Cytokines and T-Lymphocute count in patients in the acute and chronic phases of Bartonella bacilliformis infection in an endemic area in peru: a pilot study

A systematic review on antibiotic therapy of cutaneous bacillary angiomatosis not related to major immunocompromising conditions: from pathogenesis to treatment

BACKGROUND

Cutaneous bacillary angiomatosis (cBA) is a vascular proliferative disorder due to Bartonella spp. that mostly affects people living with HIV (PLWH), transplanted patients and those taking immunosuppressive drugs. Since cBA is mostly related to these major immunocompromising conditions (i.e., T-cell count impairment), it is considered rare in relatively immunocompetent patients and could be underdiagnosed in them. Moreover, antimicrobial treatment in this population has not been previously investigated.

METHODS

We searched the databases PubMed, Google Scholar, Scopus, OpenAIRE and ScienceDirect by screening articles whose title included the keywords "bacillary" AND "angiomatosis" and included case reports about patients not suffering from major immunocompromising conditions to provide insights about antibiotic treatments and their duration.

RESULTS

Twenty-two cases of cBA not related to major immunocompromising conditions were retrieved. Antibiotic treatment duration was shorter in patients with single cBA lesion than in patients with multiple lesions, including in most cases macrolides and tetracyclines.

CONCLUSIONS

cBA is an emerging manifestation of Bartonella spp. infection in people not suffering from major immunocompromising conditions. Until evidence-based guidelines are available, molecular tests together with severity and extension of the disease can be useful to personalize the type of treatment and its duration.

Cytokine Profile Response of Human Peripheral Blood Mononuclear Cells Stimulated by Bartonella bacilliformis

Carrion's disease is a neglected endemic disease found in remote Andean areas. As an overlooked disease, knowledge of innate immune responses to Bartonella bacilliformis, the etiological agent, is scarce. This study aimed to evaluate the cytokine response to B. bacilliformis using in vitro human peripheral blood mononuclear cells (PBMCs) stimulations. PBMCs from naive adults were isolated by gradient centrifugation and cocultured with heat-inactivated (HI) B. bacilliformis at different incubation times (3, 6, 12, 24, and 36 h). Cytokines, chemokines, and growth factors were determined in culture supernatants by multiplex fluorescent bead-based quantitative suspension array technology. During the first 36 h, a proinflammatory response was observed, including tumor necrosis factor-α, interleukin (IL)-1α, IL-1β, interferon-α2, and IL-6, followed by an anti-inflammatory response mainly related to IL-1RA. Moreover, high expression levels of chemokines IL-8, monocyte chemoattractant protein-1α, and macrophage inflammatory protein (MIP)-1β were detected from 3 h poststimulation and MIP-1α was detected at 24 h. Some growth factors, mainly granulocyte macrophage colony-stimulating factor and granulocyte colony-stimulating factor, and in minor concentrations vascular endothelial growth factor, epidermal growth factor, and eotaxin, were also detected. Innate response to HI B. bacilliformis stimulation consists of a rapid and strong proinflammatory response characterized by a wide range of cytokines and chemokines followed by an anti-inflammatory response and increased specific growth factors.

An autochthonous case of cutaneous bacillary angiomatosis not related to major immunosuppression: An emerging or overlooked disease?

Cutaneous bacillary angiomatosis (cBA) is a vascular proliferative disorder due to Bartonella henselae or Bartonella quintana that has been mostly described in people living with HIV. Since cBA is considered to be rare in hosts not affected by major immunosuppression, it could be underdiagnosed in this population. Moreover, antimicrobial treatment of cBA has been poorly validated, thus reporting experiences on this clinical entity is important. We reported a challenging and well-characterized case of an Italian 67-year-old gentleman without a history of major immunocompromizing conditions, although he was affected by conditions that can be associated with impaired immune function. The patient reported herein was diagnosed after a long time since the initiation of symptoms and was successfully treated with combined antibiotic therapy including macrolides and quinolones under the guidance of molecular test results. Physicians should consider cBA as a possible manifestation of Bartonella spp. Infection in patients not suffering from major immunocompromizing conditions. Until evidence-based guidelines are available, molecular tests together with severity and extension of the disease can be useful to personalize the type of treatment and its duration.

Carrion's Disease: the Sound of Silence

Carrion's disease (CD) is a neglected biphasic vector-borne illness related to Bartonella bacilliformis. It is found in the Andean valleys and is transmitted mainly by members of the Lutzomyia genus but also by blood transfusions and from mother to child. The acute phase, Oroya fever, presents severe anemia and fever. The lethality is high in the absence of adequate treatment, despite the organism being susceptible to most antibiotics. Partial immunity is developed after infection by B. bacilliformis, resulting in high numbers of asymptomatic carriers. Following infection there is the chronic phase, Peruvian warts, involving abnormal proliferation of the endothelial cells. Despite potentially being eradicable, CD has been expanded due to human migration and geographical expansion of the vector. Moreover, in vitro studies have demonstrated the risk of the development of antimicrobial resistance. These findings, together with the description of new Bartonella species producing CD-like infections, the presence of undescribed potential vectors in new areas, the lack of adequate diagnostic tools and knowledge of the immunology and bacterial pathogenesis of CD, and poor international visibility, have led to the risk of increasing the potential expansion of resistant strains which will challenge current treatment schemes as well as the possible appearance of CD in areas where it is not endemic.

