Laboratory guidelines for the diagnosis and follow-up of patients with monoclonal gammopathies

We present guidelines from the Immunochemistry group of the Spanish Society for Immunology that are designed to provide a practical tool for the diagnosis and follow-up of monoclonal gammopathies. We review the clinical and analytical features of various monoclonal gammopathies, international consensus guidelines and techniques used to detect and follow-up monoclonal components.

Genetic testing in the European Union: does economic evaluation matter?

OBJECTIVE

We review the published economic evaluation studies applied to genetic technologies in the EU to know the main diseases addressed by these studies, the ways the studies were conducted and to assess the efficiency of these new technologies. The final aim of this review was to understand the possibilities of the economic evaluations performed up to date as a tool to contribute to decision making in this area.

METHODS

We have reviewed a set of articles found in several databases until March 2010. Literature searches were made in the following databases: PubMed; Euronheed; Centre for Reviews and Dissemination of the University of York-Health Technology Assessment, Database of Abstracts of Reviews of Effects, NHS Economic Evaluation Database; and Scopus. The algorithm was "(screening or diagnosis) and genetic and (cost or economic) and (country EU27)". We included studies if they met the following criteria: (1) a genetic technology was analysed; (2) human DNA must be tested for; (3) the analysis was a real economic evaluation or a cost study, and (4) the articles had to be related to any EU Member State.

RESULTS

We initially found 3,559 papers on genetic testing but only 92 articles of economic analysis referred to a wide range of genetic diseases matched the inclusion criteria. The most studied diseases were as follows: cystic fibrosis (12), breast and ovarian cancer (8), hereditary hemochromatosis (6), Down's syndrome (7), colorectal cancer (5), familial hypercholesterolaemia (5), prostate cancer (4), and thrombophilia (4). Genetic tests were mostly used for screening purposes, and cost-effectiveness analysis is the most common type of economic study. The analysed gene technologies are deemed to be efficient for some specific population groups and screening algorithms according to the values of their cost-effectiveness ratios that were below the commonly accepted threshold of 30,000€.

CONCLUSIONS

Economic evaluation of genetic technologies matters but the number of published studies is still rather low as to be widely used for most of the decisions in different jurisdictions across the EU. Further, the decision bodies across EU27 are fragmented and the responsibilities are located at different levels of the decision process for what it is difficult to find out whether a given decision on genetic tests was somehow supported by the economic evaluation results.

Long-lasting treatment effect of rituximab in MuSK myasthenia

OBJECTIVE

Rituximab has emerged as an efficacious option for drug-resistant myasthenia gravis (MG). However, reports published only describe the short-term follow-up of patients treated and little is known about their long-term clinical and immunologic evolution. Our objective was to report the clinical and immunologic long-term follow-up of 17 patients (6 MuSK+MG and 11 AChR+MG) and compare the response between AChR+MG and MuSK+MG patients.

METHODS

Myasthenia Gravis Foundation America postintervention status and changes in treatment and antibody titers were periodically determined. Lymphocyte subpopulations, total immunoglobulin, immunoglobulin G (IgG) anti-MuSK subclasses, and anti-tetanus toxoid IgG before and after treatment were also studied.

RESULTS

After a mean post-treatment period of 31 months, 10 of the AChR+MG patients improved but 6 of them needed reinfusions. In contrast, all MuSK+MG patients achieved a remission (4/6) or minimal manifestations (2/6) status and no reinfusions were needed. Consequently, in the MuSK+MG group, prednisone doses were significantly reduced and concomitant immunosuppressants could be withdrawn. Clinical improvement was associated with a significant decrease in the antibody titers only in the 6 MuSK+MG patients. At last follow-up MuSK antibodies were negative in 3 of these patients and showed a decrease of over 80% in the other 3.

CONCLUSION

In view of the long-lasting benefit observed in MuSK+MG patients, we recommend to use rituximab as an early therapeutic option in this group of patients with MG if they do not respond to prednisone.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that IV rituximab improves the clinical and immunologic status of patients with MuSK+MG.

