Sensitivity of three commercial tests for SARS-CoV-2 serology in children: an Italian multicentre prospective study

BACKGROUND

US Food and Drug Administration has issued Emergency Use Authorizations for hundreds of serological assays to support Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) diagnosis. The aim of this study is to evaluate, for the first time in children, the performance of three widely utilized SARS-CoV-2 serology commercial assays, Diesse Diagnostics (IgG, IgA, IgM) and Roche Diagnostics, both Roche Nucleocapsid (N) IgG and Roche Spike (S) IgG assays.

METHODS

Sensitivity and 95% confidence intervals (CIs) were estimated for each of the three different serological tests and mixed and direct comparison were performed. Univariate and multivariate Poisson regression models were fitted to calculate incidence rate ratios and 95% CIs as estimate of the effects of age, gender, time on the serology title. A p-value < 0.05 indicated statistical significance.

RESULTS

Overall, 149 children were enrolled in the study. A low sensitivity was found for Diesse IgA, IgM and IgG. Compare to Diesse, Roche S had a higher sensitivity at 15-28 days from infection (0.94, 95%CI: 0.73-1.0) and Roche N at 28-84 days (0.78, 95%CI: 0.58-0.91). When a direct comparison of IgG tests sensitivity was feasible for patients with pairwise information, Roche S and Roche N showed a statistically significant higher sensitivity compared to Diesse in all the study periods, whereas there was no difference between the two Roche tests.

CONCLUSION

Roche S and Roche N serology tests seem to better perform in children. Large prospective studies are needed to better define the characteristics of those tests.

Case Report: Safety and Efficacy of Omalizumab in a 13-Year-Old Patient With Chronic Spontaneous Urticaria and Type 1 Diabetes

Chronic urticaria (CU) is defined by the presence of itchy wheals, sometimes accompanied by angioedema, lasting for at least 6 weeks. CU is treated with second-generation antihistamines, increased up to four times the normal doses for second-line treatment. Omalizumab (a monoclonal antibody anti-IgE) may be recommended as third-line therapy in children aged over 12 years. Few reports have suggested that glucose homeostasis is impaired in some type 2 diabetic patients receiving omalizumab, and even in non-diabetic patients, fasting blood glucose and HOMA-IR values appeared to be significantly increased. We report the case of a 13-year-old girl with diabetes mellitus type 1 and chronic spontaneous urticaria (CSU) refractory to standard recommended therapy that we treated with omalizumab at a standard recommended dose of 300 mg every 4 weeks. We observed a rapid and complete remission of CSU after treatment with this humanized monoclonal antibody without detrimental effects on the patient's glucose control especially in terms of HbA1c (glycated hemoglobin), time in glycemic range (TIR), and daily insulin needs.

COVID-19 cardiac involvement in a 38-day old infant

The spectrum of clinical manifestations of coronavirus disease 2019 in children is yet to be fully elucidated. We report the case of an infant who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and developed mild cardiovascular inflammation, a novelty for patients of very young age, that contributes to defining the puzzling nature of this disease in pediatric patients. The potential cardiovascular involvement of SARS-CoV-2 in children should always be taken into account.

Pru p 3 sensitization in children with allergy to Parietaria pollens

Background:

Pru p 3 is the major allergen of the peach and belongs to the LTP family. Pru p 3 sensitization has been associated with severe allergic symptoms after eating LTP-containing foods. However, a previous experience partially downsized the potential danger of Pru p 3 sensitization in a group of adult rhinitics. This study aimed to evaluate the real impact of Pru p 3 sensitization in children in a real-world setting.

Methods:

82 consecutive paediatric patients (55 males and 27 females, mean age 8.19±4.23 years) with allergic rhinitis due to Parietaria pollen allergy and sensitization to Pru p 3, documented by ISAC test, were evaluated. Serum IgE was measured by ImmunoCap method. Allergic symptoms occurring after ingesting LTP-containing foods were considered and scored as oral allergy syndrome, food allergy, and anaphylaxis.

Results:

About one-quarter of Pru p 3-sensitized children reported anaphylaxis after ingesting LTP-containing foods, about half reported food allergy or oral allergy syndrome. Only ¼ was merely sensitized.

Conclusions:

Pru p 3 sensitization deserves careful attention in children contrary to what might occur in adult patients. It could depend on the age and the serum IgE level. Thus, Pru p 3 sensitization should be adequately interepreted and managed in clinical practice. (www.actabiomedica.it)

Could Bet v 1 affect sensitization molecular pattern in children?

BACKGROUND

Allergy is characterized by allergen-specific IgE production. Molecular-based allergy diagnostic allows to define the precise sensitization profile. Bet v 1 is the major allergen of the PR-10 family. It has been reported that pan-allergens could affect the sensitization panel in adults.

OBJECTIVE

This study aimed to evaluate the impact of Bet v 1 sensitization on clinical presentation in a sample of children with Bet v 1-sensitization; oral allergy syndrome (OAS) or anaphylaxis (ANA) were considered.

METHODS

Serum IgE molecular components were assessed by ISAC method. Sera and clinical data from 132 children, 91 males (68.94%) and 41 females (31.06%), mean age 9.08 years (3.45 years), were analyzed.

RESULTS

Bet v 1-sensitized children were frequently, but not exclusively, sensitized to other molecules belonging to PR-10 family. However, there was no significant difference concerning IgE levels between children with or without food allergy and between children with OAS and ANA, but hazelnut only for generic food allergy.

CONCLUSIONS

The present study demonstrates that Bet v 1 sensitization may affect the sensitization pattern in children living in Genoa, a Mediterranean city located in a birch-free area, but it is unable to discriminate patients from a clinical point of view. So, ISAC test should be integrated with more precise IgE assay.

Necrobiosis Lipoidica Diabeticorum: A pediatric case report

Introduction: Necrobiosis lipoidica (NL) is a rare chronic granulomatous dermatitis that usually appears in the lower extremities. It affects about 0.3–1.2% of diabetic patients, the majority of whom have type 1 diabetes. The etiology and pathogenesis of this disorder are still unclear. NL is characterized by skin rash that usually affects the shins. The average onset is 30 years, with females being affected more commonly. There are very few reported cases of necrobiosis lipoidica in children.

Case report: We report a case of a 16 year old girl affected by type 1 diabetes mellitus (15 years disease duration) who developed an erythematous nodular rash on the lower extremities and interscapular area. In the suspect of necrobiosis lipoidica, a skin biopsy was performed (lower extremities and interscapular area). The microscopic evaluation of the pretibial lesions was suggestive of necrobiosis lipoidica. The smaller lesions in the interscapular area showed signs of perivascular dermatitis which could be consistent with early stages of necrobiosis lipoidica. Local treatment with tacrolimus determined a progressive improvement of the lesions.

Conclusion: In patients with T1DM, diagnosis of NL of the lower legs is usually unequivocal. However, diagnosis may be more challenging in the presence of lesions with recent onset and/or atypical clinical presentation and unusual site. In these cases, NL must always be taken in consideration in order to avoid misdiagnosis, wrong/late treatment decisions and progression to ulceration.