Geetika Singh

Prompt plasma exchanges and immunosuppressive treatment improves the outcomes of anti-factor H autoantibody-associated hemolytic uremic syndrome in children

Antibodies to complement factor H are an uncommon cause of hemolytic uremic syndrome (HUS). Information on clinical features and outcomes in children is limited. In order to explore this we studied a multicenter cohort of 138 Indian children with anti-complement factor H antibody associated HUS, constituting 56% of patients with HUS. Antibody titers were high (mean 7054 AU/ml) and correlated inversely with levels of complement C3, but not complement factor H. Homozygous deletion of the CFHR1 gene was found in 60 of 68 patients. Therapies included dialysis in 119 children, 105 receiving plasma exchanges and 26 intravenous immunoglobulin. Induction immunosuppression consisted of 87 children receiving prednisolone with or without intravenous cyclophosphamide or rituximab. Antibody titers fell significantly following plasma exchanges and increased during relapses. Adverse outcome (stage 4-5 CKD or death) was seen in 36 at 3 months and 41 by last follow up, with relapse in 14 of 122 available children. Significant independent risk factors for adverse outcome were an antibody titer over 8000 AU/ml, low C3 and delay in plasma exchange. Combined plasma exchanges and induction immunosuppression resulted in significantly improved renal survival: one adverse outcome prevented for every 2.6 patients treated. Maintenance immunosuppressive therapy, of prednisolone with either mycophenolate mofetil or azathioprine, significantly reduced the risk of relapses. Thus, prompt use of immunosuppressive agents and plasma exchanges are useful for improving outcomes in pediatric patients with anti-complement factor H-associated HUS.

Characterization of molecular genetic alterations in GBMs highlights a distinctive molecular profile in young adults.

To evaluate age-related differences in histopathologic and molecular profile of glioblastomas (GBMs) at various age groups, with special reference to TP53 mutation, epidermal growth factor receptor (EGFR) amplification, EGFR vIII mutant, PTEN deletion, and IDH1 mutation. Agewise GBM incidence was calculated over a period of 5 years (2005 to 2009). Seventy-five GBMs were selected for molecular analysis. Majority of cases were in the age group of 41 to 60 years, and mean age was 43.6 years. Histology of all 75 cases selected for molecular profiling was identical. Primary adult GBMs showed EGFR amplification and PTEN deletion in majority (37.3% and 54.9%, respectively). TP53 and IDH1 mutations were rare (11.8% cases each). In secondary GBMs, TP53 (66.7%) and IDH1 mutations (44.4%) were most frequent. PTEN deletion was seen in 33.3% and none had EGFR amplification. Pediatric GBMs (<18 y) harbored frequent TP53 mutations (46.7%) and PTEN deletion in 40%. IDH1 mutations and EGFR amplification were absent. The molecular profile of primary GBMs in young adults (19 to 40 y) was distinctly different from that of adults older than 40 years. TP53 mutation was present in 20% cases. The frequency of EGFR amplification (13.3%) and PTEN deletion (33.3%) was significantly low (P=0.028 and 0.046, respectively). IDH1 mutation, which is rare in primary adult GBMs, was present in 40% of cases. Molecular heterogeneity exists within GBMs of different age cohorts. The molecular profile of GBMs in young adults is distinctly different. Thus, there is a strong need for further studies in various age groups to provide guidelines for therapeutic targeting.

Transient Receptor Potential Channel 6 (TRPC6) Protects Podocytes during Complement-mediated Glomerular Disease