Immunosuppressive and angiogenic cytokine profile associated with Bartonella bacilliformis infection in post-outbreak and endemic areas of Carrion's disease in Peru

Analysis of immune responses in Bartonella bacilliformis carriers are needed to understand acquisition of immunity to Carrion's disease and may allow identifying biomarkers associated with bacterial infection and disease phases. Serum samples from 144 healthy subjects from 5 villages in the North of Peru collected in 2014 were analyzed. Four villages had a Carrion's disease outbreak in 2013, and the other is a traditionally endemic area. Thirty cytokines, chemokines and growth factors were determined in sera by fluorescent bead-based quantitative suspension array technology, and analyzed in relation to available data on bacteremia quantified by RT-PCR, and IgM and IgG levels measured by ELISA against B. bacilliformis lysates. The presence of bacteremia was associated with low concentrations of HGF (p = 0.005), IL-15 (p = 0.002), IL-6 (p = 0.05), IP-10 (p = 0.008), MIG (p = 0.03) and MIP-1α (p = 0.03). In multi-marker analysis, the same and further TH1-related and pro-inflammatory biomarkers were inversely associated with infection, whereas angiogenic chemokines and IL-10 were positively associated. Only EGF and eotaxin showed a moderate positive correlation with bacteremia. IgM seropositivity, which reflects a recent acute infection, was associated with lower levels of eotaxin (p = 0.05), IL-6 (p = 0.001), and VEGF (p = 0.03). Only GM-CSF and IL-10 concentrations were positively associated with higher levels of IgM (p = 0.01 and p = 0.007). Additionally, IgG seropositivity and levels were associated with high levels of angiogenic markers VEGF (p = 0.047) and eotaxin (p = 0.006), respectively. Our findings suggest that B. bacilliformis infection causes immunosuppression, led in part by overproduction of IL-10. This immunosuppression probably contributes to the chronicity of asymptomatic infections favoring B. bacilliformis persistence in the host, allowing the subsequent transmission to the vector. In addition, angiogenic markers associated with bacteremia and IgG levels may be related to the induction of endothelial cell proliferation in cutaneous lesions during chronic infections, being possible candidate biomarkers of asymptomatic infections.

Infection-induced anaemia: a cross-sectional study of 14,636 German travellers aged 20-49 years

BACKGROUND

Anaemia is a frequently diagnosed condition which can develop as a consequence of numerous factors, including infectious diseases (IDs). Travelling, especially in sub-/tropical regions, leads to an elevated risk of contracting IDs. The aim of our study was to assess the epidemiological significance of IDs in inducing anaemia among a large cohort of returned travellers.

METHODS

This was a cross-sectional study in which data on 17,009 returned travellers aged 20-49 years who consulted the travel medicine clinic of the University of Munich between 1999 and 2011 were retrieved and analysed.

RESULTS

Of the returned travellers, 8.3 % (6.0 % of males/10.4 % of females) were diagnosed with anaemia. The prevalence of anaemia was significantly elevated among patients of African (21.4/28.3 %) and Asian (11.6/15.7 %) origin. When the study population was restricted to the 14,636 travellers of German origin, 7.1 % of the returned travellers (4.6/9.6 %) were diagnosed with anaemia. The prevalence was significantly elevated among patients who travelled for >30 days (5.7 of males/10.6 % of females) and for male travellers visiting friends and relatives (7.7 %). However, these correlations were confounded by malaria. The prevalence of anaemia was significantly elevated only among returned travellers diagnosed with malaria (36.1 of males/26.9 % of females) and with symptomatic intestinal Entamoeba histolytica infections (30.0/33.3 %).

CONCLUSION

Following the exclusion of confounding by malaria from the statistical analysis, the prevalence of anaemia was found to be significantly elevated among patients of African and Asian origin, and among patients of German origin who had travelled for >30 days, it could be mainly attributable to chronic, long-lasting causes. Although more than 550 travel-associated IDs were assessed in our study, only symptomatic intestinal Entamoeba histolytica infections and, to an even larger extent, malaria were determined to be of epidemiological significance for inducing anaemia among travellers.

Intruders below the radar: molecular pathogenesis of Bartonella spp

Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. Infections with Bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. Upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted to involve the manipulation of nucleated host cells, e.g., in the microvasculature. Consistently, in vitro research showed that Bartonella harbors an ample arsenal of virulence factors to modulate the response of such cells, gain entrance, and establish an intracellular niche. Subsequently, the bacteria are seeded into the bloodstream where they invade erythrocytes and give rise to a typically asymptomatic intraerythrocytic bacteremia. While this course of infection is characteristic for natural hosts, zoonotic infections or the infection of immunocompromised patients may alter the path of Bartonella and result in considerable morbidity. In this review we compile current knowledge on the molecular processes underlying both the infection strategy and pathogenesis of Bartonella and discuss their connection to the clinical presentation of human patients, which ranges from minor complaints to life-threatening disease.

Bartonella infection in immunocompromised hosts: immunology of vascular infection and vasoproliferation

Most infections by genus Bartonella in immunocompromised patients are caused by B. henselae and B. quintana. Unlike immunocompetent hosts who usually develop milder diseases such as cat scratch disease and trench fever, immunocompromised patients, including those living with HIV/AIDS and posttransplant patients, are more likely to develop different and severe life-threatening disease. This paper will discuss Bartonella's manifestations in immunosuppressed patients and will examine Bartonella's interaction with the immune system including its mechanisms of establishing infection and immune escape. Gaps in current understanding of the immunology of Bartonella infection in immunocompromised hosts will be highlighted.