Drug insight: autoimmune effects of medications-what's new?

Sequential carbonyl derivatives and hydrazone adduct formation on myeloperoxidase contribute to development of ANCA vasculitis

Drug-induced autoimmune diseases are increasingly recognized, although mechanistic insight into disease causation is lacking. Hydralazine exposure has been linked to autoimmune diseases, including antineutrophil cytoplasmic autoantibody (ANCA) vasculitis. Our hypothesis posits that hydralazine covalently binds to myeloperoxidase (MPO), triggering the autoimmune response in ANCA vasculitis. In vitro, we observed formation of carbonyl derivatives on amine groups in the presence of acrolein. This facilitated the subsequent binding of hydralazine to heme-containing proteins, including MPO, via a Michael addition. Our studies demonstrated that carbonyl derivatives and hydrazone adducts induced conformational changes in the MPO heavy chain, potentially changing its immunogenicity. We identified hydrazone adducts on circulating MPO in patients with hydralazine-associated ANCA vasculitis. These patients exhibited elevated anti-MPO IgM levels, while anti-MPO IgG levels were comparable between hydralazine-associated and nonhydralazine-associated vasculitis patients. IgM isolated from patients with hydralazine-associated MPO ANCA demonstrated a heightened affinity to hydralazine-modified MPO and activated neutrophil-like HL-60 cells. Hydralazine-modified MPO was pathogenic, as demonstrated by splenocyte transfer in a mouse model of ANCA vasculitis. Our findings unveil a mechanism of drug-induced autoimmunity wherein stepwise chemical modifications of MPO lead to conformational changes and hydrazone adduct formation, producing a neoantigen that generates pathogenic autoantibodies.

Ulcerative colitis and bullous pemphigoid: Direct association or a medication side effect: A case report

BACKGROUND

Bullous pemphigoid (BP) is an autoimmune blistering skin disorder. It is associated with other autoimmune disorders and the use of certain drugs. We describe a case of BP in a patient with ulcerative colitis (UC) treated with mesalamine.

CASE SUMMARY

A 38-year-old male patient with UC and a history of multiple flares was maintained on mesalamine with good clinical response. One year after starting mesalamine, he sought medical care following the onset of a severe itchy rash of several weeks' duration with a recent appearance of skin bullae. A biopsy of the skin revealed subepidermal blistering dermatitis with focal eosinophilic spongiosis. Direct immunofluorescence studies revealed linear IgG and C3 immune reactant deposits at the dermoepidermal junction, consistent with the diagnosis of BP. Prednisone therapy alleviated his symptoms. However, tapering prednisone led to re-eruption of the bullae.

CONCLUSION

BP should be considered when patients with UC develop skin manifestations. Although BP is not one of the extraintestinal manifestations of UC, there may be an association between these two conditions. Whether treatment with mesalamine or other therapeutic agents plays a role in the development of BP remains unclear.

Evaluation of ILAR and PRINTO classifications for juvenile idiopathic arthritis: oligoarticular JIA vs early-onset ANA-positive JIA

OBJECTIVES

The International League of Associations for Rheumatology (ILAR) juvenile idiopathic arthritis (JIA) classification was revisited by the Pediatric Rheumatology International Trials Organization (PRINTO) in 2018. Classifications should establish uniform groups to assist physicians in providing optimal care. Therefore, we evaluated changes proposed by PRINTO to highlight their impact on forming consistent groups regarding uveitis and treatment responses, particularly focusing on early-onset anti-nuclear antibody (ANA)-positive JIA.

METHODS

Pediatric patients diagnosed with JIA according to ILAR and PRINTO classification, with a minimum of 1-year of follow-up, were enrolled, excluding those meeting the exclusion criteria for both the oligoarticular JIA and the early-onset ANA-positive JIA groups.

RESULTS

Among the 139 enrolled patients, 110 (79.1%) had oligoarticular JIA, while 15 (10.8%) had early-onset ANA-positive JIA. The below-age-5 criterion demonstrated the strongest association with uveitis, while the below-age-7 provided similar associations without substantial exclusions (odds ratio (OR) 8.62 [2.50-29.81] vs 7.45 [2.37-26.66]). Patients with a single ANA positivity at a titer ≥ 1/160 and age of onset below 7 had a notably higher risk of new-onset uveitis and biologic DMARD requirement (OR 7.95 [2.37-26.66] and 3.6 [1.42-9.09], respectively).

