Two cases of lymphadenopathy with liver dysfunction due to Mycoplasma pneumoniae infection with mycoplasmal bacteraemia without pneumonia

Establishment of a Mouse Model of Mycoplasma pneumoniae-Induced Plastic Bronchitis

Plastic bronchitis (PB) constitutes a life-threatening pulmonary disorder, predominantly attributed to Mycoplasma pneumoniae (MP) infection. The pathogenic mechanisms involved remain largely unexplored, leading to the absence of reliable approaches for early diagnosis and clear treatment. Thus, the present investigation aimed to develop an MP-induced mouse model of PB, thereby enhancing our understanding of this complex condition. In the first stage, healthy BALB/c mice were utilized to investigate the optimal methods for establishing PB. This involved the application of nebulization (15-20 min) and intratracheal administration (6-50 μL) with 2-chloroethyl ethyl sulfide (CEES) concentrations ranging from 4.5% to 7.5%. Subsequently, the MP model was induced by administering an MP solution (2 mL/kg/day, 108 CFU/50 μL) via the intranasal route for a duration of five consecutive days. Ultimately, suitable techniques were employed to induce plastic bronchitis in the MP model. Pathological changes in lung tissue were analyzed, and immunohistochemistry was employed to ascertain the expression levels of vascular endothelial growth factor receptor 3 (VEGFR-3) and the PI3K/AKT/mTOR signaling pathway. The administration of 4.5% CEES via a 6 µL trachea was the optimal approach to establishing a PB model. This method primarily induced neutrophilic inflammation and fibrinous exudate. The MP-infected group manifested symptoms indicative of respiratory infection, including erect hair, oral and nasal secretions, and a decrease in body weight. Furthermore, the pathological score of the MP+CEES group surpassed that of the groups treated with MP or CEES independently. Notably, the MP+CEES group demonstrated significant activation of the VEGFR-3 and PI3K/AKT/mTOR signaling pathways, implying a substantial involvement of lymphatic vessel impairment in this pathology. This study successfully established a mouse model of PB induced by MP using a two-step method. Lymphatic vessel impairment is a pivotal element in the pathogenetic mechanisms underlying this disease entity. This accomplishment will aid in further research into treatment methods for patients with PB caused by MP.

Lymph-node-first presentation of Kawasaki disease in a 12-year-old girl with cervical lymphadenitis caused by Mycoplasma pneumoniae: A case report

BACKGROUND

To the best of our knowledge, cases of Kawasaki disease (KD) occurring at the age of 12 are rare, even in Asia where the incidence of KD is high. We report a case of lymph-node-first presentation of KD (NFKD) in a 12-year-old girl with Mycoplasma pneumoniae (M. pneumoniae) infection who presented with prolonged fever and lymphadenitis refractory to macrolide antibiotics.

CASE SUMMARY

A previously healthy 12-year-old girl presented with fever, myalgia, sore throat, swelling, and tenderness on the right side of the neck. She was initially diagnosed with lymphadenitis caused by M. pneumoniae refractory to macrolide antibiotics. She had elevated brain natriuretic peptide (BNP) levels. Finally, the patient was diagnosed with KD. After receiving intravenous immunoglobulin, the fever resolved, and her symptoms improved.

CONCLUSION

NFKD should be differentiated from adolescent lymphadenitis presenting with prolonged fever by checking the BNP level early.

Prevalence and clinical characteristics of septicemia in children with Mycoplasma pneumoniae pneumonia

Background

Mycoplasma pneumoniae (MP) pneumonia in children can be challenging to treat, and the impact of MP blood infection is unclear. The present study aims to determine the prevalence and clinical characteristics of MP septicemia among pediatric patients.

Methods

Children hospitalized at our center for MP pneumonia between October 2017 and June 2018 were included. Healthy controls visiting our outpatient clinic for regular physical examinations were also enrolled. MP was detected by real-time polymerase chain reaction (qPCR) analysis of plasma and peripheral blood mononuclear cell (PBMC) samples.

Results

Sixty-one children with MP pneumonia and 30 healthy children were included. Among children with MP infection, 31 (50.8%) were positive for MP by qPCR (19 in plasma samples, 8 in PBMC samples, and 4 in both). All healthy controls were negative for MP by qPCR.

Conclusions

The prevalence of MP septicemia in children with MP pneumonia is moderate. However, detection of MP in blood samples may have limited clinical value for guiding treatment.

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.

Pediatric Mycoplasma pneumoniae Infection Presenting with Acute Cholestatic Hepatitis and Other Extrapulmonary Manifestations in the Absence of Pneumonia

Mycoplasma pneumoniae infections mainly involve respiratory tract; however, also can manifestate other symptoms by site involved. Extrapulmonary manifestations of M. pneumoniae infection are rarely known to occur without pneumonia. Herein we report a case of a 9-year-old boy who presented with acute cholestatic hepatitis in the absence of pneumonia. Rhabdomyolysis, skin rash, and initial laboratory results suspicious of disseminated intravascular coagulopathy were also observed in this patient. M. pneumoniae infection was identified by a 4-fold increase in immunoglobulin G antibodies to M. pneumoniae between acute and convalescent sera by enzyme-linked immunosorbent assay. This is the first pediatric case in Korea of M. pneumoniae infection presenting with acute cholestatic hepatitis in the absence of pneumonia.