Toll-like receptor 4 D299G polymorphism and the incidence of infections in cirrhotic patients

BACKGROUND

Toll-like receptor (TLR) 4 genetic polymorphisms, mainly D299G, have been associated with increased predisposition to infection in several populations.

AIM

To retrospectively analyse the relationship between the presence of the TLR4 D299G polymorphism and the incidence of bacterial infections in cirrhotic patients.

METHODS

We included 111 consecutive cirrhotic patients hospitalized with ascites and we determined the presence of the TLR4 D299G polymorphism by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) and its relationship with the incidence of previous bacterial infections.

RESULTS

Ten out of 111 (9%) cirrhotic patients presented with the TLR4 D299G polymorphism. The mean follow-up from first decompensation of cirrhosis until current admission was longer in D299G polymorphism patients than in wild-type patients (53.8 +/- 40.7 vs. 35.4 +/- 48.3 months, P = 0.03). D299G polymorphism patients showed a trend towards a higher incidence of history of previous infections (80% vs. 56.4%, P = 0.19), as well as a higher number of infections (2.8 +/- 2.3 vs. 1.0 +/- 1.3, P = 0.01) and bacteriaemias (0.4 +/- 1.0 vs. 0.04 +/- 0.2, P = 0.02) per patient than wild-type patients.

CONCLUSIONS

Toll-like receptor 4 D299G polymorphism could influence not only the predisposition to bacterial infections but also the evolution of the disease in cirrhotic patients. Further prospective studies in larger series of patients are warranted.

[Total IgE in the sputum and serum of patients with asthma]

BACKGROUND

The correlation between total IgE in induced sputum (IS) and serum is not well defined. The aim of this study was to investigate the relationship between total IgE in IS and total IgE in serum and airway inflammation.

METHODS

Twenty-one patients with stable asthma and thirteen healthy controls were studied. Clinical and spirometric data were collected and a skin prick test to the 13 most common aeroallergens in our area was performed in all subjects. Total IgE in IS and serum was determined by the UNICAP immunoanalysis system (Pharmacia Uppsala, Sweden) while albumin concentration in IS and serum was determined using the Cobas Integra turbidimetric method (Roche Diagnostics, Basel, Switzerland).

RESULTS

The percentage of eosinophils in EI was 8.7 (11.8) in asthmatic subjects and was 0.5 (1) in healthy controls. Total IgE (KU/L) was 43.2 (23) in asthmatics vs 25.6 (3) in healthy controls in IS, and was 329 (413) in asthmatics vs 57 (78) in controls in serum. Total IgE in IS was significantly correlated with total IgE in serum; r = 0.71 (p = 0.048), but not with the albumin relative index. No correlation was found between IgE and the number of eosinophils in IS.

CONCLUSIONS

Total IgE can be measured in IS. Total IgE in IS is mildly correlated with total IgE measured in serum. The lack of correlation between total IgE and albumin in IS suggests that IgE in IS could be locally produced, at least in part.

Relevance of genetically determined host factors to the prognosis of meningococcal disease

To assess the relevance of genetically determined host factors for the prognosis of meningococcal disease, Fc gamma receptor IIA (FcgammaRIIA), the tumor necrosis factor alpha (TNF-alpha) gene promoter region, and plasminogen-activator-inhibitor-1 (PAI-1) gene polymorphisms were studied in 145 patients with meningococcal disease and in 290 healthy controls matched by sex. Distribution of FcgammaRIIA, TNF-alpha, and PAI-1 alleles was not significantly different between patients and controls. Patients with the FcgammaRIIA-R/R 131 allotype scored > or =1 point in the Barcelona prognostic system more frequently than patients with other allotypes (odds ratio, 18.6; 95% confidence interval, 7.1-49.0, P<0.0001), and they had a higher risk of sequelae (odds ratio, 3.5; 95% confidence interval, 1.1-11.7; P=0.03). Fc gamma receptor IIA polymorphism was associated with markers of disease severity, but TNF-alpha and PAI-1 polymorphisms were not.