CONCLUSION

The inclusion of age of disease onset and ANA positivity with a titer ≥ 1/160 has enhanced uniformity in uveitis risk and treatment response, including failure of conventional synthetic DMARDs. Additionally, a single ANA positivity at a ≥ 1/160 titer rather than requiring two instances yields similar consistency. However, the joint count criteria failed to form consistent groups. PRINTO's classification places a significant proportion of patients into the "other JIA" group, necessitating further classification for improved clinical utility. Key Points •Inclusion of age and ANA positivity criteria increased uniformity among the subgroups. •Single ANA positivity at a ≥ 1/160 titer can be sufficient instead of twice. •Early utilization of bDMARDs may be beneficial for early-onset ANA-positive JIA group. •PRINTO classification must further classify the "other JIA" before being implemented in clinical practice.

A Spotlight on Drug-Induced Vasculitis

PURPOSE OF REVIEW

Drug-induced vasculitis (DIV) is a rare form of vasculitis related to the use of various drugs. DIV primarily affects small to medium size vessels, but it can potentially involve vessels of any size. Differentiating between primary systemic vasculitis and DIV can be challenging; however, it is crucial, so that the offending agent can be discontinued promptly.

RECENT FINDINGS

The clinical phenotype of DIV is protean and depends on the size of the affected vessels. It ranges from arthralgias, to an isolated cutaneous rash, to severe single or multi-organ involvement. While withdrawal of the offending drug is the most important step in management, a significant number of patients require immunosuppressive therapy for varying periods of time. DIV can affect any vascular bed size, leading to protean vasculitic syndromes. Increased awareness among general practitioners, specialty, and subspecialty physicians is crucial for early recognition, and withdrawal of drug for better outcomes.

Autoimmune blistering diseases provoked during the treatment of chronic inflammatory disease with biologic agents: a systematic review

BACKGROUND

To investigate the clinical course of autoimmune blistering diseases (AIBDs) following treatment with biologic agents (BAs) for chronic inflammatory diseases.

METHODS

A comprehensive review of available, published literature was performed using PubMed and CINAHL search engines. Diagnostic criteria of AIBD included positive direct immunofluorescence studies and/or positive serology with clinically suggestive features.

RESULTS

A total of 22 cases of AIBDs provoked by the use of BAs were found. The most commonly implicated agents were tumor necrosis factor-alpha inhibitors (n = 14). The mean age of onset of AIBD was 59.4 years (median 61.5 years, range 31-82). Average time to onset of AIBD following initiation of the suspected BA was 33.7 ± 43.8 weeks (range 3 days to 152 weeks). Psoriasis was the most common associated condition for which the BA was prescribed (n = 11), followed by rheumatoid arthritis (n = 6) and ulcerative colitis (n = 5). Of the 21 cases reporting AIBD outcome, 17 reported remission or complete resolution upon stopping treatment with the involved BA. Four cases reported continued bullae formation without worsening of disease following cessation of the BA or systemic corticosteroids used to treat the AIBD. Five cases rechallenged the patient with the involved BA and four of the five reported recurrence, often with quicker onset and more severe symptoms.

CONCLUSIONS

BAs may be suspected in patients developing AIBD while being treated for chronic inflammatory diseases. A majority of cases resolve upon cessation of the offending agent.

Minocycline attenuates ethanol-induced cell death and microglial activation in the developing spinal cord

Developmental exposure to ethanol may cause fetal alcohol spectrum disorders (FASD), and the immature central nervous system (CNS) is particularly vulnerable to ethanol. In addition to vulnerability in the developing brain, we previously showed that ethanol also caused neuroapoptosis, microglial activation, and neuroinflammation in the spinal cord. Minocycline is an antibiotic that inhibits microglial activation and alleviates neuroinflammation. We sought to determine whether minocycline could protect spinal cord neurons against ethanol-induced damage. In this study, we showed that minocycline significantly inhibited ethanol-induced caspase-3 activation, microglial activation, and the expression of pro-inflammatory cytokines in the developing spinal cord. Moreover, minocycline blocked ethanol-induced activation of glycogen synthase kinase 3 beta (GSK3β), a key regulator of microglial activation. Meanwhile, minocycline significantly restored ethanol-induced inhibition of protein kinase B (AKT), mammalian target of the rapamycin (mTOR), and ERK1/2 signaling pathways, which were important pro-survival signaling pathways for neurons. Together, minocycline may attenuate ethanol-induced damage to the developing spinal cord by inhibiting microglial activation/neuroinflammation and by restoring the pro-survival signaling.

