Department of Translational Medical Sciences, Section of Pediatrics, Federico II University, Via S. Pansini, 5, 80131, Naples, Italy.
Since the discovery of FOXN1 deficiency, the human counterpart of the nude mouse, a growing body of evidence investigating the role of FOXN1 in thymus and skin, has been published. FOXN1 has emerged as fundamental for thymus development, function, and homeostasis, representing the master regulator of thymic epithelial and T cell development. In the skin, it also plays a pivotal role in keratinocytes and hair follicle cell differentiation, although the underlying molecular mechanisms still remain to be fully elucidated. Read More
Prolonged excretion of poliovirus can occur in immunodeficient patients who receive oral polio vaccine, which may lead to propagation of highly divergent vaccine-derived polioviruses (VDPVs), posing a concern for global polio eradication. This study aimed to estimate the proportion of primary immunodeficient children with enterovirus infection and to identify the long-term polio/nonpolio enterovirus excreters in a tertiary care unit in Mumbai, India. During September 2014-April 2017, 151 patients received diagnoses of primary immunodeficiency (PID). Read More
Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, 161, Section 6, MinChuan East Road, Neihu, Taipei 114, Taiwan.
Aims/hypothesis: The relative contribution of T helper (Th)1 and Th17 cells in graft rejection is inconclusive, on the basis of evidence provided by different T cell-related cytokine-deficient animal models and graft types.
Methods: We used novel antigen-presenting-cell-specific Il-12p35 (also known as Il12a)-knockout (KO), IL-23p19-knockdown (KD) and IL-27p28-KD strategies to investigate T cell differentiation in islet graft rejection.
Results: In vitro dendritic cell-T cell coculture experiments revealed that dendritic cells from Il-12p35-KO and IL-23p19-KD mice showed reduced ability to stimulate IFN-γ and IL-17 production in T cells, respectively. Read More
Oncol Lett 2017 Sep 18;14(3):3536-3544. Epub 2017 Jul 18.
Department of Gynecological Oncology, The First Hospital of Jilin University, Changchun, Jilin 130021, P.R. China.
The aim of the present study was to identify and characterize side population (SP) cells in primary cervical cancer. A primary culture was successfully established, and the SP cells were isolated via fluorescence-activated cell sorting. Subsequently, in vitro analysis of clonogenic capacity by soft agar assay and in vivo analysis of tumorigenicity were performed. Read More
Normal adult mammary stem cells (AMSCs) are promising sources for breast reconstruction, particularly following the resection of breast tumors. However, carcinogenic events can potentially convert normal AMSCs to cancer stem cells, posing a safety concern for the use of AMSCs for clinical tissue regeneration. In the present study, AMSCs and autologous primary breast cancer cells were isolated and compared for their ability to differentiate, their gene expression profile, and their potential to form tumors in vivo. Read More
Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, Louisiana. Electronic address:
Aberrant expression and regulation of miRNAs have been implicated in multiple stages of tumorigenic processes. The current study was designed to explore the biological function and epigenetic regulation of miR-34a in human cholangiocarcinoma (CCA). Our data show that the expression of miR-34a is decreased significantly in CCA cells compared with non-neoplastic biliary epithelial cells. Read More
b Allergy Immunology and Blood and Marrow Transplant Division , University of California San Francisco, Benioff Children's Hospital , San Francisco , CA.
Introduction: Newborn screening has led to a better understanding of the prevalence of Severe Combined Immunodeficiency (SCID) overall and in terms of specific genotypes. Survival has improved following hematopoietic stem cell transplantation (HCT) with the best outcomes seen following use of a matched sibling donor. However, questions remain regarding the optimal alternative donor source, appropriate use of conditioning and the impact of these decisions on immune reconstitution and other late morbidities. Read More
JAK3 is a tyrosine kinase essential for signaling downstream of the common gamma chain subunit shared by multiple cytokine receptors. JAK3 deficiency results in T(-)B(+)NK(-) severe combined immune deficiency (SCID). We report a patient with SCID due to a novel mutation in the JAK3 JH4 domain. Read More
Hematol Oncol Clin North Am 2017 Oct 29;31(5):823-834. Epub 2017 Jun 29.
