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Functional characterization of the human dendritic cell immunodeficiency associated with the IRF8K108E mutation.

Blood. 2014 Aug 13;

Authors: Salem S, Langlais D, Lefebvre F, Bourque G, Bigley V, Haniffa M, Casanova JL, Burk D, Berghuis A, Butler KM, Leahy TR, Hambleton S, Gros P

Abstract
We have previously reported on a unique patient in whom homozygosity for a mutation at IRF8 (IRF8(K108E)) causes a severe immunodeficiency. Laboratory evaluation revealed a highly unusual myeloid compartment, remarkable for the complete absence of CD14(+) and CD16(+) monocytes, absence of CD11c(+) conventional dendritic cells (DCs) and of CD11c(+)/CD123(+) plasmacytoid DCs (pDCs), and striking granulocytic hyperplasia. The patient initially presented with severe disseminated mycobacterial and mucocutaneous fungal infections and was ultimately cured by cord blood transplant. Sequencing RNA from the IRF8(K108E) patient’s primary blood cells prior to transplant shows not only depletion of IRF8-bound and -regulated transcriptional targets, in keeping with the distorted composition of the myeloid compartment, but also a paucity of transcripts associated with activated CD4(+) and CD8(+) T lymphocytes. This suggests that T cells reared in the absence of a functional antigen-presenting compartment in IRF8(K108E) are anergic. Biochemical characterization of the IRF8(K108E) mutant in vitro shows that loss of the positively charged side chain at K108 causes loss of nuclear localization and loss of transcriptional activity, which is concomitant with decreased protein stability, increased ubiquitination, increased SUMOylation, and enhanced proteasomal degradation. These findings provide functional insight into the molecular basis of immunodeficiency associated with loss of IRF8.

PMID: 25122610 [PubMed – as supplied by publisher]

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Pulmonary manifestations of primary immunodeficiency disorders in children.

Front Pediatr. 2014;2:77

Authors: Jesenak M, Banovcin P, Jesenakova B, Babusikova E

Abstract
Primary immunodeficiencies (PIDs) are inherited disorders in which one or several components of immune system are decreased, missing, or of non-appropriate function. These diseases affect the development, function, or morphology of the immune system. The group of PID comprises more than 200 different disorders and syndromes and the number of newly recognized and revealed deficiencies is still increasing. Their clinical presentation and complications depend on the type of defects and there is a great variability in the relationship between genotypes and phenotypes. A variation of clinical presentation across various age categories is also presented and children could widely differ from adult patients with PID. Respiratory symptoms and complications present a significant cause of morbidity and also mortality among patients suffering from different forms of PIDs and they are observed both in children and adults. They can affect primarily either upper airways (e.g., sinusitis and otitis media) or lower respiratory tract [e.g., pneumonia, bronchitis, bronchiectasis, and interstitial lung diseases (ILDs)]. The complications from lower respiratory tract are usually considered to be more important and also more specific for PIDs and they determinate patients’ prognosis. The spectrum of the causal pathogens usually demonstrates typical pattern characteristic for each PID category. The respiratory signs of PIDs can be divided into infectious (upper and lower respiratory tract infections and complications) and non-infectious (ILDs, bronchial abnormalities – especially bronchiectasis, malignancies, and benign lymphoproliferation). Early diagnosis and appropriate therapy can prevent or at least slow down the development and course of respiratory complications of PIDs.

PMID: 25121077 [PubMed]

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Enhancing Patient Flexibility of Subcutaneous Immunoglobulin G Dosing: Pharmacokinetic Outcomes of Various Maintenance and Loading Regimens in the Treatment of Primary Immunodeficiency.