When Chest Pain Reveals More: A Case of Hydrochlorothiazide-Induced Systemic Lupus Erythematosus

BACKGROUND Drug induced lupus erythematosus is considered an autoimmune entity which is precipitated by medications. Hydrochlorothiazide has been recognized to cause subacute cutaneous lupus erythematosus, but very few cases of systemic drug induced lupus systemic erythematosus have been reported. CASE REPORT A 57-year-old Caucasian male with a past medical history of hypertension and hyperlipidemia presented with recurrent fevers, chest pain, and dyspnea. Initial evaluation revealed diffuse ST elevations, small pericardial effusion, anemia, and leukopenia. He was initially treated with nonsteroidal anti-inflammatory drugs and prednisone for pericarditis. Six months later, he reported fatigue, arthralgias, morning stiffness, weight loss, fevers, and night sweats. Laboratory tests revealed persistent anemia and leukopenia. Extensive workup, including bone marrow biopsy and infectious evaluations, was negative. Autoimmune workup, however, revealed positive antihistone and antichromatin antibodies despite negative antinuclear antibody. A diagnosis of drug induced lupus secondary to hydrochlorothiazide was made. The medication was stopped, and prednisone was initiated resulting in marked improvement in his symptoms and hematologic abnormalities. CONCLUSIONS This report is one of the few known cases of systemic lupus erythematosus most likely induced by hydrochlorothiazide. Based on our finding, hydrochlorothiazide should be considered a possible offending agent when a patient presents with symptoms suspicious of drug induced lupus.

Prescription medication use and antinuclear antibodies in the United States, 1999-2004

BACKGROUND

Clinical reports link specific medications with the development of antinuclear antibodies (ANA), but population-based evidence is limited.

OBJECTIVE

The present study investigated associations between prescription medication use and ANA in a representative sample of the adult noninstitutionalized US population, first focusing on medications previously related to ANA and then considering all medications reported in the National Health and Nutrition Examination Survey (NHANES).

METHODS

Based on NHANES data (1999-2004) for 3608 adults (ages ≥18 years), we estimated odds ratios (ORs) and 95% confidence intervals (CIs) to assess associations between recent medication use and ANA (overall and in sex and age subgroups), adjusted for potential confounders and the survey sampling design.

RESULTS

We found no evidence that most medications previously associated with ANA in specific individuals were risk factors for ANA in the general population, although statistical power was limited for some medications. Overall, ANA were less prevalent in adults who recently used any prescription medications compared with those who did not (OR = 0.73; CI = 0.57,0.93), and likewise several classes of medications were inversely associated with ANA, including hormones (OR = 0.73; CI = 0.55,0.98), thiazide diuretics (OR = 0.43; CI = 0.24,0.79), sulfonylureas (OR = 0.41; CI = 0.19,0.89), and selective serotonin reuptake inhibitor antidepressants (OR = 0.65; CI = 0.42,0.98). Positive associations with ANA were seen for loop diuretics (OR = 1.72; CI = 1.03,2.88) in all adults, and for benzodiazepines (OR = 2.11; CI = 1.09,4.10) and bronchodilators (OR = 1.83; CI = 1.00,3.38) in older (ages ≥60) adults. Estrogens were positively associated with ANA in older women (OR = 1.80; CI = 1.00,3.23) but inversely associated with ANA in younger (ages 18-59) women (OR = 0.43; CI = 0.20,0.93). Regarding individual medications, ANA were positively associated with ciprofloxacin (OR = 4.23; CI = 1.21,14.8), furosemide (OR = 1.79; CI = 1.09,2.93), and omeprazole (OR = 2.05; CI = 1.03,4.10) in all adults, and with salmeterol (OR = 3.76; CI = 1.66,8.52), tolterodine (OR = 6.64; CI = 1.45,30.5), and triamterene (OR = 3.10; CI = 1.08,8.88) in older adults. Also, in younger adults, hydrochlorothiazide was inversely associated with ANA (OR = 0.44; CI = 0.20,0.98).

