Alterations in natural killer cells and natural killer T cells during acute viral hepatitis E

The mechanism of liver damage in acute hepatitis E is poorly understood. In this study, we assessed the frequency and activation status of natural killer (NK) and natural killer T (NKT) cells and cytotoxic activity of NK cells in the peripheral blood mononuclear cells (PBMCs) obtained from patients with hepatitis E (n = 41) and healthy controls (n = 61). Flow cytometry was used to assess NK (CD3(-)/CD56(+)) and NKT cell (CD3(+)/CD56(+)) fractions (% of PBMCs) and activation status (CD69(+); % of NK, NKT cells). NK cell cytotoxicity was assessed using major histocompatibilities complex-deficient K562 cells as target cells. In 14 patients, the studies were repeated during the convalescence period. Patients had fewer median (range) NK cells [8.9% (2.4-47.0) vs 11.2% (2.6-35.4)] and NKT cells [8.7% (2.8-34.1) vs 13.6% (2.3-36.9)] than controls (P < 0.05 each). Activation markers were present on large proportion of NK cells [43.5% (11.2-58.6) vs 15.5% (3.0-55.8)] and NKT cells [41.5% (17.4-71.1) vs 12.8% (3.3-63.2); P < 0.05 each] from patients. NK cell cytotoxicity was similar in patients and controls. During convalescence, all the parameters normalized. In conclusion, reversible alterations in NK and NKT cell number and activation status during acute hepatitis E suggest a role of these cells in the pathogenesis of this disease.

Prophylactic efficacy of high-molecular-weight antigenic fractions of a recent clinical isolate of Leishmania donovani against visceral leishmaniasis

T-cell mediated immune responses are key determinants to the natural course of infection caused by intracellular parasites such as Leishmania. Thus, T-cell activating proteins of these microbes continue to generate active interest particularly in view of their possible role in the design and development of newer and more effective vaccines. We have recently reported the presence of T-cell immunostimulatory antigens with the high-molecular-weight (MW) fractions (134-64.2 kDa) of whole Leishmania donovani antigen (strain 2001), which stimulated variable amounts of IFN-gamma, IL-12 and IL-10 in exposed immune individuals. The present study was undertaken to further evaluate these high-MW antigenic fractions (MW range >100-60 kDa) for potential protective efficacy. The high-MW region of the parasite was resolved into five antigenic fractions (Prep A-E) using continuous elution gel electrophoresis. Prior to in vivo protection studies in hamsters, these fractions were used to evaluate in vitro cellular responses in eight Leishmania-exposed individuals and treated cured hamsters. The protective efficacy of prep (A + B), C, D and E in combination with BCG was evaluated in inbred hamsters using standard immunization protocol. Proliferative responses were seen in all eight of eight exposed individuals to prep D [median stimulation index (SI): 5.2 (range 3.9-7.1)] and E [median SI: 5.6 (range 4.4-8.2)], five of eight individuals to prep B and prep C and three of eight to prep A [median SI: 0.2 (range 0.1-7.2)]. The median proliferative responses to prep D and prep E were significantly higher than to fraction prep A; (P < 0.05) but not to prep B and prep C. However, prep A-E induced equivalent levels of IFN-gamma, IL-10 and IL-12 cytokines. Fractions D and E also exhibited marked parasite inhibition in spleen (52.5% and 73.7%) and liver (65% and 80.2%) as compared with prep (A + B) (23% in spleen and 24% in liver) and prep C (38% in spleen and 24% in liver). Prep D and prep E vaccinated animals showed higher in vitro stimulatory responses (mean SI: 6.6 and 8.8) and nitric oxide (NO) induction (mean NO levels: 6.4 and 10.7 mug/ml) against whole cell extract as compared with other groups. The protection also correlated with presence of suppressed Leishmania-specific IgG levels in prep D and prep E immunized hamsters. These studies indicate the presence of immunostimulatory and protective molecules in 60-80 kDa region of L. donovani, which may be further exploited for developing a subunit vaccine.