Biol Ther. 2014 Aug 14;

Authors: Sidhu J, Rojavin M, Pfister M, Edelman J

Abstract
INTRODUCTION: Standard treatment for patients with primary immunodeficiency (PID) is monthly intravenous immunoglobulin (IVIG), or weekly/biweekly subcutaneous immunoglobulin (SCIG) infusion. We used population pharmacokinetic modeling to predict immunoglobulin G (IgG) exposure following a broad range of SCIG dosing regimens for initiation and maintenance therapy in patients with PID.
METHODS: Simulations of SCIG dosing were performed to predict IgG concentration-time profiles and exposure metrics [steady-state area under the IgG concentration-time curve (AUC), IgG peak concentration (C max), and IgG trough concentration (C min) ratios] for various infusion regimens.
RESULTS: The equivalent of a weekly SCIG maintenance dose administered one, two, three, five, or seven times per week, or biweekly produced overlapping steady-state concentration-time profiles and similar AUC, C max, and C min values [95% confidence interval (CI) for ratios was 0.98-1.03, 0.95-1.09, and 0.92-1.08, respectively]. Administration every 3 or 4 weeks resulted in higher peaks and lower troughs; the 95% CI of the AUC, C max, and C min ratios was 0.97-1.04, 1.07-1.26, and 0.86-0.95, respectively. IgG levels >7 g/L were reached within 1 week using a loading dose regimen in which the weekly maintenance dose was administered five times in the first week of treatment. In patients with very low endogenous IgG levels, administering 1.5 times the weekly maintenance dose five times in the first week of treatment resulted in a similar response.
CONCLUSIONS: The same total weekly SCIG dose can be administered at different intervals, from daily to biweekly, with minimal impact on serum IgG levels. Several SCIG loading regimens rapidly achieve adequate serum IgG levels in treatment-naïve patients.

PMID: 25118975 [PubMed – as supplied by publisher]

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Hematopoietic stem cell transplantation of an adolescent with neurological manifestations of homozygous missense PRF1 mutation.

Pediatr Blood Cancer. 2014 Aug 11;

Authors: Hussein AA, Hamadah T, Qandeel M, Sughayer M, Amarin R, Mansour A, Chiang SC, Al-Zaben A, Meeths M, Bryceson YT

Abstract
Individuals with biallelic truncating PRF1 mutations typically present with fulminant early-onset familial hemophagocytic lymphohistiocytosis (FHL). We report a 19-year-old male with a 5-year history of recurrent fever and headaches progressing to refractory seizures. Brain imaging revealed multiple ring enhancing lesions. Laboratory investigations demonstrated that the patient displayed defective lymphocyte cytotoxicity and carried a homozygous missense PRF1 mutation, c.394G > A (p.Gly132Arg). The patient was successfully treated with chemo-immunotherapy followed by matched related allogeneic hematopoietic stem cell transplantation (HSCT). Our findings demonstrate that prompt HSCT of late-onset FHL with primarily neurological manifestation can reverse central nervous system symptoms and improve long-term outcome. Pediatr Blood Cancer © 2014 Wiley Periodicals, Inc.

PMID: 25110876 [PubMed – as supplied by publisher]

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Comparison of outcomes of hematopoietic stem cell transplantation without chemotherapy conditioning by using matched sibling and unrelated donors for treatment of severe combined immunodeficiency.

J Allergy Clin Immunol. 2014 Aug 7;

Authors: Dvorak CC, Hassan A, Slatter MA, Hönig M, Lankester AC, Buckley RH, Pulsipher MA, Davis JH, Güngör T, Gabriel M, Bleesing JH, Bunin N, Sedlacek P, Connelly JA, Crawford DF, Notarangelo LD, Pai SY, Hassid J, Veys P, Gennery AR, Cowan MJ

Abstract
BACKGROUND: Patients with severe combined immunodeficiency disease who have matched sibling donors (MSDs) can proceed to hematopoietic cell transplantation (HCT) without conditioning chemotherapy.
OBJECTIVE: We sought to determine whether the results of HCT without chemotherapy-based conditioning from matched unrelated donors (URDs), either from volunteer adults or umbilical cord blood, are comparable with those from MSDs.
METHODS: We performed a multicenter survey of severe combined immunodeficiency transplantation centers in North America, Europe, and Australia to compile retrospective data on patients who have undergone unconditioned HCT from either URDs (n = 37) or MSDs (n = 66).
RESULTS: Most patients undergoing URD HCT (92%) achieved donor T-cell engraftment compared with 97% for those with MSDs; however, estimated 5-year overall and event-free survival were worse for URD recipients (71% and 60%, respectively) compared with MSD recipients (92% and 89%, respectively; P < .01 for both). URD recipients who received pre-HCT serotherapy had similar 5-year overall survival (100%) to MSD recipients. The incidences of grade II to IV acute and chronic graft-versus-host disease were higher in URD (50% and 39%, respectively) compared with MSD (22% and 5%, respectively) recipients (P < .01 for both). In the surviving patients there was no difference in T-cell reconstitution at the last follow-up between the URD and MSD recipients; however, MSD recipients were more likely to achieve B-cell reconstitution (72% vs 17%, P < .001).
CONCLUSION: Unconditioned URD HCT achieves excellent rates of donor T-cell engraftment similar to that seen in MSD recipients, and reconstitution rates are adequate. However, only a minority will have myeloid and B-cell reconstitution, and attention must be paid to graft-versus-host disease prophylaxis. This approach might be safer in children ineligible for intense regimens to spare the potential complications of chemotherapy.

