Increase of bone mineral density and anabolic variables in patients with rheumatoid arthritis resistant to methotrexate after cyclosporin A therapy

OBJECTIVE

To determine the bone mineral density (BMD) and anabolic variables in a cohort of patients with severe, early rheumatoid arthritis (RA) resistant to weekly doses of methotrexate (MTX), after addition of cyclosporin A (CyA) therapy.

METHODS

We studied 10 rheumatoid factor positive patients of 58 with early erosive, aggressive RA with poor response to a 6 month course of MTX (< 20% improvement in the American College of Rheumatology core set of criteria). BMD was assessed at entry, after 6 months of MTX, and after a further 6 months of combination therapy of MTX plus CyA. Bone Gla protein (BGP) dehydroepiandrosterone sulfate (DHEAS), and insulin-like growth factor-1 (IGF-1, somatomedin C) levels were determined along with clinical variables and acute phase reactants (C-reactive protein, erythrocyte sedimentation rate).

RESULTS

An average BMD decline of 4.05 +/- 0.8% (mean, SD) occurred in the first 6 months of MTX treatment, along with a statistically significant decline of IGF-1 (-24.8%), DHEAS (-21.6%), and BGP (-19.7%) levels. After adding CyA 3 mg/kg daily for 6 months, BMD had increased by 3.9 +/- 0.97%, IGF-1 by 42.4%, DHEAS by 34.2%, BGP by +34.3%. These changes mirrored the clinical variables (Health Assessment Questionnaire, morning stiffness, joint count) and acute phase reactants, which improved in a statistically significant manner.

CONCLUSION

Patients with active RA, even in the early phases, lose bone very rapidly. Effective control of systemic inflammation allowed a rapid rescue of BMD, at least in the short term. This happened with a simultaneous increase in some anabolic variables such as IGF-1, BGP, and DHEAS.

Slow progression of joint damage in early rheumatoid arthritis treated with cyclosporin A

OBJECTIVE

To evaluate the ability of low-dose cyclosporin A (CsA) to control radiologic disease progression, and to assess the clinical efficacy and tolerability of CsA, compared with conventional disease-modifying antirheumatic drugs (DMARDs), in patients with early active rheumatoid arthritis (RA).

METHODS

In this long-term, multicenter, prospective, open, blinded end point, randomized trial, 361 consenting patients with early (<4 years since diagnosis) active RA were enrolled. Of the eligible patients, 167 were treated with CsA at 3 mg/kg/day, and 173 with DMARDs. The decision to use conventional antirheumatic drugs as controls was based on the fact that joint erosion could be expected to occur after 1 year regardless of the type of DMARD being used. The possibility of switching therapies in both groups was intended to keep the largest possible number of patients in the study.

RESULTS

Blinded evaluation of hand and foot radiographs after 12 months of treatment showed that CsA led to a significant (P < 0.001) delay in the mean +/- SD progression in the eroded joint count (1.3 +/- 3.1 versus 2.4 +/- 3.0 for the control group) and in the joint damage score (3.6 +/- 8.9 versus 6.9 +/- 9.1 for the control group), both measured by the Larsen-Dale method. When only the patients without erosion at baseline were considered (37 in the CsA-treated group and 54 in the control group), erosion appeared in only 10.8% of the CsA-treated patients, but in 51.8% of the controls (P = 0.00005). Low-dose CsA was as effective as traditional DMARDs in controlling clinical symptoms. Maintenance on the initially prescribed treatment regimen ("survival on treatment") was also better at 12 months with CsA than with DMARDs (89.2% versus 77.5%; P = 0.002). The tolerability of CsA was acceptable.

CONCLUSION

These 12-month results suggest that low-dose CsA decreases the rate of further joint damage in previously involved joints as well as the rate of new joint involvement in previously uninvolved joints, in patients with early RA.

