Performance of a real time PCR for leishmaniasis dignosis using a L. (L.) infantum hypothetical protein as target in canine samples

Visceral leishmaniasis represents an important public health issue in different parts of the world, requiring that measures be put in place to control the spread of the disease worldwide. The canine leishmaniasis diagnosis is not easy based on clinical signs, since dogs may not develop the infection with recognizable signs. Thus, the laboratorial diagnosis is essential to ascertain the incidence and prevalence of canine leishmaniasis especially in areas with major control efforts. Although, the diagnosis can be performed by the use of different approaches, the molecular methods such as PCR have become an indispensable tool for leishmaniases diagnosis. A TaqMan assay for real-time PCR (Linj31-qPCR) was developed to determine the parasite occurrence in clinical cases of leishmaniasis. The assay targets an L. (L.) infantum hypothetical protein region. The specificity of the assay was verified by using Leishmania World Health Organization reference strains including parasites belonging to subgenus L. (Leishmania), subgenus L. (Viannia), other Leishmania species and Trypanosoma cruzi. The sensitivity was verified by using isolates of L. (L.) amazonensis and L. (L.) infantum. The usefulness of the assay for diagnosis was ascertained by testing 277 samples from dogs in regions endemic for visceral and/or cutaneous leishmaniasis and from regions in which leishmaniasis was not endemic in São Paulo State, Brazil. Diagnosis of canine visceral leishmaniasis (CVL) was determined on these animals by conventional PCR and three serological tests. The dog samples were divided into four groups. I, dogs with CVL (n = 101); II, dogs with other diseases and without CVL (n = 97); III, dogs with American cutaneous leishmaniasis (n = 7), and, IV, dogs without CVL (n = 72) from areas where leishmaniasis was not endemic as control group. Results indicated that Linj31-qPCR was able to identify parasites belonging to subgenus L. (Leishmania) with no cross-amplification with other parasite subgenera. The Linj31-qPCR detected Leishmania parasites DNA in 98% of samples from Group I. In conclusion this methodology can be used as routine diagnostic tools to detect parasites from subgenus Leishmania.

Immunogenicity assay of the Leishmune vaccine against canine visceral leishmaniasis in Brazil.

Leishmune is the industrialized version of the FML-saponin vaccine which has been shown to develop 92-95% protection in vaccinated dogs and 76-80% vaccine efficacy against field canine visceral leishmaniasis (CVL) in Brazil. Leishmune has been proven to be safe and tolerable and a transmission-blocking vaccine which renders vaccinated dogs non-infectious to sand fly vectors. In the present investigation, 550 healthy seronegative dogs of endemic and epidemic areas of Brazil were monitored for Leishmune-induced immunogenicity during a 2-year trial. Another group of 588 untreated exposed dogs was also studied in parallel. Both groups were seronegative on day 0. The strong immunogenicity induced by Leishmune vaccine was demonstrated by the 98% of FML-seroconversion, increase in absorbencies, the 82.7% DTH positive reactions and increase in skin test size diameters, the average increase in CD8+ total lymphocytes population in blood (27.1%), expected for QS21 saponin-containing vaccine, the sustained proportions of CD4+ T cells, and the average increased proportions of CD21+ B lymphocytes (42.3%). The Leishmune-induced protection against CVL is demonstrated by the results: 98.8% asymptomatic dogs (at the end of first year) and 99% healthy survivors (at the end of the second year) among vaccinated dogs, compared to the 79.4% asymptomatic and 61% survivor dogs (p<0.001) monitored in the untreated exposed cohort. In spite of the low vaccine coverage, it was possible to detect a 66.1% (p<0.005) reduction in Belo Horizonte and an 80.2% (p<0.005) reduction in Araçatuba of the incidence of CVL among vaccinated dogs, when compared to the global incidence of CVL of each town, respectively. Our preliminary results support the potential use of Leishmune to prevent CVL epidemics.

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 (1mg of saponin rather than 0.5mg), 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.

