Clinical implications of the immunomodulatory effects of macrolides

Immunomodulatory role of azithromycin: Potential applications to radiation-induced lung injury

Radiation-induced lung injury (RILI) including radiation-induced pneumonitis and radiation-induced pulmonary fibrosis is a side effect of radiotherapy for thoracic tumors. Azithromycin is a macrolide with immunomodulatory properties and anti-inflammatory effects. The immunopathology of RILI that results from irradiation is robust pro-inflammatory responses with high levels of chemokine and cytokine expression. In some patients, pulmonary interstitial fibrosis results usually due to an overactive immune response. Growing clinical studies recently proposed that the anti-inflammatory and immunomodulatory effects of azithromycin may benefit patients with acute lung injury. It has been shown potential benefits for patients with RILI in preclinical studies. Azithromycin has a variety of immunomodulatory effect to improve the process of disease, including inhibition of pro-inflammatory cytokines production participating in the regulatory function of macrophages, changes in autophagy, and inhibition of neutrophil influx. We review the published evidence of mechanisms of azithromycin, and focus on the potential effect of azithromycin on the immune response to RILI.

Effect of spiramycin versus aminoguanidine and their combined use in experimental toxoplasmosis

Toxoplasmosis is one of the widest spread parasitic infections which is caused by Toxoplasma gondii protozoon. Many experimental studies have evaluated the effect of aminoguanidine upon parasitic load and inflammatory process. However, few reports have illustrated the impact of combining aminoguanidine with spiramycin in the treatment of toxoplasmosis. Therefore, our study aimed to explore the possible effects of spiramycin used alone and combined with aminoguanidine against the avirulent (ME49) Toxoplasma gondii strain in experimental toxoplasmosis. Fifty-five Swiss albino mice were included in the study and were divided into five groups: (GI): non-infected control group; (GII): infected untreated control group; (GIII): infected- spiramycin treated group; (GIV): infected-aminoguanidine treated group; (GV): infected and received combination of spiramycin and aminoguanidine. Obtained results exhibited a significant increase in brain cysts numbers in aminoguanidine treated groups compared to infected untreated control groups. Histopathological studies denoted that combination between spiramycin and aminoguanidine improved the pathological features only in liver and heart tissues of the studied groups. Moreover, it was noticed that spiramycin administered alone had no effect on nitric oxide expression, whereas its combination with aminoguanidine had an inhibitory effect on inducible nitric oxide synthase enzyme in brain, liver and heart tissues of different study groups. In conclusion, the combination of spiramycin and aminoguanidine significantly reduced the parasitic burden, yet, it failed to resolve the pathological sequels in brain tissues of Toxoplasma gondii infected mice.

Clarithromycin Inhibits Pneumolysin Production via Downregulation of ply Gene Transcription despite Autolysis Activation

Streptococcus pneumoniae, the most common cause of community-acquired pneumonia, causes severe invasive infections, including meningitis and bacteremia. The widespread use of macrolides has been reported to increase the prevalence of macrolide-resistant S. pneumoniae (MRSP), thereby leading to treatment failure in patients with pneumococcal pneumonia. However, previous studies have demonstrated that several macrolides and lincosamides have beneficial effects on MRSP infection since they inhibit the production and release of pneumolysin, a pneumococcal pore-forming toxin released during autolysis. In this regard, we previously demonstrated that the mechanisms underlying the inhibition of pneumolysin release by erythromycin involved both the transcriptional downregulation of the gene encoding pneumolysin and the impairment of autolysis in MRSP. Here, using a cell supernatant of the culture, we have shown that clarithromycin inhibits pneumolysin release in MRSP. However, contrary to previous observations in erythromycin-treated MRSP, clarithromycin upregulated the transcription of the pneumococcal autolysis-related lytA gene and enhanced autolysis, leading to the leakage of pneumococcal DNA. On the other hand, compared to erythromycin, clarithromycin significantly downregulated the gene encoding pneumolysin. In a mouse model of MRSP pneumonia, the administration of both clarithromycin and erythromycin significantly decreased the pneumolysin protein level in bronchoalveolar lavage fluid and improved lung injury and arterial oxygen saturation without affecting bacterial load. Collectively, these in vitro and in vivo data reinforce the benefits of macrolides on the clinical outcomes of patients with pneumococcal pneumonia.

IMPORTANCE Pneumolysin is a potent intracellular toxin possessing multiple functions that augment pneumococcal virulence. For over 10 years, sub-MICs of macrolides, including clarithromycin, have been recognized to decrease pneumolysin production and release from pneumococcal cells. However, this study indicates that macrolides significantly slowed pneumococcal growth, which may be related to decreased pneumolysin release recorded by previous studies. In this study, we demonstrated that clarithromycin decreases pneumolysin production through downregulation of ply gene transcription, regardless of its inhibitory activity against bacterial growth. Additionally, administration of clarithromycin resulted in the amelioration of lung injury in a mouse model of pneumonia induced by macrolide-resistant pneumococci. Therefore, therapeutic targeting of pneumolysin offers a good strategy to treat pneumococcal pneumonia.

Nonantimicrobial Actions of Macrolides: Overview and Perspectives for Future Development

Macrolides are among the most widely prescribed broad spectrum antibacterials, particularly for respiratory infections. It is now recognized that these drugs, in particular azithromycin, also exert time-dependent immunomodulatory actions that contribute to their therapeutic benefit in both infectious and other chronic inflammatory diseases. Their increased chronic use in airway inflammation and, more recently, of azithromycin in COVID-19, however, has led to a rise in bacterial resistance. An additional crucial aspect of chronic airway inflammation, such as chronic obstructive pulmonary disease, as well as other inflammatory disorders, is the loss of epithelial barrier protection against pathogens and pollutants. In recent years, azithromycin has been shown with time to enhance the barrier properties of airway epithelial cells, an action that makes an important contribution to its therapeutic efficacy. In this article, we review the background and evidence for various immunomodulatory and time-dependent actions of macrolides on inflammatory processes and on the epithelium and highlight novel nonantibacterial macrolides that are being studied for immunomodulatory and barrier-strengthening properties to circumvent the risk of bacterial resistance that occurs with macrolide antibacterials. We also briefly review the clinical effects of macrolides in respiratory and other inflammatory diseases associated with epithelial injury and propose that the beneficial epithelial effects of nonantibacterial azithromycin derivatives in chronic inflammation, even given prophylactically, are likely to gain increasing attention in the future. SIGNIFICANCE STATEMENT: Based on its immunomodulatory properties and ability to enhance the protective role of the lung epithelium against pathogens, azithromycin has proven superior to other macrolides in treating chronic respiratory inflammation. A nonantibiotic azithromycin derivative is likely to offer prophylactic benefits against inflammation and epithelial damage of differing causes while preserving the use of macrolides as antibiotics.

Azithromycin for the Treatment of Chronic Cough in Idiopathic Pulmonary Fibrosis: A Randomized Controlled Cross-over Trial

RATIONALE

Patients with idiopathic pulmonary fibrosis (IPF) frequently suffer from difficult to treat chronic cough, which substantially affects their quality of life. Azithromycin has been demonstrated to relieve chronic cough in some populations, however this has not been investigated in IPF.

OBJECTIVES

To determine the safety and efficacy of azithromycin for the treatment of chronic cough in patients with IPF.

METHODS

In a double-blind randomized controlled cross-over trial, patients with IPF underwent two 12-week intervention periods (azithromycin 500mg or placebo 3 times per week). The primary outcome was change in cough-related quality of life measured by the Leicester cough questionnaire (LCQ). Secondary outcomes included cough severity measured using Visual Analog Scale (VAS), health-related quality of life assessed by the St. George's Respiratory Questionnaire (SGRQ), and objective cough frequency using audiovisual readings from 24h respiratory polygraphy.

RESULTS

25 patients were randomized (23 men, 2 women), 20 patients completed the study. Mean (standard deviation, SD) age was 67 (8) years, mean (SD) forced vital capacity (FVC) was 65 (16) %-predicted, and diffusion capacity (DLCO) 43 (16) %-predicted. Mean (SD) baseline LCQ was 11.7 (3.7) and 11.3 (3.3) for the azithromycin and the placebo period, respectively, and the corresponding mean (SD) cough VAS 5.6 (2.3) and 5.8 (2.1). There was no significant change in LCQ and VAS with azithromycin or placebo. Similarly, there was no significant difference in change in polygraphy measured cough frequency between the azithromycin and placebo periods. Gastrointestinal adverse effects were more frequent with azithromycin than with placebo (diarrhea 43% vs 5%, p=0.03).

CONCLUSIONS

This randomized controlled trial does not support the use of low dose azithromycin for chronic cough in patients with IPF. Clinical trial registered with ClinicalTrials.gov (NCT02173145).