Widespread clonal B-cell disorder in Sjögren's syndrome predisposing to Helicobacter pylori-related gastric lymphoma

Helicobacter pylori has been identified as a critical antigenic stimulus to the development of gastric lymphoma, but additional factors should be required for such evolution. This topic is now of major importance to clarify the pathobiology of gastric lymphomagenesis. Peculiar autoimmune diseases, such as Sjögren's syndrome, are well known to predispose to B-cell lymphomas. We report on a patient with Sjögren's syndrome and a widespread B-cell lymphoproliferative disorder. A pathological picture of low-grade lymphoma was observed in the stomach, concomitantly with H. pylori infection. However, the B-cell disorder was definitely nonmalignant in the other tissues involved, i.e., the parotid gland and lymph nodes, which are the characteristic targets of Sjögren's syndrome-associated lymphoproliferation. After H. pylori eradication, a dramatic regression of gastric lymphoma into chronic gastritis was observed, but no amelioration occurred in the parotid and nodal involvement. Multiple molecular analyses showed the expansion of the same B-cell clone in synchronous and metachronous lymph node, parotid, and gastric lesions before and after H. pylori eradication. Thus, H. pylori played a crucial role in the local boosting of B-cell lymphoproliferation, but the underlying B-cell disorder was that associated with the autoimmune disease and was nonmalignant. The comprehensive clinical, pathological, and molecular approach allowed us to then distinguish the role of peculiar individual predisposing factors and of local infection in the pathobiology of mucosa-associated lymphoid tissue-associated lymphoproliferation.

Methotrexate in polymyalgia rheumatica: preliminary results of an open, randomized study

OBJECTIVE

Steroids are the only treatment of polymyalgia rheumatica (PMR). We report the effects of methotrexate (MTX) plus prednisone versus prednisone alone in PMR.

METHODS

Twenty-four patients with recent onset PMR were studied in a randomized prospective study lasting one year. Patients were given MTX (MTX arm) 10 mg intramuscularly plus prednisone every week, or prednisone alone (Pred arm). After 6 months an attempt was made to stop prednisone, and to use the lowest possible dose over the next 6 months.

RESULTS

At the 12th month, all patients were in clinical remission, acute phase reactants were in the normal range in both arms of the study, 6 patients were no longer taking steroids in the MTX arm versus 0/12 in the Pred arm, and the amount of prednisone in the 2 groups was statistically different (1.84 versus 3.2 g; p < 0.0001). In addition, bone mineral density was significantly decreased in the Pred arm, but not in the MTX arm.

CONCLUSION

The MTX regimen allowed the use of much less prednisone over one year to obtain full control of PMR with no loss of efficacy. It also allowed sparing of bone in elderly patients at increased risk of osteoporotic fractures.

Hepatitis C virus within a malignant lymphoma lesion in the course of type II mixed cryoglobulinemia

Hepatitis C virus (HCV) has been implicated as the major etiologic factor sustaining B-cell clonal expansion in type II mixed cryoglobulinemia (MC). A putative pathogenetic role of HCV in the development of MC-associated B-cell malignancies has also been speculated. We report for the first time the localization of HCV within a parotid non-Hodgkin's lymphoma (NHL) lesion in the course of HCV-related type II essential MC, an important step to implicate any infectious agent in the lymphomagenesis. Plus and minus strand HCV RNA was first demonstrated by polymerase chain reaction on the whole RNA from the lesion. Further immunohistochemical studies localized HCV c22 proteins in the residual ductal or acinar parotid structures, which also abnormally expressed HLA-DR antigens. Weak c22 signals were inconstantly detected in cells strictly confined around the residual epithelium, while all the remaining infiltrating cells in the parotid lesion stained c-22-negative. Staining for c33 and c100 HCV antigens was negative. In situ hybridization (ISH) studies again identified the residual parotid epithelial cells as the site of HCV infection and replication in the NHL lesion. Sialotropic viruses previously involved in lymphoproliferation, ie, Epstein-Barr virus and human herpesvirus-6, were absent in the same tissue lesion. According to the current models of B-cell lymphomagenesis, a role of HCV as an exogenous antigenic stimulus should be considered for NHL development in the present case, whereas malignant B cells do not appear permissive of active HCV replication. Further efforts would be worthwhile to clarify a role of HCV infection in the development of some B-cell malignancies.

Local cytokine expression in the progression toward B cell malignancy in Sjögren's syndrome

OBJECTIVE

Sjögren's syndrome (SS) has been indicated as an ideal human model to investigate B cell lymphomagenesis. Our aim was to investigate similarities or differences in cytokine expression in both prelymphomatous and frank B cell lymphomatous SS lesions, as well as in SS related lesions versus SS unrelated malignant B cell non-Hodgkin's lymphomas.

