Disseminated Mycobacterium marinum infection in a patient with rheumatoid arthritis receiving infliximab therapy

Host-directed therapy to combat mycobacterial infections

Upon infection, mycobacteria, such as Mycobacterium tuberculosis (Mtb) and nontuberculous mycobacteria (NTM), are recognized by host innate immune cells, triggering a series of intracellular processes that promote mycobacterial killing. Mycobacteria, however, have developed multiple counter‐strategies to persist and survive inside host cells. By manipulating host effector mechanisms, including phagosome maturation, vacuolar escape, autophagy, antigen presentation, and metabolic pathways, pathogenic mycobacteria are able to establish long‐lasting infection. Counteracting these mycobacteria‐induced host modifying mechanisms can be accomplished by host‐directed therapeutic (HDT) strategies. HDTs offer several major advantages compared to conventional antibiotics: (a) HDTs can be effective against both drug‐resistant and drug‐susceptible bacteria, as well as potentially dormant mycobacteria; (b) HDTs are less likely to induce bacterial drug resistance; and (c) HDTs could synergize with, or shorten antibiotic treatment by targeting different pathways. In this review, we will explore host‐pathogen interactions that have been identified for Mtb for which potential HDTs impacting both innate and adaptive immunity are available, and outline those worthy of future research. We will also discuss possibilities to target NTM infection by HDT, although current knowledge regarding host‐pathogen interactions for NTM is limited compared to Mtb. Finally, we speculate that combinatorial HDT strategies can potentially synergize to achieve optimal mycobacterial host immune control.

Flare or foe? - Mycobacterium marinum infection mimicking rheumatoid arthritis tenosynovitis: case report and literature review

Background

Rheumatoid arthritis is the most common type of inflammatory arthritis affecting about 1% of the population. With the advent of disease-modifying anti-rheumatic drugs the disease can be well controlled in many cases. Patients, however, are prone to developing infectious complications. In rare cases, these can mimic a flare of the underlying itself.

Case presentation

We report the case of a 45-year-old female patient with a history of seronegative rheumatoid arthritis (RA) who presented with swelling and tenderness of the third metacarpophalangeal joint of the right hand. A flare of her RA was suspected based on clinical and ultrasound findings which showed a tenosynovitis with intense power doppler activity. Her steroid dose was increased but the clinical response to glucocorticoid therapy was very limited. Subsequently, she developed skin manifestations of ‘swimmer’s granuloma’ over the next 2 weeks after first presentation. Finally, a diagnosis of a Mycobacterium marinum infection was established with the help of tissue biopsy and culture, and the patient received appropriate antibiotic treatment with the desired effect.

Conclusions

This case highlights the difficulty of distinction between infection and inflammation in patients with joint swelling and pain, especially in the age of disease-modifying drugs (DMARDs) and the concomitant risk of atypical infections. A review of the literature identified eight additional published cases, which suggests that Mycobacterium marinum infection is a rare but recognized complication of DMARD therapy. It can mimic a flare of the underlying arthritis potentially leading to diagnostic delays, and requires differential diagnostic methods to identify the pathogen and pave the way for appropriate treatment.

Clinical, Dermatoscopical and Laboratory Essentials of Fish Tank Granuloma

In immunocompetent individuals Mycobacterium marinum (M. marinum) infection usually presents with localized skin lesions, better known as “swimming pool granuloma” or “fish tank granuloma” (FTG). When establishing the diagnosis of FTG, doctors encounter several problems in the clinical practice: granulomas are detected in less than two thirds of biopsies and acid-fast bacilli are identified only in a minority of cases. Majority of disseminated and aggressive FTG forms are unrecognized at the beginning, and occur in immunosuppressed patients, including organ transplant patients. Functional impairment or even amputation of the extremity, visceral involvement and lethal outcome have been reported. Although more than one thousand cases of FTG have been reported worldwide, dermatoscopy of FTG, as a diagnostic aid, has not been reported yet. Presenting the case of FTG of recent onset where, guided by dermatoscopy, microorganisms were isolated and identified from the biopsy material, we summarize the essentials of clinical and laboratory diagnostics of M. marinum infection.

Disseminated Invasive Mycobacterium marinum Infection Involving the Lung of a Patient with Diabetes Mellitus

Mycobacterium marinum infection in humans occurs mainly as a granulomatous infection after exposure of traumatized skin to contaminated water. It is usually confined to the skin and soft tissue. Disseminated disease involving other organs rarely occurs in immunocompetent patients. Here, we report a case of disseminated M. marinum infection involving not only the cutaneous tissue, but also the lung of a male patient with uncontrolled diabetes and a previous history of steroid injection who was employed by a deep-water fishery.