CONCLUSIONS

Our findings in the general population do not confirm most clinically reported positive associations between specific medications and ANA in some individuals. However, novel positive ANA associations with other medications, as well as unexplained inverse associations with certain classes of medications and overall medication use, deserve further research to clarify the possible roles of medications as risk and protective factors in the development of autoantibodies and autoimmune disease.

Bullous Pemphigoid Associated with Adalimumab Therapy in a Patient with Ulcerative Colitis

Bullous pemphigoid (BP) is a blistering autoimmune disease mainly observed in elderly patients. Several triggers are known for this autoimmune disease and some drugs are known to be a cause of BP. However, there are only few case reports on the induction of BP under adalimumab therapy. Other autoimmune diseases, such as lupus erythematosus, are also known to occur under TNF inhibition. Here, we report on an 81-year-old patient who received adalimumab for ulcerative colitis and subsequently developed BP. Other causes of BP (tumors, other drugs, viral or toxoplasma infections) were excluded. We initiated a topical and systemic therapy (prednisolone 1 mg/kg/day) and stopped the adalimumab injections. The patient's symptoms resolved quickly and we were able to taper corticosteroid therapy. This rare case highlights the importance to monitor for autoimmune events during TNF inhibition.

A role for muscarinic receptors in neutrophil extracellular trap formation and levamisole-induced autoimmunity

Levamisole, an anthelmintic drug with cholinergic properties, has been implicated in cases of drug-induced vasculitis when added to cocaine for profit purposes. Neutrophil extracellular trap (NET) formation is a cell death mechanism characterized by extrusion of chromatin decorated with granule proteins. Aberrant NET formation and degradation have been implicated in idiopathic autoimmune diseases that share features with levamisole-induced autoimmunity as well as in drug-induced autoimmunity. This study's objective was to determine how levamisole modulates neutrophil biology and its putative effects on the vasculature. Murine and human neutrophils exposed to levamisole demonstrated enhanced NET formation through engagement of muscarinic subtype 3 receptor. Levamisole-induced NETosis required activation of Akt and the RAF/MEK/ERK pathway, ROS induction through the nicotinamide adenine dinucleotide phosphate oxidase, and peptidylarginine deiminase activation. Sera from two cohorts of patients actively using levamisole-adulterated cocaine displayed autoantibodies against NET components. Cutaneous biopsy material obtained from individuals exposed to levamisole suggests that neutrophils produce NETs in areas of vasculitic inflammation and thrombosis. NETs generated by levamisole were toxic to endothelial cells and impaired endothelium-dependent vasorelaxation. Stimulation of muscarinic receptors on neutrophils by cholinergic agonists may contribute to the pathophysiology observed in drug-induced autoimmunity through the induction of inflammatory responses and neutrophil-induced vascular damage.

S2k guideline for treatment of cutaneous lupus erythematosus - guided by the European Dermatology Forum (EDF) in cooperation with the European Academy of Dermatology and Venereology (EADV)

Cutaneous lupus erythematosus (CLE) is a rare inflammatory autoimmune disease with heterogeneous clinical manifestations. To date, no therapeutic agents have been licensed specifically for patients with this disease entity, and topical and systemic drugs are mostly used 'off-label'. The aim of the present guideline was to achieve a broad consensus on treatment strategies for patients with CLE by a European subcommittee, guided by the European Dermatology Forum (EDF) and supported by the European Academy of Dermatology and Venereology (EADV). In total, 16 European participants were included in this project and agreed on all recommendations. Topical corticosteroids remain the mainstay of treatment for localized CLE, and further topical agents, such as calcineurin inhibitors, are listed as alternative first-line or second-line topical therapeutic option. Antimalarials are recommended as first-line and long-term systemic treatment in all CLE patients with severe and/or widespread skin lesions, particularly in patients with a high risk of scarring and/or the development of systemic disease. In addition to antimalarials, systemic corticosteroids are recommended as first-line treatment in highly active and/or severe CLE. Second- and third-line systemic treatments include methotrexate, retinoids, dapsone and mycophenolate mofetil or mycophenolate acid, respectively. Thalidomide should only be used in selected therapy-refractory CLE patients, preferably in addition to antimalarials. Several new therapeutic options, such as B-cell- or interferon α-targeted agents, need to be further evaluated in clinical trials to assess their efficacy and safety in the treatment of patients with CLE.