METHODS

The mRNA expression of interleukin (IL)-1 beta, IL-2, IL-3, IL-4, IL-6, IL-6R, IL-9, IL-10, IL-12, tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and transforming growth factor beta (TGF-beta) was analyzed by a sensitive reverse transcriptase polymerase chain reaction technique in 10 SS tissue samples from 10 consecutive patients [7 nonmalignant parotid myoepithelial sialadenitis (MESA) lesions with evidence of B cell clonal expansion, and 3 B cell non-Hodgkin's lymphomas] as well as a series of 11 SS unrelated B cell non-Hodgkin's lymphomas.

RESULTS

IL-1, IL-2, IL-3, IL-6, IL-6R, IL-10, IL-12, IFN-gamma, TNF-alpha, and TGF-beta mRNA was expressed in all or in the vast majority of the samples analyzed. IL-4 mRNA was detected in 2/3 SS related and in 3/11 SS unrelated non-Hodgkin's lymphomas, while SS related MESA samples were characterized by an IL-4 negative pattern and lacked IL-3 or IFN-gamma expression in 3/7 cases and in 2/7 cases, respectively.

CONCLUSION

Many cytokines may be involved in the evolution of prelymphomatous to definite B cell malignant lesions in SS, as well as in the development of SS unrelated B cell non-Hodgkin's lymphomas. A putative pathobiological role of the IL-12/IL-4 balance, in the presence of cytokines that may sustain B cell proliferation (i.e., IL-3, IL-6, IL-10), may represent a major point for future research. Finally, our data reinforce the view of SS as a human model of B cell lymphomagenesis.

Cyclosporin A increases somatomedin C insulin-like growth factor I levels in chronic rheumatic diseases

OBJECTIVE

To determine whether anabolic hormones that affect the musculoskeletal system and active on the immune cells changed during cyclosporin A (CysA) therapy.

METHODS

We carried out a randomized study of patients with rheumatic disease attending the outpatient clinic for rheumatic diseases. Twenty-four patients with chronic arthritis [20 with rheumatoid arthritis (RA) and 4 with psoriatic arthritis (PsA)] were divided into 2 groups (10 RA, 2 PsA) and randomly given CysA 5 mg/kg daily or hydroxychloroquine (OH-Chlor) 6 mg/kg daily in divided doses.

RESULTS

A significant increase of insulin-like growth factor I (IGF-I) (somatomedin C) levels and of bone Gla protein was shown after 2 months in the CysA treated group, but not in the OH-Chlor group. A statistically significant correlation was observed between changes of IGF-I levels and of dehydroepiandrosterone sulphate (DHEAS). This finding was confirmed in a further series of 39 patients. No changes were seen in 25 OH-D, 1-25(OH)2-D3 or parathyroid hormone after CysA.

CONCLUSION

The effects of CysA on IGF-I may explain some of the clinical, immunologic, and metabolic results during CysA treatment of rheumatic diseases.

Mild sialoadenitis: a common finding in patients with hepatitis C virus infection

BACKGROUND

Sjögren's syndrome (SS) is an autoimmune disease of presumed viral origin; sialoadenitis has been reported to occur in hepatitis C virus (HCV) infection.

METHODS

Lip biopsy specimens were graded in 32 consecutive patients with either HCV-related chronic liver disease or SS.

RESULTS

Seventeen of 22 HCV-positive patients had sialoadenitis, although generally mild (15 of 17, grades I-II). Severe inflammation (grades III-IV) was observed in 8 of 10 patients with SS (chi-square = 12.6; P < 0.0005). Moreover, HCV-positive patients with sialoadenitis differed from patients with SS in female sex prevalence (6 of 17 versus 10 of 10; chi-square = 10.9; P = 0.0001) and presence of serum antinuclear autoantibodies (0 of 17 versus 9 of 10; chi-square = 23.0; P < 0.0001). Five of 13 HCV-positive patients and 7 of 8 patients with SS were HLA-DR3-positive (chi-square = 4.9; P < 0.05).

CONCLUSIONS

Sialoadenitis of HCV-related liver disease is common but differs from SS with regard to predisposing genetic factors, expression of autoimmune markers, and histopathologic severity.

