Elsevier

The Journal of Pediatrics

Volume 150, Issue 1, January 2007, Pages 109-111.e2
The Journal of Pediatrics

Clinical and laboratory observation
Histopathologic Abnormalities of the Lymphoreticular Tissues in Organic Cation Transporter 2 Deficiency: Evidence for Impaired B Cell Maturation

https://doi.org/10.1016/j.jpeds.2006.09.042Get rights and content

Immunohistology of lymphoreticular tissues of a fatal case of organic cation transporter 2 deficiency revealed inhibited proliferation with increased apoptosis in the germinal centers, resulting in “burned out” follicles. This is indicative of impaired antigen driven B cell affinity maturation. Defective humoral immune response might explain the recurrent infections in untreated organic cation transporter 2 deficiency.

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Methods

In a large family, we found an 844 delC homozygous deletion of the SLC22A5 gene. After the identification of the family,5 autopsy samples were obtained from the male patient reported here. During his life, he had numerous episodes of respiratory tract infections, including otitis, pharyngitis, and pneumonia. He also had hepatomegaly with repeatedly normal transaminases and cardiomegaly with borderline function on ultrasound scanning, which was present since the patient was 1 year old. At the

Results

Well-stratified follicles were present in the lymph nodes (Figure 2, left frame). The mantle zones were separated from the germinal centers; identifiable IgD positive cells were detected in the mantle zone of the lymph node (center frame). The germinal center compartment exhibited pathological hallmarks, which implied a decreased proliferation, as indicated by the decrease of the dark labels of the MIB-1 immunostainings (right frame).

In the spleen, lymph nodes, bone marrow, and only slightly in

Discussion

Besides the typical hepatic and cardiac manifestations, episodes of infections are often reported in patients with OCTN2 deficiency. In our patient, relapses of respiratory tract infections occured almost monthly. This clinical observation pointed toward an impairment of the immune response in OCTN2 deficiency. The availability of autopsy materials pooled from a patient who was OCTN2 deficient enabled us to reveal pathologic alterations in tissues involved in the immune response.

The observed

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Supported by grants from OTKA (T-049589) and ETT (497/2006).

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