Clinical Signs and Treatment of New-Onset Bone Marrow Failure Associated SARS-CoV-2 Infection in Children: A Single Institution Prospective Cohort Study.

Background: Viral infections can cause direct and indirect damage to hematopoietic stem cells. The objectives of this study were to identify the frequency and severity of aplastic anemia in children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as recognize the response to treatment. Methodology: 13 children with newly diagnosed severe aplastic anemia were enrolled in this prospective clinical trial. Blood samples were obtained from all patients to detect SARS-CoV-2 antibodies, and nasopharyngeal swabs were collected for reverse-transcription Polymerase Chain Reaction to detect SARS-CoV-2 viruses. According to the laboratory results, patients were classified as having SARS-CoV-2 positive antibodies and SARS-CoV-2 negative antibodies. Both groups received combined cyclosporine (CsA) + Eltrombopag (E-PAG). The hematological response, either complete response (CR) or partial response (PR), no response (NR), and overall response (OR) rates of combined E-PAG + CsA treatment after 6 months were evaluated. Results: Four children were recognized to have aplastic anemia and SARS-CoV-2 positive antibodies. Two patients fulfilled the hematological criteria for CR and no longer required transfusion of packed red blood cells (PRBCs) or platelets, and one had PR and was still PRBC transfusion-dependent but no longer required platelet transfusion. The remaining patient showed NR, and he had died before reaching the top of the HSCT waiting list. Moreover, six patients in the SARS-CoV-2 negative antibodies group had CR, while three patients had PR. The difference in ANC, Hg, and platelet counts between both groups was not significant. Conclusion: The SARS-CoV-2 virus is added to several viral infections known to be implicated in the pathogenesis of aplastic anemia. Studies are needed to establish a definitive association and determine whether the response of bone marrow failure to standard therapy differs from that of idiopathic cases.

Increase in polymorphonuclear myeloid-derived suppressor cells and regulatory T-cells in children with B-cell acute lymphoblastic leukemia.

Our study aimed to evaluate the levels of MDSCs and Tregs in pediatric B-cell acute lymphoblastic leukemia (B-ALL), their relation to patients' clinical and laboratory features, and the impact of these cells on the induction response. This study included 31 pediatric B-ALL patients and 27 healthy controls. All patients were treated according to the protocols of the modified St. Jude Children's Research Hospital total therapy study XIIIB for ALL. Levels of MDSCs and Tregs were analyzed using flow cytometry. We observed a reduction in the levels of CD4 + T-cells and an increase in both the polymorphonuclear MDSCs (PMN-MDSCs) and Tregs. The frequencies of PMN-MDSCs and Tregs were directly related to the levels of peripheral and bone marrow blast cells and CD34 + cells. Complete postinduction remission was associated with reduced percentages of PMN-MDSCs and Tregs, with the level of PMN-MDCs in this subpopulation approaching that of healthy controls. PMN-MDSCs and Tregs jointly play a critical role in maintaining an immune-suppressive state suitable for B-ALL tumor progression. Thereby, they could be independent predictors of B-ALL progress, and finely targeting both PMN-MDSCs and Tregs may be a promising approach for the treatment of B-ALL.

Role of pretreatment inflammatory indicators in pediatric acute leukemias; where do we stand? A prospective cohort study.

BACKGROUND AND AIM: There is a limited data at the moment regarding the clinical value of inflammatory indices and malnutrition markers in children with acute leukemias. We have examined the usefulness of prognostic nutritional index (PNI), Glasgow prognostic score (GPS), Prognostic Index (PI), monocyte to lymphocyte (MLR), neutrophil to lymphocyte (NLR), and platelet to lymphocyte (PLR) ratios to stratify patients as regards the response to induction therapy correlating them to different prognostic factors. PATIENTS AND METHODS: Children with acute leukemia and without microbial-induced inflammation at the time of diagnosis were prospectively recruited. Preliminary total and differential CBC, c-reactive protein (CRP), serum albumin (ALB) were used to calculate different inflammatory indicators including NLR, MLR, PLR, PNI, GPS, and PI. RESULTS: Higher PNI was significantly more associated to children who achieved remission as compared to those without remission (p< 0.0001). Patients without remission had GPS 1 or 2 compared to GPS 0 or 1 in those who entered remission (p= 0.001). NLR was significantly lower in patients in remission than in those without remission (p= 0.005). Similarly, complete remission was significantly associated to MLR ⩽ 0.45 as compared to MLR > 0.45 (p< 0.0001). CONCLUSION: Pretreatment PNI, GPS, CRP, serum albumin, NLR, MLR, and PLR are remission promising prognostic markers in pediatric acute leukemias, which deserve to be further investigated in large-scale studies.

