Helicobacter pylori (H. pylori) molecular signature in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma

Influence of gut microbiota on eye diseases: an overview

The microbiota is a dynamic ecosystem that plays a major role in the host health. Numerous studies have reported that alterations in the intestinal microbiota (dysbiosis) may contribute to the pathogenesis of various common diseases such as diabetes, neuropsychiatric diseases, and cancer. However, emerging findings also suggest the existence of a gut-eye axis, wherein gut dysbiosis may be a crucial factor influencing the onset and progression of multiple ocular diseases, including uveitis, dry eye, macular degeneration, and glaucoma. Currently, supplementation with pre- and probiotics appears is the most feasible and cost-effective approach to restore the gut microbiota to a eubiotic state and prevent eye pathologies. In this review, we discuss the current knowledge on how gut microbiota may be linked to the pathogenesis of common eye diseases, providing therapeutic perspectives for future translational investigations within this promising research field.

Involvement of Helicobacter Pylori in Ocular Adnexa Lymphoma

Helicobacter pylori has been proposed as a possible etiologic factor of ocular adnexa lymphoma (OAL), although with conflicting results. To assess the involvement of H. pylori in OAL, as (1) H. pylori DNA positivity on OAL specimens, and (2) prevalence of H. pylori gastric infection in patients with OAL. A systematic review of studies assessing H. pylori in patients with OAL was conducted by searching electronic databases from their inception to May 2019. Pooled positivity for H. pylori in OAL specimens detected by polymerase chain reaction, and pooled prevalence of H. pylori gastric infection, were calculated with 95% confidence interval (CI). Eleven studies with 308 patients were included. Pooled positivity for H. pylori was 16.8% in all OALs and 22.7% in MALT OAL, with high heterogeneity among studies. Pooled prevalence of H. pylori gastric infection in patients with OAL was 34.7%, with low statistical heterogeneity. In conclusion, H. pylori seems to be involved in a subset of OAL, but the heterogeneity found needs to be investigated in further studies. The prevalence of H. pylori gastric infection in patients with OAL does not seem to differ from that of the general population.

Do epigenetic changes caused by commensal microbiota contribute to development of ocular disease? A review of evidence

There is evidence that genetic polymorphisms and environmentally induced epigenetic changes play an important role in modifying disease risk. The commensal microbiota has the ability to affect the cellular environment throughout the body without requiring direct contact; for example, through the generation of a pro-inflammatory state. In this review, we discuss evidence that dysbiosis in intestinal, pharyngeal, oral, and ocular microbiome can lead to epigenetic reprogramming and inflammation making the host more susceptible to ocular disease such as autoimmune uveitis, age-related macular degeneration, and open angle glaucoma. Several mechanisms of action have been proposed to explain how changes to commensal microbiota contribute to these diseases. This is an evolving field that has potentially significant implications in the management of these conditions especially from a public health perspective.

An Unusual Presentation of Pediatric Conjunctival Mucosa-Associated Lymphoid Tissue Lymphoma

Ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma is uncommon in the pediatric population. Initial misdiagnosis is common and there is lacking consensus regarding the optimal approach to treatment. Herein, we report an atypical presentation of pediatric conjunctival MALT lymphoma and review the presentation and management of this rare condition.

Conjunctival dysbiosis in mucosa-associated lymphoid tissue lymphoma

To investigate the conjunctival microbiota and the association between the development of conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma and dysbiosis, DNA samples were collected from 25 conjunctival MALT lymphoma patients and 25 healthy controls. To compare the microbiota, samples were collected from the following four body locations: conjunctiva, meibomian gland, periocular skin and hand. Extracted DNA was analyzed by 16S rRNA sequences, and libraries were sequenced on an Illumina MiSeq sequencer. The differences in bacteria were characterized by using principal coordinate analysis of metagenomics data, and the differences in bacterial compositions were evaluated by linear discriminant analysis effect size. The conjunctival microbiota of MALT lymphoma patients was compositionally different from that of healthy controls. For the conjunctival MALT lymphoma patients, alterations in the microbial composition were detected, and a remarkable change was detected at the conjunctiva. Detailed analysis showed that a specific population of the microbiota, the genus Delftia, was significantly more abundant in conjunctival MALT lymphoma patients, and the genera Bacteroides and Clostridium were less abundant in the MALT lymphoma patients. A specific microbiota on the ocular surface in conjunctival MALT lymphoma patients was detected, and dysbiosis may play an important role in the pathophysiology of conjunctival MALT lymphoma.

