Allogeneic hematopoietic stem cell transplantation to cure sickle cell disease: A review.

Sickle cell disease (SCD) had first been mentioned in the literature a century ago. Advancement in the molecular basis of the pathophysiology of the disease opens the door for various therapeutic options. Though life-extending treatments are available for treating patients with SCD, allogeneic hematopoietic stem cell transplantation (HSCT) is the only option as of yet. A major obstacle before HSCT to cure patients with SCD is the availability of donors. Matched sibling donors are available only for a small percentage of patients. To expand the donor pool, different contrasting approaches of allogeneic HSCT like T-cell replete and deplete have been tested. None of those tested approaches have been without the risk of GvHD and graft rejection. Other limitations such as transplantation-related infections and organ dysfunction caused by the harsh conditioning regimen need to be addressed on a priority basis. In this review, we will discuss available allogeneic HSCT approaches to cure SCD, as well as recent advancements to make the approach safer. The center of interest is using megadose T-cell-depleted bone marrow in conjugation with donor-derived CD8 veto T cells to achieve engraftment and tolerance across MHC barriers, under reduced intensity conditioning (RIC). This approach is in phase I/II clinical trial at the MD Anderson Cancer Centre and is open to patients with hemoglobinopathies.

Correction of murine sickle cell disease by allogeneic haematopoietic cell transplantation with anti-3rd party veto cells.

Despite advances in gene therapy allogeneic hematopoietic stem cell transplants (HSCT) remains the most effective way to cure sickle cell disease (SCD). However, there are substantial challenges including lack of suitable donors, therapy-related toxicity (TRM) and risk of graft-versus-host disease (GvHD). Perhaps the most critical question is when to do a transplant for SCD. Safer transplant protocols for HLA-disparate HSCT is needed before transplants are widely accepted for SCD. Although risk of GvHD and TRM are less with T-cell-deplete HSCT and reduced-intensity conditioning (RIC), transplant rejection is a challenge. We have reported graft rejection of T cell-depleted non-myeloablative HSCT can be overcome in wild type fully mis-matched recipient mice, using donor-derived anti-3rd party central memory CD8-positive veto cells combined with short-term low-dose rapamycin. Here, we report safety and efficacy of this approach in a murine model for SCD. Durable donor-derived chimerism was achieved using this strategy with reversal of pathological parameters of SCD, including complete conversion to normal donor-derived red cells, and correction of splenomegaly and the levels of circulating reticulocytes, hematocrit, and hemoglobin.

Evaluation of Taenia solium cyst fluid-based enzyme linked immunoelectro transfer blot for Neurocysticercosis diagnosis in urban and highly endemic rural population of North India.

BACKGROUND: Neurocysticercosis (NCC) is infection by cestode Taenia solium/pork tapeworm. Sero-diagnosis of NCC is still a challenge. Radiological imaging (CT/MRI) are cost intensive, requires technical expertise and resource intensive. Hence, its availability is restricted in endemic zone. Existing Enzyme electro immune transfer blot (EITB) antigens are difficult to make and is not standardized for endemic population. Therefore, there is a definite need for easy and reliable EITB tool. METHODS: T. solium metacestode were harvested from naturally infected swine post slaughter. The cyst fluid/vesicular fluid was aspirated and processed with ultracentrifugation and immune blot was performed with this antigen. RESULTS: A total of 406 cases [rural 256 (NCC 78, seizures other than NCC 108 and healthy controls 70); urban 150 (NCC 41, seizures other than NCC 59 and healthy controls 50)] were enrolled. Positive EITB (detection of band <50 kDa) was significantly associated with NCC patients of urban population only (p < 0.001) but not in rural populations (p = 0.292). However, identification of 15 kDa band had significant association with NCC both in urban and rural populations with overall sensitivity of 91.5% and specificity of 91.6%. Presence of 35 kDa band was associated with multiple NCC (p < 0.001). The study shows that 15 kDa reactive band on EITB is highly sensitive and specific for diagnosis of NCC in endemic population. CONCLUSIONS: Presence of 35 kDa band on EITB was associated with infection by multiple cysticerci. The observations demand purification of cyst fluid antigens to develop simple and easy to execute test in field studies.

Interleukin-1B (IL-1B-31 and IL-1B-511) and interleukin-1 receptor antagonist (IL-1Ra) gene polymorphisms in primary immune thrombocytopenia.