PMID: 25109802 [PubMed – as supplied by publisher]

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Applying T-cell receptor excision circles and immunoglobulin κ-deleting recombination excision circles to patients with primary immunodeficiency diseases.

Ann Med. 2014 Aug 11;:1-11

Authors: Lee WI, Huang JL, Lin SJ, Yeh KW, Chen LC, Ou LS, Yao TC, Jaing TH, Shih YF, Tseng TY, Lin YL

Abstract
Background. Biomarkers of T-cell receptor excision circles (TRECs) and immunoglobulin κ-deleting recombination excision circles (KRECs) reflect naïve T and B cell emigrants. This study assessed the biomarkers in patients with primary immunodeficiency diseases (PIDs) to determine the lymphocyte output disturbance and the correlation to lymphocytes. Methods. A standard plasmid was constructed to calculate TRECs and KRECs in 250 ng genomic DNA from whole blood of PIDs patients. These were correlated to naïve and memory lymphocytes for further classification and adequate treatment. Results. In 69 studied patients, the low TRECs mainly included those with severe combined T and B immunodeficiency (SCID, 7/8), combined immunodeficiency (CID, 4/4), and common variable immunodeficiency (CVID, 6/7). The diminished KRECs was in SCID (4/8), CID (4/4), CVID (7/7), Bruton’s tyrosine kinase mutation (Btk, 3/4), anti-B cell deletion (by anti-CD20 antibody in 1), and Behçet syndrome under steroid treatment (1). The TRECs and KRECs positively correlated to absolute naïve T (CD4 + CD45RA+) and naïve B (CD19 + CD27-), and to memory B (CD19 + CD27+) numbers, respectively. Conclusion. This study validates that low TRECs and KRECs values reflect low naïve T and B lymphocytes in ‘combined immunodeficiencies’ and in some CVID patients with the potential to develop the CID phenotype.

PMID: 25109505 [PubMed – as supplied by publisher]

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CD18 deficiency evolving to megakaryocytic (M7) acute myeloid leukemia: Case report.

Blood Cells Mol Dis. 2014 Aug 5;

Authors: de Moraes Vasconcelos D, Beitler B, Martinez GA, Pereira J, Amigo Filho JU, Klautau GB, Lian YC, Della Negra M, Duarte AJ

Abstract
Leukocyte adhesion deficiency type 1 (LAD 1 – CD18 deficiency) is a rare disease characterized by disturbance of phagocyte function associated with less severe cellular and humoral dysfunction. The main features are bacterial and fungal infections predominantly in the skin and mucosal surfaces, impaired wound healing and delayed umbilical cord separation. The infections are indolent, necrotic and recurrent. In contrast to the striking difficulties in defense against bacterial and fungal microorganisms, LAD 1 patients do not exhibit susceptibility to viral infections and neoplasias. The severity of clinical manifestations is directly related to the degree of CD18 deficiency. Here, a 20year-old female presenting a partial CD18 deficiency that developed a megakaryocytic (M7) acute myeloid leukemia is described for the first time. The clinical features of the patient included relapsing oral thrush due to Candida, cutaneous infections and upper and lower respiratory tract infections, followed by a locally severe necrotic genital herpetic lesion. The patient’s clinical features improved for a period of approximately two years, followed by severe bacterial infections. At that time, the investigation showed a megakaryocytic acute myeloid leukemia, treated with MEC without clinical improvement. The highly aggressive evolution of the leukemia in this patient suggests that adhesion molecules could be involved in the protection against the spread of neoplastic cells.