Leishmania donovani infection down-regulates TLR2-stimulated IL-12p40 and activates IL-10 in cells of macrophage/monocytic lineage by modulating MAPK pathways through a contact-dependent mechanism

The failure of Leishmania, an intracellular pathogen, to stimulate a pro-inflammatory response following entry into macrophages has been well reported. This occurs in spite of the fact that ligands for the toll-like receptors (TLR) have been recently shown on the parasite surface and their role in disease protection well documented. The outcome of infection in leishmaniasis is determined by the Th1 versus Th2 nature of the effector response and the generation of IL-12 and IL-10 by the infected macrophages is important for this decision. We evaluated the effect of L. donovani infection of monocytes (cell line THP-1, and monocytes derived from human peripheral blood) on Pam3cys (TLR2 ligand) and lipopolysaccharide (TLR4 ligand) stimulated production of IL-12p40 and IL-10. L. donovani infection caused suppression of TLR2 and TLR4-stimulated IL-12p40, with an increase in IL-10 production. Parasites also modulated the TLR2-stimulated mitogen-activated protein kinase (MAPK) pathway by suppressing MAPK P(38) phosphorylation and activating extracellular regulated kinase (ERK)1/2 phosphorylation. These effects could be reversed either by using a MAPK P(38) activator, anisomycin, or ERK1/2 inhibitor, U0126. L. donovani caused modulation of TLR2-stimulated MAPK pathways in a contact-dependent mechanism. In addition parasite structural integrity but not viability was required for suppression of TLR2-stimulated IL-12p40 and activation of IL-10. These observations suggest that L. donovani has evolved survival strategies that subvert the pro-inflammatory response generated through TLRs.

Frequency of Helicobacter pylori and CagA antibody in patients with gastric neoplasms and controls: the Indian enigma

BACKGROUND

Despite association between H. pylori and gastric neoplasm (GN) from the developed world, studies from India, where infection is more common and acquired early, are scant and contradictory.

METHODS

Two hundred and seventy-nine patients with GN from two northern and one eastern Indian centers during the period 1997-2005, 101 non-ulcer dyspepsia (NUD), and 355 healthy volunteers (HV) were evaluated for H. pylori [rapid urease test (RUT), histology and anti-H. pylori, and CagA IgG serology].

RESULTS

Patients with GN [263 gastric carcinoma and 16 (6%) primary gastric lymphoma, 208 male] were older than HV (n = 355, 188 male) and NUD (n = 101, 54 male) patients (53 +/- 12 versus 44 +/- 17 and 43 +/- 13 years, respectively; P < 0.001). Eastern Indian patients with GN (n = 145) were younger than those from northern India (n = 134; 52 +/- 12 versus 55 +/- 12 years; P < 0.007, t-test). In GN and NUD patients H. pylori positivity by RUT [86/225 (38%) versus 46/101 (46%)], anti-H. pylori IgG [154/198 (78%) versus 85/101 (84%)], and histology [136/213 (64%) versus 55/101 (55%)] were comparable (chi(2)-test). Serum IgG anti-H. pylori antibody was more common among HV than among GN patients [300/355 (85%) versus 154/198 (78%); P = 0.04, chi(2)-test]. Intestinal metaplasia was more common in GN than in NUD patients [101/252 (40%) versus 2/98 (2%), P < 0.000, chi(2)-test]. CagAIgG was more common in GN than in NUD patients [124/163 (76%) versus 64/101 (63%)] but comparable to that in HV patients [87/98 (89%), P = NS].

CONCLUSION

Frequency of H. pylori as detected using endoscopy and serology-based tests is not higher among patients with GN as compared with controls in India.