Brucella Endocarditis: Clinical, Diagnostic, and Therapeutic Approach

Brucella endocarditis is an uncommon focal complication of brucellosis. Presented here are 11 cases of Brucella endocarditis, all managed uniformly. The median duration of symptoms prior to diagnosis was 3 months. Five patients (45%) had underlying valvular damage, and in six (55%) endocarditis involved a normal valve. There was a predominance of aortic involvement (82%) and a high incidence of left ventricular failure (91%). Diagnostic suspicion was essential in order to test blood cultures correctly, which in this series were positive in 63% of the patients. Surgical treatment was undertaken in eight patients (72%), all with aortic involvement and left ventricular failure impossible to control with medication. One patient died during the immediate postoperative period. All the other patients received antibiotic therapy for 3 months, with no signs of relapse of the infection or malfunction of the prosthesis during a minimum follow-up period of 24 months.

Memory to the hapten in non-immediate cutaneous allergic reactions to betalactams resides in a lymphocyte subpopulation expressing both CD45RO and CLA markers

The cutaneous lymphocyte-associated antigen (CLA) is a homing receptor expressed in a subpopulation of memory T lymphocytes that migrates to the skin and participates in different inflammatory processes. The aim of the study was to compare the T cell response to betalactams in both CLA+ and CLA- memory T cell subsets from subjects with non-immediate allergic reactions to these drugs. Three patients with a non-immediate reaction to penicillins were studied during their acute episodes. Peripheral blood mononuclear cells were isolated by Ficoll density gradient and were used for flow cytometry and lymphocyte transformation test assays. CD3+ cells were purified via high affinity negative selection columns. CD45RA+ and CD45RO+ subpopulations were obtained by magnetic sorting and the memory subpopulation was subdivided into CLA+ and CLA- fractions. These were cultured in triplicate together with feeder cells and different concentrations of amoxicillin and benzylpenicillin. In all cases, the proliferative responses to the drugs were confined to the CD45RO+CLA+ subpopulation. The CD45RO+CLA- subset showed no proliferative response to either drug at any concentration. We have shown that the in vitro memory to penicillins in non-immediate cutaneous allergic reactions to these drugs resides in the CD45RO+CD3+ subset expressing CLA, which enables these T cells to migrate to the skin. These findings may have relevance to understanding the involvement of T cells in allergic reactions to penicillins.

Monoclonal antibodies to amoxicillin express different idiotypes determined by anti-idiotype antibodies production

Penicillins are beta-lactam antibiotics able to generate several antigenic determinants that are recognized by the immune system. To study the differences in the antigen binding site of two monoclonal antibodies (Mab) specific to amoxicillin, polyclonal rabbit anti-idiotypic antibodies were produced. One Mab, AO3.2 (IgG2a), specific to a structure formed by the acyl-side chain structure and a part of the nuclear region of amoxicillin. The second one, AO6.2 (IgE), is specific to the side chain of amoxicillin, although it also recognizes the side chain of other penicillins (penicillin G and ampicillin). These antibodies were used to immunize rabbits in order to produce polyclonal anti-idiotypic antibodies, which were purified in several steps by affinity chromatography. The specificity and cross-reactivity studies were made by ELISA and ELISA inhibition. The results suggest that the anti-Id antibodies produced are the internal image of the antigen, since the binding to their specific idiotype is blocked mainly by the original hapten (amoxicillin): in 98% of the cases with anti-id-1 (induced against AO3.2) and in 59% with anti-id-2 (induced against AO6.2). The absence of cross-reactivity of each anti-idiotypic antibody with the different Mabs specific to amoxicillin shows that the idiotypes induced by the same hapten have differences that are reflected by the nonrecognition of these anti-idiotypes. We conclude that such a small molecule as amoxicillin can present several antigenic determinants that induce a panel of antibody specificities especially directed against the side chain.

In vitro T-cell responses to beta-lactam drugs in immediate and nonimmediate allergic reactions

BACKGROUND

beta-Lactam drugs may induce both cellular and humoral allergic reactions, and there is evidence that T cells play an important role in the pathogenesis of these reactions. The aim of this work was to assess the sensitivity and specificity of the lymphocyte transformation test (LTT) as an in vitro diagnostic tool, in patients with either an immediate or a nonimmediate reaction to penicillin G and/or amoxicillin.

