Intestinal microbiota disruption limits the isoniazid mediated clearance of Mycobacterium tuberculosis in mice.

Tuberculosis (TB) continues to remain a global threat due to the emergence of drug-resistant Mycobacterium tuberculosis (Mtb) strains and toxicity associated with TB drugs. Intestinal microbiota has been reported to affect the host response to immunotherapy and drugs. However, how it affects the potency of first-line TB drug isoniazid (INH) is largely unknown. Here, we examined the impact of gut microbial dysbiosis on INH efficiency to kill Mtb. In this study, we employed in vivo mouse model, pretreated with broad-spectrum antibiotics (Abx) cocktail to disrupt their intestinal microbial population prior to Mtb infection and subsequent INH therapy. We demonstrated that microbiota disruption results in the impairment of INH-mediated Mtb clearance, and aggravated TB-associated tissue pathology. Further, it suppressed the innate immunity and reduced CD4 T-cell response against Mtb. Interestingly, a distinct shift of gut microbial profile was noted with abundance of Enterococcus and reduction of Lactobacillus and Bifidobacterium population. Our results show that the intestinal microbiota is crucial determinant in efficacy of INH to kill Mtb and impacts the host immune response against infection. This work provides an intriguing insight into the potential links between host gut microbiota and potency of INH.

Efficacy and tolerability of desensitization in the treatment of delayed drug hypersensitivities to anti-tuberculosis medications.

BACKGROUND: Delayed drug hypersensitivity to first-line anti-tuberculosis medication is a major challenge in tuberculosis treatment. OBJECTIVE: This study was performed to investigate the efficacy/tolerability of desensitization therapy in treatment of first-line anti-tuberculosis medication hypersensitivity and the usefulness of immunologic evaluation therein. METHODS: This study was conducted as a prospective, observational cohort study. Subjects who experienced hypersensitivity reactions, including maculopapular exanthema (MPE) and drug reaction with eosinophilia and systemic symptoms (DRESS), to first-line anti-tuberculosis medications (isoniazid [INH], ethambutol [EMB], rifampin [RFP], and pyrazinamide [PZA]) were enrolled. Patch, intradermal, lymphocyte transformation, and oral provocation tests were performed to determine culprit drugs, which were desensitized with rapid and graded challenge protocols. Breakthrough reactions (BTRs) during or after desensitization were assessed. RESULTS: In total, 31 desensitization treatments (INH, 8; EMB, 8; RFP, 11; PZA, 4) to 12 patients (8 with MPE and 4 with DRESS) were performed. The overall success rate of desensitization was 80.7%. All the study subjects except one completed the full course of anti-tuberculosis treatment. The overall BTR free rate was 64.5%. Sixteen (80%) treatments for MPE and four (36.4%) for DRESS were BTR free (P = 0.023). Drugs that were positive on any two of three immunologic studies showed significantly high BTR rates (P = 0.014), although this was not correlated with desensitization failure rate. CONCLUSION: Rapid desensitization therapy to multiple anti-tuberculosis medications for delayed drug hypersensitivity was safe and successful. Combination of multiple immunologic evaluations may predict BTR although it needs validation in larger studies.

Drug-specific CD4+ T-cell immune responses are responsible for antituberculosis drug-induced maculopapular exanthema and drug reaction with eosinophilia and systemic symptoms syndrome.

BACKGROUND: A multidrug regimen including isoniazid, rifampicin, pyrazinamide and ethambutol is commonly used as first-line treatment for tuberculosis. However, this regimen can occasionally result in severe adverse drug reactions, such as drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome and drug-induced liver injury. The culprit drug and mechanistic basis for the hypersensitive reaction are unknown. OBJECTIVES: To investigate drug-specific T-cell responses in patients with antituberculosis drug (ATD)-induced cutaneous hypersensitivity and its underlying mechanism. METHODS: We enrolled eight patients with ATD-induced maculopapular exanthema and DRESS and performed a lymphocyte transformation test. Subsequently, drug-specific T-cell clones were generated from four of the patients who showed proliferation in response to ATDs. We measured the drug-specific proliferative responses and counted the drug-specific interferon (IFN)-γ/granzyme B-producing cells after drug stimulation. Antihuman leukocyte antigen (HLA) class I and class II blocking antibodies were used to analyse human leukocyte antigen-restricted T-cell responses. RESULTS: Positive proliferative responses to ATDs were mostly found in patients with cutaneous hypersensitivity. Furthermore, we isolated isoniazid/rifampicin-specific T cells from patients, which consisted primarily of CD4+ T cells. Drug-specific CD4+ T cells proliferated and secreted IFN-γ/granzyme B when stimulated with isoniazid or rifampicin, respectively. Isoniazid-responsive T-cell clones did not proliferate in the presence of rifampicin and vice versa. Drug-specific T-cell responses were blocked in the presence of anti-HLA class II antibodies. CONCLUSIONS: This study identifies the presence of isoniazid/rifampicin-specific T cells in patients with ATD-induced maculopapular exanthema and DRESS. Furthermore, it highlights the important role of drug-specific T-cell immune responses in the pathogenesis of these reactions.