Withania somnifera inhibits NF-kappaB and AP-1 transcription factors in human peripheral blood and synovial fluid mononuclear cells

Withania somnifera (WS) is an important herb with known antiinflammatory activity. Its molecular mechanism of action has not been investigated. The effect of a WS crude ethanol extract was studied on peripheral blood mononuclear cells of normal individuals and rheumatoid arthritis (RA) patients and synovial fluid mononuclear cells of RA patients in vitro. The WS extract significantly suppressed lipopolysaccharide (LPS) induced production of proinflammatory cytokines TNF-alpha, IL-1beta and IL-12p40 in normal individuals and RA patients, but had no effect on IL-6 production at the protein and transcript level. WS also suppressed LPS activated nitric oxide production in the mouse macrophage cell line, RAW 264.7. The extract inhibited nuclear translocation of the transcription factors NF-kappaB and AP-1 and phosphorylation of IkappaBalpha in normal and RA patients' mononuclear cells. HPLC analysis of the crude extract showed the presence of withaferin A and pure withaferin A also inhibited NF-kappaB translocation. The study demonstrated that the WS crude ethanol extract suppressed the production of proinflammatory molecules in vitro. This activity is partly through the inhibition of transcription factors NF-kappaB and AP-1 by the constituent withanolide. The role of additional constituents needs to be studied. Studies on the mechanism of action of the extract may yield potentially useful compounds for the treatment of inflammatory diseases.

Presence of hepatitis E virus in sewage in Northern India: frequency and seasonal pattern

Outbreaks of acute hepatitis E, associated with consumption of contaminated drinking water, are frequent in India. Sewage is a major source for contamination of surface water. Data on the presence of hepatitis E virus (HEV) in sewage in India are limited. The aim of this study was to look for the presence of HEV RNA in concentrates of sewage specimens collected from a major open sewage drain in Lucknow, India during August 2004 to July 2006, by the polymerase chain reaction, using primers specific for human HEV (genotype 1) or Indian swine HEV (genotype 4). Of the 192 sewage specimens tested, 79 (41%) showed presence of human HEV RNA. The positivity rate was higher during the second year (52/103 [51%]) than during the first year (27/89 [30%]; P = 0.005). The seasonal pattern of HEV RNA positivity was as follows: winter months (November to February): 28 of 61 (46%); summer months (March to June): 36 of 66 (55%); and, monsoon months (July to October) 15 of 65 (23%). There was no reported outbreak of hepatitis E in the city during the study period. Swine HEV RNA was not detected in any of the 69 specimens tested. Repeat testing confirmed the reproducibility of the results. In addition, nucleic acid sequencing of six sewage isolates showed that these belonged to HEV genotype 1. The study suggests that HEV infection and fecal viral excretion may be common in HEV-endemic regions throughout the year even during non-epidemic periods.

Oesophageal and tracheal perforation in thyroid B-cell lymphoma

We report an unusual case of spontaneous oesophageal and tracheal perforation secondary to thyroid B-cell lymphoma in a previously healthy 76-year-old woman. Findings on chest radiography, CT and oesophagram are correlated to endoscopy, surgery and pathology. Such perforation is a rare and serious complication that should be specifically considered when a patient with a neck neoplasm develops acute respiratory or gastrointestinal symptoms.

Immune response to leishmania: paradox rather than paradigm

The leishmaniases are a group of diseases caused by protozoan parasites of the genus Leishmania. Various Leishmania species can cause human infection, producing a spectrum of clinical manifestations. It is estimated that 350 million people are at risk, with a global yearly incidence of 1-1.5 million for cutaneous and 500,000 for visceral leishmaniasis (VL). VL is a major cause of morbidity and mortality in East Africa and the Indian subcontinent. Coinfection with HIV enhances the risk of the disease. The only control measure currently available in India is case detection and treatment with antimonial drugs, which are expensive, not always available and cannot be self-administered. Newer drugs like oral miltefosine have not become widely available. Vector and reservoir control is difficult due to the elusive nature of the vector and the diversity of the animal reservoir. A detailed knowledge of immune response to the parasite would help in designing prophylactic and therapeutic strategies against this infection.

