AB0570 CLINICAL AND IMMUNOLOGICAL MANIFESTATIONS IN SLE PATIENTS IN A THIRD LEVEL HOSPITAL IN ROSARIO, ARGENTINA

Background

Systemic lupus erythematosus (SLE) is a chronic and complex inflammatory disease which predominantly affects young females during reproductive ages. Its prognosis is worse in males, young people, Afro-American and Latin patients. Clinical and immunological features had been described around the world but few reports had been done in Argentinian patients.

Objectives

The purpose of this study was to describe the clinical and immunological pattern in SLE patients, characteristics of lupus nephritis (LN), disease male’s course of SLE, treatments and causes of hospitalization.

Methods

Retrospective study including patients (>18 years) followed in Rheumatology Department, which had unless two visits in the last year before data collection, its clinical reports were complete, and fulfilled SLICC or EULAR/ACR SLE criteria. We recorded data from the medical reports.

Results

Of the 70 patients, 63 were female (90%). The mean age at diagnosis was 27,86 ± 9,4 years. The most frequent manifestations were arthritis (75,7%), malar rash (65,7%), photosensitivity (31,4%), leukopenia (31,4%), alopecia (31,4%), Raynaud’s phenomenon (24,3%) and nasal and oral ulcerations (21,4%).

94,3% of patients were positive for antinuclear antibodies, 45,7% had anti-Ro/SSa, 28,6% anti-RNP and 21% anti-Smith. 75% had low complement and 45,7% anti-DNA antibodies.

LN occurred in the 50% of patients, and class IV was the most prevalent in this group. 66% of patients developed LN in the first year of SLE diagnosis. Autoantibodies in this manifestation were: anti-DNA 60%, anti-Ro/SSa 37%, 31% anti-RNP and 26% anti-Smith.

The most common comorbidity was high blood pressure followed by hypothyroidism (34,3% and 25,7% respectively). All patients received hydroxychloroquine and 62,9% prednisone; half of the patients who were into prednisone treatment received 5mg or less. Other treatments were cyclophosphamide (42,9%), mycophenolate (28,6%) and methotrexate (15,7%). 60% of patients had been hospitalized because of SLE flares and 15,7% due to infections. 75% of flares were due to LN and 8% because of serositis.

Is known that SLE in male patients is more aggressive and with poor prognosis. Although this study had only 7 men, 86% had LN, 29% had pericardial and pleural effusion and 29% thrombocytopenia, were we found several differences in female’s SLE presentation.

Conclusion

This study shown similar results reported in other populations. We found that 50% of SLE patients developed LN, which is the most important cause of hospitalization. Although cutaneous and musculoskeletal manifestations were the most frequent, it’s important to take into account the clinical and prognostic differences between male and female.

References

[1]Pons Estel B et al. The GLADEL, multinational Latin American prospective inception cohort of 1214 patients with systemic lupus erythematosus: ethnic and disease heterogeneity among Hispanics. Medicine 2004;83;1-17

[2]Alarcón GS, Friedman AW, Straaton KV, et al. Systemic lupus erythematosus in three ethnic groups: III. A comparison of characteristics early in the natural history of the LUMINA cohort. LUpus in MInority populations: NAture vs. Nurture. Lupus 1999;8:197–209

[3]Aringer M et al. 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus. Arthritis & Rheumatology. 2019;71;1400-1412

[4]Cervera R et al. Morbidity and mortality in systemic lupus erythematosus during a 10-year period. Medicine 2003; 82: 299-308

Disclosure of Interests

None declared

AB1358 AN OLD METHOD FOR CURRENT CHALLENGES: SKIN TEST CONVERSION OF PURIFIED PROTEIN DERIVATIVE (PPD) IN RHEUMATOLOGICAL PATIENTS TREATED WITH ANTI-TNF-α

Background

Anti-TNF-α are a cornerstone for the treatment of multiple rheumatic diseases. They are associated with an increased risk of developing tuberculosis (TB), which is endemic in several countries and an important burden across the globe. Purified protein derivative (PPD) is one of the tests used to demonstrate a latent TB infection (LTBI). Screening is recommended for TB prior to the onset of anti-TNF-α and monitoring evaluating possible conversion of PPD during treatment, defined as the change from a negative (<5 mm) to positive result (≥5 mm). Identification and treatment of LTBI can reduce the risk of disease development by up to 90%. Currently the results of PPD conversion and its interpretation during anti-TNF-α treatment are variable and that is why we set out to know the frequency of conversion of PPD in this group of patients in our environment.

Objectives

To identify PPD conversion in patients with rheumatological diseases undergoing anti-TNF-α treatment.

Methods

A descriptive, analytical, observational, retrospective study was conducted from January 1, 2018 to January 1, 2022. Inclusion criteria: Patients >18 years old, diagnosed with rheumatological diseases and treated with anti-TNF-α for more than 3 consecutive months, with a negative PPD (<5 mm diameter) previous starting anti-TNF-α and a normal chest X-ray.

Results

62 patients (age 45.8 ± 12.5 years), with rheumatological diseases (41 rheumatoid arthritis, 7 juvenile idiopathic arthritis, 5 ankylosing spondylitis, 4 psoriatic arthritis, 4 uveitis and 1 interstitial keratitis) under anti-TNF-α therapy (35 adalimumab, 18 certolizumab, 9 etanercept) were included. Concomitant use of immunomodulators (52 methotrexate, 23 leflunomide, 10 hidroxicloroquine, 3 sulfasalazine, 2 azathioprine and 1 mycophenolate mofetil) and glucocorticoids (33/62) was observed. The conversion of PPD took place in 4 patients (6.5%) (Table 1).

