Non invasive tests for diagnosis of parasitic infections of CNS

Central nervous system (CNS) infections are among the most devastating diseases with high mortality and morbidity. In the pre-human immunodeficiency virus (HIV) era, the occurrence of CNS infections was very infrequent. However, in the past four decades or so, with a global increase in the immunocompromised population, the incidence of opportunistic infections of the CNS has changed. This includes a global increase in the incidence of parasitic infections such as Toxoplasma gondii. Infections such as neurocysticercosis and cerebral malaria are quite prevalent in developing countries. Early diagnosis of these infections is crucial for instituting accurate therapy and preventing mortality and morbidity. Despite advances in neuroimaging techniques, laboratory diagnosis remains the mainstay for confirmation of diagnosis. We present an update on the noninvasive tests available for laboratory diagnosis of parasitic infections of the CNS.

No evidence of association of xenotropic murine leukemia virus‑related virus with oral cancers: Experience from a tertiary care center in South India.

BACKGROUND: Development of oral cancer, a widely prevalent cancer in India, is multifactorial with increased risk in those habituated to smoking, consuming alcohol and chewing paan and tobacco. This does not preclude other etiological factors in the causation of this cancer. Exploratory studies on several oncogenic viruses have found varied associations with oral cancers. AIM: The aim of this study was to explore the association of xenotropic murine leukemia virus‑related virus, (XMRV) a retrovirus recently implicated in oncogenesis in humans, with oral cancers. SETTINGS AND DESIGN: The presence of XMRV proviral deoxyribonucleic acid (DNA) was evaluated by standard nucleic acid amplification from DNA extracted from representative bits of tumor tissues and adjacent normal tissues from surgically resected specimens sent post‑operatively for routine histopathological testing. MATERIALS AND METHODS: This prospective study comprised 109 patients with a provisional diagnosis of oral cancer who were operated at the Oral Oncology Department of Kidwai Memorial Institute of Oncology, over a period of 10 months. RESULTS: XMRV was not found in any of the tumor tissues (squamous cell carcinomas ‑ 98; verrucous carcinomas ‑ 4) nor in any of the normal tissues. It is thus important that the absence of this oncogenic virus in all the cases makes the association of XMRV with oral cancers very unlikely. CONCLUSIONS: There is a need to investigate potentially oncogenic viruses in other solid tumors and in larger sample sizes. Any such association could have implications in detecting, preventing and treating these cancers.

Cell intrinsic & extrinsic factors in cervical carcinogenesis.

Human papillomavirus (HPV) infection is a common sexually transmitted infection which a majority of infected women are able to clear by mounting an effective immune response. Individuals with a suboptimal immune response may be at increased risk of persistent HPV infection leading to sequelae of various grades of dysplasias and / or associated malignancy. Both cell intrinsic and extrinsic phenomena work in concert to bring about oncogenesis. Cell intrinsic factors for cervical carcinogenesis are: integration of the viral genome into the genome of the host’s cell which correlates with the progression of low grade lesions into high grade ones, inactivation of tumor suppressor genes like p53 and pRB by HPV oncoproteins particularly E6 and E7, deregulation of cell cycle regulators, host DNA synthesis and apoptosis. Cell extrinsic elements include factors contributing towards immune tolerance; some incriminated in the multistep carcinogenesis of HPV induced cervical cancer are: immunoregulatory enzyme indoleamine 2,3-dioxygenase expressing antigen presenting cells, low numbers of invariant Natural Killer T cells, anergic cytotoxic T lymphocytes, regulatory T cells (Tregs), an immunoregulatory microenvironment comprising of increased IL10, TGFβ and reduced IL2; reduced intralesional ratios of effectors (CD4 and CD8) vs. Tregs; and different types of Tregs in the lesions of invasive squamous cell carcinoma. Notch signaling plays a crucial role in regulating T cell differentiation and activation including induction of Tregs. Increased expression of Notch receptor-Jagged 1 and number of Tregs were seen in invasive disease when compared to precancer in cervical cancer. Tregs impart their function either through cytokines or by cell to cell contact. Investigation of the consequences of interference of Notch signaling in terms of the dynamics of intratumoral Tregs in cervical cancer would be interesting.