Successful treatment of Nocardia nova bacteremia and multilobar pneumonia with clarithromycin in a heart transplant patient

Nocardia is an opportunistic pathogen in solid organ transplantation for which long-term sulfonamide therapy is considered the treatment of choice. We report a patient 7 months status post-orthotopic heart transplantation with Nocardia nova bacteremia and pneumonia. Initial treatment consisted of intravenous trimethoprim-sulfamethoxazole, which cleared blood cultures, but the patient subsequently went into renal failure and required alternative therapy. This report describes the first case of N nova bacteremia after orthotopic heart transplantation successfully treated with clarithromycin. All therapy should be guided by antibiotic sensitivity, and combination therapy should be considered in acutely ill patients and cases where in vitro synergy has been documented. This case suggests that clarithromycin can be an alternative treatment in cases of sulfonamide resistance, intolerance, or allergy.

Antinuclear antibodies by indirect immunofluorescence : optimum screening dilution for diagnosis of systemic lupus erythematosus

BACKGROUND & OBJECTIVES

Antinuclear antibodies (ANA) are serological hallmark of systemic lupus erythematosus (SLE). Conventionally, the test is carried out on human epithelial cells (HEp2) by indirect immunofluorescence (IIF) technique. Since culturing and maintaining HEp2 cells in the laboratory are labour intensive, in-house assays have given way to kits manufactured by commercial companies. The reference screening dilutions provided by the manufacturers are based on different ethnic population than ours. Therefore, it becomes mandatory for every laboratory to have its own screening dilutions for the local population that distinguishes best between healthy and diseased state. As, there is paucity of such data, we aimed to define the optimum screening dilution that distinguishes the patient with SLE from healthy individuals.

METHODS

Sera of patients fulfilling ACR criteria for diagnosis of SLE, idiopathic inflammatory polymyositis/dermatomyositis (PM/DM) and rheumatoid arthritis (RA), and age and sex matched healthy individuals were tested for ANA by IIF using a commercial kit (Euroimmun, Germany) at 5 dilutions, namely 1:40, 1:80, 1:160, 1:320 and 1:640. Receiver operator characteristics (ROC) curve were constructed to define the optimum dilution that distinguished healthy sera from the diseased ones.

RESULTS

Test was performed on 213 sera from 94 healthy individuals, and 43 SLE, 37 RA and 39 DM/PM patients. In healthy individuals, ANA at dilutions 1:40, 1:80, 1:160, 1:320 and 1:640 was positive in 13.8, 4.3, 2.1, 2.1 and 0 per cent respectively, whereas in SLE it was positive in 95.3, 95.3, 65.1, 53.5 and 23.3 per cent respectively.

INTERPRETATION & CONCLUSION

ROC curves analysis showed that at 1:40 dilution, sera of 95.3 per cent of SLE and 13.8 per cent of normal individuals were (ANA) positive, whereas at 1:80 dilution it was 95.3 per cent for SLE and 4.3 per cent for healthy individuals. A fluorescent intensity of > or =2 was more specific for SLE. The best discrimination between healthy individuals and the SLE patients was found at screening dilution of 1:80 and fluorescent intensity of > or =2 in our laboratory.

Cellular immune responses in acute hepatitis E virus infection to the viral open reading frame 2 protein

