PURPOSE: Hyper IgM syndrome(HIGM) is characterized by severe recurrent bacterial infections with decreased serum levels of IgG, IgA, and IgE but elevated IgM levels. Recently, it has been classified into three groups; HIGM1, HIGM2 and a rare form of HIGM. HIGM1 is a X-linked form of HIGM and has now been identified as a T-cell deficiency in which mutations occur in the gene that encodes the CD40 ligand molecule. HIGM2 is an autosomal recessive form of HIGM. Molecular studies have shown that the mutation of HIGM2 is in the gene that encodes activation-induced cytidine deaminase(AID). Recently, another rare form of X-linked HIGM syndrome associated with hypohydrotic ectodermal dysplasia has been identified. We encountered a patient with a varient form of HIGM2. To clarify the cause of this form of HIGM, we evaluated the peripheral B cells of this patient. METHODS: The lymphocytes of the patient were prepared from peripheral blood. B cells were immortalized with the infection of EBV. Cell cycle analysis was done with the immortalized B cells of the patient. Peripheral mononuclear cells were stained with monoclonal anti-CD40L antibody. Total RNA was extracted from the peripheral mononuclear cells. After RT-PCR, direct sequencing for CD40L gene and HuAID gene were done. Immunostainings of a lymph node for CD3, CD23, CD40, Fas-L, bcl-2, BAX were done. RESULTS: The peripheral B cells of this patient showed normal expression of CD40L molecule and normal sequencing of CD40L gene, and also normal sequencing of AID gene. Interestingly, the peripheral B cells of this patient showed a decreased population of G2/mitosis phase in cell cycles which recovered to normal with the stimulation of IL-4. CONCLUSION: We suspect that the cause of increased serum IgM in this patient may be from a decrease of G2/mitosis phase of the peripheral B cells, which may be from the decreased production or secretion of IL-4. Therefore, this may be a new form of HIGM.
B-Lymphocytes* ; Bacterial Infections ; CD40 Ligand ; Cell Cycle ; Cytidine ; Ectodermal Dysplasia ; Herpesvirus 4, Human ; Humans ; Hyper-IgM Immunodeficiency Syndrome* ; Hyper-IgM Immunodeficiency Syndrome, Type 1 ; Immunoglobulin A ; Immunoglobulin E ; Immunoglobulin G ; Immunoglobulin M ; Interleukin-4 ; Lymph Nodes* ; Lymphocytes ; RNA ; T-Lymphocytes

PURPOSE: The DNA repair enzyme, apurinic/apyrimidinic endonuclease (APE) plays a role in base excision repair pathway involved in repairing apurinic/apyrimidinic (AP) site after oxidative stress. To reveal the relationship between APE and neuronal apoptosis associated with oxidative stress after kainate treatment, the temporal change of APE expression was investigated in kainate-induced seizure model. METHODS: Status epilepticus was induced by unilateral intrahippocampal injection of kainate. Superoxide anion radical production and DNA oxidation were evaluated by in situ detection of oxidized hydroethidine and 8-hydroxyguanine (8-OHG) immunore activity. APE expression was examined by Western blot and immunohistochemical analysis. DNA fragmentation was visualized with terminal deoxynucleotidyl transferase-mediated uridine 5'-triphosphate-biotin nick end labeling (TUNEL) staining. RESULTS: Cell loss occurred at 24 hr in CA1, CA2, and CA3 after kainate-injection. 8-OHG immunoreactivity and oxidized hydroethidine were increased comparing with control after kainate-injection. APE immunoreactivity was decreased 4 and 24 hours in the hippocampus after kainate-injection. TUNEL-positive cells were observed 24 hours but not 4 hours in hippocampus after kainate-injection. In double labeling with APE and TUNEL, TUNEL-positive cells did not show APE immunoreactivity. These data showed that cellular oxidative stress was increased, thereby APE was decreased in the hippocampus after kainate-injection. Also, it was shown that the reduction of APE preceded DNA fragmentation. CONCLUSION: This study suggests that rapid loss of APE may produce the failure of DNA repair-machinary and then induce neuronal apoptosis following kainate-injection.
Apoptosis* ; Blotting, Western ; DNA ; DNA Fragmentation ; DNA Repair ; Epilepsy ; Hippocampus ; Hominidae ; Humans ; In Situ Nick-End Labeling ; Kainic Acid ; Neurons ; Oxidative Stress ; Seizures* ; Status Epilepticus ; Superoxides ; Uridine