Erythromycin inhibits neutrophilic inflammation and mucosal disease by upregulating DEL-1

Macrolide antibiotics exert antiinflammatory effects; however, little is known regarding their immunomodulatory mechanisms. In this study, using 2 distinct mouse models of mucosal inflammatory disease (LPS-induced acute lung injury and ligature-induced periodontitis), we demonstrated that the antiinflammatory action of erythromycin (ERM) is mediated through upregulation of the secreted homeostatic protein developmental endothelial locus-1 (DEL-1). Consistent with the anti-neutrophil recruitment action of endothelial cell-derived DEL-1, ERM inhibited neutrophil infiltration in the lungs and the periodontium in a DEL-1-dependent manner. Whereas ERM (but not other antibiotics, such as josamycin and penicillin) protected against lethal pulmonary inflammation and inflammatory periodontal bone loss, these protective effects of ERM were abolished in Del1-deficient mice. By interacting with the growth hormone secretagogue receptor and activating JAK2 in human lung microvascular endothelial cells, ERM induced DEL-1 transcription that was mediated by MAPK p38 and was CCAAT/enhancer binding protein-β dependent. Moreover, ERM reversed IL-17-induced inhibition of DEL-1 transcription, in a manner that was dependent not only on JAK2 but also on PI3K/AKT signaling. Because DEL-1 levels are severely reduced in inflammatory conditions and with aging, the ability of ERM to upregulate DEL-1 may lead to a novel approach for the treatment of inflammatory and aging-related diseases.

Low-dose macrolides for treating pediatric rhinosinusitis: A retrospective study and literature review

The effects of low-dose macrolide (LDM) therapy on pediatric chronic rhinosinusitis (CRS) patients are unknown. This study aimed to assess the effectiveness of LDM for treating pediatric refractory CRS. A retrospective study was conducted by a medical chart review. Pediatric CRS patients (age <15 years) who received LDM after standard medical treatments failure between 2013 and 2019 were identified. The LDM treatments with any macrolide agents, doses, and regimens were included. Any co-interventions were allowed. Duration of the LDM therapy was ≥6 weeks. Outcomes were the total nasal symptoms by the visual analogue scale (TNS), presence of individual symptoms, physician-assessment nasal discharge and adverse events. Six patients (67% male, mean age 7±3.4 years) were assessed. All patients had failed to intranasal steroids and nasal saline irrigation but continued. The addition of LDM significantly improved TNS (mean difference ± standard deviation 5.83 ± 1.33; 95% confidence interval 4.44-7.23, p< 0.001). At the end of treatment, the numbers of patients with individual symptoms were decreased: nasal obstruction (100%-67%), rhinorrhea (83%-50%), hyposmia (50%-0%), cough (100%-33%), and physician-assessment thick mucoid discharge (33%-0%). No patients had facial pain. One patient reported mild tolerable nausea. Preliminary findings of this study showed some beneficial effects of LDM added to intranasal steroids and nasal saline irrigation in pediatric CRS after standard treatments failure. The beneficial effects included the improvements of the TNS and individual nasal symptoms and decrease in thick mucoid discharge.

The Nonantibiotic Macrolide EM900 Attenuates House Dust Mite-Induced Airway Inflammation in a Mouse Model of Obesity-Associated Asthma

INTRODUCTION

Obesity-associated asthma is characterized by type 2-low airway inflammation. We previously showed that EM900, which is a 12-membered nonantibiotic macrolide, suppressed airway inflammation in a mouse model of asthma exacerbation. The aim of this study was to clarify the effects of EM900 in obesity-associated asthma.

METHODS

BALB/c mice were fed a low-fat diet (LFD) or high-fat diet (HFD). Mice were intranasally sensitized and challenged with house dust mites (HDMs) and were orally administered EM900. Airway inflammation was assessed using inflammatory cells in bronchoalveolar lavage (BALF). Cytokines were examined by ELISA in lung tissues. Lung interstitial macrophages (CD45+, CD11clow, CD11b+, and Ly6c-) were counted by flow cytometry in single cells from lung tissues.

RESULTS

Body weight increased significantly in the HFD compared with the LFD group. The total cell count and numbers of neutrophils and eosinophils in BALF were significantly suppressed by EM900 administration in the HFD-HDM group. The levels of interleukin (IL)-17A were increased in the HFD-HDM group compared with the LFD-HDM group, although the difference did not reach statistical significance. The levels of IL-17A, macrophage inflammatory protein 2, IL-1β, IL-5, and regulated on activation, normal T cell expressed and secreted in lung tissue were significantly suppressed by EM900 administration in the HFD-HDM group. The percentage of interstitial macrophages in lungs was significantly decreased by EM900 administration in the HFD-HDM group.

CONCLUSION

Both type 2 and type 2-low airway inflammation were attenuated by EM900 in this obesity-associated asthma model. These results show that EM900 might be a candidate agent for the treatment of obesity-associated asthma.

Inhibition of Pro-Inflammatory Cytokines by Metabolites of Streptomycetes-A Potential Alternative to Current Anti-Inflammatory Drugs?

Current treatment of chronic diseases includes, among others, application of cytokines, monoclonal antibodies, cellular therapies, and immunostimulants. As all the underlying mechanisms of a particular diseases are not always fully clarified, treatment can be inefficient and associated with various, sometimes serious, side effects. Small secondary metabolites produced by various microbes represent an attractive alternative as future anti-inflammatory drug leads. Compared to current drugs, they are cheaper, can often be administered orally, but still can keep a high target-specificity. Some compounds produced by actinomycetes or fungi have already been used as immunomodulators—tacrolimus, sirolimus, and cyclosporine. This work documents strong anti-inflammatory features of another secondary metabolite of streptomycetes—manumycin-type polyketides. We compared the effect of four related compounds: manumycin A, manumycin B, asukamycin, and colabomycin E on activation and survival of human monocyte/macrophage cell line THP-1. The anti-cancer effect of manucycine A has been demonstrated; the immunomodulatory capacities of manumycin A are obvious when using micromolar concentrations. The application of all four compounds in 0.25–5 μM concentrations leads to efficient, concentration-dependent inhibition of IL-1β and TNF expression in THP-1 upon LPS stimulation, while the three latter compounds show a significantly lower pro-apoptotic effect than manumycin A. We have demonstrated the anti-inflammatory capacity of selected manumycin-type polyketides.

Clostridioides difficile-Associated Antibiotics Alter Human Mucosal Barrier Functions by Microbiome-Independent Mechanisms

A clinically relevant risk factor for Clostridioides difficile-associated disease (CDAD) is recent antibiotic treatment. Although broad-spectrum antibiotics have been shown to disrupt the structure of the gut microbiota, some antibiotics appear to increase CDAD risk without being highly active against intestinal anaerobes, suggesting direct nonantimicrobial effects. We examined cell biological effects of antibiotic exposure that may be involved in bacterial pathogenesis using an in vitro germfree human colon epithelial culture model. We found a marked loss of mucosal barrier and immune function with exposure to the CDAD-associated antibiotics clindamycin and ciprofloxacin, distinct from the results of pretreatment with an antibiotic unassociated with CDAD, tigecycline, which did not reduce innate immune or mucosal barrier functions. Importantly, pretreatment with CDAD-associated antibiotics sensitized mucosal barriers to C. difficile toxin activity in primary cell-derived enteroid monolayers. These data implicate commensal-independent gut mucosal barrier changes in the increased risk of CDAD with specific antibiotics and warrant further studies in in vivo systems. We anticipate this work to suggest potential avenues of research for host-directed treatment and preventive therapies for CDAD.

Phase 2 study of clarithromycin, pomalidomide, and dexamethasone in relapsed or refractory multiple myeloma

The addition of clarithromycin enhances the efficacy of lenalidomide plus dexamethasone in treatment-naive multiple myeloma (MM). We conducted a phase 2 trial to evaluate the safety and efficacy of clarithromycin, pomalidomide, and dexamethasone (ClaPd) in relapsed or refractory multiple myeloma (RRMM) with prior lenalidomide exposure. One hundred twenty patients with a median of 5 prior lines of therapy received clarithromycin 500 mg orally twice daily, pomalidomide 4 mg orally on days 1 to 21, and dexamethasone 40 mg orally on days 1, 8, 15, and 22 of a 28-day cycle. The overall response rate (ORR) was 60% with 23% achieving at least a very good partial response. There was no statistical difference in response rates for patients who were refractory to lenalidomide (ORR, 58%), bortezomib (ORR, 55%), or both lenalidomide and bortezomib (ORR, 54%). Median progression-free survival (PFS) for the cohort was 7.7 months and median overall survival (OS) was 19.2 months. A history of dual-refractoriness to lenalidomide and bortezomib did not significantly impact either PFS or OS. The most common toxicities were neutropenia (83%), lymphopenia (74%), and thrombocytopenia (71%). The most common grade ≥3 toxicities included neutropenia (58%), thrombocytopenia (31%), and anemia (28%). ClaPd is an effective combination in RRMM with response and survival outcomes that are independent of lenalidomide- or bortezomib-refractory status. Toxicities are manageable with low rates of nonhematologic or high-grade events. ClaPd is a convenient, all-oral option in RRMM with comparable efficacy to other highly active, 3-drug, pomalidomide-based combinations. This trial was registered at www.clinicaltrials.gov as #NCT01159574.

Azithromycin as an add-on treatment for persistent uncontrolled asthma in adults: protocol of a systematic review and meta-analysis

INTRODUCTION

Clinical management of asthma remains a public challenge. Despite standard treatment with inhaled corticosteroids (ICS) and long-acting beta-agonists (LABAs), asthma remains uncontrolled in a substantial number of chronic asthma patients who risk reduced lung function and severe exacerbations. Azithromycin could have add-on effects for these patients. This study is proposed to systematically evaluate the efficacy of azithromycin as an add-on treatment for adults with persistent uncontrolled symptomatic asthma.