From the Cover: Characterization of Isoniazid-Specific T-Cell Clones in Patients with anti-Tuberculosis Drug-Related Liver and Skin Injury.

Isoniazid, rifampicin, pyrazinamide, and ethambutol are commonly used for the treatment of tuberculosis. Drug exposure is occasionally associated with liver and/or skin injury. The aim of this study was to determine whether drug-specific T-cells are detectable in patients with adverse reactions and if so characterize the nature of the T-cell response. Peripheral blood mononuclear cells (PBMC) from 6 patients with anti-tuberculosis drug-related adverse reactions (4 liver, 2 skin) were used to detect drug-responsive T-lymphocytes. Positive lymphocyte transformation test and/or ELIspot results were observed with all 6 patients. Over 3400 T-cell clones were generated from isoniazid, rifampicin, pyrazinamide, or ethambutol-treated PBMC. CD4+ clones from all 3 patients were activated to proliferate and secrete cytotoxic mediators (granzyme B, perforin, FasL) and effector (IFN-γ, Il-13) and regulatory (Il-10) cytokines with isoniazid, but not rifampicin, pyrazinamide, or ethambutol. Il-17 was not detected, while only 1 clone secreted Il-22. Isoniazid-responsive clones were not activated with other anti-tuberculosis drugs or isonicotinic acid albumin adducts. Activation of the clones with isoniazid was MHC class II-restricted and dependent on antigen-presenting cells. Most clones were activated rapidly even in the presence of the enzyme inhibitor 1-aminobenzotriazole. However, a time-dependent pathway of activation involving auto-oxidation of isoniazid was also observed. The discovery of isoniazid-specific CD4+ T-cell clones in patients with liver and skin injury suggests that the adaptive immune system is involved in the pathogenesis of both forms of iatrogenic disease.

IgG3 is the dominant subtype of anti-isoniazid antibodies in patients with isoniazid-induced liver failure.

Isoniazid (INH) therapy is associated with a significant incidence of idiosyncratic liver failure. We recently reported eight cases of INH-induced liver failure in which patients had antidrug and anticytochrome P450 antibodies. However, it was unclear what role these antibodies play in the mechanism of INH-induced liver injury. Here, we report that the dominant isotype of anti-INH antibodies was IgG, with IgG3 being the dominant subtype. IgG3 antibodies are associated with a Th1-type immune response and fix complement. IgG3 antibodies have been associated with other forms of liver injury and may play a pathogenic role in INH-induced liver injury.

Detection of anti-isoniazid and anti-cytochrome P450 antibodies in patients with isoniazid-induced liver failure.

UNLABELLED: Isoniazid (INH)-induced hepatotoxicity remains one of the most common causes of drug-induced idiosyncratic liver injury and liver failure. This form of liver injury is not believed to be immune-mediated because it is not usually associated with fever or rash, does not recur more rapidly on rechallenge, and previous studies have failed to identify anti-INH antibodies (Abs). In this study, we found Abs present in sera of 15 of 19 cases of INH-induced liver failure. Anti-INH Abs were present in 8 sera; 11 had anti-cytochrome P450 (CYP)2E1 Abs, 14 had Abs against CYP2E1 modified by INH, 14 had anti-CYP3A4 antibodies, and 10 had anti-CYP2C9 Abs. INH was found to form covalent adducts with CYP2E1, CYP3A4, and CYP2C9. None of these Abs were detected in sera from INH-treated controls without significant liver injury. The presence of a range of antidrug and autoAbs has been observed in other drug-induced liver injury that is presumed to be immune mediated. CONCLUSION: These data provide strong evidence that INH induces an immune response that causes INH-induced liver injury.