Hepatitis E virus (HEV) causes acute viral hepatitis and is endemic in the developing world. Few data are available on cellular immune responses in HEV infection. Using flow cytometry, we studied the frequencies of peripheral blood CD4(+) /CD8(+) T cells secreting interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-4 in 21 patients with acute hepatitis E and 18 healthy controls, after stimulation with the HEV capsid (ORF2) protein. Cytokine levels in serum specimens and culture supernatants of ORF2-stimulated peripheral blood mononuclear cells (PBMCs) were estimated in enzyme-linked immunosorbent assays. In addition, cytokine mRNA transcripts were measured in PBMCs by reverse transcription-polymerase chain reaction. In patients with acute hepatitis E, although the total CD4(+) population was expanded, the proportions of CD4(+)/CD69(+) and CD8(+) /CD69(+) cells producing IFN-gamma, TNF-alpha, and IL-4 in response to HEV ORF2 stimulation were unchanged. However, IFN-gamma levels in the supernatants and IFN-gamma mRNA transcripts in cells were elevated in ORF2-stimulated PBMCs in acute hepatitis E; levels of IL-2 or TNF-alpha were unchanged. Our findings suggest that CD4(+) IFN-gamma-secreting cells, which do not belong either to the helper T cell type 1 or type 2 phenotype, as is the case with natural killer T cells, may be involved in the pathogenesis of hepatitis E. Further, the limited immune reactivity we detected in peripheral blood cells may be related to the sequestration of immune events to the intrahepatic compartment, which is the major disease site.

Proteomic approach for identification and characterization of novel immunostimulatory proteins from soluble antigens of Leishmania donovani promastigotes

Visceral leishmaniasis (VL) caused by Leishmania donovani is a major parasitic disease prevalent in endemic regions of Bihar in India. In the absence of good chemotherapeutic options, there is a need to develop an effective vaccine against VL which should be dependent on the generation of a T helper type 1 (Th1) immune response. We have shown that soluble proteins from promastigote of a new clinical isolate of L. donovani (2001) ranging from 68 to 97.4 kDa (F2 fraction), induce Th1 responses in the peripheral blood mononuclear cells of cured Leishmania patients and hamsters and also showed significant prophylactic potential. To understand the nature of F2 proteins, it was further characterized using 2-DE, MALDI-TOF and MALDI-TOF/TOF-MS. In all, 63 spots were cut from a CBB stained gel for analysis and data was retrieved for 52 spots. A total of 33 proteins were identified including six hypothetical/unknown proteins. Major immunostimulatory proteins were identified as elongation factor-2, p45, heat shock protein (HSP)70, HSP83, aldolase, enolase, triosephosphate isomerase, protein disulfideisomerase and calreticulin. This study substantiates the usefulness of proteomics in characterizing a complex protein fraction (F2) map of soluble L. donovani promastigote antigen identified as Th1 stimulatory for its potential as vaccine targets against VL.

Hepatitis E virus infection among animals in northern India: an unlikely source of human disease

Hepatitis E virus (HEV) is a major cause of acute hepatitis in many developing countries. Based on data from nonendemic regions, an animal reservoir of HEV has been proposed; however, data from HEV-endemic regions are limited. We tested sera from 200 pigs, 98 chickens, 86 goats, 58 sheep and 30 buffaloes for anti-HEV IgG using two different enzyme immunoassays. Specificity of the detected antibodies was confirmed using inhibition assays. Stool specimens from 210 pigs, 94 piglets and 37 sheep were tested for HEV-RNA using nested amplification methods; the polymerase chain reaction products were sequenced and compared with known human and swine HEV sequences. Of the 200 swine sera, 193 and 195, respectively, tested positive in the two assays. All goat sera showed anti-HEV reactivity in both the assays. Inhibition studies confirmed the HEV specificity of antibodies detected in swine and goat sera using both the assays. Sera from sheep, buffalo and chickens also showed high rates of apparent reactivity, but inhibition studies were unable to confirm the specificity of reactions in these species. One faecal specimen showed amplification using Indian swine HEV-specific primers. The genomic sequence of the amplicon from this isolate had only 76-79% nucleotide and 93% amino acid homology with human HEV isolates reported from India and other parts of the world, and most closely resembled swine HEV isolates from other parts of India. Infection with HEV or a related agent is widespread among animals in northern India. However, the swine HEV in India differs genetically from human HEV isolates, indicating that pigs may not play an important role in the spread of human hepatitis E in endemic regions.

