Multisystem inflammatory syndrome in children (MIS-C): A nationwide collaborative study in the Greek population

Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe hyperinflammatory condition that may occur following SARS-CoV-2 infection. This retrospective, descriptive study of children hospitalized with multisystem inflammatory syndrome in children (MIS-C) in 12 tertiary care centers from 3/11/2020 to 12/31/2021. Demographics, clinical and laboratory characteristics, treatment and outcomes are described. Among 145 patients (95 males, median age 8.2 years) included, 123 met the WHO criteria for MIS-C, while 112 (77%) had serological evidence of SARS-CoV-2 infection. Fever was present in 99%, gastrointestinal symptoms in 77%, mucocutaneous involvement in 68% and respiratory symptoms in 28%. Fifty-five patients (38%) developed myocarditis, 29 (20%) pericarditis and 19 (13%) coronary aneurysms. Among the above cases 11/55 (20%), 1/29 (3.4%) and 5/19 (26.3%), respectively, cardiac complications had not fully resolved at discharge. Underlying comorbidities were reported in 18%. Median CRP value was 155 mg/l, ferritin 535 ng/ml, PCT 1.6 ng/ml and WBC 14.2 × 109/mm3. Most patients had elevated troponin (41.3%) and/or NT-pro-BNP (49.6%). Intravenous immunoglobulin plus corticosteroids were used in 117/145 (80.6%), monotherapy with IVIG alone in 13/145 (8.9%) and with corticosteroids alone in 2/145 (1.3%). Anti-IL1 treatment was added in 15 patients (10.3%). Thirty-three patients (23%) were admitted to the PICU, 14% developed shock and 1 required ECMO. Mortality rate was 0.68%. The incidence of MIS-C was estimated at 0.69/1000 SARS-CoV-2 infections. Patients who presented with shock had higher levels of NT-pro-BNP compared to those who did not (p < 0.001). Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

CONCLUSION

MIS-C is a novel, infrequent but serious disease entity. Cardiac manifestations included myocarditis and pericarditis, which resolved in most patients before discharge. Timely initiation of immunomodulatory therapy was shown to be effective. NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. Further research is required to elucidate the pathogenesis, risk factors and optimal management, and long-term outcomes of this clinical entity.

WHAT IS KNOWN

• MIS-C is an infrequent but serious disease entity. • Patients with MIS-C present with multi-organ dysfunction, primarily involving the gastrointestinal and cardiovascular systems.

WHAT IS NEW

• NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. • Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

Rotavirus epidemiology and genotype distribution in hospitalised children, Greece, 2008 to 2020: A prospective multicentre study

BackgroundTwo rotavirus (RV) vaccines were licensed in Greece in late 2006 and included in the national immunisation programme in 2012.AimTo study the epidemiology and genotype distribution of RV in children during the post-vaccination period and assess the impact of increased vaccination coverage.MethodsIn a prospective multicentre hospital-based study, hospitalised children (≤ 16 years) with an RV-positive faecal sample were recruited. Epidemiological and genotyping analyses were performed; periods of low (2008-12) and moderate (2012-20) RV vaccination coverage were compared. Statistical analysis was performed with a chi-squared or Mann-Whitney U test and logistic regression.ResultsA total of 3,874 children (55.6% male; n = 2,153) with median age of 1.4 years (IQR: 0.5-3.3) were studied during 2008-20. Most RV-infected children were aged ≤ 3 years (72.2%) and hospitalised during December-May (69.1%). Common RV genotypes (G1P[8], G2P[4], G3P[8], G4P[8], G9P[8], G12P[8]) were detected in 92.2% of samples; G-P combinations with prevalence above 1% were G4P[8] (44.1%), G1P[8] (25.4%), G2P[4] (14.9%), G9P[8] (3.5%), G12P[8] (2.2%), G3P[8] (2.1%), other (4.3%) and mixed (3.5%). Of all samples, 97.6% were homotypic or partially heterotypic to vaccines' genotypes. With moderate vaccination coverage, the seasonal peak was detected earlier, children were older and partially or fully heterotypic genotypes were increased (p < 0.001).ConclusionsIn the era of moderate RV vaccination coverage in Greece, epidemiology of RV in hospitalised children seemed to change. However, most circulating genotypes remain homotypic or partially heterotypic to RV vaccines. Continuous epidemiological surveillance and genotyping are important to monitor possible changes arising from RV vaccines' implementation.

