Association of tumor necrosis factor-alpha and interferon gamma gene polymorphisms and their plasma levels in leprosy, HIV and other peripheral neuropathies.

OBJECTIVE: Mycobacterium leprae and Human Immunodeficiency Virus (HIV) are causative agents known to be involved in nerve damage in leprosy and HIV-peripheral neuropathy (HIV-PN) respectively. Among other peripheral neuropathies the most common is diabetic neuropathy, which is metabolically induced. The proinflammatory cytokines TNF-α and IFN-γ have been implicated in the pathogenesis of peripheral neuropathy. The association between the plasma levels of these cytokines and their single nucleotide polymorphisms (SNPs) were investigated in leprosy neuropathy (LN), HIV-PN and other peripheral neuropathies (OPN). METHODS: Eighty-eight individuals with LN (PB=36; MB=52), 39 with HIV-PN, 52 patients with OPN, 101 HIV positive individuals without neuropathy (HIV) and 113 healthy subjects (HS) were included in the study. Plasma cytokine levels were measured by sandwich ELISA and one way ANOVA was carried out among the groups. SNPs of TNF-α- 308 G/A, -238 G/A and IFN-γ +874 T/A were investigated by amplification refractory mutation system polymerase chain reaction (ARMS-PCR). Their frequencies were compared between groups by Pearson's chi squared test. RESULTS: Plasma TNF-α and IFN-γ was significantly increased in LN (p<0.05), HIV-PN (p<0.05) and OPN (p<0.05) as compared to HS. A significant association was found between IFN-γ +874 A/A genotype in LN (p<0.05; OR=7.9), HIV-PN (p<0.05; OR=8.9) and OPN (p<0.05; OR=8.9) as compared to HS. CONCLUSION: Elevated levels of plasma TNF-α and IFN-γ and the association of IFN-γ +874 A/A genotype SNP in LN, HIV-PN and OPN suggests a common involvement of these cytokines in susceptibility/pathogenesis of peripheral neuropathy.

Anticeramide antibody and butyrylcholinesterase in peripheral neuropathies.

Ceramide is a glycosphingolipid, a component of nerve and non neuronal cell membrane and plays a role in maintaining the integrity of neuronal tissue. Butyrylcholinesterase (BChE) is a multifunctional enzyme, its involvement in neurodegenerative diseases has been well established. Anticeramide antibody (Ab-Cer) and enzyme BChE have been implicated in peripheral neuropathies. The present study investigates whether there is an association between Ab-Cer and BChE activities and peripheral neuropathies. Patients included: human immunodeficiency virus associated peripheral neuropathy (HIV-PN, n=39), paucibacillary leprosy (PB-L, n=36), multibacillary leprosy (MB-L, n=52), diabetic neuropathy (DN, n=22), demyelinating sensory motor polyneuropathy (DSMN, n=13) and chronic inflammatory demyelinating polyneuropathy (CIDP, n=10). Plasma Ab-Cer was measured by indirect enzyme linked immune assay (ELISA) and BChE activity in plasma was measured by colorimetric method. Ab-Cer levels were significantly elevated in MB-L and DN as compared to healthy subjects (HS). BChE levels were significantly higher in MB-L and DN as well as in HIV and HIV-PN. There is no significant difference in either Ab-Cer or BChE levels in DSMN and CIDP. Elevated plasma Ab-Cer and BChE levels may be considered significant in the pathogenesis of neuropathies. The variation in concurrent involvement of both the molecules in the neuropathies of the study, suggest their unique involvement in neurodegenerative pathways.

Detection of Tuberculosis in HIV Co-infected Individuals: Use of Multiple ELISA Responses to 38kDa, Lipoarabinomannan and ESAT- 6 of M. tuberculosis.

INTRODUCTION: There is a constant search for more sensitive and specific laboratory markers for tuberculosis (TB) infection. The early detection of TB in HIV co infected individuals is a diagnostic challenge. This is further compounded in those harbouring extrapulmonary disease. AIM: To evaluate the use of multiple Enzyme Linked Immunosorbent Assays (ELISA) quantifying antibody responses to 38kDa, LAM and ESAT-6 M.tb antigens in detection of TB in patients with TB and HIV-TB co-infection. MATERIALS AND METHODS: This is a cross-sectional study carried out in Hyderabad, India. Patient groups included 124 HIV-TB {62 with pulmonary TB (PTB) and 62 with extrapulmonary TB (ETB)}, 39 TB, 56 HIV and 57 healthy subjects (HS). A combination of anti 38kDa and LAM ELISAs measuring IgG, IgM and IgA levels and another ELISA measuring anti ESAT-6 combined antibody levels of IgG, IgM and IgA were evaluated. One-way ANOVA was performed to compare antibody responses among groups. To assess the efficacy of multiple ELISAs in detecting TB, concomitant seropositivity of an individual for all four ELISAs were evaluated for sensitivity and specificity. RESULTS: A single ELISA carried out to detect TB in HIV patients showed a sensitivity ranging from 39% to 72%. The sensitivities of concomitant evaluation of multiple ELISAs were 92% for any single, 72% for any two, 44% for any three and 14% for any four. Based on the specificities, a simple algorithm for TB detection can be deduced. When four ELISAs are positive (specificity 100%) in a patient-confirmed TB; when three ELISAs are positive (specificity 98%) - probably TB; when two ELISAs are positive (specificity 95%) - possibly TB; and when one ELISA is positive (specificity 70%) - suspicion of TB. CONCLUSION: The present study establishes the value of combining two or more M.tb antigen based ELISAs to enhance the sensitivity and specificity of TB detection in patients with tuberculosis as well as in those co-infected with HIV.