METHODS AND ANALYSIS

Two reviewers will perform a comprehensive search of PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL) and four Chinese electronic databases including China National Knowledge Infrastructure (CNKI), Chinese Biomedical Literature Database (CBM), WanFang Data and VIP Database from inception to May 2019. Only randomised controlled trials will be included. There is no restriction on language or publication status. Combined oral azithromycin and an ICS or/and a LABA will be compared with standard treatment alone or with a placebo. The primary outcomes are the number or frequency of asthma exacerbations, changes in asthma symptoms and lung function. Secondary outcomes include the number or frequency of inhalations of beta-agonists with or without corticosteroids for rescue use, eosinophil counts in blood or sputum, adverse events and others. A meta-analysis will be attempted to provide an estimate of the pooled treatment effect. Otherwise, qualitative descriptions of individual studies will be given.

ETHICS AND DISSEMINATION

Ethical approval is not required because no primary data will be collected. Study findings will be presented at scientific conferences or published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42019117272.

Randomized controlled trial on immunomodulatory effects of azithromycin in children with steroid-dependent nephrotic syndrome

BACKGROUND

Azithromycin (AZM) is a macrolide antibiotic with anti-inflammatory and immunomodulatory effects. Our aim was to compare the immunomodulatory effects of AZM combined with steroid therapy with that of steroid therapy alone in children with steroid-dependent nephrotic syndrome (SDNS).

METHODS

We enrolled 57 patients with SDNS in a multicenter randomized control trial. Patients were classified into two groups: group A (intervention group, N = 29) and group B (control group, N = 28). After achievement of remission with full-dose daily prednisone, patients in group A received AZM in conjunction with steroids which was tapered gradually, while patients in group B received steroids alone. Urine protein creatinine ratio (uPCR) and TNF-α were measured at different points of follow-up throughout the study period (5 months after achieving remission).

RESULTS

After achievement of remission by full-dose steroids, there were significant differences of TNF-α between the two groups after 1-, 3- and 5-month follow-up (p < 0.001, 0.003, and 0.001, respectively). Also, there was significant difference of TNF-α in both intervention and control groups after exclusion of the relapsed cases at 3- and 5-month follow-up (, p = 0.031 and p = 0.003, respectively). There was significant difference between both groups after 5-month follow-up as regards the number of relapsed patients (group A = 4, group B = 11, p = 0.015).

CONCLUSION

AZM was capable of reducing serum TNF-α which is one of the inflammatory cytokines implicated in the pathogenesis of NS.

Evidence that antibiotic administration is effective in the treatment of a subset of patients with intra-amniotic infection/inflammation presenting with cervical insufficiency

BACKGROUND

Cervical insufficiency is a risk factor for spontaneous midtrimester abortion or early preterm birth. Intra-amniotic infection has been reported in 8-52% of such patients and intra-amniotic inflammation in 81%. Some professional organizations have recommended perioperative antibiotic treatment when emergency cervical cerclage is performed. The use of prophylactic antibiotics is predicated largely on the basis that they reduce the rate of complications during the course of vaginal surgery. However, it is possible that antibiotic administration can also eradicate intra-amniotic infection/inflammation and improve pregnancy outcome.

OBJECTIVE

To describe the outcome of antibiotic treatment in patients with cervical insufficiency and intra-amniotic infection/inflammation.

STUDY DESIGN

The study population consisted of 22 women who met the following criteria: (1) singleton pregnancy; (2) painless cervical dilatation of >1 cm between 16.0 and 27.9 weeks of gestation; (3) intact membranes and absence of uterine contractions; (4) transabdominal amniocentesis performed for the evaluation of the microbiologic and inflammatory status of the amniotic cavity; (5) presence of intra-amniotic infection/inflammation; and (6) antibiotic treatment (regimen consisted of ceftriaxone, clarithromycin, and metronidazole). Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas, and polymerase chain reaction for Ureaplasma spp. was performed. Intra-amniotic infection was defined as a positive amniotic fluid culture for microorganisms or a positive polymerase chain reaction for Ureaplasma spp., and intra-amniotic inflammation was suspected when there was an elevated amniotic fluid white blood cell count (≥19 cells/mm³) or a positive rapid test for metalloproteinase-8 (sensitivity 10 ng/mL). For the purpose of this study, the "gold standard" for diagnosis of intra-amniotic inflammation was an elevated interleukin-6 concentration (>2.6 ng/mL) using an enzyme-linked immunosorbent assay. The results of amniotic fluid interleukin-6 were not available to managing clinicians. Follow-up amniocentesis was routinely offered to monitor the microbiologic and inflammatory status of the amniotic cavity and fetal lung maturity. Treatment success was defined as resolution of intra-amniotic infection/inflammation or delivery ≥34 weeks of gestation.

RESULTS

Of 22 patients with cervical insufficiency and intra-amniotic infection/inflammation, 3 (14%) had microorganisms in the amniotic fluid. Of the 22 patients, 6 (27%) delivered within 1 week of amniocentesis and the remaining 16 (73%) delivered more than 1 week after the diagnostic procedure. Among these, 12 had a repeat amniocentesis to assess the microbial and inflammatory status of the amniotic cavity; in 75% (9/12), there was objective evidence of resolution of intra-amniotic inflammation or intra-amniotic infection demonstrated by analysis of amniotic fluid at the time of the repeat amniocentesis. Of the 4 patients who did not have a follow-up amniocentesis, all delivered ≥34 weeks, 2 of them at term; thus, treatment success occurred in 59% (13/22) of cases.

CONCLUSION

In patients with cervical insufficiency and intra-amniotic infection/inflammation, administration of antibiotics (ceftriaxone, clarithromycin, and metronidazole) was followed by resolution of the intra-amniotic inflammatory process or intra-amniotic infection in 75% of patients and was associated with treatment success in about 60% of cases.

Azithromycin does not improve disease severity in acute experimental pancreatitis

Acute pancreatitis is a severe systemic disease triggered by a sterile inflammation and initial local tissue damage of the pancreas. Immune cells infiltrating into the pancreas are main mediators of acute pancreatitis pathogenesis. In addition to their antimicrobial potency, macrolides possess anti-inflammatory and immunomodulatory properties which are routinely used in patients with chronic airway infections and might also beneficial in the treatment of acute lung injury. We here tested the hypothesis that the macrolide antibiotic azithromycin can improve the course of acute experimental pancreatitis via ameliorating the damage imposed by sterile inflammation, and could be used as a disease specific therapy. However, our data show that azithromycin does not have influence on caerulein induced acute pancreatitis in terms of reduction of organ damage, and disease severity. Furthermore Infiltration of immune cells into the pancreas or the lungs was not attenuated by azithromycin as compared to controls or ampicillin treated animals with acute experimental pancreatitis. We conclude that in the chosen model, azithromycin does not have any beneficial effects and that its immunomodulatory properties cannot be used to decrease disease severity in the model of caerulein-induced pancreatitis in mice.

Brazilian strains of Toxoplasma gondii are controlled by azithromycin and modulate cytokine production in human placental explants

BACKGROUND

Toxoplasma gondii is a protozoan parasite that causes congenital toxoplasmosis by transplacental transmission. Parasite strains are genetically diverse and disease severity is related to the genotype. In Uberlândia city, Brazil, two virulent strains were isolated: TgChBrUD1 and TgChBrUD2. Congenital toxoplasmosis is more prevalent in South America compared to Europe, and more often associated with severe symptoms, usually as a result of infection with atypical strains.

METHODS

Considering that T. gondii has shown high genetic diversity in Brazil, the effectiveness of traditional treatment may not be the same, as more virulent strains of atypical genotypes may predominate. Thus, the aim of this study were to evaluate the Brazilian strain infection rate in human villous explants and the azithromycin efficacy with regard to the control of these strains compared to traditional therapy. Villi were infected with RH, ME49, TgChBrUD1 or TgChBrUD2 strains and treated with azithromycin, spiramycin or a combination of pyrimethamine plus sulfadiazine. The villous viability was analyzed by LDH assay and morphological analysis. Parasite proliferation, as well as production of cytokines was analyzed by qPCR and ELISA, respectively. Statistical analysis was performed using the GraphPad Prism 5.0.

RESULTS

The treatments were not toxic and TgChBrUD1 infected villi showed a higher parasite burden compared with others strains. Treatments significantly reduced the intracellular proliferation of T. gondii, regardless of the strain. TgChBrUD1-infected villi produced a larger amount of MIF, IL-6 and TGF-β1 compared with other infected villi. Azithromycin treatment increased MIF production by RH- or TgChBrUD2-infected villi, but in ME49- or TgChBrUD1-infected villi, the MIF production was not altered by treatment. On the other hand, azithromycin treatment induced lower IL-6 production by ME49- or TgChBrUD1-infected villi.

CONCLUSIONS

Azithromycin treatment was effective against T. gondii Brazilian strains compared with conventional treatment. Also, the TgChBrUD1 strain replicated more in villi and modulated important cytokines involved in parasite control, showing that different strains use different strategies to evade the host immune response and ensure their survival.

Immune Modulation in Pediatric Sepsis

The initial host immune response to sepsis in children is characterized by a proinflammatory surge that can be associated with fever, capillary leak, and organ dysfunction. There is, however, a concurrent anti-inflammatory response that results in hyporesponsiveness of innate and adaptive immune cells. When severe, this response is termed immunoparalysis and is known to be associated with prolonged organ dysfunction, increased risk for nosocomial infection, and death in septic adults and children. Sepsis-induced immune suppression can be defined in the laboratory by reduced whole blood ex vivo - stimulated cytokine production capacities, reduced expression of human leukocyte antigen (HLA)-DR on circulating monocytes, and reduced absolute cell counts. While anti-inflammatory therapies have largely been unsuccessful at improving outcomes from adult and pediatric sepsis, the use of immunostimulatory therapies such as granulocyte macrophage colony-stimulating factor (GM-CSF) in patients with sepsis-induced immunoparalysis shows promise. A greater understanding of the risk factors for immunoparalysis along with the development and execution of immunophenotype-specific clinical trials of strategies to optimize innate and adaptive immune function are needed to further improve outcomes in septic children.