Infection, Immunity, Inflammation, Molecular and Cellular Immunology Section, University College London, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK. Electronic address:
Transfer of gene-corrected autologous hematopoietic stem cells in patients with primary immunodeficiencies has emerged as a new therapeutic approach. Patients with various conditions lacking a suitable donor have been treated with retroviral vectors and a gene-addition strategy. Initial promising results were shadowed by the occurrence of malignancies in some of these patients. Read More
Successful gene therapy for genetic disorders requires marrow niches to be opened to varying degrees to engraft gene-corrected hematopoietic stem cells (HSC). For example, in severe combined immunodeficiency, relatively limited chimerism is necessary for both T- and B-cell immune reconstitution, whereas for inborn errors of metabolism maximal donor chimerism is the goal. Currently, alkylating chemotherapy is used for this purpose. Read More
T cells develop from hematopoietic stem cells in the specialized microenvironment of the thymus. The main transcriptional players of T-cell differentiation such as Notch, Tcf-1, Gata3 and Bcl11b have been identified, but their role and regulation are not yet completely understood. In humans, functional experiments on T-cell development have traditionally been rather difficult to perform, but novel in vitro culture systems and in vivo xenograft models have allowed detailed studies on human T-cell development. Read More
Aim: Severe combined immunodeficiency (SCID) is the most severe form of primary immunodeficiency and is fatal in infancy if untreated. As early diagnosis is associated with improved outcomes, SCID is an ideal condition to consider for inclusion in a newborn screening (NBS) programme in Australia. In this feasibility study, we evaluated the EnLite Neonatal TREC kit for detection of T-cell receptor excision circles (TRECs) from NBS dried blood spots for the identification of known SCID patients in Victoria. Read More
San Raffaele Scientific Institute, San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), Paediatric Immunohematology and Bone Marrow Transplantation Unit, Milan, Milan, Italy.
Twenty -five years have passed since first attempts of gene therapy (GT) in children affected by severe combined immunodeficiency (SCID) due to adenosine deaminase (ADA) defect, also known by the general public as "bubble babies". ADA-SCID is fatal early in life if untreated. Unconditioned hematopoietic stem cell (HSC) transplant from matched sibling donor represent a curative treatment, but is available for few patients. Read More
Department of Pediatrics, University of California, Los Angeles (UCLA), 3163 Terasaki Life Science Bldg., 610 Charles E. Young Drive East, Los Angeles, CA, 90095, USA.
Cellular circular RNAs (circRNAs) are generated by head-to-tail splicing and are present in all multicellular organisms studied so far. Recently, circRNAs have emerged as a large class of RNA which can function as post-transcriptional regulators. It has also been shown that many circRNAs are tissue- and stage-specifically expressed. Read More
Advances in basic immunology in 2016 included studies that further characterized the role of different proteins in the differentiation of effector T and B cells, including cytokines and proteins involved in the actin cytoskeleton. Regulation of granule formation and secretion in cytotoxic cells was also further described by examining patients with familial hemophagocytic lymphohistiocytosis. The role of prenylation in patients with mevalonate kinase deficiency leading to inflammation has been established. Read More
J Allergy Clin Immunol 2017 Aug 19. Epub 2017 Aug 19.
Division of Immunology and Allergy, Department of Pediatrics, Hospital for Sick Children and the University of Toronto, Toronto, Ontario, Canada; Canadian Centre for Primary Immunodeficiency and the Jeffrey Modell Research Laboratory for the Diagnosis of Primary Immunodeficiency, Hospital for Sick Children, Toronto, Ontario, Canada. Electronic address:
Background: Combined immunodeficiency (CID) is a T-cell defect frequently presenting with recurrent infections, as well as associated immune dysregulation manifesting as autoimmunity or allergic inflammation.
Objective: We sought to identify the genetic aberration in 4 related patients with CID, early-onset asthma, eczema, and food allergies, as well as autoimmunity.