Activation of Adenosine Monophosphate-activated Protein Kinase Suppresses Neuroinflammation and Ameliorates Bone Cancer Pain: Involvement of Inhibition on Mitogen-activated Protein Kinase

BACKGROUND

Activation of adenosine monophosphate-activated kinase (AMPK) has been associated with the inhibition of inflammatory nociception and the attenuation of morphine antinociceptive tolerance. In this study, the authors investigated the impact of AMPK activation through resveratrol treatment on bone cancer pain.

METHODS

The nociception was assessed by measuring the incidence of foot withdrawal in response to mechanical indentation in rats (n = 8). Cytokine expression was measured using quantitative polymerase chain reaction (n = 8). Cell signalings were assayed by western blot (n = 4) and immunohistochemistry (n = 5). The microglial cell line BV-2, primary astrocytes, and neuron-like SH-SY5Y cells were cultured to investigate the in vitro effects.

RESULTS

Resveratrol and 5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide, the AMPK activators, significantly attenuated bone cancer pain in rats with tumor cell implantation (TCI; threshold of mechanical withdrawal, resveratrol vs. vehicle: 10.1 ± 0.56 vs. 4.1 ± 0.37; 5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide vs. vehicle: 8.2 ± 0.17 vs. 4.1 ± 0.37, mean ± SEM); these effects were reversed by the AMPK inhibitor compound C (compound C vs. resveratrol: 6.2 ± 1.35 vs. 10.1 ± 0.56, mean ± SEM). Resveratrol has an AMPK-dependent inhibitory effect on TCI-evoked astrocyte and microglial activation. The antinociceptive effects of resveratrol were partially mediated by the reduced phosphorylation of mitogen-activated protein kinases and decreased production of proinflammatory cytokines in an AMPK-dependent manner. Furthermore, resveratrol potently inhibited inflammatory factors-mediated protein kinase B/mammalian target of rapamycin signaling in neurons. Acute pain evoked by proinflammatory cytokines in the spinal cord was significantly attenuated by resveratrol.

CONCLUSIONS

AMPK activation in the spinal glia by resveratrol may have utility in the treatment of TCI-induced neuroinflammation, and our results further implicate AMPK as a novel target for the attenuation of bone cancer pain.

The safety of therapeutic monoclonal antibodies: implications for cardiovascular disease and targeting the PCSK9 pathway

Monoclonal antibodies (mAbs) are established therapies for many conditions, including cancers, autoimmune conditions and infectious diseases. mAbs can offer benefits over conventional pharmacotherapy in terms of potency, dosing frequency and specificity for their target antigen. Mouse-derived antibodies were initially used in humans; however, patients often developed human anti-mouse antibodies, resulting in rapid antibody clearance (and a resulting loss of efficacy) and hypersensitivity reactions. Chimeric, humanized, and fully human antibodies were thus developed, with increasing amounts of human sequence, to reduce immunogenicity. Although generally well tolerated, mAbs may be associated with adverse events (AEs). Many AEs are target-related, and will be specific to the antibody target and the therapeutic area of use. However, off-target AEs, such as hypersensitivity reactions, are observed with many antibodies. Within the realm of cardiovascular medicine, new antibody-based therapies are under investigation to reduce low-density lipoprotein cholesterol (LDL-C) levels. Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates plasma LDL-C levels by increasing degradation of the LDL receptor (LDLR). Therefore, inhibition of the interaction between PCSK9 and the LDLR with mAbs targeting PCSK9 has great potential for patients with hypercholesterolaemia. Early clinical phase studies suggest these mAbs are effective and well tolerated; however, further studies are required to assess their long-term safety.

Vasculitis associated with tumor necrosis factor-α inhibitors

OBJECTIVE

To describe the clinical characteristics, histopathologic features, and outcomes of patients in whom vasculitis developed in association with use of tumor necrosis factor-α (TNF-α) inhibitors.