Table 1.

“Patient’s characteristics”

SexAgeRDanti-TNF-αTime doing anti-TNF-αDMARDGCSPPDChest X-rayTB prophylaxis1Male66PsAadalimumab6 yearsmethotrexateNo5 mmNormalIsoniazid2Female56RAadalimumab10 yearsmethotrexateNo5 mmNormalIsoniazid3Female62RAadalimumab5 yearsmethotrexateYes10 mmNormalIsoniazid4Male45AScertolizumab1 yearNoNo20 mmNormalIsoniazid

AS, ankylosing spondylitis; DMARD, disease-modifying antirheumatic drugs; GCS, glucocorticosteroids; PPD, purified protein derivative; PsA, psoriatic arthritis; RA, rheumatoid arthritis; RD, rheumatological disease; TB, tuberculosis.

Conclusion

Considering the prevalence of TB in our country, this research showed a lower PPD conversion percentage compared to previous reports. Anti-TNF-α have radically changed the evolution of rheumatological diseases, considerably improving the patient’s quality of life. With the increase in the accessibility of anti-TNF-α worldwide, new challenges have arisen regarding infectious diseases such as TB, which is endemic in some countries. PPD is a well known, cheap, sensitive and widely available method, suitable for LTBI diagnosis. Although sensitivity could be increased using, in addition, other LTBI detection methods such as IGRAs (interferon gamma release assays), they are usually unavailable in developing countries (1-3).

References

[1]Lewinsohn DM, Leonard MK, LoBue PA, et al. Official American Thoracic Society/Infectious Diseases Society of America/Centers for Disease Control and Prevention Clinical Practice Guidelines: Diagnosis of Tuberculosis in Adults and Children. Clin Infect Dis 2017; 64(2):e1-e33.

[2]Cerda O, Correa M, Granel A, Marcos A, Giraldo C, Rillo O et al. Tuberculin test conversion in patients with chronic inflammatory arthritis receiving biological therapy. European Journal of Rheumatology. 2019;6(1):19-22

[3]Busquets-Pérez N, Ponce A, Ortiz-Santamaria V, de Agustín de Oro J, Hernández-Rico Y, Vidal I et al. How many patients with rheumatic diseases and TNF inhibitors treatment have latent tuberculosis? 2020; 13(5):282-286.

Disclosure of Interests

None declared

Trabecular and cortical bone involvement in rheumatoid arthritis by DXA and DXA-based 3D modelling

Rheumatoid arthritis (RA) patients had a higher risk of developing low bone mineral density (BMD) or osteoporosis. RA patients on classic disease-modifying antirheumatic drug (c-DMARD) therapy showed significantly lower BMD than controls, while no significant differences in most parameters were found between RA patients receiving biological disease-modifying antirheumatic drugs (b-DMARDs) and controls. The 3D analysis allowed us to find changes in the trabecular and cortical compartments.

INTRODUCTION

To evaluate cortical and trabecular bone involvement of the hip in RA patients by dual-energy X-ray absorptiometry (DXA) and 3D analysis. The secondary end-point was to evaluate bone involvement in patients treated with classic (c-DMARD) or biological (b-DMARD) disease-modifying antirheumatic drug therapies and the effect of the duration of the disease and corticosteroid therapy on 3D parameters.

METHODS

A cross-sectional study of 105 RA patients and 100 subjects as a control group (CG) matched by age, sex, and BMI was carried out. BMD was measured by DXA of the bilateral femoral neck (FN) and total hip (TH). The 3D analyses including trabecular and cortical BMD were performed on hip scans with the 3D-Shaper software.

RESULTS

FN and TH BMD and trabecular and cortical vBMD were significantly lower in RA patients. The c-DMARD (n = 75) group showed significantly lower trabecular and cortical vBMD than the CG. Despite the lower values, the b-DMARD group (n = 30) showed no significant differences in most parameters compared with the CG. The trabecular and cortical 3D parameters were significantly lower in the group with an RA disease duration of 1 to 5 years than in the CG, and the trabecular vBMD was significantly lower in the group with a duration of corticosteroid therapy of 1 to 5 years than in the CG, while no significant differences were found by standard DXA in the same period.

CONCLUSIONS

RA patients had a higher risk of developing low BMD or osteoporosis than controls. RA patients receiving c-DMARD therapy showed significantly lower BMD than controls, while no significant differences in most parameters were found between RA patients receiving b-DMARDs and controls. 3D-DXA allowed us to find changes in trabecular and cortical bone compartments in RA patients.

Prevalence, serologic and genetic studies of high expressers of the blood group A antigen on platelets*

OBJECTIVE/AIM

The aim of this study is to describe the distribution of the platelet blood group A antigenicity in Euro-Brazilians (EUBs) and Afro-Brazilians (AFBs).

BACKGROUND

A small but significant proportion of individuals express high levels of A or B antigen on their platelets corresponding to the erythrocyte ABO group. The mechanism of increased antigen expression has not been elucidated.

MATERIAL/METHODS

A cohort of 241 blood group A donors was analysed by flow cytometry. Although mean fluorescence intensity (MFI) is a typical continuous variable, platelets were screened and divided into two categories: low expressers (LEs) and high expressers (HEs). A three-generation family was investigated looking for an inheritance mechanism.