Metabolomic Analysis by Nuclear Magnetic Resonance Spectroscopy as a New Approach to Understanding Inflammation and Monitoring of Pharmacological Therapy in Children and Young Adults With Cystic Fibrosis

15-F2t-Isoprostane, a reliable biomarker of oxidative stress, has been found elevated in exhaled breath condensate (EBC), a non-invasive technique for sampling of airway secretions, in patients with cystic fibrosis (CF). Azithromycin has antioxidant properties in experimental models of CF, but its effects on oxidative stress in CF patients are largely unknown. Primary objective of this pilot, proof-of-concept, prospective, parallel group, pharmacological study, was investigating the potential antioxidant effects of azithromycin in CF patients as reflected by EBC 15-F2t-isoprostane. Secondary objectives included studying the effect of azithromycin on EBC and serum metabolic profiles, and on serum 15-F2t-isoprostane. In CF patients who were on maintenance treatment with oral vitamin E (200 UI once daily), treatment with oral azithromycin (250 or 500 mg depending on body weight) plus vitamin E (400 UI once daily) (group A) (n = 24) or oral vitamin E alone (400 UI once daily) (group B) (n = 21) was not associated with changes in EBC 15-F2t-isoprostane concentrations compared with baseline values after 8-weeks treatment or 2 weeks after treatment suspension. There was no between-group difference in post-treatment EBC 15-F2t-isoprostane. Likewise, no within- or between-group differences in serum 15-F2t-isoprostane concentrations were observed in either study group. NMR spectroscopy-based metabolomics of EBC shows that suspension of both azithromycin plus vitamin E and vitamin E alone has a striking effect on metabolic profiles in EBC. Between-group comparisons show that EBC metabolite distribution after treatment and 2 weeks after treatment suspension is different. Quantitative differences in ethanol, saturated fatty acids, acetate, acetoin/acetone, and methanol are responsible for these differences. Our study was unable to show antioxidant effect of azithromycin as add-on treatment with doubling the dose of oral vitamin E as reflected by 15-F2t-isoprostane concentrations in EBC. Add-on therapy with azithromycin itself does not induce EBC metabolite changes, but its suspension is associated with EBC metabolic profiles that are different from those observed after vitamin E suspension. The pathophysiological and therapeutic implications of these findings in patients with stable CF are unknown and require further research. Preliminary data suggest that EBC NMR-based metabolomics might be used for assessing the effects of pharmacological treatment suspension in stable CF patients.

Clarithromycin expands CD11b+Gr-1+ cells via the STAT3/Bv8 axis to ameliorate lethal endotoxic shock and post-influenza bacterial pneumonia

Macrolides are used to treat various inflammatory diseases owing to their immunomodulatory properties; however, little is known about their precise mechanism of action. In this study, we investigated the functional significance of the expansion of myeloid-derived suppressor cell (MDSC)-like CD11b⁺Gr-1⁺ cells in response to the macrolide antibiotic clarithromycin (CAM) in mouse models of shock and post-influenza pneumococcal pneumonia as well as in humans. Intraperitoneal administration of CAM markedly expanded splenic and lung CD11b⁺Gr-1⁺ cell populations in naïve mice. Notably, CAM pretreatment enhanced survival in a mouse model of lipopolysaccharide (LPS)-induced shock. In addition, adoptive transfer of CAM-treated CD11b⁺Gr-1⁺ cells protected mice against LPS-induced lethality via increased IL-10 expression. CAM also improved survival in post-influenza, CAM-resistant pneumococcal pneumonia, with improved lung pathology as well as decreased interferon (IFN)-γ and increased IL-10 levels. Adoptive transfer of CAM-treated CD11b⁺Gr-1⁺ cells protected mice from post-influenza pneumococcal pneumonia. Further analysis revealed that the CAM-induced CD11b⁺Gr-1⁺ cell expansion was dependent on STAT3-mediated Bv8 production and may be facilitated by the presence of gut commensal microbiota. Lastly, an analysis of peripheral blood obtained from healthy volunteers following oral CAM administration showed a trend toward the expansion of human MDSC-like cells (Lineage⁻HLA-DR⁻CD11b⁺CD33⁺) with increased arginase 1 mRNA expression. Thus, CAM promoted the expansion of a unique population of immunosuppressive CD11b⁺Gr-1⁺ cells essential for the immunomodulatory properties of macrolides.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of anti-inflammatory myeloid progenitors that expand in response to acute and chronic inflammation as well as in various diseases, such as autoimmune diseases and cancer. The macrolide antibiotic clarithromycin has immunomodulatory effects in various inflammatory diseases, distinct from its antimicrobial effects, but the mechanism underlying these effects is unknown. The present study demonstrates that clarithromycin treatment induces a marked expansion of CD11b⁺Gr-1⁺ MDSC-like cells in the spleen and lungs, sufficient to protect mice from LPS-induced lethality and clarithromycin-resistant bacterial pneumonia via increased IL-10 and decreased IFN-γ levels. Clarithromycin-induced CD11b⁺Gr-1⁺ cell expansion was dependent on STAT3-mediated Bv8 production. Moreover, expansion of the immunosuppressive MDSC-like cell population was observed following clarithromycin treatment in humans. Collectively, these results suggest that the immunomodulatory effects of clarithromycin can be attributed to the induction of CD11b⁺Gr-1⁺ MDSC-like cells via the STAT3/Bv8 axis.

Effect of roxithromycin on mucosal damage, oxidative stress and pro-inflammatory markers in experimental model of colitis

OBJECTIVE AND DESIGN

Roxithromycin, a macrolide antibiotic, exhibits anti-inflammatory property. The present study was designed to evaluate its protective effect in a rat model of colitis.

METHODS

The anti-inflammatory property of roxithromycin was first validated in rat paw edema model at 5 and 20 mg/kg doses where it produced 19 and 51% inhibition of paw swelling induced by carrageenan. The efficacy of roxithromycin was evaluated at these doses in a rat model where colitis was induced by intra-colonic instillation of acetic acid. Rats were divided into six groups viz. normal control, experimental control and drug-treated groups: roxithromycin 5 and 20 mg/kg, diclofenac 10 mg/kg and mesalazine 300 mg/kg. All drugs were given orally 1 h before induction of colitis. The macro and microscopic changes, mean ulcer score, mucus content and markers of oxidative stress and inflammation were evaluated in all the groups after 24 h.

RESULTS

Pretreatment with roxithromycin markedly decreased hyperemia, ulceration, edema and restored histological architecture. The protection afforded by roxithromycin was substantiated by dose-dependent increase in mucus content, normalization of markers of oxidative stress (GSH and TBARS) and levels of TNF-α, PGE₂ and nitrite along with marked decrease in expression of NFκB (p65), IL-1β and COX-2. The protective effect of roxithromycin was found to be comparable to mesalazine while diclofenac was found ineffective.

CONCLUSION

Our study demonstrates that roxithromycin ameliorates experimental colitis by maintaining redox homeostasis, preserving mucosal integrity and downregulating NFκB-mediated pro-inflammatory signaling and suggests that it has a therapeutic potential in inflammatory conditions of the colon.

The Role of Macrolides in Chronic Rhinosinusitis (CRSsNP and CRSwNP)

PURPOSE OF REVIEW

We assess the literature on the pharmacokinetics, indications, important considerations, and effectiveness of long-term, low-dose macrolide antibiotics in chronic rhinosinusitis (CRS).

RECENT FINDINGS

The key to effective implementation of macrolide therapy in CRS is appropriate patient selection. Macrolides have demonstrated the most benefit in Th1-mediated non-eosinophilic CRS when used for durations of at least 3 months. Macrolide antibiotics have demonstrated great benefit when used for their anti-inflammatory or immunomodulatory properties, which include the blockage of pro-inflammatory cytokines, such as interleukin (IL)-8 and tumor necrosis factor-α (TNF-α). They have been used in CRS patients not responding to traditional corticosteroid-based treatment regimens, but appear to be most effective specifically in Th1-mediated non-eosinophilic CRS in long durations and low doses. Further research is needed to better identify characteristics known to correlate with macrolide response so early directed therapy can be implemented.

Azithromycin attenuates acute radiation-induced lung injury in mice

Radiation-induced lung injury (RILI) is a common and major obstacle in thoracic cancer radiotherapy, resulting in considerable morbidity and limiting the dose of radiation. However, an effective treatment option remains to be established. Therefore, the present study aimed to investigate the effects of azithromycin (AZM) in acute RILI with a mouse model. In the present study, C57BL/6 mice were given a single thoracic irradiation of 16 Gy and administered orally with AZM. The lung histopathological findings, the levels of malondialdehyde (MDA; an indicator of oxidative damage) and the concentration of pro-inflammatory and pro-fibrotic cytokines in plasma were assessed on 28 day following irradiation. In addition, the total cell counts in bronchoalveolar lavage fluid (BALF), the pro-inflammatory and pro-fibrotic cytokine gene expression in lung tissue were evaluated on day 7, 14 and 28 following irradiation. Administration with AZM markedly alleviated acute RILI as indicated by hematoxylin and eosin and Masson staining. The levels of MDA and total cell counts in BALF significantly reduced in AZM treated mice. AZM also down-regulated the concentration and mRNA expression of interleukin (IL)-1β, IL-6, tumor necrosis factor-α and transforming growth factor-β1. In addition, AZM attenuated the irradiation-induced increases in the mRNA expression of fibrotic markers (α-smooth muscle actin and α-1 type I collagen). AZM treatment mitigated the radiation-induced acute lung injury possibly by its anti-inflammatory and anti-fibrotic effects.

