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Combined B-Cell and T-Cell Disorders Clinical Presentation

  • Author: Francisco J Hernandez-Ilizaliturri, MD; Chief Editor: Emmanuel C Besa, MD  more...
Updated: Apr 14, 2015


The clinical manifestation landmarks of SCID are secondary to the profound degree of immune compromise leading to repetitive and frequent bacterial, viral, and fungal infections that persist despite standard medical treatment.

Patients with primary T-cell deficiency or SCID begin having infections soon after birth (ie, age 3-4 mo) compared with those that have pure B-cell disorders, who do not have an increased incidence of bacterial infections until 7-9 months after birth, when placental antibodies fall to undetectable levels.

Clinicians should focus attention on the family history, site of infection, type of microorganisms, and any adverse reactions to transfusion of blood products, which may provide clues to the significance and type of immune deficiency. It is also important to inquire about consanguineous relationships because consanguinity increases the risk of immune disorders that have autosomal recessive inheritance patterns (eg, some forms SCID or chronic granulomatous disease [CGD]). In addition, a careful family history of risk factors for human immunodeficiency virus (HIV) should be obtained to rule out secondary forms of immunodeficiency.

Upper and lower respiratory tract infections, skin infections, meningitis, bacteremias, and abscesses are common in persons with B-cell disorders. Pneumonia with P carinii or CMV, disseminated bacille Calmette-Guerin (BCG) infection,[7] or atypical mycobacterial infection and recurrent or persistent skin candidiasis are suggestive of T-cell disorders or SCID. Diarrhea with failure to thrive in children with SCID is usually related to infections with viruses such as rotaviruses and adenoviruses. Although antibody deficiency is associated with recurrent encapsulated bacteria infections, T-cell disorders or SCID are associated with opportunistic infections with fungi, viruses, or intracellular bacteria.

Reactions to blood products or vaccines should raise the suggestion of an underlying immunodeficiency, particularly IgA deficiency. Transfusion with blood products can result in significant graft versus host disease (GVHD) in SCID patients.

After a detailed inquiry, a SCID disorder should be suspected if the patient falls into one of the following groups:[8, 9, 10, 11]

  • Prenatal diagnosis
  • Neonate with a family history of a known immunologic disorder
  • Failure to thrive
  • Recurrent upper and lower respiratory tract infections that do not respond to appropriate antibiotics
  • Recurrent skin infections and delayed wound healing

The following is a summary of history and physical features that are associated with various forms of SCIDs:

  • X-linked immunodeficiency with hyper IgM syndrome (XHM)
    • XHM is a part of the hyper-IgM syndromes that includes a group of disorders characterized by recurrent bacterial infections, low serologic levels of IgG, IgA, and IgE, with relatively elevated levels of IgM.
    • XHM affects only boys and is the result of mutations in the gene that encodes the CD40 ligand (CD40L or CD154) located on chromosome X.
    • Patients with XHM present with recurrent infections of the upper and lower respiratory tracts beginning during the first 2 years of life. The susceptibility to P carinii and Clostridium parvum, both opportunistic infections controlled by cellular immunity, may be explained by the nature of the defect underlying this disease, involving T-cell CD40L.
    • These patients have a high incidence of liver disease and sclerosing cholangitis (approximately 20% of patients in a series reported by Levy et al[12] ; others report 80% by age 20 y), as well as liver and gastrointestinal malignancies.
    • Oral and rectal ulcers are common in patients with chronic neutropenia (approximately 50% of cases).
    • Autoimmune diseases such as arthritis, nephritis, and hematologic disorders have also been reported.
  • X-linked severe combined immunodeficiency (XSCID)
    • XSCID is by far the most common form of SCID, accounting for almost 50% of the cases.[13] As the affected gene is located in the X chromosome (X13q band), the disease is limited to males.Because of a defective common gamma chain (a component of cytokine receptors for IL-2, IL-4, IL-7, IL-9, and IL-15), signal transduction cannot proceed normally, which results in SCID characterized by absent T and NK cells and dysfunctional B cells. The phenotype is T–B+NK–. Infections begin in the first months of life, affecting the upper and lower respiratory tracts, gastrointestinal tract, and skin, whereas symptoms in patients with X-linked agammaglobulinemia (XLA) do not manifest symptoms until the second half of an infant's first year of life.Persistent opportunistic infections with Candida albicans or P carinii and viral infections with VZV, CMV, and EBV are common.The risk of GVHD is high inthesepatientsbecauseoftheirinabilitytorejectforeignantigens.
  • ADA deficiency
    • ADA is an enzyme of the purine salvage pathway. Deficiency leads to the accumulation of dATP and 2'-deoxyadenosine. dATP is lymphocytotoxic because of its ability to inhibit DNA synthesis via inhibition of ribonucleotide reductase. The nucleoside 2'-deoxyadenosine inhibits the enzyme SAH hydrolase, which results in accumulation of SAH, a potent inhibitor of all cellular methylation reactions. Both B and T cells are affected. The phenotype is T–B–NK–.
    • ADA deficiency is an autosomal recessive disorder in which the age at presentation varies. Failure of the immune system is progressive and may not fully manifest in certain individuals until adulthood.
    • This disease has the same symptoms of XSCID, that is, recurrent infections, persistent opportunistic infections, and GVHD susceptibility. Clinically, ADA deficiency differs from XSCID by (1) the presence of skeletal and chest wall abnormalities involving the vertebral bodies and the chondrocostal junctions and (2) the possible presence of thymic differentiation with rare Hassall concentric corpuscles.
  • JAK3 deficiency
    • JAK3 is an intracellular enzyme that is activated as a result of the binding of cytokines with their cognate receptors. The gene encoding JAK3 is located on band 19p13, and the disorder is autosomal recessive. The phenotype is T–B+NK–.
    • The symptoms of this condition are similar to those observed in persons with XSCID and include upper and lower respiratory tract infections, persistent infections with opportunistic microorganisms, and increased susceptibility to GVHD.
  • RAG1 and RAG2 deficiency
    • In patients deficient in the RAG proteins 1 and 2, the lymphocytes cannot rearrange the antigen receptors, thus leading to B- and T-lymphocyte deficiency.
    • Phenotypically, the numbers of B and T cells are decreased, whereas the number of NK cells is normal.
    • Clinically, these patients present with increased susceptibility to infection with encapsulated and intracellular bacteria, viruses, and fungi.
    • This syndrome is characterized by high serum IgE levels, decreased levels of the other immunoglobulins, and hypereosinophilia.
    • RAG1 deficiency is observed in patients with CHH. This condition is characterized by short hands; metaphysial chondroplasia; hyperextensibility of the distal joints of hands and feet; and fine, light hair.
  • CHH
    • CHH manifests in early infancy with chronic diarrhea, failure to thrive, and an erythematous rash with desquamation. Hepatosplenomegaly is common. Patients die in the first few months of life unless successful allogeneic bone marrow transplantation is performed.
  • Reticular Dysgenesis
    • This is a rare disorder that is characterized by an almost complete lack of granulocytes and lymphocytes.
    • Most patients die in early infancy or the newborn period because of severe and overwhelming infection.
    • The molecular basis of the disease is not known
  • Wiskott-Aldrich Syndrome
    • WAS affects only males because it is transmitted by an X-linked recessive gene that encodes for the WAS protein (WASP). WASP is a key regulator of actin polymerization in hematopoietic cells. Structural studies of the WASP protein have identified 5 domains that are involved in signaling, cell locomotion, and immune synapse formation. WASP regulates the nuclear factor kappaB (NF-KB) activity by promoting the nuclear translocation of NF-KB. In addition, WASP plays not only an important role in lymphoid development, but also in the maturation of myeloid monocytic cells.
    • Clinically, the syndrome is characterized by the triad of thrombocytopenic purpura, eczema, and increased susceptibility to infections.
    • Symptoms begin in the first year of life, with recurrent upper and lower respiratory tract infections with encapsulated bacteria. P carinii and herpes infections become a problem later in life
    • Most patients die of serious infections at approximately age 11 years. If these patients survive to adulthood, they are at high risk for autoimmune diseases, such as cytopenias and vasculitis, and for cancer, particularly non-Hodgkin lymphomas. The discovery of the Wiskott-Aldrich gene made possible the identification of carriers of the gene in families of WAS patients with an incomplete syndrome. Some of these patients have only the thrombocytopenia (X-linked thrombocytopenia) with no skin involvement or immunodeficiency despite inheriting the same gene mutation.