METHODS

Fifty patients with a well-documented history of allergic reactions to beta-lactams (31 immediate and 19 nonimmediate) were studied by means of skin tests (prick and intradermal), radioallergosorbent test (RAST), and, when necessary, controlled administration of the drug. Twenty-eight healthy subjects with good tolerance to penicillins served as controls. LTT was performed in all subjects.

RESULTS

Skin tests were positive in 77.4% of the patients with immediate reactions and in 36.8% of those with nonimmediate reactions. The overall sensitivity of LTT in the allergic patients was 62%, but, when analyzed separately, sensitivity was 64.5% for the immediate group and 57.9% for the nonimmediate group. The LTT specificity was 92.8%.

CONCLUSION

The LTT should be considered a useful in vitro diagnostic tool to identify subjects allergic to penicillins, especially patients with nonimmediate reactions where the LTT has a better diagnostic value than skin tests. Interestingly, positive T-cell proliferative responses can be observed 10 or more years after the occurrence of the reaction without further exposure to the drug.

Clinical aspects and prognostic factors in elderly patients hospitalised for community-acquired pneumonia

The aims of this study were to determine the clinical and epidemiological characteristics of community-acquired pneumonia (CAP) in the elderly, to identify prognostic factors, and to establish a predictive model for mortality of CAP. Elderly patients with CAP admitted to "Carlos Haya" Hospital in Malaga, Spain, over a 36-month period were included. Multivariate analysis was used to identify prognostic factors from variables present on admission, from which a discrimination rule was constructed to predict mortality. A total of 343 patients were included, with the annual incidence ranging from 16.3 to 28.1 per 1,000 admissions. Most (82.5%) had some kind of accompanying or underlying disease. Clinical presentation was atypical in 87 (25.4%). Microbiological diagnosis was made in 24.5%. There were 49 (14.3%) deaths. The prognostic factors in multivariate analysis on admission were bilateral radiographic infiltrate, a blood urea nitrogen level of more than 7 mmol/l, absence of fever, a respiratory rate of 30/min or more, confusion, and shock. The discriminating rule to predict mortality comprising three or more of these factors was 91.2% specific, with a negative predictive value of 93.4% and an overall accuracy of 86.9%. CAP in the elderly is associated with a high degree of mortality. The discriminating rule incorporating the prognostic factors identified is a powerful predictor of mortality.

Anticonvulsant-induced toxic epidermal necrolysis: monitoring the immunologic response

BACKGROUND

Toxic epidermal necrolysis is a severe reaction with skin involvement induced by different drugs and other agents. The mechanisms implicated in the induction of the reaction are poorly understood.

OBJECTIVE

Our purpose was to study the involvement of T lymphocytes and other immunocompetent cells in the peripheral blood, blister fluid, and affected skin of 3 patients who had a severe reaction after receiving anticonvulsant medication.

METHODS

Quantification of T lymphocytes expressing the skin-homing receptor (cutaneous lymphocyte-associated antigen ¿CLA) in peripheral blood, skin, and skin blister fluid and assessment of other adhesion molecules, activation markers, and inflammatory interleukins by flow cytometry, immunohistochemistry, and reverse transcription-PCR.

RESULTS

An increase in CD3(+)CLA(+) cells paralleling the severity of the disease was observed in both peripheral blood and skin, tending to normalize as soon as patient's conditions improved. E-selectin was detected in endothelial vessels in parallel with CLA expression on lymphocytes. An overexpression of TNFalpha, IFN-gamma, and IL-2 was also observed in PBMCs. The expression of the different markers changed over the course of the disease.

CONCLUSIONS

These data show an increase in activated T cells expressing the skin-homing receptor in both tissue and peripheral blood accompanying clinical symptoms, with a recruitment of macrophages and an overexpression of cytokines. All these results suggest an important role for T cells in the production of toxic epidermal necrolysis.

[Water intoxication and hyponatremia: report of two cases]

Two psychiatric patients suffering from psychogenic polydipsia, hyponatremia and water intoxication were evaluated at emergency room. Both of them showed organic psychiatric disease which improve with medical treatment. We illustrated the physiological and clinical features of polydipsia, hyponatremia and water intoxication as well as treatment modalities.