Treatment with rhDNase in patients with cystic fibrosis alters in-vitro CHIT-1 activity of isolated leucocytes

Recent data suggest a possible relationship between cystic fibrosis (CF) pharmacotherapy, Aspergillus fumigatus colonization (AC) and/or allergic bronchopulmonary aspergillosis (ABPA). The aim of this study was to determine if anti-fungal defence mechanisms are influenced by CF pharmacotherapy, i.e. if (1) neutrophils form CF and non-CF donors differ in their ability to produce chitotriosidase (CHIT-1); (2) if incubation of isolated neutrophils with azithromycin, salbutamol, prednisolone or rhDNase might influence the CHIT-1 activity; and (3) if NETosis and neutrophil killing efficiency is influenced by rhDNase. Neutrophils were isolated from the blood of CF patients (n = 19; mean age 26·8 years or healthy, non-CF donors (n = 20; 38·7 years) and stimulated with phorbol-12-myristate-13-acetate (PMA), azithromycin, salbutamol, prednisolone or rhDNase. CHIT-1 enzyme activity was measured with a fluorescent substrate. NETosis was induced by PMA and neutrophil killing efficiency was assessed by a hyphae recovery assay. Neutrophil CHIT-1 activity was comparable in the presence or absence of PMA stimulation in both CF and non-CF donors. PMA stimulation and preincubation with rhDNase increased CHIT-1 activity in culture supernatants from non-CF and CF donors. However, this increase was significant in non-CF donors but not in CF patients (P < 0·05). RhDNase reduced the number of NETs in PMA-stimulated neutrophils and decreased the killing efficiency of leucocytes in our in-vitro model. Azithromycin, salbutamol or prednisolone had no effect on CHIT-1 activity. Stimulation of isolated leucocytes with PMA and treatment with rhDNase interfered with anti-fungal defence mechanisms. However, the impact of our findings for treatment in CF patients needs to be proved in a clinical cohort.

Imipenem-cilastatin-induced psychosis: a case report

Background

Elderly patients, in particular, have been reported to develop psychiatric side effects from antibiotics. Clarithromycin, quinolones, sulfamethoxazole-trimethoprim, isoniazid, penicillin, and cephalosporins have been reported to cause psychosis. This case report bridges a void in the medical literature with regards to the psychiatric adverse effects of imipenem-cilastatin.

Case presentation

A 64-year-old Hispanic man in septic shock due to urinary tract infection was initiated on imipenem-cilastatin and mechanically ventilated, following admission to hospital. His mentation was normal for 72 hours after extubation and discontinuation of sedatives and opioids, following which he was noted to be in acute psychosis. Our patient’s imipenem-cilastatin dose had been increased 24 hours prior to his violent visual and auditory hallucinations because his renal function had improved. The physical examination and laboratory tests did not reveal evidence of a new central nervous infection or endocrinopathy. His mentation improved after his antibiotic was switched to ceftriaxone, based on culture and sensitivity testing. Similar psychiatric symptoms developed 2 months later when he was treated with imipenem for a recurrent urinary tract infection. His symptoms again resolved with modification of his antibiotic regimen.

Conclusions

Endocrine dysfunctions (thyroid, adrenal, and pituitary disorders) and toxic ingestions are medical disorders known to cause brief psychotic episodes. Fluoroquinolones, penicillins, and trimethoprim-sulfamethoxazole are common antibiotics associated with this rare adverse effect. Several pharmacokinetic hypotheses have been proposed for this adverse effect: (1) N-methyl-D-aspartate receptor hypofunctioning, (2) sequential blockade of folic acid production, (3) inhibition of prostaglandin E2 and proinflammatory cytokine production, (4) increased central dopamine turnover, and (5) accumulation of toxic levels of the drug. Pre-existing psychopathology, relevant comorbidities, slow acetylation status, and increased permeability of the blood–brain barrier have been suggested to make patients more prone to developing psychosis. According to the literature, this psychiatric manifestation resolves within 2 weeks of discontinuing the offending agent. There appears to be underreporting of the psychiatric manifestations of imipenem-cilastatin, contrary to post-marketing surveillance data. It is imperative that physicians recognize these psychiatric side effects of antibiotics, because they are a fundamental treatment option.

Pharmacological Therapy of Bronchial Asthma: The Role of Biologicals

Bronchial asthma is a heterogeneous, complex, chronic inflammatory and obstructive pulmonary disease driven by various pathways to present with different phenotypes. A small proportion of asthmatics (5-10%) suffer from severe asthma with symptoms that cannot be controlled by guideline therapy with high doses of inhaled steroids plus a second controller, such as long-acting β2 agonists (LABA) or leukotriene receptor antagonists, or even systemic steroids. The discovery and characterization of the pathways that drive different asthma phenotypes have opened up new therapeutic avenues for asthma treatment. The approval of the humanized anti-IgE antibody omalizumab for the treatment of severe allergic asthma has paved the way for other cytokine-targeting therapies, particularly those targeting interleukin (IL)-4, IL-5, IL-9, IL-13, IL-17, and IL-23 and the epithelium-derived cytokines IL-25, IL-33, and thymic stromal lymphopoietin. Knowledge of the molecular basis of asthma phenotypes has helped, and continues to help, the development of novel biologicals that target a diverse array of phenotype-specific molecular targets in patients suffering from severe asthma. This review summarizes potential therapeutic approaches that are likely to show clinical efficacy in the near future, focusing on biologicals as promising novel therapies for severe asthma.

Remission of ALK-negative primary pulmonary inflammatory myofibroblastic tumor on treatment with clarithromycin: A case report and review of the literature

Inflammatory myofibroblastic tumors (IMTs) belong to an intermediate group of soft-tissue tumors, they are relatively rare but exhibit a wide range of pathologies, from benign to malignant. At present, no standard treatment has been established, however, it is known to be important to determine the grade of malignancy of the tumor, prior to treatment. The present study reports a 73-year-old female patient with no clinical manifestations, who, when examined radiographically at a health check exhibited bilateral thoracic infiltrative shadows and nodular shadows by chest CT. A metastatic tumor or an organizing pneumonia were suspected. Blood examination showed no abnormal findings, and a pathological diagnosis of IMT was given from the histological findings of the tissue extracted by video-assisted thoracic surgery. Histological analysis established the lack of expression of anaplastic lymphoma kinase (ALK1) and immunoglobulin subtype G4 (IgG4). Alteration of the radiological shadows was observed over several weeks, and after concluding that chronic inflammation was worsening the patient's condition, clarithromycin was administered as a long-term macrolide therapy. The IMT decreased in size, and eight months later it had almost resolved. The patient was last reported to be maintaining a stable condition with no relapse. Some IMT cases have malignant pathology, and should be carefully followed-up. However, in the present case, where the IMT is both ALK1-negative and IgG4-negative, its biological immune responsiveness appears to differ from positive cases, and an inflammatory response was predominant. Clarithromycin, has immunomodulatory and anti-inflammatory effects and appeared to be effective in treating the IMT of the patient in the present study.

Successful treatment of chronic lower respiratory tract infection by macrolide administration in a patient with intralobar pulmonary sequestration and primary ciliary dyskinesia

Primary ciliary dyskinesia (PCD) is a genetic disease associated with abnormalities in ciliary structure and function. Although recurrent respiratory infection associated with ciliary dysfunction is a common clinical feature, there is no standardized treatment or management of respiratory infection in PCD patients. Here, we report that respiratory infection with PCD and intralobar sequestration (ILS) were treated successfully with clarithromycin before the surgical resection of ILS. A 15-year-old non-smoking Japanese woman was admitted for productive cough and dyspnea on exertion. Chest CT scan on admission showed complex cystic LESIONS with air-fluid level in the right lower lobe, and diffuse nodular shadows in the whole lobe of the lung. On flexible bronchoscopy examination, sputum and bronchiolar fluid cultures revealed Staphylococcus aureus (S. aureus). An electron microscopic examination of the cilia showed inner dynein arm deficiency. Administration of clarithromycin improved the lower respiratory tract infection associated with S. aureus. CT angiography after clarithromycin treatment demonstrated an aberrant systemic artery arising from the celiac trunk and supplying the cystic mass lesions that were incorporated into the normal pulmonary parenchyma without their own pleural covering. Based on these results, the patient was diagnosed with PCD and ILS. Because of the clarithromycin treatment, resection of the ILS was performed safely without any complications. Although further observation of clarithromycin treatment is needed, we believe that clarithromycin may be considered one of the agents for treating PCD.