Co-morbidity of Kawasaki disease

Despite more than four decades of investigation, the etiology of Kawasaki disease remains obscure, and none of the proposed etiologic theories for the disease have achieved independent confirmation. Clinical and epidemiologic features support an infectious cause, but the etiology remains unclear. The authors present a case of Kawasaki disease associated with Epstein-Barr virus and Mycoplasma pneumoniae infection in a 3.5-y-old boy. He received two doses of intravenous immunoglobulin due to prolonged course of Kawasaki disease but later had complicated autoimmune haemolytic anaemia. His prolonged fever subsided after azithromycin administration. Epstein-Barr virus infection was confirmed by molecular microbiological pathology of cervical lymph node and serological tests. The serological tests for Mycoplasma pneumoniae also revealed a positive result. Thus, it is concluded that Mycoplasma pneumoniae and Epstein-Barr virus infections may occur simultaneously in a child with Kawasaki disease. In addition, autoimmune hemolytic anaemia may be noted in Kawasaki disease patients after high-dose IVIG administration. To the authors' knowledge, this is the first report of Kawasaki disease with Epstein-Barr virus and Mycoplasma pneumoniae in the English-language literature.

Stevens-Johnson syndrome after Mycoplasma pneumonia infection in pediatric post-liver transplant recipient: case report and review of the literature

Although Mycoplasma pneumonia infection is relatively common among school-aged children, it rarely leads to SJS. Herein, we report a seven-yr-old girl who presented with a Mycoplasma pneumonia infection that progressed to SJS five months after liver transplant. We suggest that children presenting with symptoms of Mycoplasma pneumonia infection in the immunosuppressed post-liver transplant setting be properly diagnosed and treated rapidly, as well as observed for symptoms of SJS and potentially serious extrapulmonary complications.

Retrospective survey for sialidase activity in Mycoplasma pneumoniae isolates from cases of community-acquired pneumonia

Background

Sialidase is a well-known virulence factor of other respiratory pathogens, but was only recently documented to occur in some species of Mycoplasma. The sialidase activity expressed can vary quantitatively among strains within a species of mycoplasma, from undetectable to amounts that correlate positively with strain virulence. Very few isolates of Mycoplasma pneumoniae had ever been examined for sialidase activity, so it was unknown whether sialidase may contribute to diseases involving this species.

Findings

No sialidase activity was detected by spectrofluorometric assay of 15 laboratory strains and 91 clinical isolates of M. pneumoniae banked over many years from patients having radiologically-confirmed, uncomplicated community-acquired pneumonia.

Conclusions

The annotated genome of strain M129 (GenBank NC_000912, ATCC 29342), also isolated from a patient with pneumonia, accurately represents the absence of sialidase genes from strains of M. pneumoniae typically associated with uncomplicated community-acquired pneumonia. A possible involvement of sialidase in neurologic or other extra-respiratory manifestations of M. pneumoniae mycoplasmosis remains to be investigated.

Pathogenesis of neurologic manifestations of Mycoplasma pneumoniae infection

Mycoplasma pneumoniae has been associated with various neurologic manifestations, but exactly how the organism can cause such a wide variety of diseases is a long-standing mystery. In this respect, although pneumonia has been considered the hallmark of Mycoplasma pneumoniae infection, emerging accumulations of data have revealed that the infection can cause a number of extrapulmonary manifestations even in the absence of pneumonia. The importance of host immune response in the pathomechanism of pneumonia has been established, but the pathomechanisms of extrapulmonary manifestations remain largely unknown. For this review, extrapulmonary manifestations due to M. pneumoniae infection were classified into three categories: a direct type, in which locally induced cytokines must play a role; an indirect type, in which immune modulation such as autoimmunity must play a role; and a vascular occlusion type, in which vasculitis or thrombosis (either or both, and with or without systemic hypercoagulable state) must play a role. This classification was then applied within a literature review for neurologic manifestations. Most neurologic manifestations due to M. pneumoniae infection could be reasonably classified into and explained by one of the three types of pathomechanisms.

Mycoplasma pneumonia-associated acute hepatitis in an adult patient without lung infection

Mycoplasma pneumonia is a major cause of respiratory infections in school-aged children. Most M. pneumonia infections in adults involve the respiratory tract. Extrapulmonary manifestations of M. pneumonia infection may be found in the skin, cardiovascular, neurologic and hematologic systems. Concomitant liver disease is rare in adults. Here, we report an unusual case of a patient who presented with fever and abdominal pain, but without pulmonary manifestations. The laboratory work-up demonstrated a hepatocellular pattern of acute hepatitis caused by M. pneumonia infection. Symptoms subsided and laboratory parameters improved with antibiotics treatment. Thus, this case can help raise clinicians' awareness of the possibility of M. pneumonia infection, with or without lung involvement, as a part of the evaluation of undetermined hepatitis.