Rotavirus epidemiology and genotype distribution in hospitalised children, Greece, 2008 to 2020: A prospective multicentre study

BackgroundTwo rotavirus (RV) vaccines were licensed in Greece in late 2006 and included in the national immunisation programme in 2012.AimTo study the epidemiology and genotype distribution of RV in children during the post-vaccination period and assess the impact of increased vaccination coverage.MethodsIn a prospective multicentre hospital-based study, hospitalised children (≤ 16 years) with an RV-positive faecal sample were recruited. Epidemiological and genotyping analyses were performed; periods of low (2008-12) and moderate (2012-20) RV vaccination coverage were compared. Statistical analysis was performed with a chi-squared or Mann-Whitney U test and logistic regression.ResultsA total of 3,874 children (55.6% male; n = 2,153) with median age of 1.4 years (IQR: 0.5-3.3) were studied during 2008-20. Most RV-infected children were aged ≤ 3 years (72.2%) and hospitalised during December-May (69.1%). Common RV genotypes (G1P[8], G2P[4], G3P[8], G4P[8], G9P[8], G12P[8]) were detected in 92.2% of samples; G-P combinations with prevalence above 1% were G4P[8] (44.1%), G1P[8] (25.4%), G2P[4] (14.9%), G9P[8] (3.5%), G12P[8] (2.2%), G3P[8] (2.1%), other (4.3%) and mixed (3.5%). Of all samples, 97.6% were homotypic or partially heterotypic to vaccines' genotypes. With moderate vaccination coverage, the seasonal peak was detected earlier, children were older and partially or fully heterotypic genotypes were increased (p < 0.001).ConclusionsIn the era of moderate RV vaccination coverage in Greece, epidemiology of RV in hospitalised children seemed to change. However, most circulating genotypes remain homotypic or partially heterotypic to RV vaccines. Continuous epidemiological surveillance and genotyping are important to monitor possible changes arising from RV vaccines' implementation.

694. Unexpected Diversity of Rotavirus Genotypes in Pediatric Population

Background

Rotavirus (RV) is the leading cause of viral gastroenteritis in children. Although RV genotypes differ geographically and temporally, five are the predominant genotypes circulating worldwide. Aim of our study was to monitor possible changes in distribution of Rotavirus genotypes circulating in Greek pediatric population during the post vaccine era.

Methods

Demographic data and fecal samples were collected from children ≤15 years old with symptoms of acute gastroenteritis who visited emergency units of Pediatric Hospitals in Greece from September 2016 to August 2019. Samples were tested for RV Group A antigen with rapid immunochromatographic assay. Positive samples were further G and P typed employing RT-PCR, semi-nested multiplex PCR and Sanger sequencing of the VP7 and VP4 genes.

Results

A total of 660 children participated in the study with median age 31±29 months. Males outnumbered females (59%). Most of them lived in urban cities (85%). RV genotyping distribution was G4P[8] (41%), G1P[8] (22%), G2P[4] (14%), G9P[8] (8%), G9P[4] (5,5%), G12P[8] (2%) and G3P[8] (1,8%). Unusual and mixed genotypes were identified in 3,2% and 2,5% of the samples respectively. During 2016-2017 and 2017-2018, G4P[8] was the predominant genotype in 67% and 51% of the annual samples. However, in 2018-2019 the most common genotypes were G9P[8] and G9P[4] (33% in total) followed by G2P[4] (27%). Interestingly, the genotype G9P[4] was not detected at all in the first two years of the study.

Conclusion

This study indicates diversity of the predominant RV genotypes in Greek children during 2016-2019. The emergence of G9 as the most common genotype as well as the significant detection of uncommon ones highlight the importance of continuous surveillance of RV genotyping during the post vaccine period.

Disclosures

All Authors: No reported disclosures

Transient hypophosphataemia associated with acute infectious disease in paediatric patients

The aim of this study was to investigate the prevalence of hypophosphataemia in children with acute infection and the relationship between serum phosphate and C-reactive protein (CRP) concentration. Serum phosphate and CRP levels were measured on admission in 238 patients (aged 1 month to 14 y) with: pneumonia (n = 51), upper respiratory tract-related bacterial infection (n = 70), urinary tract infection (n = 50) and viral infection (n = 67). Patients were classified according to CRP value (0-50, 51-100, 101-150, > or = 151 mg/l) and type of infection. The prevalence of hypophosphataemia was calculated for each group. 30 children with hypophosphataemia on admission had serial measurements of serum phosphate and CRP levels. A significant negative correlation between serum phosphate and CRP levels was found (r = -0.41, p < 0.0001). Patients with CRP > or = 151 mg/l on admission had a lower mean serum phosphate value than those with CRP < or = 50 mg/l (1.17 vs 1.50 mmol/l, p < 0.0001). The overall prevalence of hypophosphataemia for patients with pneumonia, upper respiratory tract bacterial infection, urinary tract and viral infections was 45%, 35.7%, 18% and 4.4%, respectively. Hypophosphataemia occurred during the phase of rising of CRP level and resolved soon after CRP reached a plateau. In conclusion, hypophosphataemia is a relatively frequent but transient phenomenon in children with acute infectious disease. It is associated with an increase in CRP concentration and resolves before the normalization of CRP levels.

