Kelly Walkovich

Newborn Screening for Severe Combined Immunodeficiency in 11 Screening Programs in the United States

IMPORTANCE Newborn screening for severe combined immunodeficiency (SCID) using assays to detect T-cell receptor excision circles (TRECs) began in Wisconsin in 2008, and SCID was added to the national recommended uniform panel for newborn screened disorders in 2010. Currently 23 states, the District of Columbia, and the Navajo Nation conduct population-wide newborn screening for SCID. The incidence of SCID is estimated at 1 in 100,000 births. OBJECTIVES To present data from a spectrum of SCID newborn screening programs, establish population-based incidence for SCID and other conditions with T-cell lymphopenia, and document early institution of effective treatments. DESIGN Epidemiological and retrospective observational study. SETTING Representatives in states conducting SCID newborn screening were invited to submit their SCID screening algorithms, test performance data, and deidentified clinical and laboratory information regarding infants screened and cases with nonnormal results. Infants born from the start of each participating program from January 2008 through the most recent evaluable date prior to July 2013 were included. Representatives from 10 states plus the Navajo Area Indian Health Service contributed data from 3,030,083 newborns screened with a TREC test. MAIN OUTCOMES AND MEASURES Infants with SCID and other diagnoses of T-cell lymphopenia were classified. Incidence and, where possible, etiologies were determined. Interventions and survival were tracked. RESULTS Screening detected 52 cases of typical SCID, leaky SCID, and Omenn syndrome, affecting 1 in 58,000 infants (95% CI, 1/46,000-1/80,000). Survival of SCID-affected infants through their diagnosis and immune reconstitution was 87% (45/52), 92% (45/49) for infants who received transplantation, enzyme replacement, and/or gene therapy. Additional interventions for SCID and non-SCID T-cell lymphopenia included immunoglobulin infusions, preventive antibiotics, and avoidance of live vaccines. Variations in definitions and follow-up practices influenced the rates of detection of non-SCID T-cell lymphopenia. CONCLUSIONS AND RELEVANCE Newborn screening in 11 programs in the United States identified SCID in 1 in 58,000 infants, with high survival. The usefulness of detection of non-SCID T-cell lymphopenias by the same screening remains to be determined.

How to Approach Neutropenia in Childhood

1. Kelly Walkovich, MD 2. Laurence A. Boxer, MD 1. Department of Pediatrics, University of Michigan, Ann Arbor, MI. * Abbreviations: AIN: : autoimmune neutropenia AML: : acute myelogenous leukemia ANC: : absolute neutrophil count CBC: : complete blood cell count MDS: : myelodysplastic syndrome rhG-CSF: : recombinant human granulocyte colony-stimulating factor SCN: : severe congenital neutropenia SDS: : Shwachman-Diamond syndrome WBC: : white blood cell count 1. Patients presenting with recurrent fevers, mouth ulcers and gingivitis should be evaluated for neutropenia. 2. The use of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in the management of cyclic neutropenia and severe congenital neutropenia has dramatically decreased clinical symptoms and has decreased mortality from infectious causes. After completing this article, readers should be able to: 1. Recognize patients who have concerning features of history, physical examination, or laboratory results that warrant further investigation for possible neutropenia or other immunodeficiency. 2. Define mild, moderate, and severe neutropenia. 3. Understand that neutropenia can arise from acquired or intrinsic conditions. Know which causes of neutropenia are most commonly encountered in childhood. 4. Recognize why disorders of neutrophil production and release from the bone marrow carry more risk for bacterial infection than peripheral neutropenia associated with normal bone marrow morphology. 5. Understand why neutropenic patients undergoing immunosuppressive therapy are more at risk for a serious bacterial infection than patients who have isolated neutropenia. 6. Understand the impact that treatment with recombinant human granulocyte colony-stimulating factor has had on the outcome of patients who have severe congenital and cyclic neutropenia. 7. Know when to refer to a pediatric hematologist/oncologist. A case study is provided to illustrate key aspects of the care of patients who have neutropenia. A 13-month-old boy presents to his primary care physician for his standard 1-year well-child check. He has had four episodes of otitis media since starting child care, all of which resolved with standard antibiotics. His mother reports that he has been …