The physical examination may identify nonspecific signs of acute or chronic infections and those more specifically related to certain disease entities.

  • Growth and development may be delayed as a result of recurrent infections. Dysmorphic syndromes such as short-limbed dwarfism may occur. Hair abnormalities are observed in persons with CHH.
  • Lymphoid tissue and organs such as the tonsils, adenoids, and peripheral lymph nodes are underdeveloped in persons with XLA and those with various forms of SCID. Diffuse lymphadenopathy is observed in persons with CVID, XHM, and Omenn syndrome.
  • Permanent cutaneous scars are observed following skin infections. A desquamating erythematous rash is observed in persons with Omenn syndrome.
  • Evidence of past perforations, scarring, and dull tympanic membranes are observed after recurrent episodes of otitis media. Purulent nasal discharge, a cobblestone pattern of the pharyngeal mucosa, and postnasal exudate may be evident. Note the presence or absence of tonsillar tissue.
  • Evaluate for signs such as a loud pulmonic heart sound, right ventricular heave, and tricuspid regurgitation murmur. If present, these signs support the diagnosis of pulmonary hypertension. Jugular venous distention, tender hepatomegaly, and lower-extremity edema suggest cor pulmonale. Pulmonary rales, rhonchi, wheezing, and digital clubbing may be encountered.
  • Paralytic poliomyelitis may be present in patients with antibody deficiency following vaccination.
  • Deep sensory loss with decreased vibratory sense and position of limb segments are observed in persons with pernicious anemia.


SCID disorders are the result of specific genetic alterations in key regulators of B-, T- and/or NK-cell activation, proliferation, or differentiation. The genetic alterations had been identified in some of these disorders, which has led to the investigation of gene therapy as an attractive intervention to treat such conditions.

  • XSCID – Genetic defects in the gamma C gene, leading to defects in various cytokine receptors
  • ADA deficiency – Genetic mutations in the ADA enzyme
  • JAK3 deficiency – Defects in the Janus signaling kinase that interacts with the intracellular portion of the common gamma chain of various cytokine receptors
  • RAG1 and RAG2 deficiency – Specific mutations and genetic defects in the RAG1 and RAG2 enzyme
  • Omenn syndrome
  • CHH – Mutations in RMRP, the RNA component of the ribonucleoprotein complex. RNase MRP consists of an RNA molecule bound to several proteins (as described by Ridanpaa et all, it has at least 2 functions: cleavage of RNA in mitochondrial DNA synthesis and nucleolar cleaving of pre-rRNA. [14] This group of investigators recently identified several mutations in RMPR in patients with CHH.)
  • Reticular dysgenesis
  • WAS - Rare X-linked disorder with variable clinical phenotypes that correlate with the type of mutations in the WAS protein ( WASP) gene
Contributor Information and Disclosures

Francisco J Hernandez-Ilizaliturri, MD Associate Professor of Medicine, Department of Medicine, Assistant Professor of Immunology, Department of Immunology, Roswell Park Cancer Institute, University of Buffalo State University of New York School of Medicine and Biomedical Sciences

Francisco J Hernandez-Ilizaliturri, MD is a member of the following medical societies: American Association for Cancer Research, American Society of Hematology

Disclosure: Nothing to disclose.