Respiratory Infections in the U.S. Military: Recent Experience and Control

This comprehensive review outlines the impact of military-relevant respiratory infections, with special attention to recruit training environments, influenza pandemics in 1918 to 1919 and 2009 to 2010, and peacetime operations and conflicts in the past 25 years. Outbreaks and epidemiologic investigations of viral and bacterial infections among high-risk groups are presented, including (i) experience by recruits at training centers, (ii) impact on advanced trainees in special settings, (iii) morbidity sustained by shipboard personnel at sea, and (iv) experience of deployed personnel. Utilizing a pathogen-by-pathogen approach, we examine (i) epidemiology, (ii) impact in terms of morbidity and operational readiness, (iii) clinical presentation and outbreak potential, (iv) diagnostic modalities, (v) treatment approaches, and (vi) vaccine and other control measures. We also outline military-specific initiatives in (i) surveillance, (ii) vaccine development and policy, (iii) novel influenza and coronavirus diagnostic test development and surveillance methods, (iv) influenza virus transmission and severity prediction modeling efforts, and (v) evaluation and implementation of nonvaccine, nonpharmacologic interventions.

Macrolide antibiotics for treatment of asthma in adults: a meta-analysis of 18 randomized controlled clinical studies

Mounting studies have been showed that long-term macrolides used in patients with asthma could improve the lung function and symptoms. However, a large number of studies have reported inconclusive results. The aim of this meta-analysis was to investigate the effect of macrolide antibiotics in patients with asthma. We have performed a search in PubMed, Embase, China National Knowledge Internet (CNKI), and Wanfang databases. The weighed mean difference (WMD) or standardized mean difference (SMD) was used to evaluate the pooled effect. Statistical analysis was performed by STATA 11.0 software. Totally 1306 patients were included in the meta-analysis. The overall results indicated that statistically significance of long-term macrolides therapy in patients with asthma on forced expiratory volume in 1 s (FEV1) (WMD: 0.11, P < 0.01), peak expiratory flow (PEF) (SMD: 0.25, P = 0.001), airway hyper-responsiveness (AHR) (SMD: 0.90, P = 0.04), forced vital capacity (FVC) (WMD: 0.18, P = 0.05) and FEV1/FVC (WMD: 1.93, P < 0.001), but no statistically significance on FEV1/predict, FVC/predict, symptom scores, quality of life scores (QOL), reliever inhaler puffs per 24 h, and cell counts in sputum and blood. The subgroup analysis indicated macrolides could increase FEV1 and PEF in Caucasian and Asian, decrease AHR in Caucasian, while cells counts of sputum improvement among Asian. Therefore, the study suggested that long-term marolides therapy in asthma may improved the FEV1, PEF, AHR, FVC, FEV1/FVC and cells counts in sputum, but it can't improve other lung function (FEV1/predict and FVC/predict) and clinical outcomes (such as symptom, quality of life etc.).

Association of azithromycin with mortality and cardiovascular events among older patients hospitalized with pneumonia

IMPORTANCE

Although clinical practice guidelines recommend combination therapy with macrolides, including azithromycin, as first-line therapy for patients hospitalized with pneumonia, recent research suggests that azithromycin may be associated with increased cardiovascular events.

OBJECTIVE

To examine the association of azithromycin use with all-cause mortality and cardiovascular events for patients hospitalized with pneumonia.

DESIGN

Retrospective cohort study comparing older patients hospitalized with pneumonia from fiscal years 2002 through 2012 prescribed azithromycin therapy and patients receiving other guideline-concordant antibiotic therapy.

SETTING

This study was conducted using national Department of Veterans Affairs administrative data of patients hospitalized at any Veterans Administration acute care hospital.

PARTICIPANTS

Patients were included if they were aged 65 years or older, were hospitalized with pneumonia, and received antibiotic therapy concordant with national clinical practice guidelines.

MAIN OUTCOMES AND MEASURES

Outcomes included 30- and 90-day all-cause mortality and 90-day cardiac arrhythmias, heart failure, myocardial infarction, and any cardiac event. Propensity score matching was used to control for the possible effects of known confounders with conditional logistic regression.

RESULTS

Of 73,690 patients from 118 hospitals identified, propensity-matched groups were composed of 31,863 patients exposed to azithromycin and 31,863 matched patients who were not exposed. There were no significant differences in potential confounders between groups after matching. Ninety-day mortality was significantly lower in those who received azithromycin (exposed, 17.4%, vs unexposed, 22.3%; odds ratio [OR], 0.73; 95% CI, 0.70-0.76). However, we found significantly increased odds of myocardial infarction (5.1% vs 4.4%; OR, 1.17; 95% CI, 1.08-1.25) but not any cardiac event (43.0% vs 42.7%; OR, 1.01; 95% CI, 0.98-1.05), cardiac arrhythmias (25.8% vs 26.0%; OR, 0.99; 95% CI, 0.95-1.02), or heart failure (26.3% vs 26.2%; OR, 1.01; 95% CI, 0.97-1.04).

CONCLUSIONS AND RELEVANCE

Among older patients hospitalized with pneumonia, treatment that included azithromycin compared with other antibiotics was associated with a lower risk of 90-day mortality and a smaller increased risk of myocardial infarction. These findings are consistent with a net benefit associated with azithromycin use.

Biotic acts of antibiotics

Biological functions of antibiotics are not limited to killing. The most likely function of antibiotics in natural microbial ecosystems is signaling. Does this signaling function of antibiotics also extend to the eukaryotic – in particular mammalian – cells? In this review, the host modulating properties of three classes of antibiotics (macrolides, tetracyclines, and β-lactams) will be briefly discussed. Antibiotics can be effective in treatment of a broad spectrum of diseases and pathological conditions other than those of infectious etiology and, in this capacity, may find widespread applications beyond the intended antimicrobial use. This use, however, should not compromise the primary function antibiotics are used for. The biological background for this inter-kingdom signaling is also discussed.

Azithromycin treatment increases survival of high-risk corneal allotransplants

PURPOSE

To test the therapeutic efficacy of azithromycin (AZM), a macrolide antibiotic for prolonging murine "high-risk" corneal allograft survival.

METHODS

Fully major histocompatibility complex-mismatched corneas were transplanted from C57BL/6 donors to BALB/c recipients with suture-induced vascularized high-risk corneal beds. Recipient mice were either not treated or treated with topical AZM, oral AZM, or both. Evaluation of graft vascularization and clarity was performed in a masked fashion. Lymph nodes were excised and analyzed for CD4, FoxP3, and CD44 by flow cytometry, and for T-cell priming by proliferation and cytokine production in mixed lymphocyte cultures. Corneal whole mounts were evaluated by confocal microscopy.

RESULTS

The incidence of graft rejection in the control group (81.8%) was significantly reduced by AZM treatment (18.2% topical, 21.7% oral, 33.3% topical + oral), although corneal vascularization was not affected by the treatment. The frequency of corneas that retained complete clarity after transplantation was higher in the AZM-treated groups. Reduced graft rejection in the AZM-treated groups was not associated with a reduced allospecific T-cell response or increased frequency of regulatory T cells.

CONCLUSIONS

AZM is effective in prolonging survival of high-risk corneal allografts by an as yet undefined mechanism that does not seem to involve modulation of corneal neovascularization or allospecific T-cell priming.

Clarithromycin in rheumatoid arthritis: the addition to methotrexate and low-dose methylprednisolone induces a significant additive value--a 24-month single-blind pilot study

To compare the efficacy of the addition of clarithromycin (CM) to methotrexate (MTX) and methylprednisolone (MP) in active rheumatoid arthritis (RA). 32 patients with RA consecutively randomized.

CONTROL GROUP

sixteen patients treated for 24 months with MTX 10-15 mg i.m. weekly and MP 4-6 mg daily. CM group: sixteen patients treated with MTX 10-15 mg i.m. weekly and MP 4-6 mg daily for 24 months; CM therapy added in the first month (500 mg twice a day for the first 15 days followed by 500 mg a day for the remaining 15 days). Evaluation of the improvement following ACR criteria was performed at months 1 (primary endpoint), 3 and 6. Patients were furthermore observed after 12, 18 and 24 months from the study beginning. At month 1, following ACR70 improvement criteria, we found a significant additive value in CM group (10/16 = 63% vs 4/16 = 25%, p = 0.033--chi-square test). After discontinuation of CM, the difference between groups was anymore evident (month 3: CM group 10/16 = 63% vs control group 9/16 = 56%). At month 24, 7/16 (44%) in control group and 12/16 (75%) in CM group completed the follow-up. The addition of CM to MTX and MP can induce the remission ACR 70 in the majority of RA patients within 4 weeks, while MTX and MP alone need about 3 months to achieve the same result.

Complementary and integrative treatments: rhinosinusitis

Rhinosinusitis is characterized by inflammation of the mucosa involving the paranasal sinuses and the nasal cavity and is one of the most common health care problems, with significant impairment of quality of life. There is a growing amount of interest in the use of complementary and integrative medicine for the treatment of rhinosinusitis. This article focuses on an integrative approach to rhinosinusitis.

Pathogenesis and management of nasal polyposis in cystic fibrosis

Beginning in preschool age, during their lives, up to 50% of cystic fibrosis (CF) patients experience obstructing nasal polyposis (NP), which is rare in non-CF children. Pathogenetic factors of NP in general and especially in CF are still obscure. However, defective epithelial ion transport from mucosal glands plays a central role in CF, and viscous secretions impair mucociliary clearance, promoting chronic pathogen colonization and neutrophil-dominated chronic inflammation. Presently, CF-NP is not curable but can be clinically stabilized, though the large variety of proposed treatment modalities indicates a lack of standardization and of evidence of treatment efficacy. When conservative measures are exhausted, surgical intervention combining individually adapted endoscopic sinus surgery and supportive conservative treatment is performed. Topical steroids, approved as the gold standard for non-CF NP, may be beneficial, but they are discussed to be less effective in neutrophilic inflammation, and CF-specific antimicrobial and mucolytic therapy, as is true of all treatment modalities, urgently requires evaluation by controlled clinical trials within interdisciplinary networks.

