Insights into the Role of Follicular Helper T Cells in Autoimmunity

Follicular helper T (TFH) cells are recently highlighted as their crucial role for humoral immunity to infection as well as their abnormal control to induce autoimmune disease. During an infection, naive T cells are differentiating into TFH cells which mediate memory B cells and long-lived plasma cells in germinal center (GC). TFH cells are characterized by their expression of master regulator, Bcl-6, and chemokine receptor, CXCR5, which are essential for the migration of T cells into the B cell follicle. Within the follicle, crosstalk occurs between B cells and TFH cells, leading to class switch recombination and affinity maturation. Various signaling molecules, including cytokines, surface molecules, and transcription factors are involved in TFH cell differentiation. IL-6 and IL-21 cytokine-mediated STAT signaling pathways, including STAT1 and STAT3, are crucial for inducing Bcl-6 expression and TFH cell differentiation. TFH cells express important surface molecules such as ICOS, PD-1, IL-21, BTLA, SAP and CD40L for mediating the interaction between T and B cells. Recently, two types of microRNA (miRNA) were found to be involved in the regulation of TFH cells. The miR-17-92 cluster induces Bcl-6 and TFH cell differentiation, whereas miR-10a negatively regulates Bcl-6 expression in T cells. In addition, follicular regulatory T (TFR) cells are studied as thymus-derived CXCR5+PD-1+Foxp3+ Treg cells that play a significant role in limiting the GC response. Regulation of TFH cell differentiation and the GC reaction via miRNA and TFR cells could be important regulatory mechanisms for maintaining immune tolerance and preventing autoimmune diseases such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Here, we review recent studies on the various factors that affect TFH cell differentiation, and the role of TFH cells in autoimmune diseases.

Comparison of Sufentanil and Morphine with Ropivacaine for Patient-controlled Epidural Analgesia after Gastrectomy / 대한마취과학회지

BACKGROUND: Early pain control after gastrectomy is essential to minimize complication. We have compared the analgesic efficacy and side effects of sufentanil versus morphine for postoperative epidural analgesia. And we investigated the optimal dosage of sufentanil. METHODS: Sixty of seventy-five patients underwent gastrectomy were randomly allocated into three groups to receive ropivacaine 0.15% + sufentanil 0.5microgram/hour (group S1), or ropivacaine 0.15% + sufentanil 1.0microgram/hour (group S2) or ropivacaine 0.15% + morphine 32microgram/hour (group M). Before surgery, an epidural catheter was inserted at T 7-9 level and sufentanil 20microgram in group S1 and S2 or morphine 2 mg in group M were injected via the epidural catheter. After completion of surgery, continuous epidural infusion was started using PCEA device. Basal infusion rate, lock out time, bolus dose were 4 ml/hour, 20 minutes and 4 ml, respectively. Resting VAS, coughing VAS and side effects were recorded : immediate after awakening, 6, 12, 24, 48 hours after surgery. Forced vital capacity was assessed before and at 6, 24, 48 hours after surgery. RESULTS: There were no significant differences in resting VAS, coughing VAS and FVC among three groups. The number of side effects, especially pruritus and sedation were significantly more in group M than group S1 and S2 (P <0.05). No difference was seen between group S1 and S2. CONCLUSION: Thoracic epidural application of sufentanil combined with ropivacaine provides effective analgesia after gastrectomy, which is comparable to the analgesia with ropivacaine plus morphine and it provides less side effects especially pruritus and sedation. In addition, the optimal dosage of sufentanil was 2microgram/hour.

Effect of Thiopental Sodium on Hearing Outcomes Following Microvascular Decompression Surgery / 대한마취과학회지

BACKGROUND: The use of intraoperative brainstem auditory evoked potential (BAEP) has reduced the incidence of sensorineural hearing loss (SNHL) after microvascular decompression (MVD). This complication occurs due to direct compressive and/or stretching injury of the cochlear nerve or to indirect compression of the perineural vasculature during cerebellar retraction. The aim of this study was to evaluate the effect of thiopental sodium on SNHL after MVD for hemifacial spasm. METHODS: 94 hemifacial spasm patients with normal hearing function preoperatively and who underwent MVD under intraoperative BAEP monitoring were enrolled in this study. Patients were randomly divided into two groups. 52 patients were administered placebo (control group) and 42 patients were administered thiopental sodium 5 mg/kg intravenously 5 minutes before cerebellar retraction (thiopental group). The effects of thiopental on intraoperative BAEP changes and postoperative hearing functional outcomes were sought. Incidence and degree of postoperative SNHL were evaluated by pure tone audiometry threshold analysis. RESULTS: Maximal changes in intraoperative BAEP parameters did not differ between the two groups, and neither did the incidence nor degree of SNHL. In the control group, 4 transient and 4 permanent postoperative SNHL, including 2 deaf patients, occurred with an overall incidence of 15.4%. In the thiopental group, 2 transient and 1 permanent postoperative SNHL occurred, with an overall incidence of 7.1%. CONCLUSIONS: Thiopental sodium administered prior to cerebellar retraction might reduce the incidence of postoperative hearing loss.