RESULTS

The prevalence of the HE platelet phenotype among group A(1) donors was 2%. The mean of MFI on platelets of A(1) subgroup of EUBs differs from that of AFBs (P = 0·0115), whereas the frequency of the HE phenotype was similar between them (P = 0·5251). A significant difference was found between sexes (P = 0·0039). Whereas the serum glycosyltransferase from HE family members converted significantly more H antigen on group O erythrocytes into A antigens compared with that in LE serum, their ABO, FUT1 and FUT2 genes were consensus. The theoretically favourable, transcriptionally four-repeat ABO enhancer was not observed.

CONCLUSION

The occurrence of HE in several members suggests familial aggregation. Indeed, in repeated measures, stability of the MFI values is suggesting an inherited condition. Factors outside the ABO locus might be responsible for the HE phenotype. Whether the real mechanism of inheritance is either of a polygenic or of a discrete Mendelian nature remains to be elucidated.

Immunotherapy against experimental canine visceral leishmaniasis with the saponin enriched-Leishmune vaccine

In order to assess the immunotherapeutic potential on canine visceral leishmaniasis of the Leishmune^® vaccine, formulated with an increased adjuvant concentration (1 mg of saponin rather than 0.5 mg), 24 mongrel dogs were infected with Leishmania (L.) chagasi. The enriched-Leishmune^® vaccine was injected on month 6, 7 and 8 after infection, when animals were seropositive and symptomatic. The control group were injected with a saline solution. Leishmune^®-treated dogs showed significantly higher levels of anti-FML IgG antibodies (ANOVA; p < 0.0001), a higher and stable IgG2 and a decreasing IgG1 response, pointing to a TH1 T cell mediated response. The vaccine had the following effects: it led to more positive delayed type hypersensitivity reactions against Leishmania lysate in vaccinated dogs (75%) than in controls (50%), to a decreased average of CD4+ Leishmania-specific lymphocytes in saline controls (32.13%) that fell outside the 95% confidence interval of the vaccinees (41.62%, CI95% 43.93–49.80) and an increased average of the clinical scores from the saline controls (17.83) that falls outside the 95% confidence interval for the Leishmune^® immunotherapy-treated dogs (15.75, CI95% 13.97–17.53). All dogs that received the vaccine were clustered, and showed lower clinical scores and normal CD4+ counts, whereas 42% of the untreated dogs showed very diminished CD4+ and higher clinical score. The increase in clinical signs of the saline treated group was correlated with an increase in anti-FML antibodies (p < 0.0001), the parasitological evidence (p = 0.038) and a decrease in Leishmania-specific CD4+ lymphocyte proportions (p = 0.035). These results confirm the immunotherapeutic potential of the enriched-Leishmune^® vaccine. The vaccine reduced the clinical symptoms and evidence of parasite, modulating the outcome of the infection and the dog's potential infectiosity to phlebotomines. The enriched-Leishmune^® vaccine was subjected to a safety analysis and found to be well tolerated and safe.

Assessment of the monoterpene, glycidic and triterpene-moieties’ contributions to the adjuvant function of the CP05 saponin of Calliandra pulcherrima Benth during vaccination against experimental visceral leishmaniasis

The CP05 saponin from Calliandra pulcherrima Benth, shows remarkable similarities to the QS21 saponin of Quillaja saponaria Molina. Both shared a monoterpene hydrophobic moiety, a glycidic chain attached to the triterpene C28, and three sugars attached to C3. Different from QS21, the CP05 does not show the aldehyde group in triterpene C4 involved in TH1 response. Balb/c mice were immunized either intact saponin (CP05), the monoterpene-deprived (BS), the C28 carbohydrate-deprived (HS) or the sapogenin fraction, in formulation with the FML antigen of Leishmania donovani and challenged with 2 x 10(8) amastigotes of L. chagasi. While the CP05 induced 90% survival and 92.1% parasite reduction, a 100% survival and 94.1% protection were detected after the BS-vaccine treatment, indicating that the monoterpene acylated moiety, absent in the BS vaccine, is not necessary for the induction of a protective global TH1 response. Only the DTH response of BS vaccines was mildly lower than that of CP05 vaccinees. Maximal anti-FML antibody, CD4(+) and CD8(+) Leishmania specific lymphocytes, IFN-gamma splenocyte secretion, reduction in parasite load and survival was also detected for the BS vaccine. The HSFML vaccine showed diminished responses in all tested variables, except for IFN-gamma secretion, indicating that the integrity of the carbohydrate moiety attached to C28 is mandatory for the these functions. No protection was induced by the sapogenin-FML indicating that the CP05 triterpene which lacks the C4 aldehyde group, is not a immunostimulating compound. No contribution to protection was detected in the CP05 saponin treated control group supporting the specificity of the FML antigenic preparation.