T-cell epitope mapping of ORF2 and ORF3 proteins of human hepatitis E virus

Little data are available on cellular immune responses during infection with hepatitis E virus (HEV). We therefore mapped CD4 T-cell epitopes in open reading frame (ORF)2 and ORF3 proteins of HEV using lymphocyte proliferation assays and overlapping peptide libraries. Proliferation of peripheral blood mononuclear cells from 40 patients with acute hepatitis E and 21 healthy controls with recombinant HEV ORF2 protein or pools of overlapping HEV ORF2/ORF3 peptides was measured. HLA-DQB1 and HLA-DRB1 alleles were also determined. Mononuclear cells from patients with hepatitis E more often showed significant proliferation on stimulation with recombinant ORF2 protein than controls (32/40 vs 7/21), and had higher median (range) stimulation indices [2.6 (0.9-15.2) vs 1.3 (0.6-12.9)]. Peptide pools corresponding to amino acids 73-156, 289-372, 361-444 and 505-588 of HEV ORF2 protein were associated with significant proliferation. Individual peptides in these pools did not show a clear pattern of stimulation. HEV ORF3 peptide pools did not induce proliferative responses. Lymphocyte proliferation in response to the peptide pool corresponding to amino acids 289-372 of HEV ORF2 protein was associated with presence of HLA-DRB1 allele 010X. These data on mapping of T-cell epitopes in HEV proteins may prove useful for designing HEV vaccines and for studying the immunopathogenesis of hepatitis E.

Comparison of generalized autocalibrating partially parallel acquisitions and modified sensitivity encoding for diffusion tensor imaging

BACKGROUND AND PURPOSE

Diffusion tensor magnetic resonance imaging (DTI) of the brain is usually acquired with single-shot echo-planar imaging, which is associated with localized signal loss, geometric distortions, and blurring. Parallel imaging can lessen these artifacts by shortening the length of the echo-train acquisition. The self-calibrating parallel acquisition techniques, image domain-based modified sensitivity encoding (mSENSE) and k-space-based generalized autocalibrating partially parallel acquisitions (GRAPPA), were evaluated with DTI of the brain in 5 healthy subjects.

METHODS

GRAPPA and mSENSE with higher acceleration factors (R) up to 4 were compared with conventional DTI (with and without phase partial Fourier, another method of reducing the echo-train length) on a 1.5T Sonata scanner (Siemens, Erlangen, Germany). The resulting images and diffusion maps were evaluated qualitatively and quantitatively. Qualitative analysis was performed by 3 reviewers blinded to the technique using image sharpness and the level of artifacts as characteristics for scoring each set of images. Quantitative comparisons encompassed measuring signal-to-noise ratio, Trace/3 apparent diffusion coefficient (ADC), and fractional anisotropy (FA) in 6 white-matter (WM) and gray-matter (GM) regions.

RESULTS

Reviewers scored the GRAPPA and mSENSE R = 2 images better than images acquired with conventional techniques. FA contrast was improved at the GM/WM junction in peripheral brain areas. Trace/3 ADC and FA measurements were consistent for all methods. However, R = 3,4 images suffered from reconstruction-related artifacts.

CONCLUSIONS

GRAPPA and mSENSE (R = 2) minimized the susceptibility and off-resonance effects associated with conventional DTI methods, yielding high-quality images and reproducible quantitative diffusion measurements.

