Extra-pulmonary diseases related to Mycoplasma pneumoniae in children: recent insights into the pathogenesis. Curr Opin Rheumatol. 2018;30:380-387. [PMID: 29432224 DOI: 10.1097/bor.0000000000000494]

Immunological Features of Pediatric Interstitial Pneumonia Due to Mycoplasma pneumoniae

Background: Inflammatory response, oxidative stress, and immunologic mechanism are involved in the pathogenesis of Mycoplasma pneumoniae pneumonia (MPP). However, the role of immune system of pediatric interstitial pneumonia due to M. pneumoniae infections remains poorly understood. The aim of this study was to analyze the immunologic features of pediatric interstitial pneumonia due to Mycoplasma pneumoniae (M. pneumoniae). Methods: A retrospective study was conducted on a primary cohort of children with MPP. Propensity score analysis was performed to match interstitial pneumonia and pulmonary consolidation children. Results: The clinical characteristics strongly associated with the development of interstitial pneumonia were boys, age >5 years, wheezing history, hydrothorax free, lymphocytes (>3.0 × 10⁹/L), CD19⁺ (>0.9 × 10⁹/L), CD3⁺ (>2.5 × 10⁹/L), CD4⁺ (>1.5 × 10⁹/L), CD8⁺ (>0.9 × 10⁹/L), interleukin-6 (IL-6, <30 pg/ml), IL-10 (<6 pg/ml), and interferon-γ (IFN-γ, <15 pg/ml). After propensity score analysis, children with interstitial pneumonia showed significantly higher CD19⁺, CD3⁺, and CD4⁺ T cell counts, and lower serum IL-6, IL-10, and IFN-γ levels. The final regression model showed that only CD4⁺ T cells (>1.5 × 10⁹/L, OR = 2.473), IFN-γ (<15 pg/ml, OR = 2.250), and hydrothorax free (OR = 14.454) were correlated with the development of interstitial pneumonia among children with MPP. Conclusions: The M. pneumoniae-induced interstitial pneumonia showed increased CD4⁺ T cells and lower serum IFN-γ level. Specific immunologic profiles could be involved in the development of pediatric interstitial pneumonia due to M. pneumoniae infections.

Mycoplasma pneumoniae: Atypical Pathogen in Community Acquired Pneumonia

Mycoplasma pneumoniae is a one of most common reasons of respiratory tract infections in both adolescents and children with severity ranged from moderate to high. Many facts in the previous years regarding infections were induced via this organism having extra pathogenic mechanisms. Clinically, resistance to macrolide has produced internationally and represents a treatment trouble. Antimicrobial sensitivity checking out techniques have been applied, and novel antibiotics which are effective towards M. pneumoniae are present processing development. That evaluate concentrates on the several trends occurring in the previous quite a few years which beautify the grasp of that microorganism, which is one of the smallest pathogenic bacteria; however, is of extreme medical significance.

Early prediction of necrotizing pneumonia from mycoplasma pneumoniae pneumonia with large pulmonary lesions in children

To compare the different features of necrotizing pneumonia (NP) and non-NP (NNP) caused by Mycoplasma pneumoniae pneumonia (MPP) with large pulmonary lesions, and explore the predictor for NP to differentiate from MPP. A retrospective study of MPP patients with large pulmonary lesions hospitalized from January 2008 to December 2019 was enrolled, and clinical manifestations, laboratory findings, radiological findings were analyzed. Of 135 MPP patients with large pulmonary lesions, 56 were in the NP group, 79 were in the NNP group. We found the median length of fever days were much longer in NP group than those in NNP group. Higher levels of WBC, CRP, LDH, IL-6 in NP group were observed. Furthermore, the incidence of pulmonary consolidation was much higher in NP patients than that in NNP patients, while the CT value of large pulmonary lesion was much lower in NP patients. In ROC curve analysis, the cut-off values for the CT value and IFN-γ were 36.43 and 7.25 pg/ml, respectively. NP caused by MPP might be easier to suffer from prolonged clinical course, severe laboratory and radiological findings. CT value of large pulmonary lesions and IFN-γ could be used as biomarkers to predict NP from MPP with large pulmonary lesions in children.