A case of isoniazid-induced liver injury diagnosed by use of the DLST, and successful reintroduction of isoniazid for pleural tuberculosis.

A 54-year-old woman was admitted for pleural tuberculosis diagnosed by right chest pain and cough. She received combination antituberculosis therapy consisting of isoniazid, rifampicin, ethambutol, and pyrazinamide. However, liver damage was observed 15 days after initiation of therapy (aspartate aminotransferase (AST) 248 IU/l, alanine transaminase (ALT), 132 IU/l). The patient was given glycyrrhizinate intravenously, but liver damage gradually increased (AST 628 IU/l, ALT 467 IU/l) and all tuberculosis drugs were ceased. We diagnosed drug-induced liver damage due to isoniazid according to results of the drug lymphocyte stimulation test. We successfully reintroduced rifampicin and streptomycin, and carried out desensitization therapy for isoniazid without liver injury recurrence. Reintroduction of a drug suspected to cause drug-induced liver injury is generally not recommended; however, our experience suggests that isoniazid, a first-line antituberculosis drug, may be reintroduced after desensitization.

Lymphocyte transformation test for the evaluation of adverse effects of antituberculous drugs.

The usefulness of the lymphocyte transformation test (LTT) for the analysis of adverse reactions to antituberculous drugs was evaluated. - The LTT was performed with isoniazid and rifampicin in 15 tuberculosis and 2 MOTT (Mycobacteria other than tuberculosis)-infection patients who suffered drug reactions, in 23 patients without any adverse reactions, in 7 controls previously exposed to antituberculous drugs, and in 14 controls who had never been exposed. 4/15 of the hepatotoxic reactions only showed a positive LTT with rifampicin, 3/15 only with isoniazid, and in 8/15 the LTT was negative. In an anaphylactoid shock reaction the LTT was extremely exaggerated for both rifampicin and isoniazid. In patients without any side effects only one slightly increased LTT due to isoniazid was observed. Two healthy controls with previous contact to these drugs showed a positive LTT for isoniazid, one of those with both rifampicin and isoniazid. The LTT was negative in all control persons without any former contact to antituberculous medications. In most cases hepatotoxicity seems to be a pure toxic reaction without the participation of cellular immune mechanisms. LTT can be useful for identifying the drug responsible for immunological side effects.

Acquired plasma factor XIII deficiencies.

Coagulation factor XIII (FXIII) is of paramount importance in the process of fibrin stabilization, which is the final step of the coagulation cascade. The clinical significance of defective fibrin stabilization is highlighted by the severe hemorrhagic manifestations of congenital FXIII deficiency. In this paper we review the pathophysiology, clinical presentation and therapy of acquired plasma FXIII deficiencies, caused by specific inhibitors or associated with other clinical conditions. For acquired severe FXIII deficiency caused by factor-specific inhibitors, the need for prompt diagnosis and treatment is emphasized by the high hemorrhagic risk and mortality. For moderate reduction of FXIII secondary to other conditions, we discuss the relative importance of FXIII reduction in the development of clinical symptoms and the role of substitution treatment.

Drug-specific immune responses induced by procainamide, hydralazine and isoniazid in guinea-pigs.

The drug-induced graft vs host reaction (GVHR) hypothesis requires, as its first step, specific T-cell immune responses to the drug-modified self. Procainamide, isoniazid and hydralazine are known to provoke various allergic reactions including GVHR-like adverse effects in man. We now report that drug-specific immune responses can easily be induced by these drugs in guinea-pigs. Twenty-five milligrams of each of these drugs and penicillin G, which is known to make covalent bonds with proteins and to also induce drug-specific immune responses, were mixed with complete Freund's adjuvant (CFA) and subcutaneously (s.c.) injected twice at an interval of 2 weeks into female Hartley guinea-pigs. The antibodies to these drugs were assessed by means of an enzyme-linked immunosorbent assay (ELISA). Two weeks after the last injection, all animals treated with isoniazid, hydralazine and penicillin G produced high titers of antibodies to these drugs. Antibodies to procainamide were also detected, although their antibody titers were low. The specificity of the antibodies produced were tested by the inhibition of ELISA and concentration-dependent inhibition was observed. Delayed type hypersensitivity (DTH) reactions were also observed in the animals treated with procainamide, isoniazid and hydralazine 2 weeks after the last injection. These results suggest that the allergic reactions observed in clinical use are related to the inducing potential of drug-specific immune responses in an animal system. Therefore, immunization of guinea-pigs with test drugs and CFA may give useful information for predicting the occurrence of allergic reactions in man.

