Mycoplasma pneumonia Infection: A Possible Trigger for Immune Thrombocytopenia

A case of acquired transient bleeding diathesis associated with acquired platelet storage pool deficiency and defective thromboxane A2 production

Acquired disorders of platelet function are an underdiagnosed cause of bleeding tendency. A 14-year-old girl developed moderate mucocutaneous bleeding two weeks after a Mycoplasma pneumoniae infection successfully treated with clarithromycin. The patient was referred to us 7 months later for laboratory investigation of the persisting bleeding diathesis. The patient's personal and family histories were negative for bleeding disorders. Complete blood count, von Willebrand Factor levels and coagulation tests were normal; platelet aggregation, ATP secretion, δ-granules content and serum thromboxane B2 levels were defective. At follow-up visits, laboratory parameters and the bleeding diathesis progressively normalized within 2 years. The patient's condition is compatible with a diagnosis of acquired Storage Pool Deficiency (SPD), associated with defective thromboxane A2 production. To our knowledge, this is the first case of acquired, transient SPD with spontaneous remission. The pathogenic role of Mycoplasma pneumoniae infection or clarithromycin is possible, albeit uncertain.

'Candidatus Mycoplasma Haemoalbiventris' and Tick-Borne Pathogens in Black-Eared Opossum (Didelphis aurita) from Southeastern Brazil

The black-eared opossum (Didelphis aurita) is a South American synanthropic marsupial. The presence of opossums in domestic spaces is relevant in the One-Health context since they are hosts of pathogens and ectoparasites that may affect the health of domestic animals and humans. In this study, we aim to determine the occurrence of hemoplasmas and selected tick-borne pathogens in free-ranging black-eared opossums, along with their molecular characterization, hematological and biochemical evaluation and factors associated with infection, in the municipality of Viçosa, State of Minas Gerais, southeastern Brazil. Thirty black-eared opossums were trapped between March 2021 and June 2022. Ectoparasites were collected. Hematological and biochemical analyses were performed. DNA from EDTA-blood samples were analyzed by PCR and qPCR assays. By molecular analyses, 'Candidatus Mycoplasma haemoalbiventris' was the most prevalent hemoparasite (73.3%), followed by Hepatozoon sp. (22.2%). Significant differences were observed in the number of platelets, and in the concentration of protein and globulins in the animals infected by 'Ca. M. haemoalbiventris' when compared with the negative group. This is the first report of 'Ca. M. haemoalbiventris' infection in D. aurita.

Secondary Immune Thrombocytopenia Due to Mycoplasma pneumoniae Without Clinically Significant Evidence of Active Infection

Immune thrombocytopenia (ITP) is a leading cause of isolated thrombocytopenia characterized by autoantibody-mediated destruction of platelets, impaired megakaryocyte function, and pathologic T-cell recognition of platelet antigens. Several triggers for ITP have been identified. Treatment of the inciting cause decreases the antibodies responsible for molecular mimicry, and these cases are usually associated with a better outcome with a decreased probability of progression to chronic ITP. Mycoplasma pneumoniae infection is known to have extrapulmonary manifestations, and growing evidence suggests it can be a cause of secondary ITP. Many of the described cases report evidence of a pulmonary infection with severe mucosal bleeding. Here, we describe an interesting case of a patient presenting with isolated thrombocytopenia with mild mucosal bleeding, later found to be positive for Mycoplasma immunoglobulin M without clinically significant evidence of active infection. Currently, mycoplasma testing is not routinely performed as a workup for ITP. However, clinicians may consider this before proceeding with more aggressive treatment for refractory ITP (i.e., prolonged immunosuppression, splenectomy). This case illustrates that mild/asymptomatic Mycoplasma infection can also be associated with ITP.

Development and Validation of a Radiomics Nomogram for Differentiating Mycoplasma Pneumonia and Bacterial Pneumonia

Objectives: To develop and validate a radiological nomogram combining radiological and clinical characteristics for differentiating mycoplasma pneumonia and bacterial pneumonia with similar CT findings. Methods: A total of 100 cases of pneumonia patients receiving chest CT scan were retrospectively analyzed, including 60 patients with mycoplasma pneumonia and 40 patients with bacterial pneumonia. The patients were divided into the train set (n = 70) and the test set (n = 30). The features were extracted from chest CT images of each patient by AK analysis software, then univarite analysis, spearman correlation analysis, and least absolute shrinkage and selection operator (LASSO) were utilized for dimension reduction in training set. A radiomics model was built by multivariable logistic regression based on the selected features, and a radiomics-clinical multivariable logistic regression model was built by combining imaging radiomics and clinical risk factors (age and temperature). ROC, AUC, sensitivity, specificity, and accuracy were calculated to validate the two models. The nomogram of the radiomics-clinical was built and evaluated by calibration curve. The clinical benefit of the two models was measured by using decision curve. Results: A total of 396 texture features were extracted from each chest CT image, and 10 valuable features were screened out. In the radiomics model, the AUC, sensitivity, specificity, and accuracy for the train set is 0.877, 0.762, 0.821, 78.6%, and for the test set it is 0.810, 0.667, 0.750 and 70.0%, respectively. In the radiomics-clinical model, the AUC, sensitivity, specificity, and accuracy for the train set is 0.905, 0.976, 0.714, 87.1%, and for the test set is is 0.847, 0.889, 0.667 and 80.0%, respectively. Decision curve analysis shows that both the two models increase the clinical benefits of the patients, and the radiomics-clinical model gains higher clinical benefits, compared to the radiomics model. Conclusion: The radiomics-clinical nomogram had good performance in identifying mycoplasma pneumonia and bacterial pneumonias, which would be helpful in clinical decision-making.

