Immunopolarization of CD4+ and CD8+ T cells to Type-1-like is associated with melanocyte loss in human vitiligo

Vitiligo is an autoimmune condition characterized by loss of epidermal melanocytes. High frequencies of melanocyte-reactive cytotoxic T cells in the peripheral blood of vitiligo patients and the observed correlation between perilesional T-cell infiltration and melanocyte loss in situ suggest the important role of cellular autoimmunity in the pathogenesis of this disease. We isolated T cells from both perilesional and nonlesional skin biopsies obtained from five vitiligo patients, then cloned and analyzed their profile of cytokine production after short-term, nonspecific expansion in vitro. Perilesional T-cell clones (TCC) derived from patients with vitiligo exhibited a predominant Type-1-like cytokine secretion profile, whereas the degree of Type-1 polarization in uninvolved skin-derived TCC correlated with the process of microscopically observed melanocyte destruction in situ. Detailed analysis of broad spectrum of cytokines produced by perilesional- and nonlesional-derived CD4+ and CD8+ TCC confirmed polarization toward Type-1-like in both CD4 and CD8 compartments, which paralleled depigmentation process observed locally in the skin. Furthermore, CD8+ TCC derived from two patients also were analyzed for reactivity against autologous melanocytes. The antimelanocyte cytotoxic reactivity was observed among CD8+ TCC isolated from perilesional biopsies of two patients with vitiligo. Finally, in two of five patients, tetramer analysis revealed presence of high frequencies of Mart-1-specific CD8 T cells in T-cell lines derived from perilesional skin. Altogether our data support the role of cellular mechanisms playing a significant part in the destruction of melanocytes in human autoimmune vitiligo.     

Two subtypes of G protein-coupled nucleotide receptors, P2Y(1) and P2Y(2) are involved in calcium signalling in glioma C6 cells

1. In glioma C6 cells, the stimulation of P2Y receptors by ADP, ATP and UTP initiated an increase in the intracellular Ca2+ concentration, in a process that involved the release of Ca2+ from InsP(3)-sensitive store and the capacitative, extracellular Ca2+ entry. The presence of external Ca2+ was not necessary to elevate Ca(2+). 2. The rank order of potencies of nucleotide analogues in stimulating [Ca2+](i) was: 2MeSADP > ADP > 2MeSATP = 2ClATP > ATP > UTP. alpha,beta-Methylene ATP, adenosine and AMP were ineffective. 3. ADP and UTP effects were additive, while actions of ATP and UTP were not additive on [Ca2+](i) increase. Similarly, cross-desensitization between ATP and UTP but not between ADP and UTP occurred. 4. Suramin, a non-specific nucleotide receptors inhibitor, antagonized ATP-, UTP- and ADP-evoked Ca2+ responses. PPADS, a selective antagonist of the P2Y(1) receptor-generated InsP(3) accumulation, decreased ADP-initiated Ca2+ response with no effect on ATP and UTP. 5. Pertussis toxin (PTX) reduced ADP- and ATP-induced Ca2+ increases. Short-term treatment with TPA, inhibited both ATP and ADP stimulatory effects on [Ca2+](i). 6. ADP inhibited isoproterenol-induced cyclic AMP accumulation. PTX blocked this effect, but PPADS did not. 7. RT - PCR analysis revealed the molecular identity of P2Y receptors expressed by glioma C6 cells to be both P2Y(1) and P2Y(2). 8. It is concluded that both P2Y(1) and P2Y(2) receptors co-exist in glioma C6 cells. ADP acts as agonist of the first, and ATP and UTP of the second one. Both receptors are linked to phospholipase C (PLC).     

Motor and somatosensory evoked potentials in tuberculous meningitis: a clinico-radiological correlation

OBJECTIVE: The sensory and motor functions in severe tuberculous meningitis (TBM) may be difficult to assess clinically and may be helped by evoked potential studies. Lack of motor and somatosensory evoked potential studies in TBM prompted the present study. METHODS: All the patients with TBM underwent detailed neurological evaluation and cranial CT scan study. Motor and somatosensory evoked potentials to both upper and lower limbs were carried out bilaterally. The outcome was defined on the basis of 3 month Barthel Index (BI) score into good (BI > 12) and poor (BI < 12). RESULTS: Forty-one highly probable patients with TBM whose ages ranged between 8 and 64 years and 14 of whom were females were included in this study. Twenty-three patients were in stage III (meningitis, neurological signs and altered sensorium), 12 in stage II (meningitis with neurological sign) and the remaining patients were in stage I (meningitis only). Cranial CT scan was carried out in all and MRI in 18 patients. On CT scan hydrocephalus was present in 21, infarction in 14 and tuberculoma in 4 patients. Motor evoked potential (MEP) was abnormal in 18 patients (36 limbs) and SEP in 9 patients (23 limbs). Upper limb central motor conduction time to abductor digiti minimi (CMCT-ADM) was abnormal in 15 and that to tibialis anterior (TA) in 21 limbs. CMCT abnormality was lateralized in 6 and only upper or lower limbs were involved in 11 patients. The SEP abnormalities were lateralized in 2 patients and only upper or lower limbs were involved in 3. The MEP changes correlated with stage of TBM and outcome whereas SEP with outcome only. CONCLUSION: Motor and somatosensory evoked potentials may be helpful in objective documentation of respective motor and sensory functions in TBM patients with altered sensorium.     