CTLA-4 Polymorphism in Myasthenia Gravis

BACKGROUND: Cytotoxic T lymphocyte associated antigen 4 (CTLA-4) plays a role in down-regulating both the cellular and the humoral responses by suppressing the ongoing responses of activated T-cells. There are evidences to suggest the genetic contribution of the CTLA-4 locus to a number of autoimmune diseases, such as insulin dependent diabetes mellitus, multiple sclerosis and systemic lupus erythematosus. The aim of the present study is to analyze CTLA-4 gene polymorphism in patients with myasthenia gravis (MG) compared to healthy controls. METHODS: Thirty healthy controls and 31 patients with MG were genotyped into G/G, A/G and A/A of CTLA-4 gene polymorphism at position 49 and the relationship with the clinical feature was analysed. RESULTS: In the patients with MG, the genotype frequencies of G/G, A/G and A/A were 61.3%, 35.5% and 3.2%, respectively. In healthy controls, the frequencies of each genotype were 50%, 43% and 7%, respectively. There was no significant difference in the genotype frequencies of CTLA-4 gene between patients with MG and the control group. There were also no significant differences in the genotype frequencies of CTLA-4 gene between ocular and generalized MG. CONCLUSIONS: These data suggest that the CTLA-4 polymorphism at position 49 do not affect the development of MG. However, further study is needed to clarify the possible role of the CTLA-4 polymorphism in the susceptibility to MG.

Primary Aldosteronism Presenting as Bibrachial Paralysis

No abstract available.

Clinical Usefulness of T2 Relaxometry in Temporal Lobe Epilepsy

BACKGROUND: Quantitative measurement of hippocampal T2 relaxation time is an objective means of determining the frequency and severity of signal abnormalities. To evaluate the diagnostic properties of T2 relaxometry in temporal lobe epilepsy(TLE), we measured T2 relaxation time of bilateral hippocampi in pathology-proven TLE patients and normal controls. METHODS: We investigated 10 TLE patients who had temporal lobectomy with MR T2 relaxation mapping. All patients underwent in phase I or II studies, and had pathologic diagnosis. Also we measured T2 relaxation time in 10 normal volunteers. RESULTS: The pathologic findings of 10 TLE patients were followings: 8 hippocampal sclerosis (including dual pathology of necrotic granuloma), 1 calcified fibrous nodule, and 1 normal hippocampus. The mean T2 relaxation time of normal controls is 67.5msec, which is lower value than previous reports. All patients with hippocampal sclerosis in pathology showed increased T2 time greater than 2 SD of mean value of normal controls. But, the T2 values are upper normal range in non-hippocampal sclerosis. The lateralizing value of T2 relaxometry is 50% in TLE patients, and 62.5% in pathology-proven hippocampal sclerosis groups. CONCLUSIONS: There is a clear distinction of T2 relaxation time between the patients of hippocampal sclerosis and normal controls or non-hippocampal sclerosis. These findings suggest that the T2 relaxation time is a reliable objective measurement of hippocampal pathology, especially hippocampal sclerosis in TLE.

The Effects of Preemptive Intravenous Ketorolac for Total Hip Replacement Patients / 대한마취과학회지

BACKGROUND: The purpose of this study is to examine the effect of intravenous ketorolac administration before surgical stimulation for postoperative pain control. METHODS: Forty four patients scheduled for total hip replacement were randomly assigned to one of three groups of prospectively designed study. Group 1 (n=14) received intravenous saline (placebo) and Group 2 (n=15) received intravenous ketorolac (30 mg) at one hour after skin incision and Group 3 (n=15) received intravenous ketorolac (30 mg) before induction. Postoperative pain relief was provided with intravenous morphine from PCA system. Postoperative visual analogue pain score (VAS), analgesic requirement and side effects were evaluated and compared between groups for postoperative two days. RESULTS: VAS at rest were significantly less in Group 2,3 than in Group 1 at 3 hours after surgery (p<0.05) and significantly less in group 3 than in group 1 at 6 and 9 hours after surgery (p<0.05). VAS on movement were significantly less in group 3 than group 1 at 1 hour and significantly less in group 2,3 than group 1 at 3 and 6 hours after surgery (p<0.05). Patient controlled morphine consumption in group 1 was significantly higher than in group 2,3 for 12 hours after surgery. After administration of intravenous ketorolac any side effect did not occur. CONCLUSIONS: Administration of intravenous ketorolac before skin incision as a pre-emptive analgesia has better analgesia than those of 1 hour after skin incision and no administration of ketorolac.

A Case of Optic chiasmal and focal hypothalamic infarction

Ischemia is a rare cause of the optic chiasmal syndrome and is sometimes hard to define. The present report describes a 73 year ~ old male with abruptly developed visual field defect involving bitemporal hemianopsia and inferior binasal quadrantanopsia. The MRI study revealed focal anterior hypothalarnic atrophy which might be due to focal infarction. These findings are suggesting common blood supply of superior chiasmal circulation and anterior inferior hypothalamus.