Pediatric Inflammatory Multisystem Syndrome (PIMS) - Potential role for cytokines such Is IL-6

Prognostic role of euthyroid sick syndrome in MIS-C: results from a single-center observational study

Background

Euthyroid sick syndrome (ESS) is characterized by low serum levels of free triiodothyronine (fT3) with normal or low levels of thyroid stimulating hormone (TSH) and free thyroxine (fT4) and is reported in different acute clinical situations, such as sepsis, diabetic ketoacidosis and after cardiac surgery. Our aim was to evaluate the predicting role of ESS for disease severity in patients with Multisystem Inflammatory Syndrome in children (MIS-C).

Methods

A single-centre observational study on consecutive patients with MIS-C. Before treatment clinical, and laboratory data were collected and, in a subset of patients, thyroid function tests were repeated 4 weeks later. Variables distribution was analyzed by Mann-Whitney U-test and correlations between different parameters were calculated by Spearman's Rho coefficient.

Results

Forty-two patients were included and 36 (85.7%) presented ESS. fT3 values were significantly lower in patients requiring intensive care, a strong direct correlation was shown between fT3 and Hb, platelet count and ejection fraction values. A significant inverse correlation was retrieved between fT3 levels and C-reactive protein, brain natriuretic peptide, IL-2 soluble receptor and S-100 protein. Subjects with severe myocardial depression (EF < 45%) had lower fT3 values than subjects with higher EF. The thyroid function tests spontaneously normalized in all subjects who repeated measurement 4 weeks after admission.

Conclusion

ESS is a frequent and transient condition in acute phase of MIS-C. A severe reduction of fT3 must be considered as important prognostic factor for severe disease course, with subsequent relevant clinical impact in the management of these patients.

Chronic intermittent hypobaric hypoxia improves iron metabolism disorders via the IL-6/JAK2/STAT3 and Epo/STAT5/ERFE signaling pathways in metabolic syndrome rats

AIM

Our previous study demonstrated that chronic intermittent hypobaric hypoxia (CIHH) improved iron metabolism disorder in obese rats through the downregulation of hepcidin. This study aimed to observe the molecular mechanism of CIHH in improving iron metabolism disorders, especially by Janus kinase/signal transducer and activation of the transcription (JAK/STAT) signaling pathway in metabolic syndrome (MS) rats.

METHODS

Six-week-old male Sprague-Dawley rats were randomly divided into four groups: CON, CIHH (subjected to hypobaric hypoxia simulating 5000-m altitude for 28 days, 6 h daily), MS (induced by high fat diet and fructose water), and MS+CIHH. The serum levels of glucose, lipid metabolism, iron metabolism, interleukin-6 (IL-6), erythropoietin (Epo) and hepcidin were measured. The protein expressions of JAK2, STAT3, STAT5, bone morphogenetic protein 6 (BMP6), small mothers against decapentaplegic 1 (SMAD1) and hepcidin were examined. The mRNA expressions of erythroferrone (ERFE) and hepcidin were analyzed.

RESULTS

The MS rats displayed obesity, hyperglycemia, hyperlipidemia, iron metabolism disorder, increased IL-6 and hepcidin serum levels, upregulation of JAK2/STAT3 signaling pathway, decreased Epo serum levels, downregulation of STAT5/ERFE signaling pathway in spleen, upregulation of BMP/SMAD signaling pathway in liver, and increased hepcidin mRNA and protein expression compared to CON rats. All the aforementioned abnormalities in MS rats were ameliorated in MS + CIHH rats.

CONCLUSIONS

CIHH improved iron metabolism disorders, possibly by inhibiting IL-6/JAK2/STAT3 and activating Epo/STAT5/ERFE signaling pathway, thus downregulating hepcidin in MS rats.

Analysis of cytokine levels, cytological findings, and MP-DNA level in bronchoalveolar lavage fluid of children with Mycoplasma pneumoniae pneumonia

BACKGROUND

The present study was conducted to determine the inflammatory response in the lungs of children with Mycoplasma pneumoniae pneumonia (MPP).