Myositis and acute kidney injury in bacterial atypical pneumonia: Systematic literature review

BACKGROUND

Bacterial community-acquired atypical pneumonia is sometimes complicated by a myositis or by a renal parenchymal disease. Available reviews do not mention the concurrent occurrence of both myositis and acute kidney injury.

METHODS

In order to characterize the link between bacterial community-acquired atypical pneumonia and both myositis and a renal parenchymal disease, we reviewed the literature (United States National Library of Medicine and Excerpta Medica databases).

RESULTS

We identified 42 previously healthy subjects (35 males and 7 females aged from 2 to 76, median 42 years) with a bacterial atypical pneumonia associated both with myositis (muscle pain and creatine kinase ≥5 times the upper limit of normal) and acute kidney injury (increase in creatinine to ≥1.5 times baseline or increase by ≥27 μmol/L above the upper limit of normal). Thirty-six cases were caused by Legionella species (N = 27) and by Mycoplasma pneumoniae (N = 9). Further germs accounted for the remaining 6 cases. The vast majority of cases (N = 36) presented a diffuse myalgia. Only a minority of cases (N = 3) were affected by a calf myositis. The diagnosis of rhabdomyolysis-associated kidney injury was retained in 37 and that of acute interstitial nephritis in the remaining 5 cases.

CONCLUSION

Bacterial atypical pneumonia may occasionally induce myositis and secondary kidney damage.

Clinical evidences on the antiviral properties of macrolide antibiotics in the COVID-19 era and beyond

Macrolides are a large group of antibiotics characterised by the presence of a macro-lactone ring of variable size. The prototype of macrolide antibiotics, erythromycin was first produced by Streptomyces and associated species more than half a century ago; other related drugs were developed. These drugs have been shown to have several pharmacological properties: in addition to their antibiotic activity, they possess some anti-inflammatory properties and have been also considered against non-bacterial infections. In this review, we analysed the available clinical evidences regarding the potential anti-viral activity of macrolides, by focusing on erythromycin, clarithromycin and azithromycin. Overall, there is no significant evidences so far that macrolides might have a direct benefit on most of viral infections considered in this review (RSV, Influenza, coronaviruses, Ebola and Zika viruses). However, their clinical benefit cannot be ruled out without further and focused clinical studies. Macrolides may improve the clinical course of viral respiratory infections somehow, at least through indirect mechanisms relying on some and variable anti-inflammatory and/or immunomodulatory effects, in addition to their well-known antibacterial activity.

Interleukin-23 derived from CD16+ monocytes drives IL-17 secretion by TLR4 pathway in children with mycoplasma pneumoniae pneumonia

AIMS

The study aimed to investigate whether IL-23 is amplified in monocyte subsets of MP pneumonia and to determine its relevant pathway.

MATERIALS AND METHODS

We firstly analyze the IL-23p19 expression in monocyte subgroups in MP pneumonia patients and healthy controls subjects by using flow cytometry. Then, we also analyzed the percentage of IL-17⁺γδT cells and Th17 cells in patients with MP pneumonia and controls subjects. At the same time, the relation between IL-23 and IL-17 were also assessed. Furthermore, we constructed the recombinant community-acquired respiratory distress syndrome (CARDS) toxin and intend to stimulate peripheral blood mononuclear cells and RAW264.7 cells in vitro. IL-23p19 was detected by flow cytometry and the mRNA levels were measured by real-time PCR. Finally, TLR4 pathway was also investigated by TAK242 inhibitor.

KEY FINDINGS

It turned out that the expression of IL-23p19 was increased in CD14^brightCD16⁺ monocyte of MP pneumonia patients than controls subjects. The patients with MP pneumonia had significantly higher the percentage of IL-17⁺γδT cells and Th17 cells than controls subjects. Interestingly, the levels of IL-23 were positively related to IL-17 in MP pneumonia patients. CD16⁺ monocytes and RAW264.7 cells, respectively can be induced by CARDS toxin to secrete IL-23 by TLR4 pathway in vitro.