Methods: We performed whole-exome sequencing, followed by Sanger confirmation, assessment of the genetic variant effect on cell signaling, and evaluation of the resultant immune function. Read More
Department of Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, Minnesota; Department of Clinical Genomics, Mayo Clinic College of Medicine, Rochester, Minnesota. Electronic address:
Severe combined immunodeficiency (SCID) benefits from early intervention via hematopoietic cell transplantation to reverse T-cell lymphopenia (TCL). Newborn screening (NBS) programs use T-cell receptor excision circle (TREC) levels to detect SCID. Real-time quantitative PCR is often performed to quantify TRECs in dried blood spots (DBSs) for NBS. Read More
Mutations in Sp110 are the underlying cause of veno-occlusive disease with immunodeficiency (VODI), a combined immunodeficiency that is difficult to treat and often fatal. Because early treatment is critically important for patients with VODI, broadly usable diagnostic tools are needed to detect Sp110 protein deficiency. Several factors make establishing the diagnosis of VODI challenging: (1) Current screening strategies to identify severe combined immunodeficiency are based on measuring T cell receptor excision circles (TREC). Read More
Department of Pediatric Infectious Diseases, Clinical Immunology and Allergy, Istanbul University, Cerrahpasa Medical Faculty, Istanbul, Turkey. Electronic address:
Rotavirus (RV) infections are the major cause of severe gastroenteritis in children under five years of age, causing 215,000 deaths per year worldwide mainly due to dehydration in countries with weak economic resources (1). In the immunocompetent host RV infections are self-limiting and mortality is low in high-income countries. Notifications of RV cases have declined from 49,000 in season 2012/2013 to 25,000 in season 2015/2016 (2) since RV vaccination has been recommended by the Standing Committee on Vaccination (STIKO) in Germany in 2013. Read More
J Matern Fetal Neonatal Med 2017 Aug 29:1-5. Epub 2017 Aug 29.
b Department of Pediatrics , Division of Neonatal Intensive Care Unit, University of Medical Sciences Bagcilar Training and Research Hospital , Istanbul , Turkey.
Objective: Severe combined immunodeficiency (SCID) is a neonatal emergency. As the T-cell receptor excision circles (TREC) test is not cost effective for neonatal screening of SCID in developing countries, this pilot study's objective aimed at identifying preliminary data to enable SCID identification in the general population.
Methods: This observational study was performed in Bagcılar Training and Research Hospital, Istanbul, Turkey. Read More
Mesenchymal stromal cells (MSCs) represent a key component of bone marrow (BM) microenvironment and display immune-regulatory properties. We performed a detailed analysis of biological/functional properties of BM-MSCs derived from 33 pediatric patients affected by primary immune-deficiencies (PID-MSCs): 7 Chronic Granulomatous Disease (CGD), 15 Wiskott-Aldrich Syndrome (WAS), 11 Severe Combined Immunodeficiency (SCID). Results were compared with MSCs from 15 age-matched pediatric healthy-donors (HD-MSCs). Read More
Division of Molecular Therapy, Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan.
Multiple myeloma is a malignancy of plasma cells of the bone marrow. Although the prognosis is variable, no curative therapy has been defined. Vaccinia virus infects cancer cells and kills such cells in a variety of ways. Read More
Stem Cell Res Ther 2017 Aug 14;8(1):183. Epub 2017 Aug 14.
Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing Key Laboratory of Translational Medicine on Liver Cirrhosis & National Clinical Research Center of Digestive Diseases, Beijing, 100050, China.
Background: Although they are expandable in vitro, hepatic progenitors are immature cells and share many immunomarkers with hepatocellular carcinoma, raising potential concerns regarding maltransformation after transplantation. This study investigated the effects of hepatic nuclear factor (HNF) 4α on the proliferation, migration, and maltransformation of hepatic progenitors and determined the feasibility of using these manipulated cells for transplantation.
Methods: The effects of HNF4α on rat hepatic progenitors (i. Read More
Organ-specific microcirculation plays a central role in tumor growth, tumor cell homing, tissue engineering, and wound healing. Mouse models are widely used to study these processes; however, these mouse strains often possess unique microhemodynamic parameters, making it difficult to directly compare experiments. The full functional characterization of bone and striated muscle microcirculatory parameters in non-obese diabetic-severe combined immunodeficiency/y-chain; NOD-Prkds IL2rg (NSG) mice has not yet been reported. Read More
J Pediatr Hematol Oncol 2017 Aug 4. Epub 2017 Aug 4.