Downregulation of B regulatory cells and upregulation of T helper 1 cells in children with Gaucher disease undergoing enzyme replacement therapy.

Gaucher disease (GD) involves a broad spectrum of immunological cells, including T helper (Th) cells and regulatory B cells (Bregs), which function to resolve the immune response and inhibit excessive inflammation. This study aimed to explore T helper cells, B cells, and Bregs in GD children undergoing enzyme replacement therapy (ERT). Our study included 20 GD patients; six patients were categorized as type 1 and 14 as type 3 GD. All patients were on regular ERT. Twenty healthy children were enrolled as controls. All patients and controls were subjected to complete blood analysis, abdominal ultrasound, and flow cytometric detection of T helper cells, B cells, and Bregs. Despite undergoing ERT, CD4+ T helper lymphocytes and Bregs were still significantly lower in patients with GD compared with the controls. Th1 and B cells were more in the patients than in the healthy controls. Lower levels of Bregs were found in type 3, compared with type 1 patients. Increased platelet count was directly associated with increased levels of Bregs and lower levels of B cells. Elevated children's height was also accompanied by decreasing levels of Th1. Our results propose that ERT in GD is associated with partial improvement in immune status, and long-term ERT might be needed for the restoration of the desired immune response levels. Levels of Bregs and Th1 can be employed for monitoring improvement of immune status in GD patients undergoing ERT.

Upregulation of CD146 in Pediatric B-Cell Acute Lymphocytic Leukemia and Its Implications on Treatment Outcomes.

Background and Aim. We studied through flow cytometry the expression of CD146 on different T cells, and B-cell ALL blasts trying to correlate its expression with different prognostic factors of B-cell ALL and treatment outcomes. Patients and Methods. All pediatric patients with B-cell ALL were subjected to bone marrow examination and cytochemistry, flow cytometric immunophenotyping using monoclonal antibodies utilized for diagnosis of B-ALL including CD34, CD19, CD10, CD22, and intracellular IgM. The diagnosis was based on standard morphologic, cytochemical, and immunophenotypic followed by flow cytometric detection of CD146 expression on blast cells, CD4+, and CD8+ T cells. RESULTS: Significant accumulations of CD146+CD4+ cells, CD146+CD8+ cells, CD4+, CD8+, and lymphocytes in patients were compared to controls, the mean percentages of CD146+CD4+ cells, CD146+CD8+ cells, and CD146+ blasts were significantly higher in patients than controls, and in addition, these cells were associated with poor overall survival and disease-free survival. The median OS for patients with complete response was 22 ± 1.633 (95%CI = 18.799-25.201), while for those without complete response, it was 13 ± 3.928 (95%CI = 5.301-25.699), with log-rank = 5.71, P = 0.017. CONCLUSION: CD146 was expressed significantly in children's B-ALL and associated with poor prognostic features including poor response and treatment outcomes and could be a possible poor prognostic factor in pediatric B-cell ALL.

Effect of Hydroxyurea Treatment on the Inflammatory Markers Among Children With Sickle Cell Disease.

BACKGROUND: Neutrophil-to-lymphocyte ratio (NLR) was introduced as a potential inflammatory marker in sickle cell disease (SCD). This study aimed to evaluate the impact of hydroxyurea (HU) treatment on the value of NLR and some inflammatory mediators in SCD. METHODS: The hematological parameters and clinical events were analyzed in 35 children with SCD under HU treatment and followed up for 1 year and in 20 healthy controls. Enzyme-linked immunosorbent assay was performed for the evaluation of proinflammatory cytokines, including interleukin (IL) 6, IL-8, high-sensitivity C-reactive protein (hs-CRP), and tumor necrosis factor α (TNF-α). RESULTS: Hydroxyurea significantly improves most of the hematological parameters in children with SCD. The percentages of hemoglobin fraction S, serum levels of TNF-α and IL-6 were significantly decreased when compared to baseline value but did not reach the value of the healthy control. The HU treatment led to a significant decrease in NLR compared to the baseline values and reached healthy control values. Neutrophil-to-lymphocyte ratio was positively correlated with hs-CRP, TNF-α, and IL-8 serum levels and negatively correlated with percentage of fetal hemoglobin and hematocrit values. The cutoff value of NLR to expect a response to HU among SCD was 3.0, with 76% specificity and 85% sensitivity (area under the curve: 0.85, P < .0001). In conclusion, hydroxyurea induced a decrease in NLR and inflammatory cytokines, which represent a biomarker of inflammation in SCD. The calculation of NLR is a straightforward and cheap method for SCD outcome prediction in young children.