Background: Activating mutations of the calcium channel TRPC6 lead to adult onset genetic kidney disease. Results: In acquired kidney diseases, increased TRPC6 expression protects kidney podocytes against complement-mediated injury. Conclusion: The effect, protective or nocuous, of TRPC6 in podocytes is context dependent. Significance: Pharmacologic inhibition of TRPC6 in acquired kidney disease may be detrimental. Gain-of-function mutations in the calcium channel TRPC6 lead to autosomal dominant focal segmental glomerulosclerosis and podocyte expression of TRPC6 is increased in some acquired human glomerular diseases, particularly in membranous nephropathy. These observations led to the hypothesis that TRPC6 overactivation is deleterious to podocytes through pathological calcium signaling, both in genetic and acquired diseases. Here, we show that the effects of TRPC6 on podocyte function are context-dependent. Overexpression of TRPC6 alone did not directly affect podocyte morphology and cytoskeletal structure. Unexpectedly, however, overexpression of TRPC6 protected podocytes from complement-mediated injury, whereas genetic or pharmacological TRPC6 inactivation increased podocyte susceptibility to complement. Mechanistically, this effect was mediated by Ca2+/calmodulin-dependent protein kinase II (CaMKII) activation. Podocyte-specific TRPC6 transgenic mice showed stronger CaMKII activation, reduced podocyte foot process effacement and reduced levels of proteinuria during nephrotoxic serum nephritis, whereas TRPC6 null mice exhibited reduced CaMKII activation and higher levels of proteinuria compared with wild type littermates. Human membranous nephropathy biopsy samples showed podocyte staining for active CaMKII, which correlated with the degree of TRPC6 expression. Together, these data suggest a dual and context dependent role of TRPC6 in podocytes where acute activation protects from complement-mediated damage, but chronic overactivation leads to focal segmental glomerulosclerosis.

Study of clinical, biochemical and immunological factors determining stability of disease in patients with generalized vitiligo undergoing melanocyte transplantation

Background  Stability is considered the most important parameter before performing any melanocyte transplantation procedure in vitiligo; however, current criteria rely on the history given by the patients.

IDH1 mutations in gliomas: first series from a tertiary care centre in India with comprehensive review of literature.

OBJECT Mutations of the gene encoding isocitrate dehydrogenase (IDH) have been shown in a significant proportion of diffuse gliomas. These mutations are specific to gliomas and their utility for diagnosis and prognostication of these tumors is being proclaimed. The present study was conducted with the aim of assessing frequency of IDH1 mutations in gliomas, their correlation with other molecular alterations along with a comprehensive review of available literature. METHODS A total of 100 gliomas of various grades and subtypes from Indian patients were screened for assessing frequency of IDH1 mutations. The findings were correlated with TP53 mutations, 1p/19q deletion, EGFR amplification and PTEN deletion status. The detailed comprehensive review of literature was performed comparing all studies available till date. RESULTS IDH1 mutations in codon 132 were observed in 46% cases. The frequency was 68.8% in grade II, 85.7% in grade III and 12.8% in GBMs. R132H mutation was most frequent (84.8%). Overall frequency of these mutations was relatively higher in oligodendroglial tumours as compared to astrocytic phenotype (66.7% versus 38.4%; p=0.06). Primary GBMs showed IDH1 mutation in only 4.4% cases. In contrast, 66.7% of secondary GBMs harboured this alteration. Patients with IDH1 mutations were significantly younger as compared to those without mutation (p=0.001). There was a significant correlation between IDH1 mutation and TP53 mutation (p=0.004). Although IDH1 mutation showed a positive correlation with 1p/19q deletion, the association was not statistically significant (p=0.653). There was no correlation with EGFR amplification or PTEN deletion. CONCLUSION IDH1 mutations are present in large proportion of Indian patients with diffuse astrocytic and oligodendroglial neoplasms similar to the reported literature form west. The frequency is lower in primary GBMs and as compared to secondary GBMs. Association with younger age and positive correlation with TP53 mutation and 1p/19q loss is observed. More importantly it is emerging as an independent prognostic marker. Hence the greatest challenge now is establishing a reliable user friendly test for incorporating this novel genetic alteration to routine clinical practice.

Spindle cell oncocytoma of the adenohypophysis: report of a rare case and review of literature.