Immunomodulatory activity of Semecarpus anacardium extract in mononuclear cells of normal individuals and rheumatoid arthritis patients

Semecarpus anacardium (SA) Linn. (family Anacardiaceae), is a plant well-known for its medicinal value in Ayurveda. The nut extracts of this plant have been traditionally used as antihelminthic, anti-fungal, anti-carcinogenic and in the treatment of nervous debilities and arthritis. In this study we have evaluated crude ethanolic extract of SA nuts for its anti-inflammatory activities in vitro using peripheral blood and synovial fluid mononuclear cells of healthy individuals and rheumatoid arthritis (RA) patients. SA extract inhibited the spontaneous and LPS induced production of proinflammatory cytokines IL-1beta and IL-12p40 but had no effect on TNF-alpha and IL-6 production, both at protein and mRNA level. The crude extract also suppressed LPS induced nuclear translocation of transcription factors, NF-kappaB and AP-1; the inhibition of NF-kappaB was through the inhibition of IkappaBalpha phosphorylation. The extract also suppressed LPS activated nitric oxide production in mouse macrophage cell line, RAW 264.7. Our results for the first time show that SA extract can inhibit proinflammatory cytokine production and demonstrate its mechanism of action.

A potential role for interleukin-18 in inhibition of the development of Cryptosporidium parvum

Accumulating evidence suggests that intestinal epithelial cells (IECs) constitutively express the immunoregulatory cytokine interleukin (IL)-18. IECs also serve as the host cell for the intracellular parasitic protozoan Cryptosporidium parvum. In the present study, C. parvum infection of a human enterocyte cell-line HCT-8 resulted in increased expression of IL-18 mRNA as measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR). IL-18 protein was detected in control uninfected cells and following infection there was increased expression as measured by enzyme-linked immunosorbent assay (ELISA). Gene expression revealed the presence of the IL-18 receptor subunits not only in cell-lines but also in freshly isolated IECs, suggesting that IL-18-mediated signalling events may contribute to epithelial host defence during infection. Recombinant IL-18 inhibited intracellular development of the parasite in HCT-8 and HT-29 cells. Increased expression of bactericidal antibiotic peptides LL-37 and alpha-defensin 2 by IL-18 in HCT-8 and HT-29 cells may represent one mode of action by which this pluripotent cytokine aids in limiting the development of intracellular pathogens such as C. parvum in the gastrointestinal tract.

Correlation between methotrexate efficacy & toxicity with C677T polymorphism of the methylenetetrahydrofolate gene in rheumatoid arthritis patients on folate supplementation

BACKGROUND & OBJECTIVES

C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene has been proposed as a pharmacogenomic marker for toxicity of methotrexate (MTX). We studied the relationship between the C677T gene polymorphism and toxicity and efficacy of MTX in patients with rheumatoid arthritis (RA) on folate supplementation.

METHODS

A total of 150 RA patients fulfilling American College of Rheumatology (ACR) criteria and on MTX treatment were evaluated. The mean age of the patients was 42.9 +/- 11.1 yr, mean disease duration was 7.65 +/- 5.2 yr and the mean duration of MTX treatment was 26.1 +/- 20.6 months. Genotype analysis of MTHFR gene was done by PCR and restriction enzyme method. Primary endpoint for treatment efficacy was change in disease activity score 28 (DAS28) from baseline. Drug toxicity was evaluated by blood count, renal and liver function tests and a standardized questionnaire.

RESULTS

The mean DAS at baseline was 5.02 +/- 0.8. All patients received 10 mg/wk folic acid supplementation. Forty two per cent (63/150) of the patients had C677T polymorphism of which 4 were homozygous (T/T) and 59 were heterozygous (C/T). The baseline characteristics of the patients with or without polymorphism were comparable. The frequency of adverse events was not increased in patients with C677T polymorphism with 11 patients experiencing adverse events as compared to 19 in the group without polymorphism (of whom 4 and 7 patients respectively discontinued treatment). The C677T polymorphism was not associated with any difference in response to treatment.

INTERPRETATION & CONCLUSION

Our findings suggest that C677T polymorphism in the MTHFR gene is not predictive of toxicity or efficacy of MTX treatment in RA patients receiving folate supplementation. Further studies need to be done to look at polymorphisms in other enzymes that may have association with MTX clinical efficacy and toxicity.