Mycobacterium marinum

Mycobacterium marinum is a well-known pathogenic mycobacterium for skin and soft tissue infections and is associated with fishes and water. Among nontuberculous mycobacteria (NTM), it is the leading cause of extrarespiratory human infections worldwide. In addition, there is a specific scientific interest in M. marinum because of its genetic relatedness to Mycobacterium tuberculosis and because experimental infection of M. marinum in fishes mimics tuberculosis pathogenesis. Microbiological characteristics include the fact that it grows in 7 to 14 days with photochromogenic colonies and is difficult to differentiate from Mycobacterium ulcerans and other mycolactone-producing NTM on a molecular basis. The diagnosis is highly suspected by the mode of infection, which is related to the hobby of fishkeeping, professional handling of marine shells, or swimming in nonchlorinated pools. Clinics distinguished skin and soft tissue lesions (typically sporotrichoid or subacute hand nodules) and lesions disseminated to joint and bone, often related with the local use of corticosteroids. In clinical microbiology, microscopy and culture are often negative because growth requires low temperature (30°C) and several weeks to succeed in primary cultivation. The treatment is not standardized, and no randomized control trials have been done. Therapy is a combination of surgery and antimicrobial agents such as cyclines and rifampin, with successful outcome in most of the skin diseases but less frequently in deep tissue infections. Prevention can be useful with hand protection recommendations for professionals and all persons manipulating fishes or fish tank water and use of alcohol disinfection after contact.

Cellular immune responses in HIV-negative immunodeficiency with anti-interferon-γ antibodies and opportunistic intracellular microorganisms

Background

Cell-mediated immunity plays a crucial role in resistance to intracellular infection. We previously reported antibodies against interferon-gamma (IFN-γ) in HIV− negative (HIV−) patients with acquired immunodeficiency presenting with repeated episodes of disseminated infection caused by uncommon opportunistic intracellular fungal, bacterial, and viral pathogens. This follow-up study aimed to investigate cellular immune responses in these unusual patients.

Methods

Twenty HIV− patients presenting with ≥2 episodes of culture- or histopathologic-proven opportunistic infections were enrolled along with age- and sex-matched controls comprised of 20 HIV+ patients plus 20 healthy adults. Monocyte phenotyping and intracellular cytokine production were determined by staining with specific antibodies followed by flow cytometry. Anti-interferon-γ antibodies were measured by enzyme-linked immunosorbent assay, and inducible nitric oxide synthase by reverse-transcription polymerase chain reaction.

Results

There were no differences among cases, HIV+, and healthy controls in the percentage of monocytes, or CD68 and HLA-DR expression on their surfaces. FcR1 (CD119) expression on monocytes was significantly higher in cases than in HIV+ (p<0.05) and healthy controls (p<0.01), suggesting the presence of activated monocytes in the circulation. Interleukin (IL)-2 and tumor necrosis factor (TNF)-α production in CD4 cells were significantly lower in cases than in healthy controls (p<0.01 and p<0.001, respectively). CD8 production of TNF-α among cases was significantly lower than that of healthy controls (p<0.05).

Conclusion

Immunodeficiency in HIV− individuals with repeated infections with intracellular pathogens may be associated with one or more of the abnormal immune responses reflected by the reduced production of both IL-2 by CD4 T cells and TNF-α by CD4 T cells and CD8 T cells, as well as presence of anti-IFN-γ antibody, as previously reported.

Radiological features and therapeutic responses of pulmonary nontuberculous mycobacterial disease in rheumatoid arthritis patients receiving biological agents: a retrospective multicenter study in Japan

Objective

This study was performed to evaluate the radiological features of and therapeutic responses to pulmonary disease caused by nontuberculous mycobacteria (NTM) in the setting of biological therapy for rheumatoid arthritis (RA).

Methods

We conducted a retrospective chart review of 13 patients from multiple centers who had developed pulmonary NTM disease during biological therapy for RA, including infliximab, etanercept, adalimumab, and tocilizumab.

Results

Most cases were asymptomatic or resulted in only common-cold-like symptoms. Abnormalities in computed tomography (CT) imaging were protean and frequently overlapped. The most predominant pattern was nodular/bronchiectatic disease (six cases), followed by alveolar infiltrate (three cases), cavitary disease (two cases), and pulmonary nodules (two cases). In most cases, pulmonary NTM disease had spread from a preexisting lesion; in particular, bronchial/bronchiolar abnormalities. In three cases, one or more nodular lesions with or without calcification were a focus of disease. Following the discontinuation of biological agents, most patients responded to anti-NTM therapy. Two patients showed no exacerbation in the absence of any anti-NTM therapy. In one patient, restarting tocilizumab therapy while continuing to receive adequate anti-NTM therapy produced a favorable outcome. In two other patients with a previous history of pulmonary NTM disease, introducing biological therapy led to recurrence, but anti-NTM therapy was effective in these patients.

Conclusion

CT abnormalities of pulmonary NTM disease in RA patients receiving biological therapy were variable, but were not unique to this clinical setting. NTM disease can spread from preexisting structural abnormalities, even if they are minute. Contrary to our expectations, the therapeutic outcomes of pulmonary NTM disease were favorable in these patients.