Issam Makhoul, MD Associate Professor, Department of Medicine, Division of Hematology/Oncology, University of Arkansas for Medical Sciences

Issam Makhoul, MD is a member of the following medical societies: American Society of Clinical Oncology, American Society of Hematology

Disclosure: Nothing to disclose.

David Claxton, MD Professor of Medicine, Department of Internal Medicine, Section of Hematology-Oncology, Hershey Medical Center, Pennsylvania State University College of Medicine

Disclosure: Nothing to disclose.

Mohammad Muhsin Chisti, MD, FACP Assistant Professor of Hematology and Oncology, Karmanos Cancer Institute, Michigan State University College of Human Medicine

Mohammad Muhsin Chisti, MD, FACP is a member of the following medical societies: American College of Physicians, American Medical Association, American Society of Clinical Oncology, American Society of Hematology, Medical Society of the State of New York

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

Marcel E Conrad, MD Distinguished Professor of Medicine (Retired), University of South Alabama College of Medicine

Marcel E Conrad, MD is a member of the following medical societies: Alpha Omega Alpha, American Association for the Advancement of Science, American Association of Blood Banks, American Chemical Society, American College of Physicians, American Physiological Society, American Society for Clinical Investigation, American Society of Hematology, Association of American Physicians, Association of Military Surgeons of the US, International Society of Hematology, Society for Experimental Biology and Medicine, SWOG

Disclosure: Partner received none from No financial interests for none.

Chief Editor

Emmanuel C Besa, MD Professor Emeritus, Department of Medicine, Division of Hematologic Malignancies and Hematopoietic Stem Cell Transplantation, Kimmel Cancer Center, Jefferson Medical College of Thomas Jefferson University

Emmanuel C Besa, MD is a member of the following medical societies: American Association for Cancer Education, American Society of Clinical Oncology, American College of Clinical Pharmacology, American Federation for Medical Research, American Society of Hematology, New York Academy of Sciences

Disclosure: Nothing to disclose.


James O Ballard, MD Kienle Chair for Humane Medicine, Professor, Departments of Humanities, Medicine, and Pathology, Division of Hematology/Oncology, Milton S Hershey Medical Center, Pennsylvania State University College of Medicine

James O Ballard, MD is a member of the following medical societies: Alpha Omega Alpha, American College of Physicians, and American Society of Hematology

Disclosure: Nothing to disclose.

  1. Cavazzana-Calvo M, Fischer A. Gene therapy for severe combined immunodeficiency: are we there yet?. J Clin Invest. 2007 Jun. 117(6):1456-65. [Medline]. [Full Text].

  2. Khiong K, Murakami M, Kitabayashi C, et al. Homeostatically proliferating CD4 T cells are involved in the pathogenesis of an Omenn syndrome murine model. J Clin Invest. 2007 May. 117(5):1270-81. [Medline]. [Full Text].

  3. Cavazzana-Calvo M, Hacein-Bey S, de Saint Basile G, et al. Gene therapy of human severe combined immunodeficiency (SCID)-X1 disease. Science. 2000 Apr 28. 288(5466):669-72. [Medline].

  4. Sinha S, Schwartz RA. Severe combined immunodeficiency. Medscape Reference. Updated August 21, 2006. [Full Text].

  5. Bonilla FA, Geha RS. 2. Update on primary immunodeficiency diseases. J Allergy Clin Immunol. 2006 Feb. 117(2 suppl mini-primer):S435-41. [Medline].

  6. Cachafeiro T, Escobar G, Bakos L, Bakos R. Chronic cutaneous cytomegalovirus infection in a patient with severe combined immunodeficiency syndrome. Br J Dermatol. 2013 Sep 6. [Medline].

  7. Bacalhau S, Freitas C, Valente R, Barata D, Neves C, Schäfer K, et al. Successful Handling of Disseminated BCG Disease in a Child with Severe Combined Immunodeficiency. Case Report Med. 2011. 2011:527569. [Medline]. [Full Text].