BACKGROUND: Immune thrombocytopenia (ITP) is an immune-mediated disease caused by autoantibodies against platelets membrane glycoproteins GPIIb/IIIa and GPIb/IX. The etiology of ITP remains unclear. This study evaluated the association of polymorphisms in interleukin (IL)-1B-31, IL-1B-511, and IL-1Ra with ITP. METHODS: Genotyping of IL-1B-31, IL-1B-511, and IL-1Ra was performed in 118 ITP patients and 100 controls by polymerase chain reaction restriction fragment length polymorphism and detection of variable number tandem repeats. RESULTS: Genotype differences in IL-1B-31 and IL-1Ra were significantly associated with ITP. Patients showed a higher frequency of the IL-1B-31 variant allele (T) and a 1.52-fold greater risk of susceptibility to ITP (odds ratio [OR]=1.52, 95% confidence interval [CI]=1.04-2.22, P=0.034). The frequencies of both homozygous and heterozygous variant genotypes of IL-1B-31 were higher (OR=2.33, 95% CI=1.069-5.09, P=0.033 and OR=2.044, 95% CI=1.068-39, P=0.034) among patients and were significantly associated with ITP susceptibility. Both homozygous and heterozygous variant genotypes of IL-1Ra were also more frequent (OR=4.48, 95% CI=1.17-17.05, P=0.0230 and OR=1.80, 95% CI=1.03-3.14, P=0.0494) among patients and were associated with ITP risk. IL-1B-31 and IL-1Ra also showed significant association with severe ITP. However, IL-1B-511 was not associated with ITP. CONCLUSION: IL-1B-31 and IL-1Ra polymorphisms may significantly impact ITP risk, and they could be associated with disease severity, which may contribute to the pathogenesis of ITP.

Transforming growth factor beta 1 (TGF-ß1) modulates Epstein-Barr virus reactivation in absence of Helicobacter pylori infection in patients with gastric cancer.

BACKGROUND: Transforming growth factor-beta 1 (TGF-ß1), a multifunctional cytokine, acts as a key factor for Epstein-Barr virus (EBV) reactivation. We investigated the role of TGF-ß1 in latent and lytic stages of EBV in relation to Helicobacter pylori infection among patients with gastric cancer (GC) and peptic ulcer disease (PUD). METHOD: Gastric mucosal TGF-ß1 expression was determined in 95 EBV positive patients with gastroduodenal pathology [GC 40, PUD 19 and non-ulcer dyspepsia (NUD) 36] by quantitative real time PCR. Presence of H. pylori infection was diagnosed when either culture or any two of three tests (RUT, histopathology and specific ureA PCR) were positive. Serum level of TGF-ß1 was detected among 60 patients using ELISA. RESULTS: Mucosal TGF-ß1 mRNA expression was detected in 85 of 95 EBV positive patients and it was significantly higher in patients with GC (p=0.042). TGF-ß1 expression tended to be higher among H. pylori non-infected than infected patients (3.80±6.24 vs. 2.07±2.50, p=0.085). Both mRNA and serum level had significant association with lytic stage of EBV in absence of H. pylori infection when compared with its presence (5.21±4.00 vs. 2.29±2.89, p=0.040 and 842.00 [669.55] vs. 662.63 [628.76], p=0.049; respectively). CONCLUSION: TGF-ß1 expression was significantly associated with GC. TGF-ß1 was higher both at expression and translational levels in lytic EBV infection without H. pylori suggests that H. pylori infection might play important role in preventing EBV reactivation through attenuated TGF-ß1 expression. This might be a "wise host defense against EBV reactivation".

Distinct cytokine pattern in response to different bacterial pathogens in human brain abscess.

Brain abscess is a focal suppurative process. Host inflammatory response in Gram type and specific bacteria has not been studied in brain abscess. A total of 57 brain abscess patients with monomicrobial infections were studied for Th1 (TNF-α, IFN-γ, IL1-ß), Th2 (IL-4, IL-10) and Th17 (IL-17, IL-23) cytokine response by reverse-transcriptase PCR and ELISA. Th1 and Th17 cytokines were significantly elevated in Gram positive (Staphylococcus aureus and Streptococcus intermedius) and Th2 cytokine (IL-10) in Gram negative (Bacteroides fragilis and Escherichia coli) infections (p<0.05). Cytokine levels were significantly higher in abscess than blood (p<0.001). Elevated levels of several inflammatory cytokines (TNF-α, IFN-γ, IL1-ß, IL-17 and IL-23) were associated with the duration of symptoms; predisposing factors also influenced the levels of several cytokines. The expression of inflammatory cytokines in abscess was influenced by the bacterial pathogen, duration of symptoms and predisposing factors. Local milieu of brain plays significant role in secretion of various cytokines.

Evaluation of ELISA, neck muscle, tongue and eyelid examinations for the diagnosis of swine cysticercosis in a highly endemic area of north India.

