Extremely rare severe immune deficiency disorder
characterized by T-cell deficiency with little or no abnormality of γ-globulin. Clinical features include failure to thrive, recurrent lung infections, and
Immune Defect Resulting from Absence of Thymus; Severe
Combined Immunodeficiency, Nezelof Type.
Genetic disorder first reported by C. Nezelof, a French
pediatrician, in 1964.
Autosomal recessive inheritance; some X-linked
Abnormal expression of CD44 (an adhesion molecule,
interacting with the matrix ligands hyaluronan and fibronectin) could
interfere with normal thymocyte and thymic epithelial interaction, leading
to abnormal thymocyte differentiation.
Clinically evocated in patients with recurrent
infections and normal humoral immunity.
Failure to thrive is common. Main clinical
features can include metaphyseal dysostosis, chronic diarrhea,
hepatosplenomegaly, eczematoid rash, and pyoderma. Recurrent pseudomonas and
monilia infections are frequent, particularly bronchopulmonary infections.
Bronchiectasis and emphysema are often observed. Susceptibility to viral
infections. Immunologic features are remarkable: absent thymus, T-cell
deficiency, impaired antibody synthesis, cellular immune defect, decreased
lymphoid tissue while plasma cells are present, impaired delayed hypersensitivity
with poor skin graft rejection. Humoral immunity is normal, as is the
immunoglobulin level. Lymphopenia is observed.
Evaluate immunologic status (obtain
full, documented history of infection, complete immunologic status
evaluation). Evaluate respiratory function (clinical, chest radiographs/CT,
pulmonary function test, arterial blood gas analysis). Evaluate hydration
and renal function in case of severe chronic diarrhea (clinical, laboratory tests,
including urea and creatinine levels and electrolytes). Preoperative full
blood count is recommended.
Strict asepsis is needed considering
the immunity defect. Preoperative hydration correction might be
Perioperative respiratory monitoring and physiotherapy can be useful, and
postoperative mechanical ventilatory support may be anticipated if
Prophylactic antibiotics may be adapted
to immunologic status and previous infections.
Bruton Agammaglobulinemia Tyrosine Kinase X-linked:
Tonsillar system is absent.
Swiss-type Agammaglobulinemia: Thymus and tonsillar system
DiGeorge Syndrome: Parathyroids and thymus are absent.
Knutsen AP, Wall D, Mueller KR, et al: Abnormal in vitro thymocyte
differentiation in a patient with severe combined
immunodeficiency—Nezelof's syndrome. J Clin Immunol
Nezelof C, Jammet M-L, Lortholary P, et al: L'hypoplasie hereditaire du
thymus: sa place et sa responsabilite dans une observation d'aplasie
lymphocytaire, normoplasmocytaire et normoglobulinemique du nourrisson.
Arch Fr Pediatr