Diagnostic usefulness of percutaneous liver biopsy in HIV-infected patients with fever of unknown origin

OBJECTIVES

to determine the value of percutaneous liver biopsy (PLB) in the diagnosis of fever of unknown origin (FUO) in HIV-infected patients and establish a prediction model for its usefulness to enable diagnosis of FUO in these patients to be standardized.

METHODS

a total of 58 HIV-infected patients who underwent PLB for the evaluation of FUO were studied at 'Carlos Haya' Hospital in Malaga, Spain. The patients were classified into three groups, according to the results of the PLB: (a) diagnostic PLB (when a definitive diagnosis was obtained); (b) helpful PLB (the tissue sample showed suggestive, but not definitive, findings); and (c) normal or non-specific PLB (no contribution to diagnosis, the findings being normal or irrelevant). Multivariate analysis was made to establish a prediction model for the diagnostic usefulness of PLB, calculating the positive (PPV) and negative (NPV) predictive values.

RESULTS

PLB was carried out in 58 HIV-infected patients during diagnosis of FUO. Risk factors for HIV infection included intravenous drug use (72.4%), homosexual or bisexual activities (12.1%), and heterosexual transmission (15.5%). Fifty-two out of 58 patients (89.6%) had previous AIDS-defining illnesses. The mean CD4 lymphocyte count +/-SD was 56.4+/-80.9/mm3. The mean duration of fever was 43 days. Diagnosis could be established in 51 (87.9%) patients, with tuberculosis (50%) and leishmaniasis (20.7%) being the most common. The PLB was diagnostic in 25 cases (43.1%), helpful in 13 (22.4%), and normal or non-specific in the remaining 20 (34.5%). Biopsy-associated complications occurred in two cases. The presence of hepatomegaly or splenomegaly were the most useful factors in predicting the usefulness of the PLB, with a PPV of 86.1% and NPV of 68.2%. In patients with tuberculosis, an increased alkaline phosphatase and hepatomegaly had a PPV of 86.4% and a NPV of 71.4%.

CONCLUSIONS

PLB is a useful technique for the diagnosis of FUO in HIV-infected persons. Early PLB should be considered in those patients with hepatosplenomegaly and increased alkaline phosphatase levels.

[Incidence and current clinical spectrum of tuberculosis in a metropolitan area in the south of Spain]

BACKGROUND

To study the incidence and clinical spectrum of tuberculosis in the metropolitan area of Málaga (Spain).

METHODS

Prospective study which includes all patients who had a diagnosis of tuberculosis within the referral area of "Carlos Haya" Málaga Regional Hospital from March 1, 1993 to February 28, 1994.

RESULTS

During the study period, there were 138 cases of tuberculosis, with an incidence of 43.7 cases/10(5) inhabitants. Ninety one cases (66%) were male, and the mean age (SD) was 33.2 (18.3), with 88% being less than 55 years old. Thirty six patients (26.1%) were HIV-infected. Extrapulmonary tuberculosis made up 27.5% of the cases, and was more frequent in HIV-infected patients (p < 0.01; odds ratio: 2.9; 95% CI: 1.2-7.1). The mean (SD) time to diagnosis was 54.3 (76) days. The diagnosis was microbiologically confirmed in 106 cases (76.8%), histologically in 14 cases (10.1%), and the remaining 18 cases (13.1%) were clinically diagnosed. The global rate of resistance was 10.8%. The rate of primary resistance was 4.6%, and the rate of multidrug-resistant tuberculosis was 3.1%. Eighty nine patients (77.4%) were cured, six patients (5.2%) stopped the treatment, 3 (2.6%) had relapses and 1 (0.9%) was considered a therapeutic failure; 16.7% of patients were lost for follow-up. Sixteen patients died and in nine of them (6.5%) the death was attributed to tuberculosis.

CONCLUSIONS

The incidence of tuberculosis in Málaga urban area is high. It mainly affects young males of unfavored socio-economic classes. HIV-infected patients account for a high percentage of the cases. The high number of productive cases and the long time to diagnosis evidence the shortcomings of our sanitary system. These facts, together with the high rate of non-compliance, of treatment may explain the seriousness of the current situation in our country.