*Department of Pediatric Immunology, Antalya Training and Research Hospital †Department of Pediatric Bone Marrow Transplantation Unit, MedicalPark Antalya Hospital ‡Department of Pediatric Bone Marrow Transplantation Unit, MedicalPark Antalya Hospital, Antalya §Department of Pediatric Bone Marrow Transplantation Unit, MedicalPark Göztepe Hospital ∥Department of Pediatric Bone Marrow Transplantation Unit, MedicalPark Göztepe Hospital, İstanbul, Turkey.
Immune reconstitution inflammatory syndrome (IRIS) is a clinical condition emerging after immune recovery of an immunocompromised status, mostly in human immunodeficiency virus infected patients but also in several other settings, such as the recovery from the severe combined immunodeficiency status after hematopoietic stem cell transplantation. Herein, we report a patient transplanted for severe combined immunodeficiency who developed IRIS for 2 times, namely shortly after transplantation and after donor lymphocyte infusion. Pediatric transplant teams need to be aware of the previous IRIS phenomenon of BCG-adenitis while making the decision of donor lymphocyte infusions. Read More
The aim of the present study was to evaluate the development of fresh and vitrified agouti ovarian tissue after xenografting to C57Bl/6 severe combined immunodeficiency (SCID) female mice. Ovaries were obtained from five female agoutis and divided into 16 fragments. Five fragments were transplanted immediately to ovariectomised SCID mice and the others were vitrified, stored for 2 weeks and transplanted only after rewarming. Read More
Recombination-activating genes 1 and 2 (RAG1 and RAG2) play a critical role in T and B cell development by initiating the recombination process that controls the expression of T cell receptor (TCR) and immunoglobulin genes. Mutations in the RAG1 and RAG2 genes in humans cause a broad spectrum of phenotypes, including severe combined immunodeficiency (SCID) with lack of T and B cells, Omenn syndrome, leaky SCID, and combined immunodeficiency with granulomas or autoimmunity (CID-G/AI). Using next-generation sequencing, we analyzed the TCR and B cell receptor (BCR) repertoire in 12 patients with RAG mutations presenting with Omenn syndrome (n = 5), leaky SCID (n = 3), or CID-G/AI (n = 4). Read More
We report the identification, pathogenesis, and transmission of a novel polyomavirus in severe combined immunodeficient F344 rats with null Prkdc and interleukin 2 receptor gamma genes. Infected rats experienced weight loss, decreased fecundity, and mortality. Large basophilic intranuclear inclusions were observed in epithelium of the respiratory tract, salivary and lacrimal glands, uterus, and prostate gland. Read More
Clin Immunol 2017 Aug 3;183:112-120. Epub 2017 Aug 3.
Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
X-linked severe combined immunodeficiency (X-SCID), caused by defects in the common gamma chain, is typically characterized by T and NK cell defects with the presence of B cells. T cell dysfunction and impaired class-switch recombination of B cells mean that patients typically have defects in class-switched immunoglobulins (IgG, IgA, and IgE) with detectable IgM. Here, we describe two patients with X-SCID with IgG1 gammopathy, in whom we identified maternal T and B cell engraftment. Read More
Newborn screening for severe combined immunodeficiency has proven successful in identifying infants with T-cell deficiencies before they become severely ill. Additionally, the newborn screen can detect subtle early phenotypes that may become severe later in life. We present the case of siblings with features suggestive of T-cell lymphopenia identified as having low T-cell receptor excision circles counts by newborn screening. Read More
Immunologically inert allogeneic acellular dermal scaffolds provide a matrix with molecular architecture close to native tissues, which synthetic scaffolds cannot. Not all nature-derived scaffolds possess the same biological and physical properties. The different properties of scaffolds supporting cellular growth used for manufacturing tissue engineered grafts could lead to different implantation results. Read More
Aim: Haematopoietic stem cell transplantation (HSCT) is a central therapy in the treatment of primary immunodeficiency diseases (PIDs). Over the past 5 years, outcomes have been greatly improved due to earlier diagnosis, improved donor availability, advancements in graft manipulation and the use of less toxic preparative regimens. We present a 5-year audit of HSCT for PID at a single Australian tertiary hospital. Read More