  8. Verbsky JW, Baker MW, Grossman WJ, Hintermeyer M, Dasu T, Bonacci B, et al. Newborn Screening for Severe Combined Immunodeficiency; The Wisconsin Experience (2008-2011). J Clin Immunol. 2011 Nov 10. [Medline].

  9. Somech R, Lev A, Simon AJ, Korn D, Garty BZ, Amariglio N, et al. Newborn screening for severe T and B cell immunodeficiency in Israel: a pilot study. Isr Med Assoc J. 2013 Aug. 15(8):404-9. [Medline].

  10. Kelly BT, Tam JS, Verbsky JW, Routes JM. Screening for severe combined immunodeficiency in neonates. Clin Epidemiol. 2013 Sep 16. 5:363-369. [Medline]. [Full Text].

  11. Rozmus J, Junker A, Thibodeau ML, Grenier D, Turvey SE, Yacoub W, et al. Severe Combined Immunodeficiency (SCID) in Canadian Children: A National Surveillance Study. J Clin Immunol. 2013 Oct 12. [Medline].

  12. Levy J, Espanol-Boren T, Thomas C, et al. Clinical spectrum of X-linked hyper-IgM syndrome. J Pediatr. 1997 Jul. 131(1 pt 1):47-54. [Medline].

  13. Zhang C, Zhang ZY, Wu JF, Tang XM, Yang XQ, Jiang LP, et al. Clinical characteristics and mutation analysis of X-linked severe combined immunodeficiency in China. World J Pediatr. 2011 Nov 21. [Medline].

  14. Ridanpaa M, van Eenennaam H, Pelin K, et al. Mutations in the RNA component of RNase MRP cause a pleiotropic human disease, cartilage-hair hypoplasia. Cell. 2001 Jan 26. 104(2):195-203. [Medline]. [Full Text].

  15. Chin T, Alonazi N. B-cell and T-cell combined disorders. Medscape Reference. Updated April 5, 2007. [Full Text].

  16. Bertrand Y, Landais P, Friedrich W, et al. Influence of severe combined immunodeficiency phenotype on the outcome of HLA non-identical, T-cell-depleted bone marrow transplantation: a retrospective European survey from the European Group for Bone Marrow Transplantation and the European Society for Immunodeficiency. J Pediatr. 1999 Jun. 134(6):740-8. [Medline].

  17. Buckley RH, Schiff SE, Schiff RI, et al. Hematopoietic stem-cell transplantation for the treatment of severe combined immunodeficiency. N Engl J Med. 1999 Feb 18. 340(7):508-16. [Medline]. [Full Text].

  18. Gennery AR, Flood TJ, Abinun M, Cant AJ. Bone marrow transplantation does not correct the hyper IgE syndrome. Bone Marrow Transplant. 2000 Jun. 25(12):1303-5. [Medline].

  19. Kohn DB. Adenosine deaminase gene therapy protocol revisited. Mol Ther. 2002 Feb. 5(2):96-7. [Medline]. [Full Text].

  20. Casanova JL, Abel L. Primary immunodeficiencies: a field in its infancy. Science. 2007 Aug 3. 317(5838):617-9. [Medline].

  21. Husain M, Grunebaum E, Naqvi A, et al. Burkitt's lymphoma in a patient with adenosine deaminase deficiency-severe combined immunodeficiency treated with polyethylene glycol-adenosine deaminase. J Pediatr. 2007 Jul. 151(1):93-5. [Medline].

  22. Atluri S, Neville K, Davis M, et al. Epstein-Barr-associated leiomyomatosis and T-cell chimerism after haploidentical bone marrow transplantation for severe combined immunodeficiency disease. J Pediatr Hematol Oncol. 2007 Mar. 29(3):166-72. [Medline].

  23. Chapel H, Puel A, von Bernuth H, Picard C, Casanova JL. Shigella sonnei meningitis due to interleukin-1 receptor-associated kinase-4 deficiency: first association with a primary immune deficiency. Clin Infect Dis. 2005 May 1. 40(9):1227-31. [Medline]. [Full Text].

