Fethi MELLOULI, National Center of Bone Marrow Transplantation, Tunis, Tunisia
Translation: Jeddane Leïla, Morocco
Ahmed is a 7 months-old boy from 1st-degree cousins of Tunisian origin. His medical history reveals earlier death of two brothers from severe infection. His illness began at the age of three months by recurrent broncho-pulmonary and digestive infections, extensive oral thrush resistant to local antifungal treatment and purulent otitis.
Examination: The boy showed underweight at 60% for age, polypnea at 65 cycles per minute with signs of retraction , saturated with ambient air at 80 %, has dry red skin finely desquamative , scarcity of hair and hepatosplenomegaly .
Chest radiography showed interstitial lung disease with thymic hypoplasia. Bronchoalveolar lavage revealed Pneumocystis jirovecii.
CBC revealed inflammatory anemia (8.5 g/dl) , leukocytosis( 12,000/mm3) predominantly of neutrophils (8,400/mm3) and normal platelets (345,000/mm3).
Immunologic investigation disclosed agammaglobulinemia with IgG 0.7 g /l, IgA 0.05 g /l, IgM 0.4 g /l, and lymphocyte count : a total of 3000 cells/mm3 had 17% CD4 + , 18% CD8 + , 46% CD19+ .
Proliferation tests were negative.
Synthesis: 7months-old boy from a consanguineous marriage , family history of infant death. Presented repeated broncho-pulmonary and digestive infections leading to hypotrophy; alopecia, ichtyose-like erythroderma, tumoral syndrome, hypoxic P.jirovecii pneumonia . Immunologic findings is that of a combined immunodeficiency
Diagnosis hypotheses:
1/This clinical features first suggest Omenn reticulosis : Screening for the most common mutation in Tunisia, 631delT ( RAG1 ), is negative.
2 / is it then a severe combined immunodeficiency with maternal-fetal GvHD ?
Lacking molecular biology to answer this question, we examined whether circulating lymphocytes are of maternal origin or not? For this, we performed a karyotype who found a mixed chimerism 64% XX, 36% XY. This result is suggestive of a severe combined immunodeficiency where we can observe coexistence of maternal and fetal cells. In order to control its GvHD, the patient was given cyclosporin A, which reduced rapidly skin lesions within a few days . For its pneumonia, he was treated by IV cotrimoxazole at a dose of 100 mg / kg / day, with an antifungal preventive treatment with itraconazole, and IVIg. HLA typing found a HLA- genoidentical donor . The patient was then transplanted with allogeneic bone marrow without conditioning regime leading to good evolution.
Discussion:
The ichtyose-like erythroderma is not specific of Omenn reticulosis . It may be observed in severe combined immunodeficiency [1]. It is very sensitive to treatment with cyclosporin A. A molecular diagnosis is often necessary to have a precise diagnosis. With no possibility of molecular biology, the determination of lymphocyte chimerism can be of a great help. Indeed, there is mixed maternal and fetal chimera in severe combined immunodeficiency (SCID) . Making the difference between an Omenn syndrome and SCID is crucial in case of hematopoietic stem cells transplantation. Indeed, if SCID can be grafted without conditioning regimen, engraftment may be hampered by oligoclonal lymphocytes in Omenn syndrome [2].
References
1: Al Herz W, Bousfiha A, Casanova JL, et al. Primary immunodeficiency diseases: an update on the classification from the international union of immunological societies expert committee for primary immunodeficiency. Front Immunol 2011; 8(2):54.
2: Mellouli F, Torjmen L, Ksouri H, et al. Bone marrow transplantation without conditioning regimen in Omenn syndrome: a case report. Pediatr Transplant 2007; 11(8):922-6.