SIGNIFICANCE

These results indicated that IL-23-IL-17⁺γδT/Th17 axis may play a role in the pathogenesis of MP pneumonia, whereas IL-23 derived from CD16⁺ monocytes was expanded in MP pneumonia by TLR4 pathway.

Urticarial vasculitis in pediatric systemic lupus erythematosus

BACKGROUND/OBJECTIVES

To determine the prevalence of urticarial vasculitis (UV) in a pediatric systemic lupus erythematosus (pSLE) cohort of Arab ethnicity from Oman and to describe their demographic, clinical, and laboratory features.

METHODS

We conducted a retrospective multicenter study among pediatric rheumatology centers in Oman over a 10-year period from 2008 to 2018. Analyses were performed using univariate statistics.

RESULTS

A total of 148 pSLE under the age of 13 years were included of which 30% (n = 44) were men. The overall mean age at SLE diagnosis was 7.6 ± 3.5 years while the mean disease duration was 10.1 ± 5.4 years. UV was diagnosed in 36% (n = 53) of pSLE patients. Patients with pSLE and UV were more likely to be male (57% vs 15%; P < .001), diagnosed at a younger age (5.9 vs 8.5 years; P < .001), have a family history of SLE (53% vs 36%; P = .044), and have associated conjunctivitis, (32% vs 5.3%; P < .001) but less likely to have CNS involvement (7.6% vs 20%; P = .045) or hematological manifestations such as leukopenia (9.4% vs 24%; P = .028) and thrombocytopenia (5.7% vs 18%; P = .045). This subgroup was also more likely to be associated with low C3 complement count (94% vs 66%; P < .001) and positive cytoplasmic ANCA (11% vs 0%; P = .022).

CONCLUSION

We report a high occurrence of UV in a pSLE cohort associated with unique demographic, clinical, and laboratory features.

Serum Cytokines and FeNO in School-Aged Children with Mycoplasma pneumoniae Pneumonia

Background

Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) that is particularly prevalent in school-aged children. This study explored the potential involvement of cytokines in children with Mycoplasma pneumoniae pneumonia (MPP) infection.

Material/Methods

Children aged 3–7 years who were hospitalized due to CAP infection were enrolled and divided into 2 groups: an MPP group (n=33) and a NMPP group (n=38), along with 21 age-matched healthy controls. Clinical characteristics and laboratory data were recorded. Serum levels of IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 were assessed using Luminex xMAP technology. Correlation analysis and ROC curves analysis were also performed to further explore the role of these detected cytokines in CAP.

Results

Compared with the healthy controls, the serum expression of IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 were significantly higher in the MPP and NMPP groups. Furthermore, serum IL-18 expression was found to be significantly correlated with lgE, FeNO, IL-5, IL-8, and IL-13 concentrations. Significant differences were also observed between the MPP group and NMPP group patients in levels of IL-18, IL-5, and IL-6, and further ROC analysis showed that the area under the curve (AUC) of IL-18 and IL-5 were 0.813 (95% CI: 0.710–0.917; P<0.01) and 0.844 (95% CI: 0.756–0.933; P<0.01), respectively.

Conclusions

IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 serum levels showed significant differences in children with CAP. IL-18 and IL-5 were much higher in the MPP group compared to the NMPP group patients, whereas IL-6 levels were significantly lower in these 2 groups.

Clinical characteristics of Kawasaki disease complicated with Mycoplasma pneumoniae pneumonia: A retrospective study

This study aimed to investigate the inner linkage and mechanism of Mycoplasma pneumoniae (MP) infection and Kawasaki disease (KD), as well as the risk factors of outcome in this cohort of patients.A retrospective study was performed in 210 patients diagnosed with KD complicated with community acquired pneumonia (CAP) in Children's Hospital, Zhejiang University School of Medicine from January 2014 to December 2017. They were divided into two groups based on MP infection: MP infection group (n = 97) and non-MP infection group (n = 113). We compared the variables of these two groups based on medical records.The MP infection group had higher ESR than the non-MP infection group. During hospitalization, the non-MP infection group had higher levels of WBC during hospital, LDH, PCT, and lower HB when compared to the MP infection group. No differences were found in the hs-CRP level, N%, PLT, ALT, CKMB, and cytokine levels (IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ) between MP and non-MP infection group. Likewise, no difference was found in fever duration or hospital stays between them. Totally 19 patients in the infection group had CAA with a rate of 19.59%; and 27 (23.89%) patients had CAA in the non-MP infection group. Unfortunately, no difference was found in CAA rate between the two groups.MP infection may occur simultaneously in children with Kawasaki disease. KD patients with MP infection tended to occur in older population. MP infection may not increase the risk of CAA, which still needs further large-scaled studies to confirm. Clinicians should be alert to KD patients with high level of ESR. MP should be screened and early treatment with macrolides should be given timely.