Autoimmune Lymphoproliferative Syndrome Misdiagnosed as Hemophagocytic Lymphohistiocytosis

Autoimmune lymphoproliferative syndrome (ALPS) is a rare inherited disorder of apoptosis, most commonly due to mutations in the FAS (TNFRSF6) gene. It presents with chronic lymphadenopathy, splenomegaly, and symptomatic multilineage cytopenias in an otherwise healthy child. Unfortunately, these clinical findings are also noted in other childhood lymphoproliferative conditions, such as leukemia, lymphoma, and hemophagocytic lymphohistiocytosis, which can confound the diagnosis. This report describes a 6-year-old girl with symptoms misdiagnosed as hemophagocytic lymphohistiocytosis and treated with chemotherapy before the recognition that her symptoms and laboratory values were consistent with a somatic FAS mutation leading to ALPS. This case should alert pediatricians to include ALPS in the differential diagnosis of a child with lymphadenopathy, splenomegaly, and cytopenias; obtain discriminating screening laboratory biomarkers, such as serum vitamin B-12 and ferritin levels; and, in the setting of a highly suspicious clinical scenario for ALPS, pursue testing for somatic FAS mutations when germ-line mutation testing is negative.

Diagnosis and treatment of pediatric acquired aplastic anemia (AAA): An initial survey of the North American Pediatric Aplastic Anemia Consortium (NAPAAC)

Randomized clinical trials in pediatric aplastic anemia (AA) are rare and data to guide standards of care are scarce.

Somatic mutations and clonal hematopoiesis in congenital neutropenia

Severe congenital neutropenia (SCN) and Shwachman-Diamond syndrome (SDS) are congenital neutropenia syndromes with a high rate of leukemic transformation. Hematopoietic stressors may contribute to leukemic transformation by increasing the mutation rate in hematopoietic stem/progenitor cells (HSPCs) and/or by promoting clonal hematopoiesis. We sequenced the exome of individual hematopoietic colonies derived from 13 patients with congenital neutropenia to measure total mutation burden and performed error-corrected sequencing on a panel of 46 genes on 80 patients with congenital neutropenia to assess for clonal hematopoiesis. An average of 3.6 ± 1.2 somatic mutations per exome was identified in HSPCs from patients with SCN compared with 3.9 ± 0.4 for healthy controls (P = NS). Clonal hematopoiesis due to mutations in TP53 was present in 48% (13/27) of patients with SDS but was not seen in healthy controls (0/17, P < .001) or patients with SCN (0/40, P < .001). Our SDS cohort was young (median age 6.3 years), and many of the patients had multiple TP53 mutations. Conversely, clonal hematopoiesis due to mutations of CSF3R was present in patients with SCN but was not detected in healthy controls or patients with SDS. These data show that hematopoietic stress, including granulocyte colony-stimulating factor, do not increase the mutation burden in HSPCs in congenital neutropenia. Rather, distinct hematopoietic stressors result in the selective expansion of HSPCs carrying specific gene mutations. In particular, in SDS there is enormous selective pressure to expand TP53-mutated HSPCs, suggesting that acquisition of TP53 mutations is an early, likely initiating event, in the transformation to myelodysplastic syndrome/acute myeloid leukemia in patients with SDS.