Safety trial using the Leishmune vaccine against canine visceral leishmaniasis in Brazil.

A group of 600 healthy and asymptomatic dogs from Brazilian canine visceral leishmaniasis endemic areas was vaccinated with three sc doses of Leishmune which is the industrialized formulation of the FML-saponin, recently licensed for commercialization in Brazil, which previously showed 76-80% vaccine efficacy against canine visceral leishmaniasis. Safety evaluation was performed for 14 days after each vaccine injection and disclosed transient reactions of local pain (40.87%), anorexia (20.48%), apathy (24.17%), local swelling reactions (15.90%), vomit (2.4%) and diarrhoea (1.5%). All effects showed significantly correlating declines, from the first to the third dose (p<0.0001). Most of the noticed reactions of pain (73%), anorexia (79%) and local swelling (84.7%) were mild. No significant differences between puppies and adults dogs were found in the number of adverse reactions. Adult dogs developed however, 94.5% of the small swelling reactions (<3 cm), and indicating that they are more resistant to the inflammatory response promoted by the saponins. No dead by anaphylaxis occurred, and only two dogs (0.1%) showed allergic reactions (facial oedema and itching) after the third dose. Transient alopecia on injection site occurred in only five poodles (0.28%) with total recovery and no need of treatment. All the mild adverse events in response to Leishmune injection were transient and disappeared before the injection of the following vaccine dose, confirming the tolerability of the vaccine. The Leishmune preparation was less haemolytic (HD(50)=180 microg/ml) than expected for a QS21 saponin-containing vaccine, indicating that its formulation with the FML antigen diminished the potential in vitro toxicity.

Separation of two cell signalling molecules from a symbiotic sponge that modify algal carbon metabolism.

Two distinct cell signals have been isolated from the sponge host of the tropical sponge/macroalga symbiotic association Haliclona cymiformis/Ceratodictyon spongiosum. These water soluble cell signals (M(r) between 500 and 1000) modify separate steps in the carbon metabolism in both C. spongiosum and the microalga, Symbiodinium from the coral Plesiastrea versipora. The first signal, host release factor (HRF), stimulates the release of compounds derived from algal photosynthesis; the second signal, photosynthesis inhibiting factor (PIF), partially inhibits photosynthesis. Both HRF from the sponge H. cymiformis and HRF from the coral P. versipora stimulated the release of glycerol from Symbiodinium suggesting that they act at a similar step in the metabolism of this alga. This is the first time that such cell signals have been isolated from a sponge. We suggest that they belong to a family of similar cell signals from symbiotic invertebrates that modify algal carbon metabolism.

Leishmune vaccine blocks the transmission of canine visceral leishmaniasis: absence of Leishmania parasites in blood, skin and lymph nodes of vaccinated exposed dogs.

Leishmune vaccine is the first licensed vaccine against canine visceral leishmaniasis. It contains the Fucose-Mannose-ligand (FML) antigen of Leishmania donovani. The potential Leishmune vaccine effect on the interruption of the transmission of the disease, was assayed by monitoring, in untreated (n=40) and vaccinated dogs (n=32) of a Brazilian epidemic area: the kala-azar clinical signs, the FML-seropositivity and the Leishmania parasite evidence by immunohistochemistry of skin and PCR for Leishmanial DNA of lymph node and blood samples. On month 11 after vaccination, untreated controls showed: 25% of symptomatic cases, 50% of FML-seropositivity, 56.7% of lymph node PCR, 15.7% of blood PCR and 25% of immunohistochemical positive reactions. The Leishmune-vaccinated dogs showed 100% of seropositivity to FML and a complete absence of clinical signs and of parasites (0%) in skin, lymph node and blood PCR samples (p<0.01). The positivity in FML-ELISA in untreated dogs significantly correlates with the PCR in lymph node samples (p<0.001) and with the increase in number of symptoms (p=0.006) being strong markers of infectiousness. The absence of symptoms and of evidence of Leishmania DNA and parasites in Leishmune-vaccinated animals indicates the non-infectious condition of the Leishmune-vaccinated dogs.