Acylated and deacylated saponins of Quillaja saponaria mixture as adjuvants for the FML-vaccine against visceral leishmaniasis

The adjuvant of the FML-vaccine against murine and canine visceral leishmaniasis, the Riedel de Haen saponin mixture, was fractionated by ion exchange chromatography on DEAE-cellulose to afford one TLC homogeneous Quillaja saponaria Molina QS21 saponin fraction (18.0%), a mixture of two deacylsaponins (19.4%), sucrose (39.9%), sucrose and glucose (19.7%), rutin (0.8%) and quercetin (2.2%), that were identified by comparison of 1H and 13C NMR spectroscopy. The QS21 shows the typical aldehyde group in C-23 (65% equatorial) and a normonoterpene moiety acylated in C-28. The deacylsaponins show the aldehyde group but do not have the normonoterpene moiety. Balb/c mice were vaccinated with 150 microg of FML antigen of Leishmania donovani and 100 microg of each obtained fraction and further challenged by infection with 10(8) amastigotes of Leishmania chagasi. The safety analysis and the effect on humoral and cellular immune responses and in clinical signs showed that the QS21 saponin and the deacylsaponins are the most active adjuvant compounds of the Riedel the Haen saponin mixture. Both induced the highest and non-significantly different increases in DTH, CD4+ T lymphocytes in spleen, IFN-gamma in vitro, body weight gain and the most pronounced reduction of parasite burden in liver (95% for QS21 and 86% for deacylsaponins; p>0.05). While the QS21 showed mild toxicity, significant adjuvant effect on the anti-FML humoral response before and after infection, and decrease in liver relative weight, the deacylsaponins showed no toxicity, less haemolysis and antibody and DTH responses increased mainly after infection, still inducing a stronger Leishmania-specific in vitro splenocyte proliferation. Our results confirm in the Riedel de Haen saponin extract the presence of deacylsaponins normonoterpene-deprivated which are non-toxic and capable of inducing a specific and strong immunoprotective response in vaccination against murine visceral leishmaniasis.

Protective vaccination against murine visceral leishmaniasis using aldehyde-containing Quillaja saponaria sapogenins

The presence of aldehyde groups at C-23 and C-24 of the triterpen aglycon moiety was disclosed in 1H NMR spectra of both the Riedel de Haen saponin (R) (delta 9.336) and Quillaja saponaria QuilA saponin (delta 9.348). The sign of the C-28 acylated linked moiety (delta 176) was present in both saponins, while the delta 171 at C-28 (carboxy group) corresponding to the deacylated saponin, was only detected in the QuilA preparation, indicating 50% of hydrolysis of the ester moiety, probably due to the storage in aqueous solution. The normoterpen moiety was present in both saponins (signals at delta 14-18). The chemical removal of saponin glicidic moieties gave rise to their sapogenin fractions. Their 1H NMR spectra showed the presence of two signals (delta 9.226 and 9.236) for sapogenin R and two signals (delta 9.338 and 9.352) for the QuilA sapogenin. The intensity of the signals suggested two conformational isomers of sapogenin R in the ratio 53% of equatorial aldehyde group to 47% of axial aldehyde group, and two conformational isomers of QuilA sapogenin in the ratio 76% of equatorial aldehyde group to 24% of axial aldehyde group. The chemical treatment abolished the saponin slight in vivo toxicity, reduced their hemolytic potential, did not affect their aldehyde contents, but gave rise to an enriched axial aldehyde-containing sapogenin R with enhanced potential on antibody humoral response (anti-IgM, IgG, IgG1, IgG2a, IgG2b and IgG3) and to an enriched equatorial aldehyde-containing QuilA-sapogenin that induced a mainly cellular specific immune response (increased intradermal response to leishmanial antigen and IFNgamma sera levels) and effective protection against murine infection by L. donovani (77% reduction in liver parasitic load). Our results suggest that the Riedel de Haen saponin is probably a Quillaja saponaria saponin.

A novel blood group B subgroup: serological and genetic studies

A discrepancy in the ABO blood groups between a newborn child and her parents was identified. Serological and DNA investigative techniques were performed. A weak variant of B (B(w)) was detected on the erythrocytes of the child, her grandmother and great-uncle. Adsorption-elution studies showed that their erythrocytes adsorb and yield anti-B on elution. The B(w) antigenic strength of the A(1)B(w) cells of her mother and maternal aunt was reduced when compared to that of the A(2)B(w) from another family member. Only one of 15 different anti-B sera agglutinated the A(1)B(w) erythrocytes. Agglutinin anti-B that reacted strongly with normal B erythrocytes and did not agglutinate the B(w) cells, was found in the sera of the A(1)B(w) individuals. The B(w) serum glycosyltransferase could not convert O cells into B cells and no B substance was found in saliva. All family members with the B(w)/AB(w) phenotypes were heterozygous for a B allele and DNA sequencing revealed a novel missense mutation in exon 7 of the B allele (556A > G), resulting in M186V. This substitution changes a highly conserved region of the enzyme, proposed to be a disordered loop near the enzyme cleft, and is expected to diminish the enzyme's activity, leading to this B(w) phenotype.

Long lasting protection against canine kala-azar using the FML-QuilA saponin vaccine in an endemic area of Brazil (São Gonçalo do Amarante, RN)

Naturally exposed dogs of an endemic area were vaccinated with the fucose mannose ligand (FML) antigen of Leishmania donovani in formulation with QuilA saponin. The 100% of vaccinees were seropositive to FML and showed intradermal reaction to L. donovani lysate, 2 months after vaccination. The absorbency values and size of intradermal reaction were both significantly higher in vaccinees than in controls along a 3.5 years period (ANOVA, P<0.0001). The 25% of the control animals (two dogs on the first year and six dogs on the fourth year, respectively) and 5% of the vaccinees (one dog during the fourth year) developed clinical and fatal disease until the end of experiment. This difference was significant (chi(2)=3.93, P<0.05). This means that 95% protection against kala-azar was achieved in vaccinees, after FML-QuilA vaccination (80% of vaccine efficacy (VE)). Leishmania infection was also confirmed, 3.5 years after vaccination, in saline controls that showed positive polymerase chain reaction (PCR) for Leishmania DNA and FML-serology with no intradermal reaction. Higher seropositivities and intradermal reactions with no Leishmanial DNA were detected in vaccinees. The FML-QuilA vaccine induced a significant, long lasting and strong protective effect against canine kala-azar in the field.