Variation in Management of Fever and Neutropenia Among Pediatric Patients with Cancer: A Survey of Providers in Michigan

Considerable variation in the management of fever and neutropenia (FN) exists, with factors associated with treatment variation not well described. An online survey of 90 pediatric cancer providers in Michigan was performed in Spring 2014. The survey frame was pediatric patients with cancer receiving treatment, with a Port-a-cath, who were clinically stable. Criteria for “Decreased” and “Increased” risk groups were defined by respondents. Survey questions addressed FN definitions, risk groups conceptualization, routine clinical practice, and management guidelines, in the context of risk groups and distance to treating institution. Fifty providers responded (56%); the majority defined a febrile event as temperature >38.3°C and/or 2 events >38.0°C within a 24-hour period. Neutropenia was defined as current or anticipated absolute neutrophil count (ANC) <500/μL. Majority of respondents recommended “Decreased” and “Increased” patients present to a local emergency department (ED) if they live >2 hours away. Respondents were significantly more likely to have a “Decreased Risk” patient travel over 2 hours if they rated the local ED as “Poor to Fair” on ability to access Port-a-caths (P = .048). Most respondents would discharge patients who are afebrile for 24 hours, blood cultures negative for 48 hours, and neutrophil count of greater than 200/μL; 40% preferred discharge on oral antibiotics when the ANC <500/μL. Triaging for febrile pediatric patients with cancer is significantly influenced by the providers’ perceptions of local EDs. Future investigation of local hospitals’ ability to provide urgent evaluation, combined with parental perspectives, could lead to improvements in timely and effective management.

Primary immunodeficiency in the neonate: Early diagnosis and management

Many primary immunodeficiencies (PIDs) manifest in the neonatal period but can be challenging to diagnose and manage optimally. In part, the difficulty stems from the natural immaturity of the neonatal immune system that may mask immune deficits and/or complicate interpretation of clinical findings and laboratory assays. The great diversity of PIDs--from innate immune system defects to those that impact the humoral and/or cellular components of the adaptive immune system--and the rapid rate at which new PIDs are being discovered makes it challenging for practitioners to stay current. Moreover, recent appreciation for immune deficiencies that lead to autoinflammation and autoimmunity have broadened the spectrum of neonatal PID, adding additional complexity to an already intricate field. This article serves to highlight the deficiencies in the neonatal immune system, while providing a review of the more common PIDs that present in the neonate and guidelines for diagnosis and supportive care.

Hematologic Manifestations of Deficiency of Adenosine Deaminase 2 (DADA2) and Response to Tumor Necrosis Factor Inhibition in DADA2-Associated Bone Marrow Failure

To the Editor, Deficiency of adenosine deaminase 2 (DADA2) was initially described simultaneously in 2014 by two groups [1, 2]. Enzymatic deficiency occurs via autosomal recessive inheritance of CECR1 gene mutations. Early descriptions of the disorder highlighted early-onset stroke, vasculitis presenting as polyarteritis nodosa, livedo reticularis, recurrent fevers, and hypogammaglobulinemia as the predominant clinical manifestations observed in patients [1–5]. The discovery of additional patients with DADA2 has revealed a highly variable clinical presentation with many features responsive to therapy with anti-tumor necrosis factor agents [2, 6–11]. Although not described in the initial cohorts of patients, hematological manifestations now appear to be a significant clinical component of deficiency of adenosine deaminase 2 [6–9, 12]. The pathogenesis underlying the hematologic dysfunction seen in patients has yet to be elucidated, although persistently elevated levels of tumor necrosis factor (TNF)-alpha have been described to be damaging to hematopoiesis within the bone marrow [13, 14]. Here, we describe a case of two adult brothers with DADA2 presenting with cytopenias and bone marrow hypocellularity. We particularly detail the clinical course of one brother with initial partial response to equine anti-thymocyte globulin and cyclosporine with recurrence of cytopenias following withdrawal of immunosuppression. Retreatment was initiated with anti-tumor necrosis factor alpha therapy resulting in clinical symptom improvement and normalization of blood counts. Patient 1 presented at 47 years of age with leukopenia following evaluation for recurrent upper respiratory and allergy symptoms. Complete blood count (CBC) at that time was notable for white blood cell (WBC) count 2.3 K/μL (35% neutrophils, 11% bands, 28% lymphocytes, 25% monocytes, and 1% basophils), hemoglobin 14.3 g/dL, MCV 90.7 fL, and platelets 153,000 K/μL. The patient’s past medical history was notable for Bmyositis^ as a child and right lower extremity cellulitis with associated sepsis as an adult. Family history was significant for a brother with neutropenia. Physical exam was unremarkable other than diffusely dry and vasculitic-appearing darkened skin on his bilateral lower extremities (Fig. 1a). Within 3 years, he progressed to pancytopenia with hemoglobin falling to 6 g/dL requiring frequent red blood cell transfusions and platelet and absolute neutrophil counts ultimately reaching nadirs of 49,000 and 620/uL, respectively. Initial bone marrow biopsy was hypocellular (range 0–15%) with a patchy distribution of hematopoietic precursors, mild reticulin fibrosis, and an increased proportion of CD3-positive T cells distributed interstitially. Flow cytometric immunophenotyping of the bone marrow disclosed no lymphoid antigen aberrancies and no increase in blasts. Cytogenetic analysis of the bone marrow yielded a normal male karyotype (46, XY). Testing for paroxysmal nocturnal hemoglobinuria was negative. Repeat bone marrow examination performed 6 months later, prior to * Thomas F. Michniacki tmich@med.umich.edu