Central Nervous System Vasculitis as a Rare Presentation of Mycoplasma pneumoniae: A Case Report

Mycobacteria pneumoniae (MP) commonly causes upper and lower respiratory tract infections. The clinical manifestation is classified as pulmonary and extrapulmonary. These manifestations vary according to the involved system. MP may affect one system or more at a time. Commonly prodromal respiratory symptoms precede systemic involvement. Central nervous system involvement in uncommon. This report is presenting a rare case of central nervous system vasculitis secondary to MP, highlighting the diagnosis and management with a succinct literature review.

[Early differential diagnosis between COVID-19 and mycoplasma pneumonia with chest CT scan]

OBJECTIVE

To early differentiate between coronavirus disease 2019 (COVID-19) and adult mycoplasma pneumonia with chest CT scan.

METHODS

Twenty-six patients with COVID-19 and 21 patients with adult mycoplasma pneumonia confirmed with RT-PCR test were enrolled from Zibo First Hospital and Lanshan People's Hospital during December 1st 2019 and March 14th 2020. The early chest CT manifestations were analyzed and compared between the two groups.

RESULTS

The interstitial changes with ground glass density shadow (GGO) were similar in two groups during first chest CT examination (P>0.05). There were more lung lobes involved on the first chest CT in COVID-19 patients, which were mostly distributed in the dorsal outer zone (23/26, 88.5%), and nearly half of them (12/26, 46.2%) were accompanied by crazy-paving sign; while the lesions in adult mycoplasma pneumonia patients were mostly distributed along the bronchi, and the bronchial wall was thickened (19/21, 90.5%), accompanied with tree buds / fog signs (19/21, 90.5%). The above CT signs were significantly different between the two kinds of pneumonia (all P<0.01). COVID-19 had a longer course compared with mycoplasma pneumonia, the disease peaks of COVID-19 patients was on day (10.5±3.8), while the disease on CT was almost absorbed on day (7.9±2.2) in adult mycoplasma pneumonia. The length of hospital stay in COVID-19 patients was significantly longer than that of mycoplasma pneumonia patients [(19.5±4.3) d vs (7.9±2.2) d, P<0.01].

CONCLUSIONS

The lesions of adult mycoplasma pneumonia are mostly distributed along the bronchi with tree buds/fog signs, while the lesions of COVID-19 are mainly distributed in the dorsal outer zone accompanied by crazy-paving sign, which can early distinguish two diseases.

Immune Thrombocytopenic Purpura: A Sequelae of Mycoplasma pneumoniae Infection

Our patient presented with a mild upper respiratory infection, which quickly developed into atypical pneumonia. Although atypical pneumonia is a common clinical presentation, our case is unique due to the rare hematologic complications associated with the underlying etiology of this atypical pneumonia case. Most cases of atypical pneumonia are simple, but ours developed immune thrombocytopenic purpura (ITP), which is a rare complication associated with an acute Mycoplasma pneumoniae infection (evidenced by positive IgM titers). Although our patient did not develop significant bleeding, our review of the literature demonstrated that ITP associated with M. pneumoniae infection can be fatal. Platelet count should be closely monitored and promptly treated.

Acute Bronchitis Caused by Bordetella Pertussis Possibly Co-Infected with Mycoplasma Pneumoniae

BACKGROUND Mycoplasma pneumoniae and Bordetella pertussis are among the causative pathogens of human acute bronchitis, which usually has mild symptoms. However, if there is a co-infection, the symptoms often can be prolonged and occasionally can lead to severe respiratory complications. CASE REPORT A 49-year-old Japanese female, who had not been vaccinated for B. pertussis, developed a persistent productive cough which became vigorous, and occasionally caused difficulty breathing and vomiting. Since serum IgM to M. pneumoniae was positive and IgG to B. pertussis was significantly elevated, and there were no findings of pneumonia on a chest x-ray film, we made a diagnosis of acute bronchitis caused by B. pertussis with possible co-infection with M. pneumoniae. The use of garenoxacin, a quinolone derivative, failed to work; however, a macrolide antibiotic clarithromycin dramatically improved her symptoms shortly after its administration. CONCLUSIONS In this patient case, because of the lymphocyte-stimulatory nature of M. pneumoniae and B. pertussis, an increased immunological response was likely to be involved in the pathogenesis of the symptoms. The immunosuppressive effect of clarithromycin was considered to repress the increased lymphocyte activity, facilitating the remission of the disease.