PATIENTS AND METHODS

This is a retrospective review of patients evaluated at Mayo Clinic, Rochester, Minnesota, from January 1, 1998, through March 31, 2011, with a diagnosis of vasculitis induced by anti-TNF-α therapy.

RESULTS

Of 8 patients with vasculitis associated with anti-TNF-α therapy (mean age, 48.5 years), 6 (75%) were female. Four (50%) had rheumatoid arthritis, 1 (13%) had Crohn disease, and 3 (38%) had ulcerative colitis. Five (63%) were treated with infliximab, 2 (25%) with etanercept, and 1 (13%) with adalimumab. The mean duration of treatment before development of vasculitis was 34.5 months. The skin was the predominant organ affected (5 patients [63%]), with the most common cutaneous lesion being palpable purpura (4 of 5 [80%]). Two organs involved in systemic vasculitis were the peripheral nervous system (4 patients [50%]) and kidney (1 patient [13%]). All cases of vasculitis were histopathologically confirmed. Seven of 8 patients improved with discontinuation of therapy (mean time to resolution, 6.9 months) and adjuvant treatment (all 8 received prednisone; another agent was also used in 7); rechallenge with anti-TNF-α therapy was not attempted in any patient. At last follow-up, no patients had experienced a recurrence of vasculitis after therapy discontinuation.

CONCLUSION

Cutaneous small-vessel vasculitis was the most common finding, but systemic vasculitis, including peripheral nerve and renal vasculitis, was also frequently observed.

Use of statins is associated with an increased risk of rheumatoid arthritis

OBJECTIVES

Statins offer significant cardiovascular benefits. Their use, however, influences immune regulation, which may potentially facilitate autoimmunity, eventually resulting in autoimmune diseases such as rheumatoid arthritis (RA).The authors studied whether statin use was associated with an increased risk of developing RA by conducting a case-control study using the Netherlands Information Network of General Practice database.

METHODS

The authors identified 508 patients aged 40 years or older with a first-time diagnosis of RA in the period 2001-2006. Each RA case was matched to five controls for age, sex and index date, which was selected 1 year before the first diagnosis of RA. Odds ratios for the first-time diagnosis of RA were verified by a referral to a rheumatologist and/or at least one prescription of disease-modifying anti-rheumatic drugs and/or two prescriptions of corticosteroids after the date of first diagnosis.

RESULTS

Cases were more often users of statins (15.9%) compared to controls (8.6%). After adjustment for cardiovascular risk factors and use of comedication, statin use was associated with an increased risk of incident RA (adjusted OR, 1.71 (95% CI 1.16 to 2.53); p=0.007). A consistent trend of increasing risk with increased cumulative duration, cumulative defined daily doses and number of prescriptions was not observed. However, a small trend between the potency of statin treatment and the risk of RA was found.

CONCLUSIONS

Statin use seems to be associated with an increased risk of developing RA. Our findings should be replicated by additional studies.

Onset of lupus like syndrome in patients with spondyloarthritis treated with anti-TNF-α

Background

The anti-TNFα therapy has been since its approval by the FDA, along with nonsteroidal antiinflammatory drugs (NSAIDs), one of the most important therapies for control of spondyloarthritis (SpA). The onset of Lupus Like Syndrome (LLS) has been described in patients with rheumatoid arthritis (RA) treated with anti-TNFα therapy but there is little literature on the occurrence of this entity in patients with SpA.

Methods

We studied 57 patients with SpA who received more than 1 year of anti-TNFα therapy (infliximab, adalimumab or etanercept). Patients were analyzed for the development of LLS, in addition to measuring ANA levels ≥ 1:160 and Anti-dsDNA (measured by IIF).

Results

In total, 7.01% of patients treated with anti-TNFα had titers of ANA ≥ 1:160, whereas 3.5% of patients had serum levels of dsDNA. However, only one patient (1.75%; n = 1) experienced clinical symptoms of LLS; this was a female patient with a history of psoriatic arthritis.

Conclusions

The presence of LLS secondary to anti-TNFα therapy in patients with SpA is observed less frequently compared with patients with RA. LLS was only detected in a patient with a history of psoriasis since youth, who developed psoriatic arthritis after 27 years of age and had received anti-TNFα therapy for > 2 years. This may be because LLS is an entity clearly associated with innate immunity, with little central role of B and T cells.