Effect of azithromycin on systemic markers of inflammation in patients with cystic fibrosis uninfected with Pseudomonas aeruginosa

BACKGROUND

While the mechanism of action by which azithromycin exerts positive effects inpatients with cystic fibrosis remains unclear, evidence suggests that azithromycin may act as an immunomodulatory agent. We examined changes in systemic inflammatory markers in a doubleblind, randomized, controlled trial of oral azithromycin in patients 6-18 years of age with cystic fibrosis who were uninfected with Pseudomonas aeruginosa.

METHODS

WBC counts and differential, serum myeloperoxidase (MPO), high-sensitivity C reactive protein (hsCRP), intracellular adhesion molecule 1, IL-6, calprotectin, serum amyloid A (SAA),and granulocyte colony-stimulating factor (G-CSF) were measured at baseline and after 28 and 168 days of treatment in patients receiving either oral azithromycin or placebo.

RESULTS

Inflammatory markers were similar in both groups at baseline. HsCRP, MPO, SAA, calprotectin,and the absolute neutrophil count (ANC) significantly decreased from baseline today 28 in the azithromycin group compared with the placebo group ( P < .05). This treatment effect was sustained at day 168 for ANC, calprotectin, and SAA ( P < .05). Changes in hsCRP, calprotectin,and SAA at day 28 were negatively correlated with changes in FEV 1 (L) and FEV 1(% predicted), as well as both absolute and relative changes in weight ( P < .05). Except for weight (%),the associations remained significant for calprotectin; FEV 1 (L) and weight (%) remained significantly correlated with the 168-day change in hsCRP. The 168-day change in ANC was significantly correlated with changes in lung function, but not in weight; the change in G-CSF was significantly correlated with the change in weight (%) only.

CONCLUSIONS

In patients not infected with P aeruginosa , oral azithromycin significantly reduced neutrophil counts and serum inflammatory markers within 28 days of initiating treatment.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00431964; URL: www.clinicaltrials.gov

Macrolide-based regimens in absence of bacterial co-infection in critically ill H1N1 patients with primary viral pneumonia

PURPOSE

To determine whether macrolide-based treatment is associated with mortality in critically ill H1N1 patients with primary viral pneumonia.

METHODS

Secondary analysis of a prospective, observational, multicenter study conducted across 148 Intensive Care Units (ICU) in Spain.

RESULTS

Primary viral pneumonia was present in 733 ICU patients with pandemic influenza A (H1N1) virus infection with severe respiratory failure. Macrolide-based treatment was administered to 190 (25.9 %) patients. Patients who received macrolides had chronic obstructive pulmonary disease more often, lower severity on admission (APACHE II score on ICU admission (13.1 ± 6.8 vs. 14.4 ± 7.4 points, p < 0.05), and multiple organ dysfunction syndrome less often (23.4 vs. 30.1 %, p < 0.05). Length of ICU stay in survivors was not significantly different in patients who received macrolides compared to patients who did not (10 (IQR 4-20) vs. 10 (IQR 5-20), p = 0.9). ICU mortality was 24.1 % (n = 177). Patients with macrolide-based treatment had lower ICU mortality in the univariate analysis (19.2 vs. 28.1 %, p = 0.02); however, a propensity score analysis showed no effect of macrolide-based treatment on ICU mortality (OR = 0.87; 95 % CI 0.55-1.37, p = 0.5). Moreover, the sensitivity analysis revealed very similar results (OR = 0.91; 95 % CI 0.58-1.44, p = 0.7). A separate analysis of patients under mechanical ventilation yielded similar results (OR = 0.77; 95 % CI 0.44-1.35, p = 0.4).

CONCLUSION

Our results suggest that macrolide-based treatment was not associated with improved survival in critically ill H1N1 patients with primary viral pneumonia.

Pathogen- and host-directed anti-inflammatory activities of macrolide antibiotics

Macrolide antibiotics possess several, beneficial, secondary properties which complement their primary antimicrobial activity. In addition to high levels of tissue penetration, which may counteract seemingly macrolide-resistant bacterial pathogens, these agents also possess anti-inflammatory properties, unrelated to their primary antimicrobial activity. Macrolides target cells of both the innate and adaptive immune systems, as well as structural cells, and are beneficial in controlling harmful inflammatory responses during acute and chronic bacterial infection. These secondary anti-inflammatory activities of macrolides appear to be particularly effective in attenuating neutrophil-mediated inflammation. This, in turn, may contribute to the usefulness of these agents in the treatment of acute and chronic inflammatory disorders of both microbial and nonmicrobial origin, predominantly of the airways. This paper is focused on the various mechanisms of macrolide-mediated anti-inflammatory activity which target both microbial pathogens and the cells of the innate and adaptive immune systems, with emphasis on their clinical relevance.

Clarithromycin suppresses human respiratory syncytial virus infection-induced Streptococcus pneumoniae adhesion and cytokine production in a pulmonary epithelial cell line

Human respiratory syncytial virus (RSV) sometimes causes acute and severe lower respiratory tract illness in infants and young children. RSV strongly upregulates proinflammatory cytokines and the platelet-activating factor (PAF) receptor, which is a receptor for Streptococcus pneumoniae, in the pulmonary epithelial cell line A549. Clarithromycin (CAM), which is an antimicrobial agent and is also known as an immunomodulator, significantly suppressed RSV-induced production of interleukin-6, interleukin-8, and regulated on activation, normal T-cell expressed and secreted (RANTES). CAM also suppressed RSV-induced PAF receptor expression and adhesion of fluorescein-labeled S. pneumoniae cells to A549 cells. The RSV-induced S. pneumoniae adhesion was thought to be mediated by the host cell's PAF receptor. CAM, which exhibits antimicrobial and immunomodulatory activities, was found in this study to suppress the RSV-induced adhesion of respiratory disease-causing bacteria, S. pneumoniae, to host cells. Thus, CAM might suppress immunological disorders and prevent secondary bacterial infections during RSV infection.

Influence of macrolide maintenance therapy and bacterial colonisation on exacerbation frequency and progression of COPD (COLUMBUS): study protocol for a randomised controlled trial

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterised by progressive development of airflow limitation that is poorly reversible. Because of a poor understanding of COPD pathogenesis, treatment is mostly symptomatic and new therapeutic strategies are limited. There is a direct relationship between the severity of the disease and the intensity of the inflammatory response. Besides smoking, one of the hypotheses for the persistent airway inflammation is the presence of recurrent infections. Macrolide antibiotics have bacteriostatic as well as anti-inflammatory properties in patients with cystic fibrosis and other inflammatory pulmonary diseases. There is consistent evidence that macrolide therapy reduces infectious exacerbations, decreases the requirement for additional antibiotics and improves nutritional measures. Because of these positive effects we hypothesised that maintenance macrolide therapy may also have beneficial effects in patients with COPD who have recurrent exacerbations. The effects on development of bacterial resistance to macrolides due to this long-term treatment are unknown. Until now, studies investigating macrolide therapy in COPD are limited. The objective of this study is to assess whether maintenance treatment with macrolide antibiotics in COPD patients with three or more exacerbations in the previous year decreases the exacerbation rate in the year of treatment and to establish microbial resistance due to the long-term treatment.

METHODS/DESIGN

The study is set up as a prospective randomised double-blind placebo-controlled single-centre trial. A total of 92 patients with COPD who have had at least three exacerbations of COPD in the previous year will be included. Subjects will be randomised to receive either azithromycin 500 mg three times a week or placebo. Our primary endpoint is the reduction in the number of exacerbations of COPD in the year of treatment.

DISCUSSION

We investigate whether long-term therapy with macrolide antibiotics can prevent exacerbations in patients with COPD. Additionally, our study aims to assess the effect of long-term use of macrolide on the development of antimicrobial resistance and on inflammatory parameters related to COPD. We believe this study will provide more data on the effects of macrolide treatment in patients in COPD and will add more knowledge on its working mechanisms.

TRIAL REGISTRATION

http://www.clinicaltrials.gov NCT00985244.

Macrolides in chronic inflammatory skin disorders

Long-term therapy with the macrolide antibiotic erythromycin was shown to alter the clinical course of diffuse panbronchiolitis in the late 1980s. Since that time, macrolides have been found to have a large number of anti-inflammatory properties in addition to being antimicrobials. These observations provided the rationale for many studies performed to assess the usefulness of macrolides in other inflammatory diseases including skin and hair disorders, such as rosacea, psoriasis, pityriasis rosea, alopecia areata, bullous pemphigoid, and pityriasis lichenoides. This paper summarizes a collection of clinical studies and case reports dealing with the potential benefits of macrolides antibiotics in the treatment of selected dermatoses which have primarily been classified as noninfectious and demonstrating their potential for being disease-modifying agents.