Spindle cell oncocytoma of the adenohypophysis was first escribed by Roncaroli et al. in 2002, in their multi-institutional eries of 5 cases [1]. Since then ten reports of thirteen cases of this umor have been published in literature bringing the total number f reported cases to eighteen [2–11]. This new entity was included n the WHO classification of tumors of the Central Nervous System n 2007 [12]. In nearly all the cases presentation was akin to a non unctioning pituitary adenoma in an elderly patient, however the ehaviour of these tumors varied as seven of the eighteen published ases showed recurrence with or without morphological features of naplasia in the form of nuclear pleomorphism, frequent mitoses, igh Ki-67 index and/or foci of necrosis [2–8]. We report the nineeenth case of spindle cell oncocytoma (SCO) in a 68-year-old male atient and review the available English literature till date on this umor.

A study of clinico‐pathological parameters and O6 – methylguanine DNA methyltransferase (MGMT) promoter methylation status in the prognostication of gliosarcoma

Gliosarcoma is a rare variant of glioblastoma multiforme (GBM) with similar clinical presentation and prognosis but a distinct genetic profile. The clinicopathological features of 22 cases of gliosarcoma were analyzed with respect to age, sex, KPS score, operative diagnosis, extent of resection and histopathological subtype (predominantly sarcomatous [PS], predominantly gliomatous [PG] or mixed). Twelve cases were PS, six were PG and four were mixed. The histological subtype did not correlate with the operative diagnosis; however, it did significantly correlate with the extent of resection (P = 0.014). In 14 cases with available survival data it was found that none of the clinicopathological parameters significantly correlated with survival (P > 0.05). Methyl guanine DNA methyl transferase promoter methylation studies were performed using methylation‐specific PCR in 16 cases which showed a methylation rate of 31.25% (5/16). The promoter methylation status did not correlate with the histological subtype and did not significantly affect survival (P > 0.05). Although gliosarcomas continue to be treated in the same way as GBM, the role of chemotherapy with temozolomide is not clear. This cohort is the largest to date to uniformly receive the Stupps protocol which is currently “standard of care” for GBM. A median overall survival of 18.5 months is substantially higher than previous studies, suggesting that temozolomide should be included in gliosarcoma therapy.

Epithelial-myoepithelial carcinoma of the lacrimal gland: a rare case

Epithelial-myoepithelial carcinoma is a rare tumor of the salivary gland constituting only 1% of all tumors. It is a low-grade malignancy characterized by a classical biphasic morphology and immunophenotype. In the lacrimal gland, it is extremely rare with only 3 cases reported in the English medical literature. We describe the fourth case of epithelial-myoepithelial carcinoma, the first case in a female patient, and review the available literature.

Molecular profiling of ETS and non-ETS aberrations in prostate cancer patients from northern India

Molecular stratification of prostate cancer (PCa) based on genetic aberrations including ETS or RAF gene‐rearrangements, PTEN deletion, and SPINK1 over‐expression show clear prognostic and diagnostic utility. Gene rearrangements involving ETS transcription factors are frequent pathogenetic somatic events observed in PCa. Incidence of ETS rearrangements in Caucasian PCa patients has been reported, however, occurrence in Indian population is largely unknown. The aim of this study was to determine the prevalence of the ETS and RAF kinase gene rearrangements, SPINK1 over‐expression, and PTEN deletion in this cohort.

Monoclonal gammopathy of renal significance with light-chain deposition disease diagnosed postrenal transplant: a diagnostic and therapeutic challenge

Patients with light‐chain deposition disease (LCDD) frequently do not meet criteria for myeloma. In such cases, despite low tumor burden, the circulating monoclonal immunoglobulins cause renal damage, are responsible for post‐transplant recurrence, and are rightly categorized as monoclonal gammopathy of renal significance (MGRS) requiring chemotherapy. A 65‐year male with uncharacterized nodular glomerulopathy presented with proteinuria 3 years postrenal transplant. His allograft biopsies were diagnostic of light‐chain deposition disease (likely recurrent), and in the absence of myeloma, he was labeled as MGRS. Based on the limited literature available, he was treated with bortezomib which resulted in normalization of serum‐free light‐chain ratios and resolution of proteinuria. He, however, later succumbed to complications of chemotherapy. This case highlights the diagnostic difficulties in LCDD, the importance of an accurate pretransplant diagnosis, and treatment of the malignant clone, in the absence of which post‐transplant management of recurrence is challenging with poor outcomes.