Safety profile and practical considerations of monoclonal antibody treatment

INTRODUCTION

Monoclonal antibodies are immunoglobulins specially designed to act against specific targets, in such a way that their administration stops a specific pathogenic process, stimulates a particular cellular action, or changes a cell mechanism to another pathway of interest. Their production is based on the establishment of modified immortal B lymphocytes to produce a specific immunoglobulin. Depending on the level of purity, this immunoglobulin may be murine complement (ending in "o", for example muromonab); chimeric, in which all the immunoglobulin is human, except in the variable region which is murine (ending in "xi", for example, rituximab); humanised, in which all the immunoglobulin is human, except in the variable complement region which remains murine (ending in "zu", for example, natalizumab); and human complement (ending in "u", for example, adalimumab). Therefore, there will be two types of secondary effects: those arising from the action of the antibody, such as opportunistic infections due to immunosuppression, and those arising from the administration of a protein, such as anaphylactic reactions. The sources used for the present articles were articles published in PubMed, located by searching for "Monoclonal antibodies and Secondary effects", and the web pages of the European Medicines Agency (EMEA) and the US Food and Drus Administration (FDA).

DEVELOPMENT

The secondary effects arising from the mechanisms of action were opportunistic infections, common infections, development of tumours and autoimmune phenomena, and those arising from the administration of proteins: anaphylactic reaction, cytokine release syndrome, and the development of neutralising antibodies. Finally, the management of monoclonal antibodies in clinical practice and in special situations is discussed, including administering vaccines, pregnancy and paediatric use. Reference will be made to immune recovery syndrome.

CONCLUSIONS

Monoclonal antibodies are highly effective drugs when specifically indicated, but they also may incur serious secondary effects, which although incidence is low, require close monitoring of the patients receiving these treatments.

The safety and side effects of monoclonal antibodies

Monoclonal antibodies (mAbs) are now established as targeted therapies for malignancies, transplant rejection, autoimmune and infectious diseases, as well as a range of new indications. However, administration of mAbs carries the risk of immune reactions such as acute anaphylaxis, serum sickness and the generation of antibodies. In addition, there are numerous adverse effects of mAbs that are related to their specific targets, including infections and cancer, autoimmune disease, and organ-specific adverse events such as cardiotoxicity. In March 2006, a life-threatening cytokine release syndrome occurred during a first-in-human study with TGN1412 (a CD28-specific superagonist mAb), resulting in a range of recommendations to improve the safety of initial human clinical studies with mAbs. Here, we review some of the adverse effects encountered with mAb therapies, and discuss advances in preclinical testing and antibody technology aimed at minimizing the risk of these events.

Drug-induced autoimmunity

PURPOSE OF REVIEW

This review aims to draw attention to the increased spectrum of the features of drug-induced autoimmunity (DIA), including both clinical and autoantibody profiles in addition to the potential chronicity of the syndrome.

RECENT FINDINGS

In recent years, not only has the number of medications causing DIA increased but the spectrum of the features has broadened as well. With the use of newer medications, especially biologics, mostly directed towards immune system manipulation, the range of signs and symptoms of DIA as well as the patterns of autoantibody profiles have widened. Rashes and visceral involvement have started to be reported more often, especially with tumor necrosis factor antagonists. In addition, autoantibodies such as antidouble-stranded DNA, which are usually seen with idiopathic systemic lupus erythematosus, are appearing in place of the antihistone antibodies, typically found in drug-induced lupus. Finally, some medications have been implicated in causing the very same entity, which they may be used to treat. It is clear that progress in the field of pharmacogenetics and pharmacogenomics will help further our understanding of these and other adverse effects of medications.

SUMMARY

Even though DIA has been known for many years, the underlying mechanisms remain unclear. However, with recently described new and unexpected features, novel hypotheses have been proposed, thus opening doors to further research in understanding these mechanisms.

Lupus-like syndrome attributable to anti-tumor necrosis factor alpha therapy in 14 patients during an 8-year period at Mayo Clinic

OBJECTIVE

To examine clinical characteristics, laboratory features, and outcomes of patients with lupus-like syndrome attributable to anti-tumor necrosis factor alpha (TNF-alpha) therapy.