Background: Epithelial-to-mesenchymal transition (EMT) is associated with downregulated E-cadherin and frequently with decreased proliferation. Proliferation may be restored in secondary metastases by mesenchymal-to-epithelial transition (MET). We tested whether E-cadherin maintains epithelial proliferation in MDA-MB-468 breast cancer cells, facilitating metastatic colonization in severe combined immunodeficiency (SCID) mice. Read More
Vici syndrome is one of the most extensive inherited human multisystem disorders and due to recessive mutations in EPG5 encoding a key autophagy regulator with a crucial role in autophagosome-lysosome fusion. The condition presents usually early in life, with features of severe global developmental delay, profound failure to thrive, (acquired) microcephaly, callosal agenesis, cataracts, cardiomyopathy, hypopigmentation, and combined immunodeficiency. Clinical course is variable but usually progressive and associated with high mortality. Read More
After the discovery of naturally occurring severe combined immunodeficiency (SCID) within a selection line of pigs at Iowa State University, we found two causative mutations in the Artemis gene: haplotype 12 (ART12) and haplotype 16 (ART16). Bone marrow transplants (BMTs) were performed to create genetically SCID and phenotypically immunocompetent breeding animals to establish a SCID colony for further characterization and research utilization. Of nine original BMT transfer recipients, only four achieved successful engraftment. Read More
Background: Severe combined immunodeficiency (SCID) is fatal unless treated with hematopoietic stem cell transplant. Delay in diagnosis is common without newborn screening. Family history of infant death due to infection or known SCID (FH) has been associated with earlier diagnosis. Read More
Department of Pediatrics, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University.
Mutations in the RAG1/RAG2 genes are associated with a broad spectrum of clinical phenotypes, ranging from severe combined immunodeficiency to various autoimmune diseases. The diversity of the clinical symptoms is determined not only by the residual RAG recombinase enzyme activity as determined by the mutations, but also by multiple environmental factors and, in rare cases, by second site mutations within the RAG1/RAG2 genes. The residual recombinase activity is responsible for the oligoclonal expansion of autoreactive T cells. Read More
Severe combined immunodeficiency (SCID) is impaired in lymphocyte development and function. Affected children have extreme susceptibility to infections, which are fatal in the first year of life without treatment. The estimate of incidence is one in approximately 50,000 live birth. Read More
Centre for Diabetes, Obesity & Endocrinology, The Westmead Institute for Medical Research (WIMR), Room 2040, Level 2, Darcy Rd, Westmead Hospital, The University of Sydney, Sydney, NSW, 2145, Australia.
Aims/hypothesis: Beta cell replacement is a potential cure for type 1 diabetes. In humans, islet transplants are currently infused into the liver via the portal vein, although this site has disadvantages. Here, we investigated alternative transplantation sites for human and murine islets in recipient mice, comparing the portal vein with quadriceps muscle and kidney, liver and spleen capsules. Read More
Research Center for Immunodeficiencies, Pediatrics Center of Excellence, Children's Medical Center, Tehran University of Medical Science, Tehran, Iran. Electronic address:
Non-homologous end-joining (NHEJ) is a pathway that repairs double-strand breaks (DSB) in DNA and plays a vital role in V(D)J recombination of immunoglobulin genes. Cernunnos is a DNA repair factor that is involved in nonhomologous end-joining (NHEJ) process. Impairment in Cernunnos leads to a genetic disease characterized by neural disorders, immunodeficiency and increased radiosensitivity. Read More
From the University of Zimbabwe Clinical Research Center, Harare, Zimbabwe (J.H., M.B.-D., G.M., K.N.); Joint Clinical Research Center, Kampala (V.M., C.K., P.M.), Mbarara (A.L.), and Fort Portal (S. Kabahenda) - all in Uganda; Medical Research Council Clinical Trials Unit at University College London (A.J.S., S.L.P., A.G., M.J.T., A.S.W., D.M.G.), Wellcome Trust Centre for Clinical Tropical Medicine and Department of Paediatrics, Imperial College (K.M.), and Queen Mary University of London (A.J.P.), London, and the Centre for Health Economics, University of York, York (S.W.) - all in the United Kingdom; the Department of Medicine and Malawi-Liverpool-Wellcome Trust Clinical Research Program, Blantyre, Malawi (J.M., S. Kaunda); and Moi University School of Medicine, Eldoret (A.S., M.K.), and the Kenya Medical Research Institute (KEMRI) Wellcome Trust Research Program, Kilifi (C.A., K.M.) - both in Kenya.