Progression of erosion and joint space narrowing scores in rheumatoid arthritis assessed by nonlinear models

OBJECTIVE

To determine whether the first order kinetics model or the function proportional to the square root of disease duration better represents the progression of radiographic damage according to the disease duration than a linear model in rheumatoid patients.

METHODS

Two hundred twenty-eight patients assessed at a single time point were studied by using 2 nonlinear models of radiographic damage. In 44 patients a second radiographic analysis was taken within a 3-year period.

RESULTS

In this data set, both models reveal the highest rate of progression in the first 3 years of the disease. The square root of the disease duration seems to better depict the whole disease course.

CONCLUSION

Nonlinear models should be compulsory in the assessment of radiographic damage, especially when slow acting antirheumatic drug effects after 5 years of disease duration are studied.

The polymerase chain reaction detects B cell clonalities in patients with Sjögren's syndrome and suspected malignant lymphoma

OBJECTIVE

To investigate the usefulness of the polymerase chain reaction (PCR) to detect B cell clonal expansions in tissues where lymphoproliferative disease was suspected in the course of Sjögren's syndrome (SS).

METHODS

Tissue samples from 7 patients with definite (5 cases) or probable (2 cases) SS were subjected to routine histopathologic studies, immunophenotyping, and genotypic analysis, including Southern blotting and PCR amplification of immunoglobulin heavy chain (IgH) variable-diversity-joining (VDJ) region gene rearrangements.

RESULTS

Malignant lymphoma was detected in 3 cases, and myoepithelial sialadenitis in the remaining 4. B cell clonal expansion was detected in 7/7 cases by PCR, 5/7 by Southern blotting, and in no case of myoepithelial sialadenitis by kappa/lambda light chain immunophenotyping.

CONCLUSION

PCR may represent a quick and powerful tool to detect B cell clonalities in SS. Such information may provide new insights into the pathogenesis of the disease and may improve the clinical approach to the patients.

Somatomedin C (insulin-like growth factor 1) levels decrease during acute changes of stress related hormones. Relevance for fibromyalgia

OBJECTIVE

To determine the effects of stress hormones on insulin-like growth factor 1 (IGF-1).

METHODS

Insulin induced hypoglycemia (< 3 mmol/l) and clonidine induced depression of noradrenergic tone were used to assess the acute effects of cortisol, human growth hormone (hGH), and norepinephrine (NE).

RESULTS

Despite the increase of hGH during hypoglycemia, a statistically significant decrease of IGF-1 was observed along with the expected rise of cortisol and NE. To eliminate the role played by NE, NE tone was depressed by administering clonidine. A statistically significant decrease of IGF-1 was also observed.

CONCLUSION

Acute cortisol release or a NE decrease induce low IGF-1 levels.

[Polymyalgia rheumatica and malignant neoplasms. A report of 3 cases]

Polymyalgia rheumatica (PMR) is an inflammatory disease which mainly affects elderly patients and is highly responsive to steroid therapy. PMR can be associated with giant cell arteritis and, less frequently, with malignancy. The authors describe three cases of paraneoplastic PMR. In one patient PMR has been the initial manifestation of a B-cell non-Hodgkin lymphoma, in two of a malignant neoplasm of the gastrointestinal system. In two patients the response to steroid therapy was documented. A careful clinical evaluation and a long term follow-up is needed before considering PMR an idiopathic disease.

Peripheral neuropathy in essential mixed cryoglobulinaemia

The prevalence of various forms of peripheral neuropathy has not been previously assessed in large series of patients with essential mixed cryoglobulinaemia (EMC). Clinical and electrophysiological signs of peripheral neuropathy were observed in 21 of 37 EMC patients, consisting of polyneuropathy in 19, mononeuropathy or multiple mononeuropathy in eight, and both in six. The various forms of peripheral neuropathy occurred differently in the subgroups of EMC. Isolated polyneuropathy was more common with type II (eight of 10) than type III EMC (two of eight). Multifocal neuropathy, in association with polyneuropathy, was the most common form in type III EMC (five of eight). Patients with peripheral neuropathy and type II EMC were significantly older than type II EMC patients without neuropathy, regarding present age and age of onset of EMC. Patients with peripheral neuropathy and type III EMC tended to have higher values of ESR and IgM than type III EMC patients without neuropathy. Electrophysiological findings and sural nerve biopsy specimens (nine cases) showed prominent axonal changes. Vascular changes included vasculitis and alterations of the endoneurial microvessels in type II and type III EMC. Our findings suggest that distinct pathogenic factors are implicated in the subgroups of cryoglobulinaemic neuropathy, possibly inducing different types of vascular changes underlying polyneuropathy or, respectively, mononeuropathy and multiple mononeuropathy.