Elderly patients with community-acquired pneumonia: optimal treatment strategies

Community-acquired pneumonia (CAP) is a common infectious disease that still causes substantial morbidity and mortality. Elderly people are frequently affected, and several issues related to care of this condition in the elderly have to be considered. This article reviews current recommendations of guidelines with a special focus on aspects of the care of elderly patients with CAP. The most common pathogen in CAP is still Streptococcus pneumoniae, followed by other pathogens such as Haemophilus influenzae, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Legionella species. Antimicrobial resistance is an increasing problem, especially with regard to macrolide-resistant S. pneumoniae and fluoroquinolone-resistant strains. With regard to β-lactam antibacterials, resistance by H. influenzae and Moraxella catarrhalis is important, as is the emergence of multidrug-resistant Staphylococcus aureus. The main management decisions should be guided by the severity of disease, which can be assessed by validated clinical risk scores such as CURB-65, a tool for measuring the severity of pneumonia based on assessment of confusion, serum urea, respiratory rate and blood pressure in patients aged ≥65 years. For the treatment of low-risk pneumonia, an aminopenicillin such as amoxicillin with or without a β-lactamase inhibitor is frequently recommended. Monotherapy with macrolides is also possible, although macrolide resistance is of concern. When predisposing factors for special pathogens are present, a β-lactam antibacterial combined with a β-lactamase inhibitor, or the combination of a β-lactam antibacterial, a β-lactamase inhibitor and a macrolide, may be warranted. If possible, patients who have undergone previous antibacterial therapy should receive drug classes not previously used. For hospitalized patients with non-severe pneumonia, a common recommendation is empirical antibacterial therapy with an aminopenicillin in combination with a β-lactamase inhibitor, or with fluoroquinolone monotherapy. With proven Legionella pneumonia, a combination of β-lactams with a fluoroquinolone or a macrolide is beneficial. In severe pneumonia, ureidopenicillins with β-lactamase inhibitors, broad-spectrum cephalosporins, macrolides and fluoroquinolones are used. A combination of a broad-spectrum β-lactam antibacterial (e.g. cefotaxime or ceftriaxone), piperacillin/tazobactam and a macrolide is mostly recommended. In patients with a predisposition for Pseudomonas aeruginosa, a combination of piperacillin/tazobactam, cefepime, imipenem or meropenem and levofloxacin or ciprofloxacin is frequently used. Treatment duration of more than 7 days is not generally recommended, except for proven infections with P. aeruginosa, for which 15 days of treatment appears to be appropriate. Further care issues in all hospitalized patients are timely administration of antibacterials, oxygen supply in case of hypoxaemia, and fluid management and dose adjustments according to kidney function. The management of elderly patients with CAP is a challenge. Shifts in antimicrobial resistance and the availability of new antibacterials will change future clinical practice. Studies investigating new methods to detect pathogens, determine the optimal antimicrobial regimen and clarify the duration of treatment may assist in further optimizing the management of elderly patients with CAP.

Targeting inflammation to prevent bronchopulmonary dysplasia: can new insights be translated into therapies?

Bronchopulmonary dysplasia (BPD) frequently complicates preterm birth and leads to significant long-term morbidity. Unfortunately, few therapies are known to effectively prevent or treat BPD. Ongoing research has been focusing on potential therapies to limit inflammation in the preterm lung. In this review we highlight recent bench and clinical research aimed at understanding the role of inflammation in the pathogenesis of BPD. We also critically assess currently used therapies and promising developments in the field.

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.

Macrolide immunomodulation of chronic respiratory diseases

Important immunomodulatory properties of 14- and 15-membered macrolides may benefit patients with respiratory diseases associated with chronic inflammation. These properties include decreased neutrophil chemotaxis and infiltration into the respiratory epithelium, inhibition of transcription factors leading to decreased proinflammatory cytokine production, downregulation of adhesion molecule expression, inhibition of microbial virulence factors including biofilm formation, reduced generation of oxygen-free radicals, enhanced neutrophil apoptosis, and decreased mucus hypersecretion with improved mucociliary clearance. Chronic, low-dose macrolides have dramatically improved survival in patients with diffuse panbronchiolitis (DPB). Given the overlap in pathogenesis between DPB and other chronic respiratory diseases, macrolides are being investigated for cystic fibrosis, asthma, chronic bronchitis, chronic sinusitis, and chronic obstructive pulmonary disease. Preliminary data (largely from open-label trials) are promising, but conclusive results are needed.

Azithromycin decreases crevicular fluid volume and mediator content

Azithromycin enhances the response to root planing and produces anti-inflammatory effects in treating chronic lung disease. This led us to hypothesize that azithromycin inhibits inflammatory mediator production in gingiva, leading to decreased gingival crevicular fluid (GCF) volume. To test this hypothesis, ten periodontally healthy volunteers received azithromycin every 24 hours for 48 hours. GCF samples were collected from 12 maxillary interproximal sites prior to azithromycin (baseline) and 2, 4, 7, and 14 days later. Samples were assayed for IL-1beta, IL-8, TNF-alpha, VEGF, IL-6, and IL-10. With azithromycin treatment, GCF volume decreased significantly on days 2 through 7 (P < 0.05), but increased toward baseline levels on day 14. This was accompanied by a transient decrease in the content of IL-1beta, IL-8, TNF-alpha, and VEGF (P < 0.05). IL-6 and IL-10 were not detected. Since plaque was absent throughout the study, the findings suggest that azithromycin produces anti-inflammatory effects in gingiva.

Azithromycin alters macrophage phenotype and pulmonary compartmentalization during lung infection with Pseudomonas

Infection with mucoid strains of Pseudomonas aeruginosa in chronic inflammatory diseases of the airway is difficult to eradicate and can cause excessive inflammation. The roles of alternatively activated and regulatory subsets of macrophages in this pathophysiological process are not well characterized. We previously demonstrated that azithromycin induces an alternatively activated macrophage-like phenotype in vitro. In the present study, we tested whether azithromycin affects the macrophage activation status and migration in the lungs of P. aeruginosa-infected mice. C57BL/6 mice received daily doses of oral azithromycin and were infected intratracheally with a mucoid strain of P. aeruginosa. The properties of macrophage activation, immune cell infiltration, and markers of pulmonary inflammation in the lung interstitial and alveolar compartments were evaluated postinfection. Markers of alternative macrophage activation were induced by azithromycin treatment, including the surface expression of the mannose receptor, the upregulation of arginase 1, and a decrease in the production of proinflammatory cytokines. Additionally, azithromycin increased the number of CD11b(+) monocytes and CD4(+) T cells that infiltrated the alveolar compartment. A predominant subset of CD11b(+) cells was Gr-1 positive (Gr-1(+)), indicative of a subset of cells that has been shown to be immunoregulatory. These differences corresponded to decreases in neutrophil influx into the lung parenchyma and alteration of the characteristics of peribronchiolar inflammation without any change in the clearance of the organism. These results suggest that the immunomodulatory effects of azithromycin are associated with the induction of alternative and regulatory macrophage activation characteristics and alteration of cellular compartmentalization during infection.

Low expression of T-cell co-stimulatory molecules in bone marrow-derived dendritic cells in a mouse model of chronic respiratory infection with Pseudomonas aeruginosa

Pseudomonas (P.) aeruginosa frequently colonizes the respiratory tract of patients with chronic respiratory tract infections such as diffuse panbronchiolitis (DPB). The number of dendritic cells (DCs) that play a central role in immune functions as antigen-presenting cells is reportedly increased in the bronchiolar tissues of patients with DPB. However, the functions of DCs in chronic P. aeruginosa respiratory tract infection have not been defined. Here, we assessed the functions of DCs and the effect of macrolide antibiotics that are therapeutic agents for DPB, in a murine model of DPB caused by P. aeruginosa. Mice were intubated with either P. aeruginosa- or saline-precoated tubes for 80 days. Thereafter, the expression of T-cell co-stimulatory molecules (CD40, CD80, and CD86) and cytokine secretion (interleukin (IL)-10, IL-6, IL-12p40, and tumor necrosis factor (TNF)-alpha) on bone marrow-derived DCs stimulated by lipopolysaccharide were examined by flow cytometry and enzyme-linked immunosorbent assays. The expression of co-stimulatory molecules was significantly decreased in mice infected with P. aeruginosa compared to the saline-treated control mice, but production of these cytokines did not significantly differ between the two groups. Pretreatment with clarithromycin ex vivo decreased CD40 expression on DCs obtained from P. aeruginosa-infected mice and also decreased the production of IL-6, IL-12p40 and TNF-alpha by DCs. These findings suggest that chronic P. aeruginosa infection alters DC functions and that macrolides function as anti-inflammatory agents by modulating the functions of DCs in chronic P. aeruginosa infection.

Autoimmune hypoparathyroidism in a 12-year-old girl with McKusick cartilage hair hypoplasia

McKusick type metaphyseal chondrodysplasia, or cartilage hair hypoplasia (CHH), is a rare autosomal recessive osteochondrodysplasia secondary to a mutation in the RMRP gene. In addition to the metaphyseal chondrodysplasia and the short-limb dwarfism, patients may present with a multisystemic disease, associating immune deficiency with recurrent infantile or childhood infections, hematological abnormalities, and gastrointestinal dysfunction. The probability of malignancy is increased in these patients, as are disimmune manifestations. We report on a 12-year-old girl with a new mutation of the RMRP gene and a severe multisystemic CHH (hematological and pulmonary lesions, severe immune deficiency, arthritis, pancreatic insufficiency, malabsorption, chronic diarrhea) receiving parenteral nutrition who presented with acute symptomatic hypocalcemia and hypercalciuria associated with the presence of autoantibodies directed against the calcium-sensor receptor. At the same time, there was an important escalation of diarrhea. Corticosteroids led to a progressive improvement of biological signs (hypocalcemia, hypoparathyroidism). By contrast, gastrointestinal symptoms and malabsorption did not improve. To our knowledge, this is the first report of autoimmune hypoparathyroidism in CHH.