Immune Thrombocytopenia Associated with Mycoplasma pneumoniae Infection

Immune thrombocytopenia (ITP) related to Mycoplasma pneumoniae infection is a rare condition and usually associated with a severe clinical course. We here report a case of a young man with a clinical diagnosis of severe ITP secondary to M. pneumoniae infection. The clinical features, therapy and outcome are presented.

Multi-system manifestations of Mycoplasma pneumoniae infection in a young patient

Introduction.Mycoplasma pneumoniae is a small cell-wall-lacking bacterium that belongs to the mycoplasma (Mollicutes) prokaryote micro-organisms. It is a common cause of both upper and lower respiratory tract infections in all age groups. Respiratory illness is the most common manifestation of M. pneumoniae infection; however, extrapulmonary involvement may be present or predominant. The skin, mucus membranes, central nervous system, cardiovascular system, haematopoietic system, kidneys and musculoskeletal system are the most commonly involved extrapulmonary sites. Immune thrombocytopenia purpura has been reported as a rare haematological manifestation of mycoplasma infection. Here, we report, with a literature review, the case of a young adult with M. pneumoniae infection, presenting with acute febrile illness, myringitis, erythema multiforme, mild Raynaud’s phenomenon symptoms and severe thrombocytopenia.

Case presentation. Our patient was a 24-year-old healthy man who presented to an emergency department with acute febrile illness, upper respiratory tract infection symptoms, myringitis, erythema multiforme skin lesions, severe thrombocytopenia, and pale and cold hands. Mycoplasma serology suggested acute M. pneumoniae infection. The patient had a complete resolution of symptoms and gradual recovery from the thrombocytopenia after a course of anti-Mycoplasma therapy with azithromycin. Our case illustrates the multi-system involvement of M. pneumoniae infection.

Conclusion.M. pneumoniae is a frequent cause of upper and lower respiratory tract infections in children and young adults. Multi-system involvement including the skin, vascular and haematological systems in young adults with upper or lower respiratory tract infection, as in our patient, should raise the suspicion of Mycoplasma infection. Our case also illustrates an excellent clinical response and recovery from thrombocytopenia shortly after anti-Mycoplasma antimicrobial therapy.

Mycoplasma pneumoniae from the Respiratory Tract and Beyond

Mycoplasma pneumoniae is an important cause of respiratory tract infections in children as well as adults that can range in severity from mild to life-threatening. Over the past several years there has been much new information published concerning infections caused by this organism. New molecular-based tests for M. pneumoniae detection are now commercially available in the United States, and advances in molecular typing systems have enhanced understanding of the epidemiology of infections. More strains have had their entire genome sequences published, providing additional insights into pathogenic mechanisms. Clinically significant acquired macrolide resistance has emerged worldwide and is now complicating treatment. In vitro susceptibility testing methods have been standardized, and several new drugs that may be effective against this organism are undergoing development. This review focuses on the many new developments that have occurred over the past several years that enhance our understanding of this microbe, which is among the smallest bacterial pathogens but one of great clinical importance.

Usefulness of targeting lymphocyte Kv1.3-channels in the treatment of respiratory diseases

T lymphocytes predominantly express delayed rectifier K(+)-channels (Kv1.3) in their plasma membranes. Patch-clamp studies revealed that the channels play crucial roles in facilitating the calcium influx necessary to trigger lymphocyte activation and proliferation. Using selective channel inhibitors in experimental animal models, in vivo studies further revealed the clinically relevant relationship between the channel expression and the development of chronic respiratory diseases, in which chronic inflammation or the overstimulation of cellular immunity in the airways is responsible for the pathogenesis. In chronic respiratory diseases, such as chronic obstructive pulmonary disease, asthma, diffuse panbronchiolitis and cystic fibrosis, in addition to the supportive management for the symptoms, the anti-inflammatory effects of macrolide antibiotics were shown to be effective against the over-activation or proliferation of T lymphocytes. Recently, we provided physiological and pharmacological evidence that macrolide antibiotics, together with calcium channel blockers, HMG-CoA reductase inhibitors, and nonsteroidal anti-inflammatory drugs, effectively suppress the Kv1.3-channel currents in lymphocytes, and thus exert anti-inflammatory or immunomodulatory effects. In this review article, based on the findings obtained from recent in vivo and in vitro studies, we address the novel therapeutic implications of targeting the lymphocyte Kv1.3-channels for the treatment of chronic or acute respiratory diseases.