Swine cysticercosis is very common in the developing countries where pigs are raised. Undercooked measly pork consumption leads to taeniasis; Taenia carriers act as source of human and swine cysticercosis and neurocysticercosis. Diagnosis of swine cysticercosis is important to break the cycle of disease transmission. The present study compared the neck muscle, tongue and eye examinations, and serum ELISA with different preparations (crude lysate, cyst fluid, scolex and cyst wall antigens) of Taenia solium cyst for the diagnosis of swine cysticercosis. Total of 24 pigs initially identified by neck muscle, tongue and eyelid examinations were purchased from local slaughter house and subjected to MRI for confirmation of cysticercosis. Sera from 20 MRI confirmed infected pigs and 50 disease free controls were subjected to ELISA with T. solium cyst antigens. Neck muscle examination was 100% sensitive and 75% specific for the diagnosis of swine cysticercosis, whereas tongue and eye examinations were 70% and 25% sensitive, respectively. ELISA with crude lysate had 85% sensitivity and 98% specificity. ELISA with cyst fluid, scolex and cyst wall antigens showed 70%, 65%, and 45% sensitivity, respectively. The present study showed that neck muscle examination was highly sensitive but less specific, while ELISA with crude antigens had reasonable sensitivity and high specificity for diagnosis of swine cysticercosis. ELISA with crude lysate can be used as a screening tool for swine infection.

Toll-like receptor 4 polymorphism and its association with symptomatic neurocysticercosis.

BACKGROUND: Symptoms and signs of neurocysticercosis (NCC) are nonspecific and depend upon several factors, including the host immune response to the parasite. Toll-like receptors (TLRs) play an important role in innate immunity. Susceptibility of humans to NCC in relation to TLR polymorphism is unknown. The present study examines TLR4 polymorphism in human NCC and its role in symptomatic disease. METHODS: A total of 140 patients with NCC (82 symptomatic [ie, with active epilepsy] and 58 asymptomatic) and 150 healthy control subjects were examined for TLR4 Asp299Gly and Thr399Ile polymorphisms by means of polymerase chain reaction and restriction fragment-length polymorphism. RESULTS: TLR4 Asp299Gly and Thr399Ile were significantly associated with the occurrence of NCC (P < .001 for Asp299Gly; P = .003 for Thr399Ile) and progression to symptomatic NCC, compared with control subjects (P < .001 for Asp299Gly; P < .001 for Thr399Ile) or asymptomatic NCC (P < .001 for Asp299Gly; P = .002 for Thr399Ile). Frequency of haplotype Gly/Thr (P <.001) was observed to be a risk factor for susceptibility to NCC. Gly and Ile carriers had a statistically significant association with NCC (P < .001 for Gly; P = .003 for Ile) and symptomatic NCC (P < .001 for Gly; P

Association of TLR4 Asp299Gly and Thr399Ile polymorphisms with Guillain-Barré syndrome in Northern Indian population.

Molecular mimicry between Campylobacter jejuni lipopolysaccharide and host gangliosides induces an immune response leading to axonal damage and Guillain-Barré syndrome (GBS). TLR polymorphisms are associated with many autoimmune diseases. The role of the TLR4 gene in GBS susceptibility largely remains unknown. We investigated TLR4 polymorphism in GBS. One hundred and twenty GBS patients and 150 healthy controls were included. TLR4 (Asp299Gly and Thr399Ile) genes were studied by PCR-RFLP. TLR4 (Asp299Gly) polymorphism was significantly associated with GBS (p, 0.045; OR, 8.75; 95% CI, 1.05-72.88); only acute motor axonal neuropathy (AMAN) was associated with Gly299Gly homozygote (p, 0.027; OR, 12.40; 95% CI, 1.33-115.77) and Thr399Ile (p, 0.019; OR, 3.42; 95% CI, 1.22-9.54) heterozygote, and TLR4-399Ile allele (p, 0.045; OR, 2.63; 95% CI, 1.02-6.75) compared to controls. In conclusion, TLR4 (Asp299Gly) polymorphism is associated with an increased susceptibility to GBS. Besides Asp299Gly, AMAN subtype is also associated with Thr399Ile polymorphism.

Human cysticercosis and Indian scenario: a review.

Cysticercosis, caused by Taenia solium larva is a major public health problem,especially in the developing world and neurocysticercosis (NCC) is considered to be the most common parasitic infestation of the central nervous system. NCC is identified as the single most common cause of community acquired active epilepsy; 26.3% to 53.8% active epilepsy cases in the developing world including India and Latin America are due to NCC.It is also becoming more common in the developed world because of increased migration of people with the disease or Taenia solium carriers and frequent travel to the endemic countries. It is estimated that three quarters of the estimated 50 million people with active epilepsy live in the poor countries of the world. Recent Indian studies using neuroimaging techniques suggest that the disease burden in India surpasses many other developing countries. Hence it is important to know the epidemiology,pathogenesis and diagnostic criteria so as to assess the disease burden and adopt interventional strategies for its control.Literature search was done for this review with special emphasis on Indian studies to create awareness about the disease in India,since cysticercosis is preventable and potentially eradicable.