Is continuation of anti-tumor necrosis factor-α therapy a safe option for patients who have developed pulmonary mycobacterial infection? : Case presentation and literature review

Continuation of anti-tumor necrosis factor-α (TNFα) therapy generally has not been recommended for patients who have developed nontuberculous mycobacterial (NTM) diseases; in daily practice, however, we often encounter patients with refractory rheumatoid arthritis (RA) who experience uncontrollable flares following withdrawal of anti-TNFα agents. Here, we report a case of pulmonary NTM disease caused by Mycobacterium intracellulare occurring in a patient with refractory RA undergoing etanercept therapy. Since there was the concern of an exacerbation of RA symptoms, etanercept was continued during anti-NTM therapy. The patient's pulmonary symptoms and radiological abnormalities were found to have markedly improved in a relatively short time period after beginning the anti-NTM therapy. Additionally, her RA symptoms were adequately controlled without the occurrence of any unexpected adverse events. The continuation of etanercept therapy may be a safe option during anti-NTM therapy if patients' underlying diseases would otherwise be difficult to control. Strictly supervised anti-NTM therapy and patients' informed consent are mandatory. We review the medical literature on NTM disease associated with anti-TNFα therapy for rheumatic diseases and discuss the safety of simultaneous use of anti-TNFα agents in patients during anti-NTM therapy.

Soft tissue infections caused by marine bacterial pathogens: epidemiology, diagnosis, and management

Skin and soft tissue infections (SSTIs) are one of the most common infection syndromes and may be caused by a large number of microorganisms. Some principles of aquatic injuries are different than those of land-based trauma. Wounds sustained in marine environment are exposed to a milieu of bacteria rarely encountered in different settings. These include Vibrio spp., Aeromonas spp., Shewanella spp., Erysipelothrix rhusiopathiae, Mycobacterium marinum, Streptococcus iniae, and other microbes. Failure to recognize and treat these uncommon pathogens in a timely manner may result in significant morbidity or death. These infections are frequently contracted as a result of recreational swimming, fishing injuries, or seafood handling. The spectrum of manifestations is wide, varying from cases of mild cellulitis, to severe life-threatening necrotizing fasciitis requiring radical surgery, to sepsis and death. This review will focus on the epidemiology, clinical manifestations, and treatment of SSTIs caused by the most important marine pathogens.

Disseminated Mycobacterium marinum infection in a hematopoietic stem cell transplant recipient

Mycobacterium marinum is a photochromogenic mycobacterium that is ubiquitous in the aquatic environment. In the general population, exposure to aquaria is the most common cause of M. marinum infection. Known as "swimmer's granuloma" or "fish tank granuloma," M. marinum is an occupational hazard for aquarium cleaners and fishermen. There are several reports in the literature of M. marinum infection in immunocompromised hosts, including those with solid organ transplants, but none in patients who have received stem cell transplants (SCTs). To our knowledge, this is a first report of disseminated M. marinum infection in an SCT recipient who continued to develop new skin lesions even after months of targeted therapy. The implications are that elderly patients who receive T-cell-depleted SCTs may be at prolonged risk for pathogens dependent on cellular immunity, and the presentation of illness with such pathogens may be more severe and widely disseminated than might otherwise be expected.

Mycobacterium marinum infection complicated by anti-tumour necrosis factor therapy

Mycobacteria other than tuberculosis infections in patients taking various tumour necrosis factor (TNF)-α inhibitors have been reported in the literature. We describe sporotrichoid spread of Mycobacterium marinum in a man with Crohn's disease treated with infliximab. After starting ethambutol and rifampicin and discontinuing infliximab, a worsening appeared. M. marinum infection may have a potential local spread and systemic dissemination in patients treated with TNF-α inhibitors.

[Cutaneous infection due to Mycobacterium chelonae during anti-TNF therapy]

BACKGROUND

Mycobacterium chelonae is a ubiquitous, rapidly growing, opportunistic, non-tuberculous mycobacterium that can cause skin and bone tissue infections. We report a case of cutaneous infection due to M. chelonae following anti-TNF therapy.

CASE REPORT

A 70-year-old woman with a medical history of rheumatoid arthritis was admitted for several purple nodular cutaneous lesions on her right leg evolving for 2 months. At admission, she was on prednisone, methotrexate and adalimumab for her rheumatoid arthritis. Skin lesions appeared 5 days before etanercept, which was taken for 5 months before being discontinued for adalimumab. Both the histopathological examination and bacterial culture of involved skin showed the presence of M. chelonae. Adalimumab was immediately discontinued and a combination of amoxicillin-clavulanic acid and tigecyclin was started.

DISCUSSION

TNF-alpha plays a pivotal role in immune reaction to intracellular pathogens. Very few cases of cutaneous infection involving M. chelonae in association with an anti-TNF-alpha therapy have been reported in the literature. To our knowledge, this is the first case occurring during treatment with etanercept and symptoms worsened with the introduction of adalimumab. In addition, this case underlines the difficulties of effectively treating this mycobacterium.