Acute cholestatic hepatitis revealing Mycoplasma pneumoniae infection without lung involvement in an adult patient

Liver involvement is an unusual manifestation of Mycoplasma pneumoniae infection. Cases of cholestatic hepatitis without pulmonary involvement have been described in children with M. pneumoniae infection but only two cases of cytolytic hepatitis have been reported in adults. We report here the case of an 18-year-old woman who presented with febrile epigastric pain of short duration associated with an elevation of gamma-glutamyl transpeptidase and alkaline phosphatase levels and with a mononuclear syndrome. Serological tests for M. pneumoniae were positive for IgG and IgM. Clinical symptoms and blood test perturbations completely resolved after treatment with macrolide.

Unusual haematologic manifestations of Mycoplasma pneumoniae infection

A 2-year-old male presented with fever, cervical lymphadenopathy, anaemia, neutrophilia and thrombocytosis. There was no evidence of pulmonary disease. Severe cold antibody (IgM) mediated haemolytic anaemia developed during admission. Infection with Mycoplasma pneumoniae was demonstrated, highlighting the extrapulmonary manifestations of the infection, in the absence of pulmonary signs.

Erythema multiforme due to Mycoplasma pneumoniae infection in two children

Mycoplasma pneumoniae is an important and highly relevant cause of bullous erythema multiforme, isolated mucositis, and Stevens-Johnson syndrome in children. In this article, we present two children with respiratory Mycoplasma pneumoniae infection and associated cutaneous findings within the spectrum of erythema multiforme. We review the literature associating these three entities with Mycoplasma pneumoniae infection and discuss controversies regarding the classification of erythema multiforme, as well as update reported infectious causes of the bullous form. Many understand the erythema multiforme spectrum to include bullous erythema multiforme, mucositis, and Stevens-Johnson syndrome in the order of increasing severity. We feel that this relationship should be reconsidered to help better understand the prognosis and outcomes. It is our opinion that bullous erythema multiforme is a separate, yet related condition that can occur in the context of Mycoplasma pneumoniae infection. With many similarities to mucositis and Stevens-Johnson syndrome, bullous erythema multiforme can be considered part of a spectrum of disease that includes Stevens-Johnson syndrome. Unlike mucositis and Stevens-Johnson syndrome, bullous erythema multiforme caused by Mycoplasma pneumoniae infection has low morbidity for the child. Mycoplasma pneumoniae-associated mucositis and Stevens-Johnson syndrome seem to occur along a spectrum with separate prognosis and potential pathogenesis compared with bullous erythema multiforme. Making the distinction between these conditions is valuable for predicting the child's prognosis. Patients who develop symptoms consistent with these conditions should be appropriately evaluated for Mycoplasma pneumoniae infection and closely monitored.

Acute hepatitis due to Mycoplasma pneumoniae infection without lung involvement in adult patients

Mycoplasma pneumoniae has been associated with cholestatic hepatitis in children, while in adults, the lack of liver involvement has been considered as a typical feature of M. pneumoniae infection. Controversial data have been reported about the possibility of liver involvement with M. pneumoniae community-acquired pneumonia. We present two cases of acute hepatitis associated with M. pneumoniae infection without lung involvement.

Elevated serum alanine aminotransferase (ALT) levels in patients with serologically verified Mycoplasma pneumoniae pneumonia

The possibility of liver involvement in Mycoplasma pneumoniae pneumonia is still controversial. This study investigated 33 adult patients with serologically confirmed M. pneumoniae community-acquired pneumonia (CAP) (median age 31 years) and 38 patients with bacteraemic Streptococcus pneumoniae CAP (median age 54 years), all without pre-existing liver disease. Serum alanine aminotransferase (ALT) levels were elevated in 12 (36.4%) patients with M. pneumoniae CAP (median 53.5 U/L), and in four (10.5%) patients with S. pneumoniae CAP (median 61 U/L) (p 0.025). In most patients with M. pneumoniae CAP, the elevated ALT levels decreased during macrolide therapy, although this decrease was not significant.

Mycoplasma pneumoniae infection in a child after renal transplantation

Although Mycoplasma pneumoniae infections are common among school children and young adults, they have been rarely reported in renal transplant recipients. Herein, we report an 8-yr-old boy who had M. pneumoniae infection 1 yr after transplantation and showed liver dysfunction during the course of the disease. In children who underwent renal transplantation and receive immunosuppressive treatment, we suggest that symptoms of a simple upper respiratory tract infection may precede M. pneumoniae disease with potentially serious extrapulmonary complications.

Fulminant Mycoplasma pneumoniae infection with multi-organ involvement: a case report

A 50-year-old man with no medical history was admitted because of progressive respiratory distress, aseptic meningitis, disseminated intravascular coagulation, cholestatic hepatitis, and renal failure. Mycoplasma pneumoniae infection was confirmed serologically. The patient was treated with erythromycin and showed a favorable recovery. Although M. pneumoniae infection is usually a benign, self-limited acute respiratory disease, on rare occasions it can manifest itself with a fulminant course and multi-organ involvement, even in normal healthy individuals.