Toxoplasma seroprevalence in healthy voluntary blood donors from urban Karnataka.

BACKGROUND & OBJECTIVES: Although many infections can be transmitted through blood transfusion, it is not possible to carry out screening tests for all. Among the protozoal diseases transmitted by blood transfusion in India the most important is malaria, followed by toxoplasmosis. Screening for malaria is mandatory in India. We evaluated the seroprevalence of Toxoplasma gondii in healthy adult population of blood donors in Karnataka, south India. METHODS: A total of 1000 serum samples collected in two batches (500 each) in the years 2004 and 2005 from healthy voluntary blood donors were tested for T. gondii antibodies by ELISA method, in addition to the other five mandatory tests. RESULTS: Overall 20.3 per cent were positive for T. gondii IgG antibody, of which, 63 per cent had high and 7 per cent low avidity, 3.6 per cent IgM positive. IgG titre ranged from 18-362 IU/ml. INTERPRETATION & CONCLUSION: Our study showed a high prevalence of T. gondii antibodies in healthy voluntary blood population. It may be appropriate to include screening for T. gondii also in the pretransfusion blood testing schedule.

Strongyloides stercoralis eggs in the stools during anticancer therapy.

We report a 45-year-old man with granulocytic sarcoma who, following anticancer chemotherapy, developed florid strongyloidiasis, wherein eggs of Strongyloides stercoralis embedded in the exfoliated mucosa were seen in the stools. The eggs were interspersed with numerous rhabditiform larvae. He was treated with albendazole.

Prevalence of HIV infection in voluntary blood donors and cancer patients.

The HIV infection pattern amongst cancer patients and voluntary blood donors was studied at an oncology centre in South India. The study period was from May 1991 to March 1994. A total of 18,260 subjects were screened for HIV infection. Of which 14,266 were voluntary blood donors and 3994 were cancer patients. The HIV infection rate amongst voluntary blood donors and cancer patients was 0.042% (6/14266) and 0.4% (16/3994) giving a seropositivity rate of 0.42 and 4.0 per 1000 respectively.

Pneumocystis carinii pneumonia in two patients with Hodgkin's disease.

The incidence of Pneumocystis carinii pneumonia (PCP) in immunocomprOMised patients is on the increase. We describe two patients with Hodgkin's disease who were proved to have P. carinii pneumonia by toluidene blue "O" (TBO) staining of their induced sputa. To the best of our knowledge, there are no reports from our country regarding P. carinii infection in patients with malignancy.

Assessment of suitability & ease of performance of seven commercial assay systems for the detection of antibodies to HIV-1.

In this study, we have evaluated the suitability and ease of performance of seven HIV assays namely: Vironostika anti-HIV Uni-Form; Vironostika HIV MIXT; Elavia MIXT; Genelavia MIXT; Serodia-HIV; Immunocomb Bi-spot; and Test pack HIV-1 and 2 Abbott, for use in Indian laboratories. A panel of 41 blind coded Western blot confirmed sera were used for this purpose. Rapid assays like Immunocomb Bi-Spot, Serodia HIV and Test pack HIV-1/HIV-2 Abbott were found to be more suitable and easy to perform as compared to the ELISAs. Sensitivity of all the assays was excellent (100%). Specificity of Serodia HIV, Immunocomb Bi-spot, Test pack HIV-1 and 2 Abbott and Elavia MIXT were excellent (100%), while that of Vironostika MIXT and Vironostika anti-HIV Uni-Form was poor. Positive predictive value of the assays ranged from 64.5 to 100 per cent. Negative predictive value of six of the assays was 100 per cent and that of Vironostika anti-HIV Uni-Form was very poor.