Impact of canine control on the epidemiology of canine and human visceral leishmaniasis in Brazil

Brazil is the only country endemic for zoonotic visceral leishmaniasis (ZVL) that regularly conducts epidemiologic and prophylactic control programs that involve the treatment of human cases, insect vector control, and the removal of seropositive infected dogs. This report reviews 60 studies reporting data on the efficacy of these recommended control tools and concludes that in Brazil 1) eradication of the disease in Minas Gerais was achieved by the concomitant use of the three control methods, 2) although seropositivity by an immunofluorescent assay is not completely related to infectiousness, the removal of seropositive dogs leads to a significant reduction of canine and human incidence, 3) improvement of the sensitivity of the diagnostic tool used for canine control should optimize the efficacy of control, and 4) although difficult and expensive, the public health dog control campaigns performed in Brazil reduced the incidence of ZVL and should be maintained since treatment of dogs is an unrealistic intervention, both because of its prohibitive cost and relatively poor effectiveness.

New genetic data on Amerindians from the Paraguayan Chaco

New data on 17 blood group and protein genetic systems obtained among the Ayoreo and Lengua Indians of Paraguay are presented. They include the first report on the red cell band-3 protein investigated among South American Indians. This information was integrated with previous results available for these two and four other groups. Five of the six populations reside in the Chaco area, while the sixth was included as an outgroup living elsewhere in Paraguay. Four of the five Chaco tribes exhibit good genetic homogeneity, but the Ayoreo are somewhat different. The results confirm the Chaco as a distinct biological (as well as cultural and economic) region, which should be considered in evaluations of genetic variability among South American Indians.

Occurrence of Leishmania donovani parasitemia in plasma of infected hamsters

Intracardiac transfusion of plasma, mononuclear cell fraction and blood of infected hamster donors induced visceral leishmaniasis in normal hamster receptors. At the moment of transfusion, the donors already showed all the typical signs of the disease: ascites, cachexia, as well as splenomegaly and a high parasite load in the spleen and liver. All transfused hamsters developed typical visceral leishmaniasis between 90 and 120 days, indicating that all blood products were infectious. Transfusion of the mononuclear cell fraction induced the highest values of parasitic load (spleen, 766 Leishman Donovan Units (LDU); liver, 2650 LDU), splenomegaly and hepatomegaly (spleen-liver/body relative weight: 1.130 and 6.870, respectively). Animals that received the plasma fraction also developed visceral leishmaniasis, showing similar parasitic load (spleen, 107 LDU; liver, 220 LDU) and spleen-liver/body relative weight (1.005 and 6.35, respectively) than those transfused with whole blood. The finding of typical Leishmania donovani infection in animals transfused with plasma demonstrates the possibility of the extracellular location of parasites, free in this blood fraction deprived of red and white blood cells. Fluorescence-assisted cell sorter analysis (FACS) of plasma showed the presence of particles corresponding in size to amastigotes, which fluoresced strongly with the serum of a patient with Kala-azar (73%), but not with normal serum.

Genetic relationships between Amerindian populations of Argentina

A total of 495 individuals from five different Argentinian tribes was examined for variation in 23 blood group and protein genetic systems, and the results were integrated with previous data on some of these systems. These tribes generally present RH * R1, PGM1 * 1, and ACP * A frequencies lower and RH * R2, ESD * 1, and GLO * 1 prevalences higher than those observed in other South American Indian groups. Earlier studies with mitochondrial DNA showed that haplogroup A was present in low frequencies in these tribes, but haplogroup B showed a high prevalence among the Mataco. Average heterozygosities are very similar in the five tribes, while estimates of non-Indian ancestry are generally low. Both the blood group and protein, as well as the mtDNA data sets, divide the five tribes into two groups, and the relationships obtained with the blood group and protein systems are exactly those expected on the basis of geography and language. However, the topology obtained with the mtDNA results was different, possibly due to sampling effects or diverse patterns of exchange between the groups related to sex.

Vaccination of Balb/c mice against experimental visceral leishmaniasis with the GP36 glycoprotein antigen of Leishmania donovani

Leishmania donovani GP36 glycoprotein is the main antigen of the FML Fucose Mannose Ligand (FML) complex specifically recognized by sera of kala-azar human patients. The GP36 was isolated by chemical elution + sonication and used for Balb/c mouse vaccination in combination with saponin, by the s.c. route, inducing a strong and specific protective effect against experimental visceral leishmaniasis shown by the increase of: specific IgG antibodies (82.6%), mainly IgG2a, the delayed type of hypersensitivity to promastigote lysate (37.8%, P < 0.001), the in vitro cellular proliferative response to GP36 of ganglia lymphocytes (53.5%, P < 0.005) and the decrease of liver parasite burden (68.1%, P < 0.025). Saponin treated controls reacted significantly differently from GP36 vaccinated animals at all the assayed variables (P < 0.05). GP36 induced significant protection against murine visceral leishmaniasis at concentrations commonly used for vaccination with recombinant antigens.