Analysis of disability in knee osteoarthritis. Relationship with age and psychological variables but not with radiographic score

Sixty-one women with symptomatic knee osteoarthritis were given the Italian version of Arthritis Impact Measurement Scale which showed a good construct through the factorial analysis. The disability index was then related to the body mass index, the anatomical/radiographic damage, to the severity of pain assessed either through the McGill Pain Questionnaire or a visual analog scale, and finally to the degree of anxiety and depression as obtained from the Zung depression and anxiety inventory scores. A statistically significant relationship was found between radiographic damage and body weight, while disability correlated with the degree of psychological involvement and with the age of the patients. Through the stepwise multiple regression analysis we demonstrated that the pain experience and disability scores are strongly influenced by psychological impact. Our data may have important therapeutic implications.

[Peripheral neuropathy with mixed cryoglobulinemia]

Among 54 patients with mixed cryoglobulinemia a peripheral neuropathy was demonstrated in 23 patients (42.6%). Five patients had a secondary form while the majority (18) had essential cryoglobulinemia. The immunoglobulin components were polyclonal in 5 cases, only present in trace amounts in 5 and of type II in 13 patients. Fifteen patients had symptoms of polyneuropathy, but in 18 cases the symptomatology had symmetrical features and in two cases asymmetrical characteristics. In 8 patients a mono-polyneuropathy was observed. The most significant electrophysiological finding was the decreased amplitude of the sensory action potential of the sural nerve, which we observed in 95% of the instances, whereas a decreased sensory conduction velocity was seen in 8/23 cases only. A biopsy of the sural nerve, performed in eleven cases, always showed abnormal epi- and endoneurial vessels. Epineurial vessel vasculitis was found in 4 cases and fibrous thickening of the vessel wall in two cases. Endothelial swelling of the endoneurial vessels was observed in 7 patients and luminal obliteration in 3 samples. Axonal degeneration demonstrated in 7 of the 11 processed sample tissues was the main pathological finding. Signs of de/remyelination were associated in 3 cases, and were the dominant lesions in a single specimen. The simultaneous biopsy of the peroneus brevis muscle showed signs of denervation in all samples, vasculitis in 7 cases and deposits of filaments plus annular bodies of the vessel wall in 2 samples. All these data support the hypothesis that ischaemic damage may be the final common pathway of the majority of peripheral neuropathies in mixed cryoglobulinemia patients.

Association between DR antigens, rheumatoid arthritis with and without extraarticular features and systemic lupus erythematosus in northern Italy

Seventy-two patients with rheumatoid arthritis (RA) and 18 with systemic lupus erythematosus (SLE) were typed for HLA class I and II antigens. No association was found with any of the antigens tested. However, B8 and DR3 were increased in patients with extraarticular features (EAF), while DR1 was increased in those with RA without EAF. In SLE a trend towards an increased frequency of DR7 was observed. DR5 was the negative marker in both diseases. Our results confirm the peculiar genetic characteristics in our population.

EMG-biofeedback training in fibromyalgia syndrome

Fifteen patients with fibromyalgia syndrome were given EMG-BFB (biofeedback) training sessions because of persistent aches after one year of monthly courses of NSAID. A long-lasting clinical benefit was observed in 56%. The improvement was found in those without overt psychopathological disturbances. In fact, a subgroup of clinically depressed patients responded poorly. Our findings were confirmed in a controlled study. Six patients were allocated into "true EMG-BFB" and 6 into "false EMG-BFB" treatment in a blinded fashion. The rheumatological assessment revealed a significant improvement in most of the variables only in the "true EMG-BFB" group.

Cryoprecipitation. In vitro studies on fibronectin as an independent cryoprecipitagogue

Fifteen patients affected by essential mixed cryoglobulinemia or secondary cryoglobulins were studied. Fibronectin was detected in the majority of essential mixed cryoglobulinemias, but in a minority of secondary cryoglobulins. In vitro studies gave strong evidence of an interaction between fibronectin and heat-aggregated gammaglobulins. The effects of fibronectin on cryoprecipitation of heat-aggregated gammaglobulins seem to support the independent role of the glycoprotein in the cryoformation mechanism, although its presence does not appear essential for cryoglobulin appearance.