Comprehensive polymerase chain reaction assay for detection of pathogenic DNA in lymphoproliferative disorders of the ocular adnexa

Infectious agents have been identified as a major cause of specific types of human cancers worldwide. Several microorganisms have been identified as potential aggravators of ocular adnexal neoplasms; however, given the rarity of these neoplasms, large epidemiological studies are difficult to coordinate. This study aimed to conduct an exhaustive search for pathogenic DNA in lymphoproliferative disorders (LPD) of the ocular adnexa in a total of 70 patients who were diagnosed with LPD of the ocular adnexa between 2008 and 2013. Specimens were screened for bacterial, viral, fungal, and parasitic DNA by multiplex polymerase chain reaction (PCR) and quantitative real-time PCR. Among cases of conjunctival mucosa-associated lymphoid tissue lymphoma, human herpes virus (HHV)-6, HHV-7, chlamydia, Epstein-Barr virus (EBV) and bacterial 16S ribosomal DNA were detected. In cases of IgG4-related ocular disease, similar pathogens were detected but in a larger number of patients. Our PCR assays detected DNAs of various infectious agents in tumor specimens, especially HHV6, HHV7, and EBV, with different positive rates in various types of LPD. Chronic inflammatory stimulation or activation of oncogenes from these infectious agents might be involved in the pathogenesis of LPD of the ocular adnexa.

Ocular adnexal non-Hodgkin's lymphoma: a review of epidemiology and risk factors

Ocular adnexal non-Hodgkin's lymphoma (NHL), the most common form of ophthalmic NHL, has a unique incidence pattern showing a steady and rapid increase in the past few decades, nearly equal rates among both genders, and predominance among Asians/Pacific Islanders. No major cause for ocular adnexal NHL has been identified, although infectious agents, immune disorders and genetic/epigenetic factors have all been implicated in its etiology. Identifying putative risk factors and biologic mechanisms leading to carcinogenesis in ocular adnexal NHL may enable implementation of effective preventive and/or therapeutic approaches for this malignancy. This article summarizes current knowledge on epidemiology of ocular adnexal NHL and the role of various potential risk factors in its etiology.

Lack of association of conjunctival MALT lymphoma with Chlamydiae or Helicobacter pylori in a cohort of Chinese patients

BACKGROUND

This study was conducted to detect microbial pathogens in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma specimens in an attempt to determine possible associations between conjunctival MALT lymphoma and microbial infections.

MATERIAL/METHODS

Using PCR technique, freshly obtained tumor specimens from 16 cases of conjunctival MALT lymphoma, as confirmed by postoperative pathology, were analyzed for DNA of Chlamydia psittaci (C. psittaci), Chlamydia trachomatis (C. trachomatis), Chlamydia pneumoniae (C. pneumoniae) and Helicobacter pylori (H. pylori). Synthetic C. psittaci, C. trachomatis, C. pneumoniae and H. pylori DNA were used as positive control, and blank plasmid DNA as negative control.

RESULTS

Electrophoresis showed that no bands corresponding to the positive control were observed in the specimens, indicating that no DNA of the 4 microorganisms was detected in the specimens of the 16 cases of conjunctival MALT lymphoma.

CONCLUSIONS

The PCR technique was able to detect the positive control quickly and accurately, but the results of PCR in analyzing the 16 specimens were negative, indicating that there is no association between conjunctival MALT lymphoma and the 4 microorganisms in Chinese patients.

Orbital lymphoma masquerading as panuveitis

PURPOSE

To describe a case of orbital mucosa-associated lymphoid tissue (MALT) lymphoma masquerading as unilateral panuveitis.

METHODS

Retrospective chart review.

RESULTS

A 53-year-old female patient with unilateral vitritis and exudative retinal detachment refractory to immunosuppressive treatment was eventually diagnosed with orbital MALT lymphoma. Following treatment with radiotherapy and rituximab, the patient's intraocular inflammation and retinal detachment resolved.

CONCLUSIONS

Orbital MALT lymphoma can masquerade as refractory unilateral panuveitis with exudative retinal detachment and appears to respond to a combination of radiotherapy and specific B-cell-targeted systemic therapy.

Ocular surface tumors

Tumors of the conjunctiva and cornea comprise a large and varied spectrum of conditions. These tumors are grouped into two major categories of congenital and acquired lesions. The acquired lesions are further subdivided based on origin of the mass into surface epithelial, mucoepidermoid, melanocytic, vascular, fibrous, neural, histiocytic, myxoid, myogenic, lipomatous, lymphoid, leukemic, metastatic and secondary tumors. Ocular surface tumors include a variety of neoplasms originating from squamous epithelium, melanocytic tumors and lymphocytic resident cells of the conjunctival stroma. In this review, we highlight clinical features of these lesions, important diagnostic and investigative tools and standard care of management.

