In-Depth Immunological Typization of Children with Sickle Cell Disease: A Preliminary Insight into Its Plausible Correlation with Clinical Course and Hydroxyurea Therapy.

Sickle cell disease (SCD) is a condition of functional hypo-/a-splenism in which predisposition to bacterial infections is only a facet of a wide spectrum of immune-dysregulation disorders forming the clinical expression of a peculiar immunophenotype. The objective of this study was to perform an in-depth immunophenotypical characterization of SCD pediatric patients, looking for plausible correlations between immunological biomarkers, the impact of hydroxyurea (HU) treatment and clinical course. This was an observational case−control study including 43 patients. The cohort was divided into two main groups, SCD subjects (19/43) and controls (24/43), differing in the presence/absence of an SCD diagnosis. The SCD group was split up into HU+ (12/19) and HU− (7/19) subgroups, respectively receiving or not a concomitant HU treatment. The principal outcomes measured were differences in the immunophenotyping between SCD patients and controls through chi-squared tests, t-tests, and Pearson's correlation analysis between clinical and immunological parameters. Leukocyte and neutrophil increase, T-cell depletion with prevalence of memory T-cell compartment, NK and B-naïve subset elevation with memory and CD21low B subset reduction, and IgG expansion, significantly distinguished the SCD HU− subgroup from controls, with naïve T cells, switched-memory B cells and IgG maintaining differences between the SCD HU+ group and controls (p-value of <0.05). The mean CD4+ central-memory T-cell% count was the single independent variable showing a positive correlation with vaso-occlusive crisis score in the SCD group (Pearson's R = 0.039). We report preliminary data assessing plausible clinical implications of baseline and HU-related SCD immunophenotypical alterations, which need to be validated in larger samples, but potentially affecting hypo-/a-splenism immuno-chemoprophylactic recommendations.

Refractory immune thrombocytopenia successfully treated with bortezomib in a child with 22q11.2 deletion syndrome, complicated by Evans syndrome and hypogammaglobulinemia.

Treatment of refractory autoimmune cytopenias (AICs) and Evans syndrome (ES) represent a great challenge in pediatric setting, where an underlying primary immunodeficiency is recurrent. Frequently, second or third line treatments are employed, with an increased risk of toxicity and infections. The advent of novel drugs is the object of research in order to modify the management of these patients.We report a case of successful use of bortezomib in a child with 22q11.2 deletion syndrome and CVID-like phenotype with a multi-refractory severe ES. Last flares were prolonged and dominated by severe and symptomatic ITP, refractory to different courses of high dose steroid and IVIG, mofetil mycophenolate, thrombopoietin receptor agonists, sirolimus, and rituximab. Persistence of AICs in subjects with depletion of CD20 + B-cells and IgG strengthens the hypothesis about the production of autoantibodies by terminally differentiated plasma-cells, not targetable from immunosuppressants and rituximab.In the attempt to enhance plasma-cells inhibition, the child was addressed to bortezomib, with a good response at 6 month follow-up without side effects. Nowadays, the use of bortezomib in ES/AICs is based only on small retrospective studies and case reports. Despite the lack of long term follow-up, our work highlights the potential role of bortezomib in the management of pediatric patients with multi-resistant AICs secondary to immune-system impairment.

Naïve/Effector CD4 T cell ratio as a useful predictive marker of immune reconstitution in late presenter HIV patients: A multicenter study.

