The IL‐23/Th17 axis is involved in the adaptive immune response to Bacillus anthracis in humans

The neutralization of toxins is considered essential for protection against lethal infection with Bacillus anthracis (BA), a select agent and bioterrorism threat. However, toxin‐neutralizing activity alone would not be expected to provide sterile immunity. Therefore, we hypothesized that the development of an adaptive immune response against BA is required for bacterial clearance. We found that human monocyte‐derived dendritic cells (hDCs) kill germinated BA bacilli, but not nongerminated BA spores. hDCs produce IL‐1β, IL‐6, IL‐12, and IL‐23, and these cytokines are differentially regulated by germination‐proficient versus germination‐deficient BA spores. Moreover, the IL‐23 response to BA spores is regulated by IL‐1R‐mediated signaling. hDCs infected with germinating BA spores stimulated autologous CD4⁺ T cells to secrete IL‐17A and IFN‐γ in a contact‐dependent and antigen‐specific manner. The T‐cell response to BA spores was not recapitulated by hDCs infected with germination‐deficient BA spores, implying that the germination of spores into replicating bacilli triggers the proinflammatory cytokine response in hDCs. Our results provide primary evidence that hDCs can generate a BA‐specific Th17 response, and help elucidate the mechanisms involved. These novel findings suggest that the IL‐23/Th17 axis is involved in the immune response to anthrax in humans.     

A genetic association study of D-dimer levels with 50 K SNPs from a candidate gene chip in four ethnic groups

Introduction

D-dimer, a fibrin degradation product, is related to risk of cardiovascular disease and venous thromboembolism. Genetic determinants of D-dimer are not well characterized; notably, few data have been reported for African American (AA), Asian, and Hispanic populations.

Materials and Methods

We conducted a large-scale candidate gene association study to identify variants in genes associated with D-dimer levels in multi-ethnic populations. Four cohorts, comprising 6,848 European Americans (EAs), 2,192 AAs, 670 Asians, and 1,286 Hispanics in the National Heart, Lung, and Blood Institute Candidate Gene Association Resource consortium, were assembled. Approximately 50,000 genotyped single nucleotide polymorphisms (SNPs) in 2,000 cardiovascular disease gene loci were analyzed by linear regression, adjusting for age, sex, study site, and principal components in each cohort and ethnic group. Results across studies were combined within each ethnic group by meta-analysis.

Results

Twelve SNPs in coagulation factor V (F5) and 3 SNPs in the fibrinogen alpha chain (FGA) were significantly associated with D-dimer level in EAs with p < 2.0 × 10^− 6. The signal for the most associated SNP in F5 (rs6025, factor V Leiden) was replicated in Hispanics (p = 0.023), while that for the top functional SNP in FGA (rs6050) was replicated in AAs (p = 0.006). No additional SNPs were significantly associated with D-dimer.

Conclusions

Our study replicated previously reported associations of D-dimer with SNPs in F5 and FGA in EAs; we demonstrated replication of the association of D-dimer with FGA rs6050 in AAs and the factor V Leiden variant in Hispanics.     

Primary scrotal tuberculosis: A rare but intriguing entity

Introduction

Tuberculosis (TB) of the genitourinary tract is usually secondary to a primary site in another part of the body. Primary scrotal TB is an extremely rare condition and it may mimic viral orchitis, epididymitis, hydrocele, spermatocele, testicular torsion, scrotal trauma, or a tumour.

Case presentation

A 45-year-old man presented with a 3-month history of diffuse scrotal enlargement followed a month later by swelling in the left groin. Scrotal ultrasonography revealed a 4 cm x 4 cm hypoechoic, heterogeneous, inflammatory mass with multiple fistulae at the bottom of the scrotum without any extension to the deeper structures, and bilateral multiple inguinal adenopathy.

Discussion

Genitourinary TB may present with adrenal insufficiency, renal disease, obstructive uropathy and chronic cystitis with sterile pyuria. Although scrotal USG is very helpful, it is not a definitive diagnostic tool. Histopathology is mandatory either in the form of FNAB or formal biopsy. Most cases respond well to antitubercular drugs only.

Conclusion

An optimum diagnostic and therapeutic protocol is urgently needed for cases of primary scrotal TB to prevent misuse of costly investigations and treatments and to avoid unnecessary surgical interventions when the patient can be cured by antitubercular treatment only.     