Signal transducer and activator of transcription 1 in human muscle: implications in inflammatory myopathies

Polymyositis (PM) and dermatomyositis (DM) are two major and distinct inflammatory myopathies. Cytokines, implicated in the immune process, have been recognized in the muscle tissue from PM and DM patients, but their functional in situ role has not been identified. We analyzed the expression of the signal transducer and activator of transcription 1 (STAT1), a molecule whose up-regulation indicates the interaction of cytokines, or growth factors, with their target receptors in muscle fibers and inflammatory infiltrates in PM and DM. An immunohistochemical analysis was performed using monoclonal antibodies to STAT1 in 57 muscle biopsies from 10 patients with DM, 10 with PM, and 37 controls. The profile of STAT1 up-regulation was also investigated in cultured muscle stimulated by interferon-gamma, epidermal growth factor, platelet-derived growth factor, and interleukin-2, using semiquantitative polymerase chain reaction and Western blot. High STAT1 expression was observed in many perifascicular atrophic muscle fibers from DM patients in 10/10 biopsies. In contrast, only a few muscle fibers undergoing necrosis were STAT1 positive in 2/10 patients with PM and in 2/37 controls. STAT1 reactivity was noted in most cells of the infiltrates in DM, PM, and controls. In vitro, STAT1 was stimulated by interferon-gamma but not by the other molecules studied. These results suggest that in DM, but not in PM, there is distinctive functional local cytokine activity able to increase STAT1 expression in muscle fibers. As interferon-gamma specifically activates STAT1 in vitro, this cytokine in conjunction with ischemia is probably involved in perifascicular muscle fiber pathology in DM.

[Compliance, efficacy and tolerability of the therapeutic regimen recommended by National Consensus on Tuberculosis]

BACKGROUND

To study the degree of adhesion, efficacy, and tolerance of therapeutic guidelines advocated by the National Consensus on tuberculosis.

METHODS

A prospective study of a cohort of 84 patients receiving a diagnosis of tuberculosis in a Basic General Health Area between 1-3-1993 and 28-2-1994 treated with the regimen recommended by the National Council. The patients were evaluated clinically and microbiologically during the treatment and during twelve months follow-up.

RESULTS

Fifty-two patients (61.9%) were male and 32 (38.1%) female, aged 29.9 +/- 19.7 years (r = 1-84 years). Seventy-four (88.1%) were index cases and 10 (11.4%) household contacts. Eight patients (9.5%) were also infected with HIV, 71 (84.5%) presented pulmonary tuberculosis and 13 (15.5%) extrapulmonary forms. Therapeutic compliance was correct in 80 cases (95.2%) and incorrect in 4 (4.8%). It was well-tolerated in 73 patients (91.2%), there was slight toxicity in five (6.3%) and severe in two (2.5%). Seventy-four patients (88.1%) were cured, there was one therapeutic failure (1.2%) and five relapses (6%). Overall mortality was 4.8% and attributable mortality 1.2%.

CONCLUSION

Our results seem to confirm a high degree of adhesion, good tolerance and acceptable therapeutic efficacy of the scheme proposed by the National Council.

Complications associated with Brucella melitensis infection: a study of 530 cases

We carried out a prospective study of 530 patients older than 14 years of age with brucellosis. We describe the incidence and clinical features of the focal forms of the disease, analyzing some of the possible factors associated with their appearance. One hundred sixty-nine patients (31.9%) had a focal form or complication. Osteoarticular complications were the most frequent, totaling 113 cases (66%), followed by genitourinary with 18 cases (5.1% of males), hepatic (2.5%), neurologic (1.7%), and heart (1.5%). Nine patients (1.7%) had more than 1 complication. In a multivariate analysis, diagnostic delay greater than 30 days (OR 2.0), ESR > 40 mm/hr (OR 1.9), and levels of alpha-2 globulin > 7.5 g/L (OR 6.8) were statistically significant independent variables associated with the presence of focal forms. Twenty-five patients with complications (14.8%) required surgical treatment. The relapse rate was 3.6% for those patients without complications and 4.1% for patients with focal forms (p > 0.05). However, when therapeutic failure, relapses, and mortality were considered together, the risk of an unfavorable evolution was significantly greater in patients with focal forms (10.6% versus 3.6% in patients without complications; OR 1.9, 95% CI 1.4-7.1, p < 0.005). Given the worse prognosis, knowledge and early diagnosis of the focal forms of B. melitensis infection is especially important.