  24. Chun HJ, Zheng L, Ahmad M, et al. Pleiotropic defects in lymphocyte activation caused by caspase-8 mutations lead to human immunodeficiency. Nature. 2002 Sep 26. 419(6905):395-9. [Medline].

  25. Conley ME, Notarangelo LD, Etzioni A. Diagnostic criteria for primary immunodeficiencies. Representing PAGID (Pan-American Group for Immunodeficiency) and ESID (European Society for Immunodeficiencies). Clin Immunol. 1999 Dec. 93(3):190-7. [Medline].

  26. Cooper MD, Lanier LL, Conley ME, Puck JM. Immunodeficiency disorders. Hematology Am Soc Hematol Educ Program. 2003. 314-30. [Medline]. [Full Text].

  27. Creagh EM, Conroy H, Martin SJ. Caspase-activation pathways in apoptosis and immunity. Immunol Rev. 2003 Jun. 193:10-21. [Medline].

  28. Fischer A, Le Deist F, Hacein-Bey-Abina S, et al. Severe combined immunodeficiency. A model disease for molecular immunology and therapy. Immunol Rev. 2005 Feb. 203:98-109. [Medline].

  29. Gennery AR, Cant AJ. Diagnosis of severe combined immunodeficiency. J Clin Pathol. 2001 Mar. 54(3):191-5. [Medline]. [Full Text].

  30. Hadzic N, Pagliuca A, Rela M, et al. Correction of the hyper-IgM syndrome after liver and bone marrow transplantation. N Engl J Med. 2000 Feb 3. 342(5):320-4. [Medline]. [Full Text].

  31. Hermanns P, Bertuch AA, Bertin TK, et al. Consequences of mutations in the non-coding RMRP RNA in cartilage-hair hypoplasia. Hum Mol Genet. 2005 Dec 1. 14(23):3723-40. [Medline]. [Full Text].

  32. Kohn DB. Gene therapy for genetic haematological disorders and immunodeficiencies. J Intern Med. 2001 Apr. 249(4):379-90. [Medline]. [Full Text].

  33. Kuska B. Wiskott-Aldrich syndrome: molecular pieces slide into place. J Natl Cancer Inst. 2000 Jan 5. 92(1):9-11. [Medline]. [Full Text].

  34. Notarangelo LD, Forino C, Mazzolari E. Stem cell transplantation in primary immunodeficiencies. Curr Opin Allergy Clin Immunol. 2006 Dec. 6(6):443-8. [Medline].

  35. Revy P, Malivert L, de Villartay JP. Cernunnos-XLF, a recently identified non-homologous end-joining factor required for the development of the immune system. Curr Opin Allergy Clin Immunol. 2006 Dec. 6(6):416-20. [Medline].

  36. Torgerson TR, Ochs HD. Regulatory T cells in primary immunodeficiency diseases. Curr Opin Allergy Clin Immunol. 2007 Dec. 7(6):515-21. [Medline].

  37. Zhu Q, Watanabe C, Liu T, et al. Wiskott-Aldrich syndrome/X-linked thrombocytopenia: WASP gene mutations, protein expression, and phenotype. Blood. 1997 Oct 1. 90(7):2680-9. [Medline]. [Full Text].

Table 1. Classification of SCID
Pathophysiology Cells Affected Inheritance Genes Involved
Premature cell death T, B, NK AR ADA
Defective cytokine–dependent survival signaling T, NK AR

γ c type-XL

JAK3, IL7RA (T cells only), γ c
Defective V(D)J rearrangement T, B AR RAG1, RAG2, Artemis
Defective pre-TCR and TCR signaling T AR CD3 δ, CD3 ζ, CD3 ε,


AR = autosomal recessive; JAK3 =Janus tyrosine kinase 3; RAG1, RAG2 = recombinase activating gene 1 and 2, respectively; TCR = T-cell receptor; XL = X-linked; V(D)J = variable diversity joining.
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