Posterior cerebral artery occlusion associated with Mycoplasma pneumoniae infection

Cerebral infarction is a rare complication of Mycoplasma pneumoniae infection. In all cases previously reported in the literature, vascular occlusion occurred in the anterior brain circulation, either the internal carotid or the middle cerebral artery. We report a case of a child with posterior cerebral artery occlusion and resultant hemiparesis associated with M. pneumoniae infection.

Continuous neostigmine infusion in post-thymectomy juvenile myasthenic crisis

A 10-year-old boy with myasthenia gravis had severe post-thymectomy myasthenic crisis necessitating reintroduction of mechanical ventilation on the 5th day after thymectomy. He did not respond to therapy with oral pyridostigmine, corticosteroids, or high-dose intravenous immunoglobulin. Finally, in addition to the usual supportive care, he was treated successfully with continuous intravenous infusion of neostigmine. Continuous infusion of neostigmine was used for the first time in post-thymectomy myasthenic crisis in a child to the best of our knowledge.

Association of unstable hemoglobin variants and heterozygous beta-thalassemia: example of a new variant Hb Acharnes or [beta53(D4) Ala --> Thr]

We report here the functional and structural characterization of Hb Acharnes [beta53(D4) Ala --> Thr], an unstable and electrophoretically silent variant, that was found associated in trans with a beta(0)-thalassemic mutation (IVSI-1 G --> A), in a patient with thalassemia intermedia syndrome. This case is discussed in comparison with other sporadic cases that we have previously investigated, resulting from the co-inheritance of a beta(0)-thalassemic mutation (CD39 C --> T) with two other types of unstable hemoglobins, Hb Köln [beta98(FG5) Val --> Met], and Hb Arta [beta45(CD4) Phe --> Cys]. It may be concluded that, in these associated forms, both the degree of instability of the variant and the altered oxygen binding properties (affecting the degree of tissue hypoxia) are major determinants of their clinical expression.

Clinical value of bone marrow cultures in childhood pure red cell aplasia

PURPOSE

We assessed the value of marrow cultures for defining the pathophysiology, diagnosis, and therapeutic response to immunosuppressive therapy in childhood pure red cell aplasia (PRCA).

PATIENTS AND METHODS

Patients were evaluated either at diagnosis (n = 23) or at the time of treatment failure (n = 2). Twelve patients had transient erythroblastopenia of childhood (TEC), 4 had Diamont-Blackfan anemia (DBA), and 9 had acquired sustained PRCA (A-Su-PRCA). Bone marrow mononuclear cells were cultured with combination of human recombinant (rhu) erythropoietin (EPO), granulocyte monocyte colony stimulating factor (GM-CSF), granulocyte colony stimulating factor (G-CSF), Interleukin 3 (IL-3), either with or without stem cell factor (SCF), and burst forming unit of erythroid (BFU-E) growth was assessed.

RESULTS

The combination of growth factors without SCF failed to induce any erythropoiesis (BFU-E < 10/10(5) mononuclear cells) in 10 patients (2 with TEC, 2 with DBA, and 6 with A-Su-PRCA), although the growth of erythroid colonies was substantially lower in the remaining patients than in controls (45.5 +/- 15.4 versus 91.7 +/- 12.7, p < 0.05). Addition of SCF restored erythropoiesis in all but 6 patients (5 with A-Su-PRCA and 1 with DBA). Five of 6 nonresponders did not respond to any immunomodulating therapy; of the 5, 3 had or developed some evidence of myelodysplasia.

CONCLUSION

Our data indicate that in vitro colony studies might prove to be a useful diagnostic tool, because erythropoiesis' poor response to growth factors, including SCF, may suggest the diagnosis of myelodysplasia. Moreover, it may have predictive value; in cases of PRCA, regardless of etiology, poor growth of erythropoietic colonies may predict refractoriness to immunomodulating therapy.