome- and histone deacetylase 6-inhibitors. Taken together, CAM plays an important role in MM treatments through its synergistic mechanisms. In addition, CAM with its pleiotropic effects on cytokines including IL-6 and indirect antiviral effects might be worth a try for treating COVID-19.

Bacterial infection and non-Hodgkin's lymphoma

One quarter of all cancers are linked to infectious diseases. The link between viral infection and cancer has been widely studied, but few reports have focused on the carcinogenic role of bacterial infection. Nonetheless, Helicobacter pylori, Chlamydia psittaci, Coxiella burnetii, Borrelia burgdorferi and Campylobacter jejuni are bacteria that can be associated with non-Hodgkin's lymphoma (NHL), the most common haematologic malignancy. Here, we review the evidence in favour of a link between these bacterial infections and NHL. Sero-epidemiological observation makes it possible to identify a link between H. pylori, C. burnetii, B. burgdorferi infection and NHL. Helicobacter pylori, Chlamydia psittaci, Coxiella burnetii, Borrelia burgdorferi and Campylobacter jejuni could be identified in NHL tissue samples at the site of chronic inflammation, where B and T lymphocytes are attracted to participate in follicle formation. Lymphoma remissions have been observed under antimicrobial therapies supporting the carcinogenic contribution of bacteria. If the theory of causality is characterized by the lack of universal criteria for establishing a causal link between two diseases, infection and lymphoma, epidemiological, clinical, and histological evidences reported here, should lead clinicians to pay attention to these infectious agents, to detect early lymphoma transformation.

Xenophagy in cancer

Macroautophagy (herein autophagy) is an intracellular pathway in which cytoplasmic components are captured by double-membrane vesicles (autophagosomes) that eventually fuse with lysosomes to degrade the cargo. Basal levels of autophagy in all eukaryotic cells maintain cellular homeostasis and under conditions of stress, organelles and proteins not essential for survival are degraded. Apart from these functions, cargoes like aggregated proteins, damaged organelles and intracellular pathogens, which are otherwise harmful to cells, are also selectively captured by autophagy and are destined for degradation. In terms of infectious diseases, pathogens are cleared by a specific form of autophagy known as xenophagy. This lysosomal mediated degradation of pathogens also increases the antigen presentation of cells thereby inducing a further immune response. The process of xenophagy provides a broad spectrum of defense mechanism to capture bacterial, viral and protozoan pathogens. However, pathogens have developed ingenious mechanisms to modulate xenophagy to enhance their intracellular survival. Meanwhile, certain pathogens also induce deleterious effects such as chronic inflammation and overexpression of oncogenes in the host system. This over time can increase the susceptibility of the host for tumorigenesis. Hence targeting tumor through anti-microbial mechanisms like xenophagy could be a novel strategy for combinatorial anti-cancer therapy. The recent developments in understanding the role of xenophagy in combating cancer causing pathogens will be discussed in this review.

Primary Pulmonary Involvement in Mucosa-associated Lymphoid Tissue Lymphoma

Pulmonary nodules have a broad differential diagnosis with primary lung cancer, lung metastases, benign tumors, carcinoid tumors, and infectious granulomas as their common cause. While relatively rare, pulmonary lymphoproliferative disorders such as primary pulmonary lymphomas, primary pulmonary plasmacytomas, secondary lymphomas involving the lung, multiple myeloma involving the lung, leukemias involving the lung should be considered in these patients presenting with lung nodules. Primary pulmonary non-Hodgkin’s lymphoma (NHL) is an extremely rare lung tumor accounting for 0.4% of all lymphomas. Mucosa-associated lymphoid tissue (MALT) lymphoma accounts for about 70%-90% of all primary pulmonary lymphomas, constituting less than 0.5% of all the lung neoplasms. Though it usually remains localized, it is a clonal B-cell neoplasm with a potential for systematic spread and transformation to an aggressive B-cell lymphoma. We hereby discuss the case of a 66-year-old woman with primary pulmonary MALT lymphoma.