Robust Reference Intervals for Serum Kappa and Lambda Free Light Chains from a Multi Centre Study Population from Hyderabad, India: Myeloma Diagnostic Implications.

The International Myeloma Working Group considers the serum free light chain (SFLC) assay to be an adjunct to traditional tests. Apart from the FLC ratio, the absolute values of individual free light chains also are gaining importance as they appear to be more relevant in certain clinical settings. Automated assays are available for their determination. As laboratories put new test systems into use catering to different disease populations, they are required by accreditation and certification bodies to verify or establish performance specifications, including reference intervals (RIs) representative of their population. Our aim was to establish local RIs for SFLC in a multicentre representative healthy population using a robust method. There was no significant relationship between SFLC levels and age, gender and creatinine levels. The 95% RI for κSFLC was 4.81 to 33.86mg/L, for ? SFLC was 5.19 to 23.67mg/L and for κ/?SFLC was 0.36 to 2.33, significantly higher than the values given by the manufacturer. The κ/? SFLC ratio at 2.23, covering 100% of the data, showed 72% sensitivity (95% CI=39.0 - 94.0), 100% specificity (95% CI=71.5 - 100.0), 100% PPV (95% CI=21.5 - 100.0), 95% NPV (95% CI=75.4 - 99.9), and 79% accuracy (95% CI=56.0 - 93.0). In the patient group, kit RI for κ /? SFLC ratio classified 45.5% (n=5) as positive vs 9.1% (n=1) positive by the study RI, while the kit RI for kappa FLC classified 90.9% (n=10) as positive vs 54.5% (n=6) , indicating increased probability of false positive test results with the kit RI when applied to our patient population. Appropriate and specific reference intervals and criteria values result in fewer false-positive and false-negative results which means fewer wrong or missed diagnoses.

Diagnosis of Non-ST-Elevation Acute Coronary Syndrome by the Measurement of Heart-Type Fatty Acid Binding Protein in Serum: A Prospective Case Control Study.

A prospective case control study was undertaken to evaluate the diagnostic performance of serum heart-type fatty acid binding protein (HFABP) in comparison to cardiac TnT and TnI in 33 patients admitted with chest pain, diagnosed as NSTE-ACS (non ST elevation acute coronary syndrome) and 22 healthy controls. Area under the receiver operating curve (AUC) was highest for H-FABP (AUC 0.79; 95% CI 0.66-0.89) versus cTnI (AUC 0.73; 95% CI 0.59-0.84) and cTnT (AUC 0.71; 95% CI 0.57-0.83). The H-FABP level above 6.5 ng/mL showed 56.7% (CI 37.4-74.5) sensitivity, 0.5 (95% CI 0.3-0.7) negative likelihood ratio (-LR), 100% (CI 84.6-100.0) specificity, and 100% (CI 79.4-100.0) positive predictive value (PPV), 62.9% (CI 44.9-78.5) negative predictive value (NPV). cTnI level above 0.009 µg/L had 40% (CI 22.7-59.4) sensitivity, 0.6 (95% CI 0.4-0.8) -LR, 100% (CI 84.6-100.0) specificity, 100% (CI 73.5-100.0) PPV, and 55% (CI 38.5-70.7) NPV. cTnT showed 46.7% (CI 28.3-65.7) sensitivity, 0.5 (95% CI 0.4-0.7) -LR, 100% (CI 84.6-100.0) specificity, 100% (CI 76.8-100.0) PPV, and 57.9% (CI 40.8-73.7) NPV at level above 9 µg/L. +LR were 12.5 (95% CI 1.8-86.8), 1.7 (95% CI 1.0-3.0), and 1.2 (95% CI 0.8-1.9) for H-FABP, cTnI, and cTnT respectively. In conclusion measurement of H-FABP is a valuable tool in the early diagnosis of patients with chest pain (6-8 hrs) and seems to be a preferred biomarker in the differential diagnosis of NSTE-ACS. More studies are needed to determine whether serum H-FABP further improves diagnostic performance.

IgE- and IgG mediated severe anaphylactic platelet transfusion reaction in a known case of cerebral malaria.

BACKGROUND: Allergic reactions occur commonly in transfusion practice. However, severe anaphylactic reactions are rare; anti-IgA (IgA: Immunoglobulin A) in IgA-deficient patients is one of the well-illustrated and reported causes for such reactions. However, IgE-mediated hypersensitivity reaction through blood component transfusion may be caused in parasitic hyperimmunization for IgG and IgE antibodies. CASE REPORT: We have evaluated here a severe anaphylactic transfusion reaction retrospectively in an 18year-old male, a known case of cerebral malaria, developed after platelet transfusions. The examination and investigations revealed classical signs and symptoms of anaphylaxis along with a significant rise in the serum IgE antibody level and IgG by hemagglutination method. Initial mild allergic reaction was followed by severe anaphylactic reaction after the second transfusion of platelets. CONCLUSION: Based on these results, screening of patients and donors with mild allergic reactions to IgE antibodies may help in understanding the pathogenesis as well as in planning for preventive desensitization and measures for safe transfusion.