[Severe mixed immunodeficiency. Report of a case]

Area of Science:

• Immunology
• Genetics
• Pediatrics

Background:

• Severe combined immunodeficiency (SCID) is a group of rare genetic disorders characterized by profound defects in both cellular and humoral immunity.
• X-linked SCID (X-linked SCID) is the most common form, affecting males and presenting in infancy with recurrent infections.
• Mucocutaneous candidiasis resistant to treatment is a common early sign of SCID.

Purpose of the Study:

• To present the case of a male infant diagnosed with X-linked SCID.
• To document the clinical course, diagnostic challenges, and treatment outcomes.
• To highlight the pathological findings in a fatal case of X-linked SCID.

Main Methods:

• Clinical case presentation and diagnostic workup.
• Family history investigation, including post-mortem diagnosis in a relative.
• Treatment with transfer factor and hyperimmune plasma.
• Autopsy for pathological examination.

Main Results:

• The infant presented with severe mucocutaneous candidiasis unresponsive to therapy.
• Family history revealed early deaths in affected males, with one diagnosed with SCID post-mortem.
• Hematopoietic stem cell transplantation was not feasible due to lack of histocompatible relatives.
• The child died from respiratory failure secondary to Pneumocystis carinii pneumonia and cytomegalovirus infection.
• Autopsy confirmed widespread opportunistic infections and near-complete absence of lymphoid tissue.

Conclusions:

• X-linked SCID requires early diagnosis and definitive treatment, ideally hematopoietic stem cell transplantation.
• Opportunistic infections are a major cause of mortality in untreated SCID.
• The absence of histocompatible donors poses a significant therapeutic challenge.
• This case underscores the importance of recognizing early clinical signs and the devastating consequences of delayed diagnosis and treatment.