A phase III trial of efficacy of the FML-vaccine against canine kala-azar in an endemic area of Brazil (São Gonçalo do Amaranto, RN)

Protection against canine kala-azar was investigated in naturally exposed dogs of an endemic area, vaccinated with the fucose mannose ligand (FML)-vaccine of Leishmania donovani. A total of 97% of vaccinees were seropositive to FML and 100% showed intradermal reaction to L. donovani lysate, 7 months after vaccination. The absorbency values and size of intradermal reaction were both significantly higher in vaccinees than in controls (ANOVA, P<0.0001). After 2 years, 92% (chi(2)=6.996; P<0.0025) protection was achieved: only 8% of vaccinees showed mild signs of kala-azar with no deaths while 33% of controls developed clinical or fatal disease. The FML-vaccine induced a significant, long-lasting and strong protective effect against canine kala-azar in the field.

Short report: occurrence of Leishmania donovani DNA in donated blood from seroreactive Brazilian blood donors

Human visceral leishmaniasis (kala-azar) transmitted by blood transfusion has been described in previous reports. Seroprevalence of antibodies to Leishmania donovani was shown to be related to prior blood transfusions in multiply transfused hemodialysis patients in Natal, Rio Grande do Norte, Brazil. In this study, a possible correlation between seroreactivity and the presence of L. donovani DNA was investigated in asymptomatic healthy blood donors. Sera were tested using the fucose mannose ligand (FML) ELISA, which was shown to have a sensitivity of 100%, a specificity of 96-100%, reliability, and diagnostic and prognostic potential for the detection of human and canine kala-azar, respectively. Leishmanial DNA was assessed by the polymerase chain reaction (PCR) and dot-blot hybridization techniques in blood and bone marrow samples. Among 21 FML-seroreactive asymptomatic blood donors, 5 (24%) were positive by the PCR and 9 (43%) were positive in a dot-blot assay of blood samples, showing a significant correlation (chi2 = 14.24, P < 0.01). No Leishmania DNA was detected in 20 FML non-reactive blood donors. Our results point to the need for control of transmission of kala-azar by blood transfusion in areas endemic for this disease.

Vaccination of Swiss Albino mice against experimental visceral leishmaniasis with the FML antigen of Leishmania donovani

The FML antigen of Leishmania donovani in combination with saponin, aluminum hydroxide (Al(OH)3) and Freund's incomplete adjuvant (FIA) was used in vaccines tested in an outbred murine model of visceral leishmaniasis, either through intraperitoneal or subcutaneous routes. The humoral response was significantly higher in the groups treated with FML + saponin or FML + Al(OH)3 than in controls, both before and after the infection. Animals immunized by the i.p. route developed higher antibody titres. A significant and specific reduction of parasitic load in relation to saline (85%, p < 0.01) and saponin (p < 0.025) controls, was seen in animals treated with FML + saponin by the i.p. Coincidentally with this reduction, an increase in antibodies of the IgG2a subtype was detected only in animals treated with FML + saponin i.p. A reduction of 88% in parasitic load was achieved by the combination of FML + Al(OH)3 (s.c.), but the Al(OH)3 treatment itself accounted for 68% of this protection. In our conditions, vaccination with FML + saponin i.p. was superior to other treatments and had no toxic effect due to saponin.

Prevalence of anti-Leishmania donovani antibody among Brazilian blood donors and multiply transfused hemodialysis patients

The prevalence of anti-Leishmania donovani antibodies was investigated in 1,500 Brazilian blood donors and multiply transfused hemodialysis patients. Sera were tested using the fucose-mannose ligand (FML) ELISA, which was shown to have 100% sensitivity and 96% specificity for kala-azar. Among 1,194 volunteer blood donors, seroreactivity was 9%, increasing to 25% in a periurban kala-azar focus. However, higher positivity (37%) was found in multiply transfused hemodialysis patients from Natal, where kala-azar is constantly present in low numbers (endemic), with sporadic outbreaks in localized regions (endemic and epidemic). Risk factors included blood transfusion, which was significantly associated with the presence of anti-Leishmania antibodies (chi2 = 8.567, P < 0.005), but did not include potential exposure to sandfly bites (chi2 = 0.033, P > 0.1). The prevalence significantly decreased to 7% in hemodialysis patients from Rio de Janeiro, where kala-azar is only occasionally seen, and was 0% in patients undergoing continuous ambulatorial peritoneal dialysis. The prospective analysis of 27 FML-seroreactive donors from Natal revealed amastigotes of Leishmania in the bone marrow of one subject while four had clinical complaints, including splenomegaly and hepatosplenomegaly. Our results point to the need for control of blood transfusion as a possible route for transmission of kala-azar in endemic areas.