First-line antibiotic therapy in Helicobacter pylori-negative low-grade gastric mucosa-associated lymphoid tissue lymphoma

First-line antibiotic treatment for eradicating Helicobacter pylori (HP) infection is effective in HP-positive low-grade gastric mucosa-associated lymphoid tissue lymphoma (MALToma), but its role in HP-negative cases is uncertain. In this exploratory retrospective study, we assessed the outcome and potential predictive biomarkers for 25 patients with HP-negative localized gastric MALToma who received first-line HP eradication (HPE) therapy. An HP-negative status was defined as negative results on histology, rapid urease test, ¹³C urea breath test, and serology. We observed an antibiotic response (complete remission [CR], number = 8; partial remission, number = 1) in 9 (36.0%) out of 25 patients. A t(11;18)(q21;q21) translocation was detected in 7 (43.8%) of 16 antibiotic-unresponsive cases, but in none of the 9 antibiotic-responsive cases (P = 0.027). Nuclear BCL10 expression was significantly higher in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (14/16 [87.5%] vs. 1/9 [11.1%]; P = 0.001). Nuclear NF-κB expression was also significantly higher in antibiotic-unresponsive tumors than in antibiotic-responsive tumors (12/16 [75.0%] vs. 1/9 [11.1%]; P = 0.004). A substantial portion of patients with HP-negative gastric MALToma responded to first-line HPE. In addition to t(11;18)(q21;q21), BCL10 and NF-κB are useful immunohistochemical biomarkers to predict antibiotic-unresponsive status in this group of tumors.

A case of Waldenström's macroglobulinemia treated using clarithromycin and prednisolone

We report a case of Waldenström's macroglobulinemia (WM) treated using clarithromycin (CAM) and prednisolone (PSL). An 84-year-old woman was admitted to our hospital for bleeding after a tooth extraction and hematuria. Computed tomography showed multiple ill-defined nodules in the omentum (omental cake). Although the cause of the omental cake remained unclear, the patient was diagnosed with WM, based on the detection of M-protein of immunoglobulin (Ig) M in serum and lymphoplasmacytes in bone marrow. The bleeding tendency in the patient may have been due to acquired hemophilia and/or hyper IgM-induced platelet dysfunction. The patient was treated using CAM (800 mg/day) and PSL (10 mg/day). As a result, IgM levels gradually decreased. Because the omental cake contracted along with improvement in IgM, it was thought to be lymphoplasmacytic lymphoma-like lymphoma. This case shows that treatment using CAM and PSL may be effective in some cases of WM.

Repurposing Drugs in Oncology (ReDO)-clarithromycin as an anti-cancer agent

Clarithromycin (CAM) is a well-known macrolide antibiotic available as a generic drug. CAM is traditionally used for many types of bacterial infections, treatment of Lyme disease and eradication of gastric infection with Helicobacter pylori. Extensive preclinical and clinical data demonstrate a potential role for CAM to treat various tumours in combination with conventional treatment. The mechanisms of action underlying the anti-tumour activity of CAM are multiple and include prolonged reduction of pro-inflammatory cytokines, autophagy inhibition, and anti-angiogenesis. Here, we present an overview of the current preclinical (in vitro and in vivo) and clinical evidence supporting the role of CAM in cancer. Overall these findings justify further research with CAM in many tumour types, with multiple myeloma, lymphoma, chronic myeloid leukaemia (CML), and lung cancer having the highest level of evidence. Finally, a series of proposals are being made to further investigate the use of CAM in clinical trials which offer the greatest prospect of clinical benefit to patients.

Mucosa-associated Lymphoid Tissue Lymphoma of the Trachea in a Patient with Breast Cancer

We herein report the case of a 93-year-old woman with breast cancer on the left side. Preoperative computed tomography of the chest showed irregularities and narrowing of the mid-trachea. Bronchoscopy was performed, and the results of a biopsy supported a diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma. The patient responded to treatment with prednisone alone, with a reduction in the size of the lesion. MALT lymphoma of the trachea is extremely rare, and there are only a few case reports of double cancer, i.e., MALT lymphoma of the trachea and breast cancer.