METHODS

This study retrospectively analyzed cytokine levels, cytological findings, and M. pneumoniae (MP)-DNA level in the bronchoalveolar lavage fluid (BALF) of 96 children with MPP. The study utilized Spearman's correlation method to evaluate the contribution of BALF and blood parameters in MPP children.

RESULTS

(1) A total of 96 MPP children were classified into the Low MP-DNA MPP group (BALF MP-DNA ≤ 105 copies/mL) and the High MP-DNA MPP group (BALF MP-DNA > 105 copies/mL); the Non-fever MPP group (no fever during the entire course of pneumonia) and the Fever MPP group; the Defervescence MPP group (fever had subsided at the time of bronchoscopy) and the Fervescence MPP group; and the Mild MPP group and the Severe MPP group. (2) The High MP-DNA MPP, Fever MPP, Fervescence MPP, and Severe MPP groups had higher levels of interleukin (IL)-6, IL-10, and tumor necrosis factor-α (TNF-α) in their BALF (all p < .05). (3) The proportions of neutrophils and macrophages in the BALF of the High MP-DNA MPP and Fever MPP groups increased and decreased, respectively (all p < .05). (4) In the BALF of MPP children, MP-DNA, IL-6, IL-10, TNF-α, and interferon gamma (IFN-γ) levels positively correlated with neutrophil proportion while negatively correlated with macrophage proportion (all p < .05). (5) The MP-DNA, IL-6, IL-10, TNF-α, and IFN-γ levels in the BALF of MPP children were positively correlated with the levels of C-reactive protein, procalcitonin, lactic dehydrogenase, fibrinogen, and d-dimer, while they were negatively correlated with the albumin level (all p < .05).

CONCLUSIONS

In children with MPP, the pulmonary inflammatory immune response was stronger in the High MP-DNA MPP, Fever MPP, Fervescence MPP, and Severe MPP groups. The relationship between pulmonary cytokine levels, MP-DNA load, and serum inflammatory parameters were found to be weak.

Autoimmunity, cancer and COVID-19 abnormally activate wound healing pathways: critical role of inflammation

Recent evidence indicates that targeting IL-6 provides broad therapeutic approaches to several diseases. In patients with cancer, autoimmune diseases, severe respiratory infections [e.g. coronavirus disease 2019 (COVID-19)] and wound healing, IL-6 plays a critical role in modulating the systemic and local microenvironment. Elevated serum levels of IL-6 interfere with the systemic immune response and are associated with disease progression and prognosis. As already noted, monoclonal antibodies blocking either IL-6 or binding of IL-6 to receptors have been used/tested successfully in the treatment of rheumatoid arthritis, many cancer types, and COVID-19. Therefore, in the present review, we compare the impact of IL-6 and anti-IL-6 therapy to demonstrate common (pathological) features of the studied diseases such as formation of granulation tissue with the presence of myofibroblasts and deposition of new extracellular matrix. We also discuss abnormal activation of other wound-healing-related pathways that have been implicated in autoimmune disorders, cancer or COVID-19.

Changes in the cardiovascular system in children with pediatric multisystem inflammatory syndrome temporally associated with COVID-19 – A single center experience

Background

Pediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS) is a serious complication of a previous SARS-CoV-2 infection in the group of pediatric patients. Despite the fact that this disease affects only about 1 of 1000 children, it may be severe, and changes in the cardiovascular system may cause long-term complications and the need for longitudinal patient care.

Methods

It is a single-center retrospective study considering 51 patients with PIMS-TS. The aim of this study was to analyze patients with PIMS-TS, taking into account demographic data, clinical course, laboratory tests and cardiovascular system assessment (electrocardiography, echocardiography, etc.).