Haemolytic activities of plant saponins and adjuvants. Effect of Periandra mediterranea saponin on the humoral response to the FML antigen of Leishmania donovani

An 87.7% (P < 0.01) and 84% (P < 0.001) of protection against visceral leishmaniasis was achieved in CB hamsters and Balb/c mice, respectively, with saponin combined to the fucose-mannose ligand of Leishmania donovani (FML). However, an undesirable haemolytic effect was described for several saponins. Aiming to improve the formulation with FML/saponin, we comparatively analysed the haemolytic potential of recently characterized plant saponins and currently used adjuvants. The haemolytic activity of steroidic saponins from Agave sisalana; Smilax officinalis as well as commercial saponin (Riedel De Haën's), was higher than that of triterpenoid ones (Bredemeyera floribunda; Periandra mediterranea) and the Freund's complete adjuvant. The concentration resulting in 50% haemolysis was 500 micrograms ml-1 for aluminum hydroxide. The low haemolytic effect of P. mediterranea saponin was abolished by removal of its glycidic moiety and its sapogenin fraction as well as the Freund's Incomplete Adjuvant were non-haemolytic within this range. Furthermore, the adjuvant effect of three doses of P. mediterranea saponin injected with the FML antigen of L. donovani, was assayed in mice, either by the intraperitoneal (i.p.) or the subcutaneous (s.c.) route. The anti-FML IgG antibody levels increased and detectable levels were observed up to 3 months in the s.c. group. The response was expanded in both groups after an injection with a fourth vaccine dose. The IgG response showed increased levels of IgG2a only in the i.p. group, while IgG2b and IgG1 but not IgG3 antibodies were higher than controls in both groups. In conclusion, the results suggest that the recently described triterpenoid fractions of P. mediterranea can be safely used as adjuvant with low or non-haemolytic effect.

Electrophoretic variation of hair proteins

Hair follicle cells secrete a complex assortment of proteins that form the hair shaft, and can be classified into two major groups. The low-sulfur proteins are keratins that contribute to the backbone of intermediate filaments, and the high-sulfur proteins are associated with these filaments. In the present investigation we describe a comparative electrophoretic study of normal human hair proteins from 182 individuals, including some families. Hair proteins were extracted in urea buffer (pH 9.3), examined by 10% polyacrylamide gel electrophoresis (pH 8.8) in the presence of sodium dodecyl sulfate and stained with Coomassie brilliant blue. Eighteen bands appeared and were reproducible in most individuals, with apparent molecular mass ranging from 10.0 to approximately 100 kDa. Based on the most prominent bands, an electrophoretic profile defined as the "frequent profile" was observed. This profile was observed in 180 individuals and consisted of 6 prominent bands, 4 of them of apparent molecular mass in the 40-70-kDa range, which is characteristic of keratins (61.9 +/- 1.02, 58.5 +/- 1.21, 47.9 +/- 1.58, and 45.4 +/- 1.53 kDa), and 2 bands with lower molecular mass (18.9 +/- 0.75 and 13.7 +/- 0.91 kDa). In 2 samples from unrelated women, an additional band of 42.1 +/- 1.72 kDa appeared. The meaning of this variant is still under investigation.

An improved method for the isolation of erythrocyte antigen band-3

An improved method for isolation of human and Rhesus monkey band-3 separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) is described. Purified band-3 was obtained from human hemoglobin-free ghosts (Hb-free ghosts) after SDS-PAGE by chemical elution+sonication (CE+S). The section of the gel corresponding to the antigen was cut out, mechanically disrupted and incubated in 1% NaHCO3 containing 1% SDS, for 2 h, with shaking, at room temperature, followed by overnight incubation at 4 degrees C. The preparation was subsequently sonicated and clarified by centrifugation. Supernatants were dialyzed against distilled water, their protein contents were measured, and the presence of purified band-3 was demonstrated by SDS-PAGE. A calibration curve was developed for assay of CE+S material using densitometric evaluation of the protein profile on SDS-PAGE. An amount of 37.5 mg of Hb-free ghosts gave 3.15 mg of purified band-3 after CE+S, corresponding to an 8.4% yield. Rabbits were immunized with 50 micrograms CE+S antigen. Sera were collected and assayed by Western blot analysis against its proteolytic fragments, which were obtained from packed red blood cells by treatment with protease type VI from Streptomyces griseus (1 h at 37 degrees C), followed by extensive washing and hypotonic lysis. Specific antibodies recognized band-3 and its proteolytic fragments 60 and 63 kDa in human ghosts obtained from different blood donors, confirming the genetic polymorphism. Analogous serum obtained against the Rhesus monkey band-3 proteolytic fragment 63 kDa recognized the human antigen and its respective fragments. These results indicate the existence of similarities between these two species of band-3, suggesting the potential use of this technique in taxonomic and phylogenetic studies. Purification by CE+S is an efficient and rapid method for isolation of band-3 and its fragments with satisfactory yields and maintenance of both their immunogenic and antigenic properties.

Leishmania donovani: titration of antibodies to the fucose-mannose ligand as an aid in diagnosis and prognosis of visceral leishmaniasis

The fucose-mannose ligand (FML) is a complex glycoprotein fraction present on promastigotes and amastigotes of Leishmania donovani. It participates in parasite interaction with host macrophages in a species-specific pattern. We have tested its use in immunodiagnosis of visceral leishmaniasis (VL) in a recent outbreak in Rio Grande do Norte, north-east Brazil. Enzyme-linked immunosorbent assay (ELISA) of low concentrations of FML in 462 sera showed 100% sensitivity and 96% specificity. The FML-ELISA identified patients with overt VL (P < 0.001, compared to normal sera). It could also identify inhabitants of the endemic area who had incipient or subclinical infection with potentially severe clinical disease: more than 20% of apparently healthy subjects with a positive ELISA for FML developed overt VL during the following 10 months. FML-ELISA reactivity decreased in all patients during treatment, and became negative after parasitological cure. No cross-reaction was observed in patients infected with other Leishmania species, nor in those with Chagas disease. Determination of antibody response to FML may be useful in diagnosis of VL and in identifying patients without overt disease but with a high risk of developing severe VL.