Natural Killer and Natural Killer T Cells in Juvenile Systemic Lupus Erythematosus: Relation to Disease Activity and Progression.

The contribution of innate immune cells, including natural killer (NK) and natural killer T (NKT) cells, in systemic lupus erythematosus (SLE) is still unclear. Herein, we examined the frequency of peripheral NK cells, CD56dim and CD56bright NK cells, and NKT cells in patients with juvenile SLE and their potential relations to SLE-related clinical and laboratory parameters. The study included 35 SLE children and 20 apparently healthy controls. After baseline clinical and lab work, SLE Disease Activity Index (SLEDAI-2K) and Pediatric Systemic Lupus International Collaborative Clinics/American College of Rheumatology (SLICC/ACR) Damage Index (Ped-SDI) scores were assessed. The frequency of peripheral NK cells, CD56dim and CD56bright NK cells, and NKT cells was examined using flow cytometry. SLE patients showed significantly lower frequency of NK cells and NKT cells and higher frequency of CD56bright NK cells compared to controls. Disease activity, urea, and creatinine correlated negatively with NK, but positively with CD56bright NK cells. NK and NKT cells exhibited inverse correlation with the renal biopsy activity index; however, CD56bright NK cells showed direct correlations with both activity and chronicity indices. Regarding Ped-SDI, renal, neuropsychiatry disorders, and growth failure correlated inversely with NK but directly with CD56bright NK cells. NKT cell inversely correlated with renal damage and delayed puberty. In conclusion, low frequency of NK and NKT and expansion of CD56bright NK cells are marked in juvenile SLE, particularly with activity. These changes have direct effect on renal impairment and growth failure, reflecting their potential influence on disease progression.

Characterization of Regulatory T Cells in Preterm and Term Infants.

Our study aimed to study regulatory T cells (Tregs) and their expression of CD45RA, HLA-DR, and CD39 in preterm and full-term infants. In an observational study, we used a three-color flow cytometry for determination of Tregs and their expression of CD45RA, HLA-DR, and CD39 in preterm and full-term infants. The percentages of CD4+CD25+highFoxp3+, CD39+ Tregs, HLA-DR+ Tregs and the expression of Foxp3+ in CD4+CD25+highFoxp3 Tregs cells were significantly lower in neonates when compared to healthy adult controls. The levels of naïve resting Tregs (CD45RA+Tregs) were significantly higher in neonates than controls. The percentages of CD4+CD25+highFoxp3+Tregs, total CD4+CD25+ and CD4+CD25+high were significantly higher in preterm infants when compared to the full-term group. Moreover, CD45RA+Tregs were significantly higher in preterm than in term infants. We found significant inverse correlations between the gestational age and the levels of both Tregs (r = - 0.395, p = 0.017) and CD45RA+Tregs (r = - 0.422, p = 0.010). Relative to full-term, the frequencies, and phenotypes of Tregs were affected by prematurity. A larger longitudinal study with a sufficient number of newborns is needed to investigate the Treg pool of term and preterm infants thoroughly and to explore the association between the Treg pool and clinical variables.

Activated and Memory T Lymphocytes in Children with Gaucher Disease.

Gaucher disease (GD) is the most prevalent lysosomal storage disorder. Gaucher disease is associated with remarkable alterations in the immune system, and GD patients are more susceptible to infections and are at a higher risk of developing autoimmune disorders and malignancies. In a case-control study, we used three-color flow cytometric immunophenotyping for determination of the frequency of lymphocyte subpopulations and activated T lymphocytes among 18 children with GD1 under enzyme replacement therapy managed in Assiut University Hospitals. We found significant increases in the frequencies of total lymphocytes, CD19+, CD3+, CD4+, and CD8+ in children with GD1 when compared to healthy control. The frequencies of activated T lymphocytes (CD3+HLA-DR+), activated T-helper cells (CD4+HLA-DR+), and activated T-suppressor/cytotoxic cells (CD8+HLA-DR+) were significantly higher in GD1 as compared to healthy children. Our data show that the increased proportion of activated T lymphocytes in children with GD1 raises the issue of their possible involvement in the pathogenesis of the immune dysfunction seen in these patients. Our data suggested that the activated T lymphocytes could play a role in the clinical course of GD1. The relationship of these cells to immune disorders in GD1 children remains to be determined.

Regulatory B cells (CD19(+)CD38(hi)CD24(hi)) in alloimmunized and non-alloimmunized children with ß-thalassemia major.