Results

From June 2020 to October 2021, 51 patients with PIMS-TS were hospitalized in our center. In the studied group, 26/51 children (51%) were girls. The mean age of patients was 7 years. Changes in electrocardiograms were found in 21/51 patients. Echocardiography revealed pericardial fluid in most patients. In addition, heart valve insufficiency was found. Changes in the coronary vessels in the form of dilatations and even aneurysms were found in 42 patients. Myocardial hypokinesis was visualized in more than 1/4 of the patients. Sixteen patients (31.3%) required transfer to the intensive care unit (ICU) due to severe hypotension. Laboratory tests revealed increased levels of markers of heart failure and enzymes of myocardial damage.

Conclusions

Changes in the cardiovascular system in the course of PIMS-TS are of various nature, but in most patients they require close cardiac supervision and long-term follow-up.

Risk factors of a severe course of pediatric multi-system inflammatory syndrome temporally associated with COVID-19

Pediatric multi-system inflammatory syndrome temporally associated with COVID-19 (PIMS-TS) is a serious complication of a previous SARS-CoV-2 infection. The disease causes multiple organ failure, but in some patients, a more severe course of the disease is observed. The treatment is multidirectional and depends on the severity and course of the disease, as some patients do not respond to the recommended treatment. The aim of this study was to identify laboratory risk factors affecting the more severe course of the disease and resistance to standard therapy. It is a single-center retrospective study considering 51 patients with PIMS-TS. Clinical features, laboratory results, and additional imaging tests data were taken into account. Fifty-one patients with PIMS-TS were hospitalized within a 16-month observation period. In the studied group, 26/51 children (51%) were girls. The mean age of patients was 7 years. Sex of the patient was not a risk factor for changes in cardiovascular system or severe course of the disease. Sixteen patients (31.3%) required transfer to the intensive care unit. Children with initially higher concentrations of NT-proBNP, troponin, creatinine, triglycerides, C-reactive protein, procalcitonin, ferritin, D-dimers and lower hematocrit, platelet count, lymphocytes, and ejection fraction should be strictly observed as they have a higher risk of severe course of the disease.

CONCLUSIONS

Laboratory parameters especially markers of myocardial damage, markers of inflammation, blood count, as wells as biochemical parameters are significant risk indicators of severe course of PIMS -TS and their concentration can be defined as predictor of disease severity.

WHAT IS KNOWN

• Pediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS) is a serious complication of a previous SARS-CoV-2 infection in the group of pediatric patients • Course of the disease may be severe, which may cause long-term complications and the need for longitudinal patient care.

WHAT IS NEW

• Children with higher concentrations of NT-proBNP, troponin, creatinine, TG, CRP, PCT, ferritin, D-dimers and lower hematocrit, PLT, lymphocytes, and EF have a higher risk of a severe course of the disease. • Patients with high concentration of NT-proBNP, troponin, CRP, lactates, ferritin, D-dimers, creatinine and a lower concentration of PLT, albumin, leukocytes; lymphopenia, hyponatremia are at risk for intravenous immunoglobulin resistance.

SARS-CoV-2 viral load assessment in lung transplantation

In the era of COVID-19 pandemic, organ transplantation programs were facing serious challenges. The lung transplantation donor pool was extremely limited and SARS-CoV-2 viral load assessment has become a crucial part of selecting an optimal organ donor. Since COVID-19 is a respiratory disease, the viral load is thought to be more important in lung transplantations as compared to other solid organ transplantations. We present two challenging cases of potential lung donors with a questionable COVID-19 status. Based on these cases, we suggest that the cycle threshold (Ct) value should always be requested from the laboratory and the decision whether to proceed with transplantation should be made upon complex evaluation of diverse criteria, including the nasopharyngeal swab and bronchoalveolar lavage PCR results, the Ct value, imaging findings and the medical history. However, as the presence of viral RNA does not ensure infectivity, it is still to be clarified which Ct values are associated with the viral viability. Anti-SARS-CoV-2 IgA antibodies may support the diagnosis and moreover, novel methods, such as quantifying SARS-CoV-2 nucleocapsid antigen in serum may provide important answers in organ transplantations and donor selections.