PATIENTS AND METHODS

We performed a retrospective review of patients with lupus-like syndrome attributable to anti-TNF-alpha therapy at Mayo Clinic's site in Rochester, MN, between July 1, 2000, and June 30, 2008.

RESULTS

Of 14 patients (mean age at disease onset, 46.2 years), 12 (86%) were female. Ten patients (71%) had Crohn disease, and 4 (29%) had rheumatoid arthritis. Thirteen patients (93%) originally were treated with infliximab, and 1 (7%) was treated with adalimumab. A lupus-ike syndrome occurred after a mean treatment duration of 16.2 months. Features of lupus included presence of antinuclear antibodies (14 patients [100%]), arthritis (13 patients [93%]), anti-double-stranded-DNA antibodies (10 patients [71%]), cutaneous findings (malar rash, discoid rash, or photosensitivity, 4 patients [29%]), serositis (4 patients [29%]), hematologic abnormalities (4 patients [29%]), oral ulcers (4 patients [29%]), and lupus anticoagulant (1 patient [7%]). No patient had renal or neurologic abnormalities. All patients improved after stopping anti-TNF-alpha therapy (mean time to improvement, 2.9 months). Four (80%) of 5 patients tolerated an alternative TNF-alpha inhibitor (adalimumab, 3 patients; etanercept, 1 patient) without recurrence of lupus-like syndrome.

CONCLUSION

Compared with previous studies, cutaneous findings were less frequent and arthritis was more frequent in our cohort of patients. Some patients were able to tolerate an alternative TNF-alpha inhibitor without recurrence of lupus-like syndrome.

Is the development of drug-related lupus a contraindication for switching from one TNF alpha inhibitor to another?

The use of TNF alpha (TNFα) inhibitors has made a strong impact on the management of rheumatoid and psoriatic arthritis, ankylosing spondylitis and Crohn disease. Side effects of these agents include the development of autoantibodies and a lupus-like syndrome (drug-related lupus, DRL). Here, a case of a patient who developed DRL while receiving infliximab therapy which resolved spontaneously upon discontinuation of the agent and did not recur with subsequent institution of adalimumab is described. A discussion on the possible pathogenic mechanisms involved in the development of drug-related autoimmunity and differences between the agents is also included.

The importance of NAD in multiple sclerosis

The etiology of multiple sclerosis (MS) is unknown but it manifests as a chronic inflammatory demyelinating disease in the central nervous system (CNS). During chronic CNS inflammation, nicotinamide adenine dinucleotide (NAD) concentrations are altered by (T helper) Th1-derived cytokines through the coordinated induction of both indoleamine 2,3-dioxygenase (IDO) and the ADP cyclase CD38 in pathogenic microglia and lymphocytes. While IDO activation may keep auto-reactive T cells in check, hyper-activation of IDO can leave neuronal CNS cells starving for extracellular sources of NAD. Existing data indicate that glia may serve critical functions as an essential supplier of NAD to neurons during times of stress. Administration of pharmacological doses of non-tryptophan NAD precursors ameliorates pathogenesis in animal models of MS. Animal models of MS involve artificially stimulated autoimmune attack of myelin by experimental autoimmune encephalomyelitis (EAE) or by viral-mediated demyelination using Thieler's murine encephalomyelitis virus (TMEV). The Wld(S) mouse dramatically resists razor axotomy mediated axonal degeneration. This resistance is due to increased efficiency of NAD biosynthesis that delays stress-induced depletion of axonal NAD and ATP. Although the Wld(S) genotype protects against EAE pathogenesis, TMEV-mediated pathogenesis is exacerbated. In this review, we contrast the role of NAD in EAE versus TMEV demyelinating pathogenesis to increase our understanding of the pharmacotherapeutic potential of NAD signal transduction pathways. We speculate on the importance of increased SIRT1 activity in both PARP-1 inhibition and the potentially integral role of neuronal CD200 interactions through glial CD200R with induction of IDO in MS pathogenesis. A comprehensive review of immunomodulatory control of NAD biosynthesis and degradation in MS pathogenesis is presented. Distinctive pharmacological approaches designed for NAD-complementation or targeting NAD-centric proteins (SIRT1, SIRT2, PARP-1, GPR109a, and CD38) are outlined towards determining which approach may work best in the context of clinical application.