Central motor conduction studies in patients with Guillain Barré syndrome.

To study the central nervous system involvement in Guillain Barre (GB) syndrome, 30 patients with GB syndrome were subjected to clinical evaluation, muscle testing as per Medical Research Council (MRC) scale, disability score on a 0-5 scale and central motor conduction studies to abductor digiti minimum (ADM), abductor pollicis bravis (APB) and tibialis anterior (TA) bilaterally. Outcome was defined at the end of 3 months into complete, partial and poor. Their age ranged between 12 and 61 years (mean 3.2) and 11 of them were females. At the peak of weakness, the limb muscle power was grade 0 in 8, grade I-II in 10 and grade III-IV in 12 patients. Grade 5 disability was present in 12, grade 4 in 12 and grade 3 in 6 patients. One of these patients had grade 3 muscle power. Central motor conduction time (CMCT) correlated with muscle power, disability score and outcome. Two of our patients expired during the acute stage and 23 could be followed up till 3 months. Three patients recovered completely, 15 partially and 5 had poor recovery. It can be concluded that mild prolongation of CMCT although occurs frequently in the patients with GB syndrome, however, pronounced slowing of CMCT is rare and may suggest central involvement.     

Pattern of sensory conduction in Guillain-Barre Syndrome.

This study in undertaken to evaluate the pattern of sensory conduction abnormalities in Guillain-Barre (GB) Syndrome. Thirty six patients with GB Syndrome following clinical and CSF examination were subjected to motor conduction studies of median, ulnar and paroneal nerves including F wave latencies and sensory conduction studies of median, ulnar and sural nerves bilaterally. Motor conduction abnormalities were seen in 32 out of 36 patients (83%) and were seen more frequently in the lower limbs than upper. Median sensory conduction was abnormal more frequently than ulnar (21 Vs 17 patients). Median sensory conduction was abnormal in 21, ulnar in 17 and sural in 10 patients. In all the patients having abnormal ulnar sensory conduction, median sensory conductions were also abnormal. The patients with abnormal sural conductions had abnormal median sensory conductions in all except one patient. A pattern of normal sural with abnormal median sensory conductions was present in 12 patients. Both sural and median sensory conductions were abnormal in 9 patients and both normal in 14 patients. One patient had abnormal sural conduction with normal median sensory conduction but he had underlying diabetes. A similar pattern was found in relation to ulnar and sural sensory conductions although it was less frequent and less specific. The discordance of sural and median sensory conduction is important in GB Syndrome. Normal sural conductions with abnormal median sensory conductions is suggestive of GB Syndrome in the presence of an appropriate clinical setting, but a reverse pattern should alert an underlying polyneuropathy.     

Plexiform neurofibromatosis presenting as dysphagia

Plexiform neurofibromatosis is a autosomal dominant disease characterized by multiple cafe aulait spots, cutaneous neurofibromatosis, CMS tumours and skeletal abnormalities. We report a child with plexiform neurofibromatosis presenting with dysphagia, an unsual presentation.     

Increased chitotriosidase activity in serum of leprosy patients: Association with bacillary leprosy

Human phagocyte-specific chitotriosidase is associated with several diseases involving macrophage activation. Since macrophage activation plays an important role in the control of Mycobacterium leprae infection, we studied the association of chitotriosidase with leprosy both in serum and in situ in lesional skin biopsies from patients. Serum samples from 78 Indonesian leprosy patients (39 non-reactional and 39 reactional leprosy patients) and 36 healthy controls (HC) from the same endemic region were investigated. The patients were classified as multibacillary (MB, n = 69) or paucibacillary (PB, n = 9) based on the bacterial index in slit-skin smears. Thirty-six of the reactional patients had erythema nodosum leprosum (ENL), while only 3 had reversal reaction (RR). Follow-up serum samples after corticosteroid treatment were also obtained from 17 patients with ENL and one with RR. Multibacillary (MB) patients showed increased chitotriosidase activity in serum as compared to paucibacillary (PB) patients and healthy controls. Although no significant difference was observed between reactional and the corresponding non-reactional groups, ENL showed significantly higher chitotriosidase activity as compared to HC. Furthermore, corticosteroid treatment resulted in significant decline of enzyme activity in ENL sera. Chitotriosidase activity correlated with levels of neopterin, another macrophage activation marker, but not with IL-6, IFN-γ, TNF-α and IL-10. Immunohistochemical staining of 6 MB (LL = 5, BL = 1) lesional skin sections from stored material showed positive staining for chitotriosidase within lipid-laden macrophages suggesting that macrophages are the source of the enzyme detected in serum. Thus, serum chitotriosidase activity is potentially useful in distinguishing MB from PB leprosy and in monitoring response to therapy in ENL.