Monocyte subsets study in children with Mycoplasma pneumoniae pneumonia

The aim of this study was to evaluate the changes in the three subsets of monocyte (classical, intermediate, and non-classical) and the expression of human leukocyte antigen-DR (HLA-DR) on monocyte subsets during MP pneumonia in children. Monocyte subsets were analyzed in the peripheral blood of healthy volunteers and MP pneumonia patients at the stages of admission and remission after clinical therapy. They were defined as classical (CD14⁺CD16^-), intermediate (CD14^brightCD16⁺), and non-classical (CD14^dimCD16⁺) using flow cytometry. Furthermore, three subsets of monocyte were analyzed for the expression of HLA-DR. Patients with MP pneumonia at admission had a higher proportion of intermediate and non-classical monocytes than healthy subjects (all P < 0.05). The proportion of intermediate subset and non-classical subset was lower in MP pneumonia patients at remission than at admission (all P < 0.05). In comparison with the other monocyte subsets, intermediate subset showed a significantly higher percentage of HLA-DR in MP pneumonia patients at admission (P < 0.05). Further analysis revealed that the expression of HLA-DR on intermediate subset was lower in severe patients than in non-severe patients (P < 0.05).Our data has shown for the first time that MP pneumonia is associated with the increased proportion of non-classical and intermediate monocytes, indicating the involvement of monocyte-related mechanisms in the pathogenesis of this disease. Additionally, the decreased expression of HLA-DR on CD14^brightCD16⁺ subset may be a potential indicator of the severity of MP pneumonia.

Respiratory failure and macrophage activation syndrome as an onset of systemic lupus erythematosus: A case report

BACKGROUND

Macrophage activation syndrome (MAS) is defined as a specific secondary hemophagocytic lymphohistiocytosis that refers particularly to those triggered by autoimmune diseases. MAS is a rare and highly lethal complication of systemic lupus erythematosus (SLE), which can be associated with, or mimic, disease flare. However, the data regarding the clinical course, management and outcome of SLE with MAS is limited, especially in adults. Lack of clinical recognition of the disease often leads to poor prognosis.

CASE SUMMARY

We report a 36-year-old Chinese woman without relevant past medical history who was admitted to hospital with a 6-d history of jaundice and a high fever of 39.4°C lasting one day. Abdominal magnetic resonance imaging excluded obstructive jaundice, no infection was identified and empiric superior antibiotic treatment (meropenem) showed no clinical improvement. However, newly emerged pancytopenia and respiratory failure endangered the patient’s life. Autoimmune work-up finally led to the diagnosis of SLE, which initially presented as MAS and manifested respiratory failure, although neither bone marrow biopsy nor lymph node biopsy showed hemophagocytosis. To our knowledge, such a scenario has never been reported in detail before. The patient had a favorable reaction to combination treatment with corticosteroid and cyclosporine A and has been in clinical remission during the 1-year follow up period.

CONCLUSION

Respiratory failure and MAS can be an onset of SLE. Early diagnosis and appropriate treatment are extremely important for a better prognosis.