The effect of prophylaxis on pediatric HIV costs

The objective of this study was to determine and compare the cost to treat HIV(+) and HIV(-) pediatric patients both before and after HIV prophylaxis became the standard of care. Retrospective chart review of a pediatric HIV/AIDS specialty clinic's medical charts was conducted for clinical and healthcare utilization data on 125 children diagnosed from 1986 to 2007. Mean HIV-related costs were compared using bootstrapped t-tests for children born in the pre-prophylaxis (1979-1993) and prophylaxis eras (1994-2007). Patients were also stratified into two categories based on death during the follow-up period. Lastly, national cost-savings were estimated using mean costs, national number of at-risk births, and national perinatal HIV transmission rates in each era. For HIV(+) children, mean annual per patient treatment cost was $15,067 (95% CI: $10,169-$19,965) in the pre-prophylaxis era (n = 40) and $14,959 (95% CI: $9140-$20,779) in the prophylaxis era (n = 14); difference not statistically significant (p > 0.05). For HIV(-) children, mean annual per patient treatment cost was $204 (95% CI: $219-$627) for the pre-prophylaxis era (n = 2) and $427 (95% CI: $277-$579) for the prophylaxis era (n = 69); difference statistically significant (p < 0.05). A projected cost-savings of $16-23 million annually in the USA was observed due to the adoption of prophylaxis treatment guidelines in pediatric HIV care. The prophylaxis era of pediatric HIV treatment has been successful in decreasing perinatal HIV transmission and mortality, as reflected by clinical trials and national cost-savings data, and emphasizes the value of the rapid adoption of evidence-based practice guidelines.     

Clinico-Pathological Spectrum of Primary Plasma Cell Leukemia Diagnosed at a Tertiary Care Centre in South India Over 5?Year Period

Plasma cell leukemia (PCL) represents a rare and aggressive form of plasma cell dyscrasia which can be primary (pPCL) or secondary (sPCL). It is diagnosed based on absolute plasma cell count of more than 2.0 × 10⁹/l or a relative proportion of greater than 20% of the peripheral blood leukocyte count. Although pPCL and sPCL share several clinical features, important differences exist. Patients with pPCL are younger; often have extra osseous organ involvement (liver, spleen and other extramedullary sites), increased frequency of renal failure, fast declining performance status and rapid progression to the terminal stage. Patients with sPCL have advanced bone disease. Presented in this article is India data of a short series of five cases of PCL diagnosed at a tertiary care centre from south India over last 5 years. All cases were de novo and had varied spectrum of presentation and so were not suspected to be plasma cell dyscrasia clinically. Detailed hemato-pathological evaluation clinched the diagnosis in all the cases.     

Study of PTPN22 1858C/T polymorphism in rheumatoid arthritis patients from Western India

BackgroundRheumatoid arthritis (RA) is an inflammatory autoimmune disorder with etiologies including genetic and environmental factors. Protein tyrosine phosphatase non-receptor type22 (PTPN22) 1858C/T polymorphism is widely suspected to be a susceptibility gene for RA in the non-HLA genes group.AimThis study aimed at determining whether PTPN22 1858C/T polymorphism is associated with RA patients from Western India and to evaluate its possible association with rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) autoantibodies.MethodsA total of 130 Indian RA patients and 100 age and sex matched normal controls were genotyped by polymerase chain reaction restriction fragment length polymorphism (PCR–RFLP) for the PTPN22 1858C/T polymorphism.ResultsRF positivity was seen among 73.8% RA patients studied and the overall incidence of anti-CCP antibodies was 86.2%. The homozygous genotype (T/T) was absent in both groups. Among RF positives, C/C homozygosity was 90.6% whereas 9.4% patients were C/T heterozygous. Among anti-CCP positives, 89.1% had C/C genotype while the remaining 10.9% have the C/T genotype. Statistically significant association was obtained between the polymorphism and anti-CCP positivity in RA patients (OR: 2.939, ‘p’ value = 0.0595).ConclusionOur study suggested that a positive autoantibody status may predispose an individual to RA. PTPN22 may act as a susceptibility gene only in certain ethnic groups and there is no direct association between PTPN22 C1858 polymorphism and RA patients from Western India. Still a larger study is needed to understand whether this polymorphism predisposes individual to disease-associated antibodies among Indian RA patients.     

Endoscopic visualization-assisted corneal bee sting removal

Purpose:Deeply embedded corneal foreign bodies and intrastromal foreign body removal can often be a challenge. The aim of this report was to describe the utility of endoscopy in visualization and removal of an embedded corneal bee stinger.Methods:A 44-year-old male patient developed toxic keratopathy after injury from a bee stinger. On examination, the bee stinger was noted to be deeply embedded in the corneal stroma. A superficial keratectomy was initially attempted; however, the stinger was noted to be intrastromal and protruding into the anterior chamber and could not be removed. An Endoscopy-assisted visualization was used to remove the stinger.Results:The bee stinger was successfully removed and the patient''s vision improved to 20/100 from an initial CFCF (counting fingers close to face) at time of presentation. At the end of 3 months follow-up, there was residual corneal edema along with cataractous changes in the lens as a sequelae of the initial bee sting injury. The patient subsequently underwent an endothelial keratoplasty along with phacoemulsification with intraocular lens implantation and the final BCVA improved to 20/40.Conclusion:Endoscopyassisted visualisation of anterior chamber and angle structures can be valuable in removal of retained and deeply embedded corneal or intracameral foreign bodies.