An Unusual Presentation of Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma as Diffuse Pulmonary Infiltrates with Spontaneous Regression

A 57-year-old woman presented with cough and dyspnea for 2 months. Computed tomography of the chest showed diffuse ground-glass opacities in both lungs. Histologic examination via thoracoscopic lung biopsy revealed atypical lymphoproliferative lesion. Her symptoms and radiologic findings of the chest improved just after lung biopsy without any treatment. Therefore, she was discharged and monitored at an outpatient clinic. Two months later, pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma was confirmed by the detection of API2-MALT1 translocation in fluorescent in situ hybridization analysis. Although the lung lesions resolved spontaneously, she received chemotherapy due to bone marrow involvement in her staging workup. Pulmonary MALT lymphoma is rare. Nodular or consolidative patterns are the most frequent radiologic findings. Although the disease has an indolent growth, it rarely resolves without treatment. We report an unusual case of pulmonary MALT lymphoma with diffuse interstitial abnormalities on image and spontaneous regression on clinical course.

Antibiotic therapy in nongastrointestinal MALT lymphoma: a review of the literature

Although antibiotic therapy has been established as the standard of care in patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma, much less is known about the value of antibiotic therapy in nongastrointestinal (non-GI) MALT lymphomas. A computerized search (Medline) accompanied by a manual search to identify clinical reports on the topic of antibacterial therapy in patients with non-GI MALT lymphomas was performed. The majority of data were available for MALT lymphoma of the ocular adnexa (OAML) including a total of 131 patients in 4 retrospective studies, 3 prospective series (including 81 patients), and 1 case report. Treatment was exclusively targeting Chlamydophila psittaci (CP), using doxycycline in all but 2 studies. The median follow-up for these studies was 25 months, and both CP-positive as well as CP-negative patients responded. Complete remission was achieved in 23 patients (18%), 36 (27%) had a partial remission, 55 (42%) had stable disease, and 8 patients (6%) had progressive disease accounting for an overall response rate of 45%. In the largest study, a better response was suggested in CP-positive patients. By contrast, only scattered reports could be found for other non-GI localizations, allowing no conclusion about the benefit of antibiotic therapy and probably resulting in a publication bias toward positive cases. Based on these results, antibiotic therapy using doxycycline appears to be a reasonable first-line therapy for patients with OAML. Antibiotics, however, remain experimental for the time being in patients with other non-GI MALT lymphomas. Further preclinical studies as well as large-scale therapeutic trials are warranted to define the role of antibiotic therapy in such patients.

Imaging manifestations of autoimmune disease-associated lymphoproliferative disorders of the lung

Lymphoproliferative disorders (LPDs) may involve intrathoracic organs in patients with autoimmune disease, but little is known about the radiologic manifestations of autoimmune disease-associated LPDs (ALPDs) of the lungs. The purpose of our work was to identify the radiologic characteristics of pulmonary involvement in ALPDs. A comprehensive search for PubMed database was conducted with the combination of MeSH words. All articles which had original images or description on radiologic findings were included in this analysis. Also, CT images of eight patients with biopsy-proven lymphoproliferative disorder observed from our institution were added. Overall, 44 cases of ALPD were identified, and consisted of 24 cases of bronchus-associated lymphoid tissue lymphoma (BALToma), eight cases of non-Hodgkin's lymphoma (NHL), six cases of lymphoid interstitial pneumonia (LIP), two cases of nodular lymphoid hyperplasia, two cases of unclassified lymphoproliferative disorder, and one case each of lymphomatoid granulomatosis and hyperblastic BALT. Multiple nodules (n = 14, 32 %) and single mass (n = 8, 18 %) were the predominant radiologic manifestations. The imaging findings conformed to previously described findings of BALToma, NHL, or LIP. Data suggest that BALToma, NHL, and LIP are the predominant ALPDs of the lung, and ALPD generally shared common radiologic features with sporadic LPDs. Familiarity with ALPDs and their imaging findings may enable radiologists or clinicians to include the disease as a potential differential diagnosis and thus, to prompt early biopsy followed by appropriate treatment.