Toxicity due to remission inducing drugs in rheumatoid arthritis. Association with HLA-B35 and Cw4 antigens

Twenty-five patients with rheumatoid arthritis (RA) who developed toxicity while taking remission inducing drugs and 30 without toxicity were studied for possible associations with class I and II HLA antigens. A strong association has been found between nephritis and dermatitis due to Tiopronin (a D-Penicillamine like compound) and class I antigens B35-Cw4, and between dermatitis due to gold thiosulphate and B35. Compared to healthy controls a lower DR5 frequency was observed in patients with RA except for the Tiopronin related nephritis group.

Interaction between fibronectin, rheumatoid factor and aggregated gamma globulins

Fibronectin (Fn) was detected in 12/14 2.5% polyethylene glycol precipitates of rheumatoid serum positive for rheumatoid factor (RF). This association led to an investigation of the capacity of Fn to interact with IgM RF and heat aggregated human IgG. Our data suggest that Fn can interact directly with both of these substances at a site in the Fc fragment of the immunoglobulin molecule. The exact cite of the interaction is still to be defined but evidence indicates that it is probably distinct from sites binding staphylococcal protein A and complement.

Indomethacin-related serum sickness-like illness with IgM lambda cryoparaprotein?

A unique association of a transient IgM lambda monoclonal gammopathy and a serum sickness-like illness, appearing after a short course of indomethacin, is described. The IgM lambda monoclone did cryoprecipitate along with fibronectin in hypotonic medium and disappeared with the resolution of the clinical picture. Emphasis is given to the role of some foreign antigens in the induction of benign monoclones.

Hypouricemic action of diflunisal in gouty patients: in vitro and in vivo studies

Sixteen hyperuricemic gouty patients were treated with diflunisal, a novel salicylate, 500 mg BID. Serum and urine uric acid along with uric acid clearances were studied before and after a 7-day treatment. A clear hypouricemic action was observed, but 2 different mechanisms of action were seen when overexcretor patients and normoexcretor patients were analyzed separately. In overexcretors an allopurinol-like action was evident, whereas in normoexcretors a uricosuric action occurred. In vitro experiments showed a competitive inhibition of xanthine-oxidase exerted by diflunisal at low concentrations.

Immunochemical analyses of components of immune complexes in the sera of patients with autoimmune diseases

Immune complexes were precipitated with polyethylene glycol (PEG) from sera of patients with rheumatoid arthritis (RA), psoriatic arthritis and systemic lupus erythematosus. Precipitates were tested for their capacity to consume complement and for the presence of fibronectin (Fn) and specific autoantibodies rheumatoid factor (RF, anti-DNA). The results showed enrichment of autoantibody activity in the precipitates. In RA, RF was especially enriched in 2.5% PEG precipitates, while IgM anti-DNA activity was more evident in 3.5% precipitates. IgG anti-DNA antibody was detected only in 3.5% precipitates from lupus sera. Complement consumption activity of precipitates was mainly related to IgM autoantibodies. There was a strong correlation between the presence of RF activity and Fn in the PEG precipitates. Nephelometric studies revealed direct interaction between the Fn and IgM RF or heat aggregated gammaglobulin. It may be possible to monitor the serum levels of immune complex material using PEG precipitation.

Controlled multicenter trial of tiopronin and d-penicillamine for rheumatoid arthritis

Fifty-seven patients took part in a controlled double-blind trial between tiopronin and D-penicillamine as basic treatment for rheumatoid arthritis. Thirty-nine (19 receiving tiopronin, 20 receiving D-penicillamine) completed the trial after 1 year. Both drugs resulted in a decrease of the erythrocyte sedimentation rate, Ritchie index, and Lee index and in a sparing effect on symptomatic antiinflammatory therapy. Improvement in these variables was statistically highly significant at any interval with tiopronin, but was sometimes less or not at all significant with D-penicillamine. Nevertheless, the difference in effects between the 2 drugs never reached statistical significance. Six patients receiving tiopronin and 6 receiving D-penicillamine were taken out of the experiment because of side effects.