A significant proportion of HIV-infected patients experiencing a late diagnosis highlights the need to define immunological protocols able to help the clinicians in identifying patients at higher risk for immunological failure. The aim of the study was to evaluate the feasibility of easy cytometric tests in defining the effect of antiretroviral treatment (cART) on immunological homeostasis and in identifying predictive markers of early immune recovery. Chronic HIV infected patients (n = 202) were enrolled in a prospective multicentric study, and their immunological profile was studied before (w0) and after 24 weeks (w24) of antiretroviral treatment (cART) using a standardized flow cytometric panel. Based on CD4 T cell count before treatment, patients were divided in late (LP: CD4 <350/mmc), intermediate (IP: 350/mmc500/mmc) presenters. In all groups, cART introduction increased CD4 and CD4/CD8 T cell ratio, naïve T cell (CD4 and CD8) and CD127-expressing CD4 T cells. In parallel, cART significantly reduced effector memory T cells (CD4 and CD8) and T cell activation (CD38+CD8 and CD95+CD4 T cells). Moreover, the frequency of Naïve and Effector CD4 T cells before treatment correlated with several immune parameters key associated with the pathogenesis of HIV, thus mirroring the health of immune system. Interestingly, we identified the Naïve/Effector CD4 T cell ratio (N/EM) at w0 as a marker able to predict early immune recovery. Specifically, in LP, N/EM ratio was significantly higher in immunological responder patients (CD4>500/mmc at w24) when compared to immunological non responder (CD4 T cells <500/mmc at w24). Finally, a multivariate analysis indicates that after 24w patients with N/EM ratio higher than 1.86 at w0 recovered 96 CD4 T cells more than those with N/EM ratio lower than 0.46. Altogether, our data define an easy protocol able to define reliable immunological markers useful for the characterization of immune profile in viremic HIV patients and identify the naïve/effector CD4 T cell ratio as a new tool able to predict an early immune reconstitution potential.

Simple method for haplotyping the poly(TG) repeat in individuals carrying the IVS8 5T allele in the CFTR gene.

BACKGROUND: The 5T allele of the polyT tract located within intron 8 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene is a variant that in trans with a severe CFTR mutation can result in normal phenotype, congenital bilateral absence of vas deferens (CBAVD), or mild cystic fibrosis. The 5T allele has been associated with the skipping of exon 9, a process that seems to be influenced by an adjacent 9-13TG tandem repeat. The 12- or 13TG repeats are often associated with an abnormal phenotype. We present here a single-step method for direct haplotyping of the TG repeats in 5T carriers. METHOD: The method is based on a single-step PCR, using a fluorescently labeled forward primer and a reverse allele-specific primer matching the 5T allele. We validated the test in 30 control samples of known 5T-poly(TG) haplotype and then used this method to evaluate 57 clinical samples. RESULTS: The expected TG genotypes were obtained for all 5T control samples, and no nonspecific amplification of either the 7T or 9T alleles was detected. In our 5T-positive collection 9 of 9 (100%) CBAVD patients, 6 of 12 (50.0%) chronic pancreatitis patients, and 12 of 36 (33.3%) individuals undergoing assisted reproduction showed 5T-12TG haplotype. CONCLUSIONS: Our method is an accurate, specific, and simple tool to characterize the 5T poly(TG) haplotype. Our results confirm the high frequency of 5T-12TG in CBAVD patients and do not preclude a potential effect also in pancreatitis. This assay can be useful in assessment of the disease risk in 5T carriers.

Mutations of the CFTR gene in pancreatic disease.

INTRODUCTION: An association has been found between CFTR gene mutations and chronic pancreatitis; however, there is a lack of information about the frequency of CFTR gene mutations in acute pancreatitis and in pancreatic cancer. AIM: To prospectively evaluate the prevalence of CFTR gene mutations in acute pancreatitis, chronic pancreatitis, and pancreatic cancer. METHODOLOGY: Ninety-eight consecutive patients were studied and divided into 3 groups: 34 patients with acute pancreatitis, 46 patients with chronic pancreatitis, and 18 patients with pancreatic cancer. The mutation analysis of the CFTR gene was carried out using diagnostic commercial kits for the simultaneous detection of 29 mutations and Tn polymorphism. RESULTS: Among the 98 patients studied, 12 (12.2%) had CFTR gene mutations: 2 of the 34 patients (5.9%) with acute pancreatitis, 9 of the 46 (19.6%) with chronic pancreatitis, and 1 of the 18 (5.6%) with pancreatic cancer. All the mutations were found in heterozygosis (2 DeltaF508, 1 W1282X, and 9 T5 allele). CONCLUSION: Our prospective study adds further information about the frequency of CFTR mutations in patients with a single episode of acute pancreatitis. Furthermore, our results suggest an association of CFTR gene mutations with chronic alcoholic pancreatitis and emphasize the need for a multicenter study, possibly multinational, to conclusively establish the role of CFTR mutations as a genetic susceptibility factor for this disease.