Studies on immunomodulatory properties of isoniazid: V. Influence of isoniazid on secretion of interleukin-1.

Isoniazid in vitro decreased interleukin-1 production by glass-adherent cells from the blood of healthy donors. The previously described modulation of T cell activation by isoniazid seems to be independent of decreased interleukin-1 secretion.

[The role of phenotypic factors in predicting the effectiveness of pharmacological prevention of tuberculosis in children]. / Rol' fenotipicheskikh faktorov pri prognozirovanii éffektivnosti khimioprofilaktiki tuberkuleza u detei.

The role of genetic markers such as dermatoglyphics, sex and INH inactivation in predicting the efficiency of tuberculosis chemoprophylaxis has been studied in 76 children (41 boys and 35 girls) with a tuberculin reaction reversal. The dermatoglyphic signs and the type of INH inactivation were found to be related to the efficiency of chemoprophylaxis. This makes it possible to use the child's phenotype for prognosis and better individual approach to tuberculosis chemoprophylaxis. An association has been found between the INH inactivation type and dermatoglyphics.

Detection of IgE antibodies specific to isonicotinic acid hydrazide and its metabolite by enzyme-linked immunosorbent assay and the mechanism of sensitization by inhalation or ingestion of this compound.

A female hospital pharmacist and a nurse developed occupational asthma due to the inhalation of isonicotinic acid hydrazide (INH) powder. The mechanism of sensitization was examined in this study. Furthermore, IgE antibodies specific to INH and isonicotinic acid (INA), the major metabolite of INH, were examined by means of enzyme-linked immunosorbent assay (ELISA). IgE anti-INH antibody activity was detected by ELISA in sera from 5 out of 8 hospital workers who inhaled INH powder during the handling of INH, and in sera from 10 out of 142 tuberculosis patients receiving oral INH. IgE anti-INA antibody activity was detected in sera from 3 of the 8 hospital workers, and from 7 of the 142 tuberculosis patients. Neither IgE anti-INH nor anti-INA antibody activity was detected in sera from 45 patients with asthma or from 42 healthy volunteers. The specificity of the IgE antibodies and the cross-antigenicity between INH and INA were confirmed by ELISA inhibition studies. Our results indicate that sensitization to INH can occur not only by inhalation but also by oral administration, and that the asthmatic symptoms of the patients were caused by an IgE antibody specific to INH as a hapten.

[Clinical and biochemical characterization of isoniazid-induced auto-antibodies]. / Caracterização clínico-laboratorial de auto-anticorpos induzidos por isoniazida.

Isoniazid (INH) is one among many drugs capable of inducing autoantibodies and, in some cases, a lupus-like syndrome (LE). A longitudinal study was performed in 24 tuberculosis patients treated with INH to detect antibodies (A-AH) to total histones and fractions. Antinuclear antibodies were observed in two patients after treatment. Higher frequency of IgM-AH was also observed. IgM-AH binding to all fractions were observed in those serum samples exhibiting stronger ELISA reactivity. Conversely, binding to only H1 occurred when lower IgM-AH activity was tested. Correlations with clinical expressions of LE were not observed in the present study.

Isonicotinic acid hydrazide as an antigen.

Detection by in vitro serologic techniques of circulating antibody directed against isonicotinic acid hydrazide (INH, known as isoniazid) in humans has not been reported. In the past few months, however, sera from a patient with a recent history of isoniazid hypersensitivity of the immediate type have been studied, and reaginic antibodies (IgE) specific to INH were detected by means of an enzyme-linked allergosorbent test. Preliminary enzyme-linked allergosorbent tests also demonstrated that INH-specific IgE occurred in the serum of two of 150 patients with tuberculosis who had been treated with INH.

Contact dermatitis to antituberculosis drugs.

The literature has been reviewed for contact dermatitis occurring to antituberculosis agents. Of the 12 known drugs, 6 (isoniazid, rifampicin, ethambutol, para-aminosalicylic acid, streptomycin and kanamycin) have been documented by patch test to cause this type of dermatitis in certain individuals. Cross sensitization has been observed to contribute significantly to the allergic reactions noted from isoniazid, streptomycin, and kanamycin. Hyposensitization has also been discussed in this review.