[Neurophthalmological alterations in multiple sclerosis]

With the aim of defining the neuro-ophthalmological alterations in multiple sclerosis, both with respect to visual and oculomotor aspects, we have studied a sample of 100 clinically definite multiple sclerosis patients, all in the remittent phase of the disease. We compared them with a sample of 100 unrelated healthy controls, matched for age and sex. Visuomotor alterations were found in 99%, purely visual alterations in 38%, purely oculomotor alterations in 3%, and mixed alterations in 58% of the MS patients. Comparisons with controls showed significant statistical differences in all the tests used in the study. The neuro-ophthalmological examination in multiple sclerosis permits us to detect subclinical lesions and arrive at a better comprehension of central nervous system involvement in this disease, thereby contributing collaborating to better patient care.

Preexisting human anti-murine antibodies and the effect of immune complexes on the outcome of immunoscintigraphy

Radiolabeled monoclonal antibodies (MoAb) are useful in radionuclide imaging. Human anti-murine antibodies (HAMA), however, could produce immunologic effects or alter the outcome of immunoscintigraphy. Three patients are reported who had been exposed previously to radiolabeled MoAbs and in whom subsequent immunoscintigraphy was performed. All patients showed abnormal biodistribution of the antibody and increased hepatic uptake. Human anti-murine antibody was demonstrated in all patients. These results indicate that immune complexes are formed after HAMA-MoAb reaction and are then phagocytosed by cells of the reticuloendothelial system.

[Coronary angioplasty in the treatment of symptomatic myocardial ischemia with one vessel disease]

Our group initiated a program of coronary angioplasty (CA) in patients with symptomatic one vessel disease, or multivascular lesions with a critical "culprit" stenosis. In a 16 month period we have performed CA of 28 lesions in 25 patients (20 men) with a mean age of 54 +/- 10 years. Stable angina was diagnosed in 14 patients, unstable angina in 7, and post-myocardial infarction residual angina or stenosis in 4 patients treated with streptokinase. Successful dilatation was obtained in 23 (82.1%) of 28 stenotic segments, reducing the stenosis from 90 +/- 8% (range 70-100) to 9 +/- 12% (range 0-30; p less than 0.00001). In 4 cases with total occlusion, dilatation was not obtained, and in one case the procedure was complicated by fatal brain embolism. There were 4 complications due to coronary occlusion or spasm, all of them resolved during CA without sequelae. The 20 cases with primary success have been followed during an average of 8.6 months. In three cases (15%) restenosis was detected; two of them underwent surgery, and CA was repeated successfully in the other. Disappearance of myocardial ischemia was confirmed in 14 patients, and functional improvement in the other three. In conclusion, CA is an effective and relatively safe therapeutic alternative in different clinical forms of coronary heart disease with a single vessel stenosis, or in selected cases of multivascular lesions with a critical stenosis.

The effect of the chemical modification in human Fc gamma fragment on protein A and Fc receptor binding

The role of acidic side-chains on Fc gamma fragment in granulocyte receptor binding and in S. aureus protein A binding has been investigated by means of chemical modification. Alteration of a restricted number of carboxyl groups after 5 min of reaction is sufficient to abrogate the capacity of Fc to inhibit EA rosette formation by human neutrophils. More limited modification, which affects mainly the most exposed acidic chains, does not change receptor binding activity. In contrast, the interaction with protein A is largely unaffected, even under reaction conditions which are able to induce significant changes in the circular dichroism spectrum of Fc fragment. The results suggest that some acidic groups on Fc may be involved in the interaction with neutrophil receptor and that the binding to protein A and Fc receptor involves different sites.