The role of infectious agents in the etiology of ocular adnexal neoplasia

Given the fact that infectious agents contribute to around 18% of human cancers worldwide, it would seem prudent to explore their role in neoplasms of the ocular adnexa: primary malignancies of the conjunctiva, lacrimal glands, eyelids, and orbit. By elucidating the mechanisms by which infectious agents contribute to oncogenesis, the management, treatment, and prevention of these neoplasms may one day parallel what is already in place for cancers such as cervical cancer, hepatocellular carcinoma, gastric mucosa-associated lymphoid tissue lymphoma and gastric adenocarcinoma. Antibiotic treatment and vaccines against infectious agents may herald a future with a curtailed role for traditional therapies of surgery, radiation, and chemotherapy. Unlike other malignancies for which large epidemiological studies are available, analyzing ocular adnexal neoplasms is challenging as they are relatively rare. Additionally, putative infectious agents seemingly display an immense geographic variation that has led to much debate regarding the relative importance of one organism versus another. This review discusses the pathogenetic role of several microorganisms in different ocular adnexal malignancies, including human papilloma virus in conjunctival papilloma and squamous cell carcinoma, human immunodeficiency virus in conjunctival squamous carcinoma, Kaposi sarcoma-associated herpes virus or human herpes simplex virus-8 (KSHV/HHV-8) in conjunctival Kaposi sarcoma, Helicobacter pylori (H. pylori,), Chlamydia, and hepatitis C virus in ocular adnexal mucosa-associated lymphoid tissue lymphomas. Unlike cervical cancer where a single infectious agent, human papilloma virus, is found in greater than 99% of lesions, multiple organisms may play a role in the etiology of certain ocular adnexal neoplasms by acting through similar mechanisms of oncogenesis, including chronic antigenic stimulation and the action of infectious oncogenes. However, similar to other human malignancies, ultimately the role of infectious agents in ocular adnexal neoplasms is most likely as a cofactor to genetic and environmental risk factors.

The Nodosome: Nod1 and Nod2 control bacterial infections and inflammation

Toll-like receptors (TLRs) and the nucleotide-binding domain, leucine rich repeat containing family (or Nod-like receptors, NLRs) are two important families of microbial sensors that are membrane-associated and cytosolic molecules, respectively. The Nod proteins Nod1 and Nod2 are two NLR family members that trigger immune defense in response to bacterial peptidoglycan. Nod proteins fight off bacterial infections by stimulating proinflammatory signaling and cytokine networks and by inducing antimicrobial effectors, such as nitric oxide and antimicrobial peptides. Nod1 is also critically implicated in shaping adaptive immune responses towards bacterial-derived constituents. In addition, recent evidence has demonstrated that mutations in Nod1 and Nod2 are associated with a number of human inflammatory disorders, including Crohn's disease, Blau syndrome, early-onset sarcoidosis, and atopic diseases. Together, Nod1 and Nod2 represent central players in the control of immune responses to bacterial infections and inflammation.

Detection of Chlamydia pneumoniae in a bilateral orbital mucosa-associated lymphoid tissue lymphoma

PURPOSE

To detect Chlamydia pneumoniae (C. pneumoniae) gene in a patient with bilateral orbital musoca-associated lymphoid tissue (MALT) lymphoma.

DESIGN

Interventional case report.

METHODS

A 47-year-old Chinese man with recurrent bilateral orbital masses underwent surgical biopsy. Ophthalmologic and radiographic examinations, routine histology, immunohistochemistry, and molecular analysis for immunoglobulin heavy chain (IgH), bcl-2/IgH gene translocation, and Chlamydia genes were performed.

RESULTS

Pathology revealed orbital MALT lymphoma with B-cell monoclonality. In addition to IgH gene rearrangement, C. pneumoniae DNA was detected in the lymphoma.

CONCLUSIONS

The finding of C. pneumoniae molecular signatures in this case suggests a possible association of Chlamydia and orbital MALT lymphoma. The infection may contribute to the development of the lymphoma.

Detection of Helicobacter pylori and Chlamydia pneumoniae genes in primary orbital lymphoma

PURPOSE

Primary orbital non-Hodgkin's lymphoma is a mucosa-associated lymphoid tissue (MALT)-type extranodal marginal zone lymphoma. Chronic antigen stimulation is implicated as a causative agent in the development of some mature B-cell proliferations; for example, there are associations involving Helicobacter pylori with gastric or conjunctival MALT lymphoma and Chlamydia psittaci with ocular adnexal lymphoma. We examined the molecular signatures of H pylori and Chlamydia in eight orbital lymphomas.

METHODS

Polymerase chain reaction (PCR) was performed on DNA extracted from microdissected lymphoma cells. H pylori was detected with the urease B and vac/m2 primers. A multiplex touchdown enzyme time-release PCR assay designed to simultaneously detect Chlamydia trachomatis, Chlamydia pneumoniae, and C psittaci was performed. Authenticity of the PCR-amplified products was verified by Southern blot hybridization.

RESULTS

H pylori DNA was detected in an orbital lymphoma of a French patient who had positive serum H pylori titer. C pneumoniae, but neither C psittaci nor C trachomatis, DNA was detected in another orbital lymphoma of a Chinese patient from Hong Kong. H pylori, C pneumoniae, and C psittaci genes were not found in the other six orbital lymphomas.

CONCLUSION

H pylori or C pneumoniae genomic fingerprints were detected in two of seven primary orbital MALT lymphomas. These findings provide evidence for a possible involvement of particular infectious microorganisms such as H pylori and Chlamydia in primary orbital lymphoma. These different microorganisms may play similar roles in the etiology of orbital MALT lymphomas from different geographic regions. Antibiotic therapy could be considered for orbital MALT lymphomas associated with positive infection.