Genetic polymorphism of red cell membrane band 3 in Japanese Brazilians

Limited proteolysis of intact red cells has been shown to yield peptides of 60 kDa and, in some individuals, 63 kDa, from the band-3 membrane protein. In a random population sample of 117 Brazilians of Japanese origin, the allele frequencies of the band-3 variants were p60 = 0.889 +/- 0.0205 and p63 = 0.111 +/- 0.0205. The phenotype frequencies fit the Hardy-Weinberg equilibrium for the hypothesis of three phenotypes controlled by two codominant alleles of a single autosomal locus. The frequencies of the alleles in this population of Japanese ancestry are highly different from those of Brazilian Caucasoid blood donors but rather similar to those of Brazilian Negroid donors.

The 60 and 63 kDa proteolytic peptides of the red cell membrane band-3 protein: their prevalence in human and non-human primates

Three phenotypes based on the polymorphism of band-3 protein from human red cells are described. Limited proteolysis of intact red cells from most individuals (homozygotes) yields a peptide of 60 kDa, but in some cases (heterozygotes), there is also a 63-kDa peptide, and rarely only the single peptide of 63 kDa is found. This is the first description of the 63-kDa homozygote. The interpretation that the three phenotypes are controlled by two alleles of a single autosomal locus, with no dominance, is supported by population and family studies. The frequencies of the allele, which we designate as p63, is 0.041 +/- 0.0068 in Caucasoids and 0.125 +/- 0.0121 in Negroids. The electrophoretic profiles and molecular weights of the peptides obtained with several commercial proteases from Streptomyces griseus are similar to those obtained with chymotrypsin. Whereas band-3 protein in two New-World monkeys (Saimiri and Cebus) resisted pronase attack, an Old-World monkey (Macaca mulatta) was monomorphic for a 63-kDa fragment, and in an ape (Pan troglodytes), a doublet of 62 kDa and 64 kDa was found. Band-3 protein polymorphism appears to be a good marker for genetic differentiation in human populations.

Anti-T (Thomsen-Friedenreich) agglutinin in Chagas' disease

Uma amostra de soros de pacientes e controles de uma área endêmica da Doença de Chagas do País foi titulada contra hemácias de grupo O tratadas pela neuraminidase (células OT ativadas) e hemacias normais de grupo A e B (sistema ABO). Também foram feitos alguns testes de aglutinação de hemácias de pacientes com cardiomiopatia com as lectinas de amendoim (anti-T + anti-Tk) e com anticorpo humano anti-T. O escore médio da aglutinina anti-T dos pacientes foi similar ao do grupo controle. En- tretanto, o escore médio dos indivíduos com a forma cardíaca íoi significantemente maior que o dos pacientes assintomáticos e também maior que o do grupo controle. A comparação entre indivíduos com sorologia diagnóstica positiva versus negativa foi não significante. Nem a sorologia para Chagas nem as variáveis raça, sexo, idade, idade ao quadrado, in-fecção intestinal parasitária, teor de proteínas do soro, volume globular eritrocitário (hema-tócrito), grau de palidez da mucosa bucal, cardíomiopatia e os termos de interação sexo x idade, sexo x idade ao quadrado, estão associados significativamente com o logaritmo do título ou com o logaritmo do escore de aglutinação. Os escores de aglutinação das aglutininas anti-A e anti-B do sistema de grupo sangüíneo ABO estão dentro da faixa de variação normal. As hemácias de pacientes com a forma cardíaca não são aglutinadas nem pelas lectinas de amendoim (antiT + anti-Tk) e da soja (anti-T) nem pela aglutinina anti-T de origem humana. A prova de Coombs direta foi negativa em todos os pacientes, demonstrando a aparente ausência de imunoglobulinas IgG e IgM na superfície eritrocitária. O fato de que o aumento dos níveis de anti-T só foi detectado em uma das formas clínicas da doença em pacientes da mesma área endêmica constitui um argumento contra a possibilidade de que a variação observada seja produzida por uma infecção concomitante.

The ABO blood groups and the B atypical gene in Brazil: a serologic and population genetic approach to the issue

The fit to Hardy-Weinberg equilibrium is improved if an atypical B allele is assumed to exist along with the A1, Aint, A2, B, and O genes in the ABO system. This atypical B allele accounts for 37% or so of the total B gene frequency in both Brazilian whites and blacks.

Agglutinins and hemolysins from Biomphalaria tenagophila snails

A saline anti-A and incomplete anti-A,B agglutinin were found in spawn extracts of Biomphalaria tenagophila snails. Significance differences after papain and pronase treatments were also found for A1 and A2 subgroups. The hemolysin titers are high, and unspecific.

ABO aggulutinins from Biomphalari straminea snails

Extracts from B. straminea spawn are active against A and B normal red cells. A1 and A2 subgroups may be differentiated with trypsin-, papain- and pronase-treated cells. 0 cells treated with papain, pronase and neuraminidase react weakly to the extracts.

Protectins in Argentine mollusks: immunological and immunochemical aspects

Protectins and agglutinins in several organs, fluids and spawn from Argentine terrestrial and fresh-water gastropod species were examined. Differences or analogies with vertebrate immunoglobulin serological behaviour are summarized. Individual or group variability and the evolutionary meaning of the reproductive system-linked and the Ca++ ion-linked protectins are discussed.