Successful treatment of diffuse large B-cell lymphoma with clarithromycin and prednisolone

We report a case of diffuse large B-cell lymphoma (DLBCL) treated successfully with clarithromycin (CAM) and prednisolone (PSL). A 71-year-old woman presented with fever and cervical pain. DLBCL was diagnosed based on histological results from lymph node biopsy. Cervical pain was thought to be caused by the invasion of lymphoma cells into the cervical vertebrae. She initially received radiotherapy for the cervical lesion. She did not receive conventional chemotherapy because of the risk of recurrent non-tuberculous mycobacteria infection; therefore, she was treated with 20 mg/day PSL and 800 mg/day CAM to induce apoptosis in lymphoma cells. Complete remission was achieved after 6 months. The present findings suggest that CAM and PSL may be effective in some cases of DLBCL.

Immunomodulatory effects of antimicrobial agents. Part I: antibacterial and antiviral agents

Despite impressive therapeutic progresses in the battle against infections, microorganisms are still a threat to mankind. With hundreds of antibacterial molecules, major concerns remain about the emergence of resistant and multidrug-resistant pathogens. On the other hand, the antiviral drug armamentarium is comprised of only a few dozens of compounds which are highly pathogen specific, and resistance is also a concern. According to Arturo Casadevall (Albert Einstein College of Medicine, NY, USA), we have now entered the third era of anti-infective strategy, which intends to favor the interplay between active molecules and the immune system. The first part of this review focuses on the potential immunomodulating properties of anti-infective agents, beginning with antibacterial and antiviral agents.

A case of follicular B-cell lymphoma treated using clarithromycin

We report a case of follicular B-cell lymphoma (FL) treated successfully using clarithromycin (CAM). A 44-year-old man who presented with lymphadenopathy was diagnosed with FL after a histological examination of his biopsy specimens. He was administered chemotherapy with R-CHOP (rituximab, cyclophosphamide, adriamycin, vincristine, and prednisolone) following which stable disease was achieved. However, the subsequent clinical course showed partial remission of FL and stable disease with tumor regrowth, each of which was treated with chemotherapeutic regimens. Since the patient was diagnosed with leukocytopenia, he could not undergo chemotherapy for the third regrowth; hence, he was administered CAM. His lymphadenopathy regressed and the levels of soluble interleukin 2-receptor decreased. This case shows that treatment using CAM may be effective in some cases of FL.

Immunology of fibrotic lung disease: managing infections whilst preventing autoimmunity?

Interstitial lung disease (ILD) and lung fibrosis are characterized by different grades of fibrosis and inflammation. Persistent low-grade inflammation is believed to play a major pathogenic role, leading to an imbalance of cytokines, growth factors, and tissue proteinases. Recruited monocytes and macrophages play a pivotal role through their cytokine expression and possibly differentiation into fibrocytes, pericytes, or myofibroblasts. Atypical bacterial infections can cause ILD, although not usually in the form of usual interstitial pneumonia. On the other hand, bacterial colonization is frequently encountered in patients with chronic fibrotic lung disorders, and patients regularly undergo antibacterial treatment. As demonstrated in patients with diffuse panbronchiolitis and other chronic respiratory disorders, treatment with macrolides can be beneficial. This is partly explained by their antimicrobial effects but, for macrolides, immunomodulatory properties have been identified which might also be beneficial in patients with ILD or lung fibrosis. This article reviews the immunology of lung fibrogenesis and putative implications of macrolides for reinstallation of tolerance.