BACKGROUND: ß-Thalassemia major (BTM) is considered the most common hemoglobinopathy in Egypt and is one of the major health problems in our locality. MATERIALS & METHODS: We investigated the frequency of B-regulatory cells (CD19(+)CD38(hi)CD24(hi)); (Bregs) among polytransfused alloimmunized and non-alloimmunized children with BTM. The study included 110 polytransfused pediatric patients with ß-thalassemia major. Clinical and transfusion records of all studied patients were reviewed. Indirect antiglobulin test was performed to detect the presence of alloantibodies. We used flow cytometry for detection of CD19(+)CD38(hi)CD24(hi) regulatory B cells. RESULTS: Alloimmunization was detected in 35.5% of thalassemic patients (39/110). The analysis of our data showed a significantly higher frequency of Bregs (CD19(+)CD38(hi)CD24(hi)) in the peripheral blood of both alloimmunized and non-alloimmunized patients as compared to healthy controls. CONCLUSIONS: Our data showed that the frequencies of CD19(+)CD24(hi)CD38(hi) Bregs cells were significantly increased in children with BTM. Our data suggested that Bregs cells could play a role in the clinical course of BTM. The relationship of Bregs to immune disorders in BTM children remains to be determined. Further longitudinal study with a larger sample size is warranted to explore the mechanisms of Breg cells in the disease process in BTM patients.

Glucocorticoid receptors expression and histopathological types in children with nephrotic syndrome.

UNLABELLED: Abstract Background: Some children with idiopathic nephrotic syndrome (NS) patients fail to respond even when given high dose of steroid. The aim of this study was to assess the GCR expression on the T lymphocytes of children with NS and its relation to the response to steroid and to histopathological type. METHODS: Forty-six pediatric patients with idiopathic NS and 20 age and sex matched apparently healthy children as controls were included. Flow cytometry was employed to determine the percentage of CD3+/GCR+ cells which then correlated with pattern of steroid response. Renal biopsy was done for steroid-dependent and steroid-resistant cases for determination of the underlying histopathological type. RESULTS: The mean percentage of T lymphocyte expression of GCRs (CD3+/GCR) was significantly higher in early steroid responders than in late responders and was slightly lower than the controls. There was a significantly lower GCRs expression in steroid-resistant patients in comparison to early responders, late responders and controls. Renal biopsy showed that most cases of late responders were of the focal segmental glomerulosclerosis (FSGS) type. The mean percentage of lymphocyte expression of GCRs was significantly higher in patients with minimal change disease (MCD) compared to patients with FSGS. CONCLUSION: Evaluation of the expression of intracellular GCRs in T lymphocytes at time of diagnosis of NS can predict the response to steroid therapy and can help in determination of the outcome of NS patients regarding future relapses.

Hypoxia biomarkers, oxidative stress, and circulating microparticles in pediatric patients with thalassemia in Upper Egypt.

This study aimed to investigate the oxidative stress, hypoxia biomarkers, and circulating microparticles (MPs) in ß thalassemia major. The study included 56 children with thalassemia and 46 healthy controls. Hypoxia biomarkers, oxidative stress biomarkers, and total plasma fragmented DNA (fDNA) were detected by the standard methods. The MPs were assessed by flow cytometry. Hypoxia and oxidative stress biomarkers, fDNA, and MPs were higher and total antioxidant capacity (TAC) was lower in patients with thalassemia than the controls. In splenectomized patients and those who had complications, vascular endothelial growth factor (VEGF), malondialdehyde, fDNA, endothelial, platelet, and activated platelet MP levels were higher while, TAC was lower than the nonsplenectomized patients. In conclusion, the increased tissue hypoxia, oxidative stress in ß thalassemia, and its relationship with DNA damage and MPs release could explain many complications of thalassemia and may have therapeutic implications. The VEGF could serve as an important indicator for adequacy of blood transfusion in thalassemia.

T lymphocytes from malnourished infants are short-lived and dysfunctional cells.

To investigate T-cell functional molecules and inflammatory cytokines and to assess T-cell apoptosis in malnourished infants, 64 infants from undernourished women and 28 healthy control infants were recruited to the study. Malnourished infants showed a significant decrease in the levels of circulating IL-2 and IL-7 and increases in the levels of IL-1ß, IL-6, IL-10 and TNF-α, as measured by flow cytometry. There was a significant reduction in the number of CD3(+) T cells and an increase in apoptotic T cells, which was associated with an up-regulation of CD95 and PD-1 expression on CD3(+) T cells in malnourished compared to control infants. Significant reductions were also observed in the phosphorylation of AKT and STAT5 and in the expression of CCR7 and CXCR4 receptors in malnourished children, and these reductions were associated with a significant reduction in T-cell migratory capacity to their ligands CCL21 and CXCL12, respectively, as measured using an in vitro chemotaxis assay. Taken together, these data suggest that lymphocytes from malnourished infants are short-lived and dysfunctional.