Background: In sub-Saharan Africa, among patients with advanced human immunodeficiency virus (HIV) infection, the rate of death from infection (including tuberculosis and cryptococcus) shortly after the initiation of antiretroviral therapy (ART) is approximately 10%.
Methods: In this factorial open-label trial conducted in Uganda, Zimbabwe, Malawi, and Kenya, we enrolled HIV-infected adults and children 5 years of age or older who had not received previous ART and were starting ART with a CD4+ count of fewer than 100 cells per cubic millimeter. They underwent simultaneous randomization to receive enhanced antimicrobial prophylaxis or standard prophylaxis, adjunctive raltegravir or no raltegravir, and supplementary food or no supplementary food. Read More
Aims/hypothesis: Novel strategies to stimulate the expansion of beta cell mass in situ are warranted for diabetes therapy. The aim of this study was to elucidate the secretome of human bone marrow (BM)-derived multipotent stromal cells (MSCs) with documented islet regenerative paracrine function. We hypothesised that regenerative MSCs will secrete a unique combination of protein factors that augment islet regeneration. Read More
The effects of short-term alcohol abstinence on host antibacterial resistance against Enterococcus faecalis oral infection was investigated in chronic alcohol-consuming mice [mice with 0.1 g/day of 20% ethanol consumption for 12 or 16 weeks (CAC-mice)]. These mice were highly susceptible to the infection; however, after 7 days of alcohol abstinence (aaCAC-mice), their antibacterial resistances were completely restored to the normal mouse level. Read More
Quantification of T-cell receptor excision circles (TRECs) for newborn screening for SCID has advanced the diagnosis of severe combined immune deficiency (SCID). However, it has led to the identification of infants with T cell lymphopenia without known cause. The clinical characteristics, appropriate laboratory monitoring, and outcomes of patients remain unclear. Read More
Stem cell therapy is the administration of stem cells to a patient to treat or prevent a disease. Since stem cells possess the long-term self-renewal capacity and provide daughter cells that differentiate into the specialized cells of each tissue, stem cell therapy will theoretically improve the disease condition for the lifetime of the patient. As the most widely used stem cell therapy, bone marrow transplantation is the treatment of choice for many kinds of blood disorders, including anemias, leukemias, lymphomas, and rare immunodeficiency diseases. Read More
Department of Pediatrics and Developmental Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
Primary immunodeficiencies (PIDs) are a heterogeneous group of inherited diseases of the immune system. The definite diagnosis of PID is ascertained by genetic analysis; however, this takes time and is costly. Flow cytometry provides a rapid and highly sensitive tool for diagnosis of PIDs. Read More
*Department of Pediatrics, Shinshu University School of Medicine †Department of Laboratory Medicine, Shinshu University Hospital ‡Department of Infection and Host Defense, Graduate School of Medicine, Shinshu University, Matsumoto, Japan.
Severe combined immunodeficiency (SCID) is a defect in the differentiation and function of T cells. An increased malignancy risk, mainly lymphatic malignancy, has been described in patients with SCID. We report a patient with X-linked SCID who developed acute myeloid leukemia, derived from the recipient with somatic NRAS mutation 4 months after cord blood transplantation (CBT). Read More
Purine nucleoside phosphorylase (PNP) deficiency, a rare autosomal recessive metabolic disease causes combined immunodeficiency and developmental delay, hypotonia, and spasticity. Patients present with recurrent infections associated with T-lymphocytopenia, characteristically presenting later than patients with classical severe combined immunodeficiency (SCID). PNP, with adenosine deaminase (ADA), is part of the purine salvage pathway. Read More