A diagnosis of mycosis fungoides in a pediatric patient with recurrent Langerhans cell histiocytosis

To the Editor: An 8-year-old female presented with a reddish-brown papule that tripled in size. She had a history of intermittent hypopigmentation (Fig. 1A). Biopsy of the papule revealed a lymphohistiocytic infiltrate with increased CD1a and S100-positive Langerhans cells, consistent with Langerhans cell histiocytosis (LCH) (Fig. 1D). v-RAF murine sarcoma viral oncogene homolog (BRAF) mutation testing was negative. Workup for other sites of disease was negative. There was minimal response to topical steroids. She began oral prednisonewith partial response but flaredwith taper. Treatmentwith oral methotrexate and prednisone1 resulted in complete response. With discontinuation, she had recurrence of papules and hypopigmentation. Repeat biopsy confirmed LCH. Methotrexate was resumed and she had full resolution of papules but persistent hypopigmentation; however, her papules recurred with discontinuation of therapy. Repeat biopsy revealed atypical epidermotropic CD8-positive T cells that displayed loss of CD2 and diminished expression of CD7

Identification of novel MECOM gene fusion and personalized therapeutic targets through integrative clinical sequencing in secondary acute myeloid leukemia in a patient with severe congenital neutropenia: a case report and literature review

Severe congenital neutropenia (SCN) is a rare hematologic disorder characterized by defective myelopoiesis and a high incidence of malignant transformation to myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). SCN patients who develop MDS/AML have excessive toxicities to traditional chemotherapy, and safer therapies are needed to improve overall survival in this population. In this report, we outline the use of a prospective integrative clinical sequencing trial (PEDS-MIONCOSEQ) in a patient with SCN and AML to help identify oncogenic targets for less toxic agents. Integrative sequencing identified two somatic cis-mutations in the colony stimulating factor 3 receptor (CSF3R) gene, a p.T640N mutation in the transmembrane region and a p.Q768* truncation mutation in the cytoplasmic domain. A somatic mutation p.H105Y, in the runt homology domain (RHD) of runt-related transcription factor 1 (RUNX1), was also identified. In addition, sequencing discovered a unique in-frame EIF4A2-MECOM (MDS1 and ectopic viral integration site 1 complex) chromosomal translocation with high MECOM expression. His mutations in CSF3R served as potential targets for tyrosine kinase inhibition and therefore provided an avenue to avoid more harmful therapy. This study highlights the utility of integrative clinical sequencing in SCN patients who develop leukemia and outlines a strategy on how to approach these patients in a future clinical sequencing trial to improve historically poor outcomes. A thorough review of leukemia in SCN and the role of CSF3R mutations in oncologic therapy are provided to support a new strategy on how to approach MDS/AML in SCN.