PMID: 25106692 [PubMed – as supplied by publisher]

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Splice-correcting oligonucleotides restore BTK function in X-linked agammaglobulinemia model.

J Clin Invest. 2014 Aug 8;

Authors: Bestas B, Moreno PM, Blomberg KE, Mohammad DK, Saleh AF, Sutlu T, Nordin JZ, Guterstam P, Gustafsson MO, Kharazi S, Piątosa B, Roberts TC, Behlke MA, Wood MJ, Gait MJ, Lundin KE, El Andaloussi S, Månsson R, Berglöf A, Wengel J, Smith CI

Abstract
X-linked agammaglobulinemia (XLA) is an inherited immunodeficiency that results from mutations within the gene encoding Bruton’s tyrosine kinase (BTK). Many XLA-associated mutations affect splicing of BTK pre-mRNA and severely impair B cell development. Here, we assessed the potential of antisense, splice-correcting oligonucleotides (SCOs) targeting mutated BTK transcripts for treating XLA. Both the SCO structural design and chemical properties were optimized using 2′-O-methyl, locked nucleic acid, or phosphorodiamidate morpholino backbones. In order to have access to an animal model of XLA, we engineered a transgenic mouse that harbors a BAC with an authentic, mutated, splice-defective human BTK gene. BTK transgenic mice were bred onto a Btk knockout background to avoid interference of the orthologous mouse protein. Using this model, we determined that BTK-specific SCOs are able to correct aberrantly spliced BTK in B lymphocytes, including pro-B cells. Correction of BTK mRNA restored expression of functional protein, as shown both by enhanced lymphocyte survival and reestablished BTK activation upon B cell receptor stimulation. Furthermore, SCO treatment corrected splicing and restored BTK expression in primary cells from patients with XLA. Together, our data demonstrate that SCOs can restore BTK function and that BTK-targeting SCOs have potential as personalized medicine in patients with XLA.

PMID: 25105368 [PubMed – as supplied by publisher]

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Identification of copy number variants from exome sequence data.

BMC Genomics. 2014 Aug 7;15(1):661

Authors: Samarakoon PS, Sorte HS, Kristiansen BE, Skodje T, Sheng Y, Tjønnfjord GE, Stadheim B, Stray-Pedersen A, Rødningen OK, Lyle R

Abstract
BACKGROUND: With advances in next generation sequencing technologies and genomic capture techniques, exome sequencing has become a cost-effective approach for mutation detection in genetic diseases. However, computational prediction of copy number variants (CNVs) from exome sequence data is a challenging task. Whilst numerous programs are available, they have different sensitivities, and have low sensitivity to detect smaller CNVs (1-4 exons). Additionally, exonic CNV discovery using standard aCGH has limitations due to the low probe density over exonic regions. The goal of our study was to develop a protocol to detect exonic CNVs (including shorter CNVs that cover 1-4 exons), combining computational prediction algorithms and a high-resolution custom CGH array.
RESULTS: We used six published CNV prediction programs (ExomeCNV, CONTRA, ExomeCopy, ExomeDepth, CoNIFER, XHMM) and an in-house modification to ExomeCopy and ExomeDepth (ExCopyDepth) for computational CNV prediction on 30 exomes from the 1000 genomes project and 9 exomes from primary immunodeficiency patients. CNV predictions were tested using a custom CGH array designed to capture all exons (exaCGH). After this validation, we next evaluated the computational prediction of shorter CNVs. ExomeCopy and the in-house modified algorithm, ExCopyDepth, showed the highest capability in detecting shorter CNVs. Finally, the performance of each computational program was assessed by calculating the sensitivity and false positive rate.
CONCLUSIONS: In this paper, we assessed the ability of 6 computational programs to predict CNVs, focussing on short (1-4 exon) CNVs. We also tested these predictions using a custom array targeting exons. Based on these results, we propose a protocol to identify and confirm shorter exonic CNVs combining computational prediction algorithms and custom aCGH experiments.

PMID: 25102989 [PubMed – as supplied by publisher]

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Approach to pathogenesis of hematological malignancies from a viewpoint of primary immunodeficiency.

Rinsho Ketsueki. 2014 Jul;55(7):769-79

Authors: Takagi M

PMID: 25098512 [PubMed – in process]

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