Mycoplasma pneumoniae-related hepatitis in children

Mycoplasma pneumoniae (M. pneumoniae) is a small bacterium characterized by the absence of cell wall. It is a human pathogen causing upper and lower respiratory infections, both in adults and children. However, it is also considered to be implicated in the pathogenesis of several types of extra-respiratory diseases, including some gastrointestinal disorders. The liver involvement in children during or after M. pneumoniae infections is analyzed and discussed in this review. Through a systematic literature search, it is evidenced that M. pneumoniae is not infrequently associated with alteration of liver function, but rarely causes acute and severe hepatitis in children. M. pneumoniae should be considered as an unusual cause of acute hepatitis in children, whenever the most common hepatotropic viruses have been excluded. The pathogenesis of M. pneumoniae-related hepatitis is likely to be immune-mediated: both the innate and adaptive immune responses may play a fundamental role. However, the exact pathological mechanisms have to be elucidated yet. Further clinical studies are needed in order to understand the actual relevance of this microorganism in liver disease and its pathogenesis.

Anti-Mycoplasma Activity of Daptomycin and Its Use for Mycoplasma Elimination in Cell Cultures of Rickettsiae

Mycoplasma contamination detrimentally affects cellular functions and the growth of intracellular pathogens in cell cultures. Although several mycoplasmacidal agents are commercially available for sterile cell cultures, they are not applicable to rickettsia-infected cells. In our attempt to find an anti-mycoplasma drug for contaminated rickettsial cultures, we determined the susceptibilities of three common Mycoplasma species to daptomycin. Mycoplasma orale and M. arginini showed low-level resistance to daptomycin (minimum inhibitory concentration, MIC = 2 mg/L), whereas M. hyorhinis was high-level resistant (MIC = 32 mg/L). However, some Mycoplasma isolates developed higher resistance to daptomycin after failed treatments with inadequate doses or durations. An aminoglycoside (gentamicin) was still active against M. hyorhinis and could be used in Orientia cultures. For complete eradication of mycoplasmas in Rickettsia cultures, we recommend a 3-week treatment with daptomycin at 256 mg/L. In contaminated Orientia cultures, daptomycin at 32 mg/L was effective in eradicating M. orale, whereas either gentamicin or amikacin (100 mg/L) was effective in eradicating M. hyorhinis. Unlike each drug alone, the combinations of daptomycin plus clindamycin and/or quinupristin/dalfopristin proved effective in eradicating M. hyorhinis. In summary, our study demonstrated the in vitro anti-mycoplasma activity of daptomycin and its application as a new mycoplasma decontamination method for Rickettsia and Orientia cultures.

Mycoplasma pneumoniae-related extra-pulmonary diseases and antimicrobial therapy

The findings by Yang-TI et al. suggested that macrolide-resistance and/or delayed appropriate antimicrobial treatment may contribute to the development of Mycoplasma pneumoniae-related extra-pulmonary diseases in children. Indeed, these conditions can have variable clinical expression and severity, and may arise in immunologically predisposed children after recurrent/persistent exposure to Mycoplasma pneumoniae.

Impact of atopy on the severity and extrapulmonary manifestations of childhood Mycoplasma pneumoniae pneumonia

Objectives

The impact of atopy on disease severity and extrapulmonary manifestations in children with Mycoplasmapneumoniae (MP) pneumonia is unknown.

Methods

Patients diagnosed with MP pneumonia between January 2016, and December 2017, were enrolled in this study. A total of 150 MP pneumonia patients were enrolled at diagnosis and divided into the atopic group (n = 48) and the nonatopic group (n = 102). Furthermore, these patients were also assessed after being divided into the pulmonary group (n = 120) and the extrapulmonary group (n = 30). Clinical characteristics, respiratory disease severity, any allergy history, and specific allergen sensitizations were collected from all patients. The serum interleukin‐17 (IL‐17) and total immunoglobulin E (lgE) levels were also measured.

Results

More children in the atopic group than those in the nonatopic group presented with severe MP pneumonia, tachypnea, oxygen therapy, steroid treatment, atopic conditions including asthma attack, a previous history of asthma, decreased IL‐17 levels, and increased IgE levels (all P < 0.05). When compared with those in the pulmonary group, the patients in the extrapulmonary group showed higher percentages of atopy, higher total lgE levels, and lower IL‐17 levels (all P < 0.05).

Conclusions

Atopy may be a risk factor for disease severity and extrapulmonary manifestations in children with MP pneumonia.