New substances for intraocular tamponades: perfluorocarbon liquids, hydrofluorocarbon liquids and hydrofluorocarbon-oligomers in vitreoretinal surgery.

UNLABELLED: Perfluorocarbon liquids (PFCLs) and heavy fluorocarbon liquids (HFCLs) are being increasingly used as soft tools during vitreoretinal surgery. However, since long-term intraocular tolerance is still unsatisfactory, at present complete removal at the end of surgery is recommended. With the aim to improve long-term intraocular compatibility and to enlarge the spectrum of clinical applications, modified HFCLs have been developed. HFCL-oligomers with a higher viscosity represent the latest perspective. All three groups of fluorocarbon liquids will be compared with respect to their physical and chemical properties, experimental and clinical results, and prospects for clinical applications. Common features of PFCLs, HFCLs and HFCL-oligomers are biological inertness, specific gravity higher than water, immiscibility with water or blood, and a high gas binding capacity. In PFCLs such as decalin, octane, or phenanthrene. All carbon atoms of the carbon backbone are completely fluorinated. In experimental and clinical use, emulsification, vascular changes and structural alterations of the retina have been described. By only partial replacement of hydrogen atoms by fluorine, the specific gravity of HFCLs is reduced, whereas lipophilic properties increase. Thus HFCLs are potential solvents for intraocular silicone oil remnants. However. after long-term application, side-effects are similar to those observed with PFCLs. Substances of this group, such as F6H6, F6H8, 044, and 062 are used intraoperatively and are currently being investigated for clinical long-term application. With the aim to avoid emulsification and to improve intraocular tolerance, we have developed HFCL-oligomers consisting of 2-4 HFCL molecules with increased viscosity. The oligomers were tolerated well in rabbit eyes for up to 4 months. In contrast to PFCLs or monomers, they did not emulsify nor show vascular alterations. ERGs returned to normal after removal of the oligomer from the eye. Histology of the retina showed mild alterations. CONCLUSION: according to physical properties, experimental intraocular compatibility and stability against emulsification, HFCL-oligomers are promising candidates for improved long-term tamponade of the lower retina. At present, indications for an application in human eyes have to be determined in clinical trials.

Pattern and course of single-system disease in Langerhans cell histiocytosis data from the DAL-HX 83- and 90-study.

BACKGROUND: Single-system (SS) disease is the most common presentation in Langerhans cell histiocytosis (LCH) with a heterogenous clinical picture and course. Mostly bone and rarely skin or lymph nodes are involved. PROCEDURE: One hundred and seventy patients with SS-LCH were registered in the DAL-HX 83/90 studies. They were diagnosed according to uniform diagnostic criteria and followed by a standardised schedule. RESULTS: Single bone lesions were most common (68%), followed by multiple bone lesions (19%), isolated skin disease (11%), and isolated lymph node involvement (4 patients). In the detection of bone lesions radiographic skeletal survey proved to be superior to bone scan (97% vs. 82%). Treatment comprised surgery, irradiation and local instillation of steroids, and standardised chemotherapy for multifocal bone disease. After initial therapy 81% of the patients remained disease free. Reactivations restricted to the skeleton occurred in 18% of both unifocal and multifocal bone disease. Two skin patients had a chronic course. Fatality occurred only in one infant with skin disease who progressed to multi-system disease. Twenty-five percent of all patients developed permanent consequences, which were already present at diagnosis in about half of these patients and comprised mainly orthopedic problems related to lesional sites. Diabetes insipidus occurred in 3% and anterior pituitary dysfunction in 2% of the patients. CONCLUSIONS: The course in SS%LCH was benign. In bone disease reactivations remained restricted to the skeleton and did not influence survival. However, reactivations had an impact on morbidity, as permanent consequences were mostly related to the site of disease activity. Med Pediatr Oncol 2001;37:108-114.

[Long-term monitoring of therapy-induced computerized tomographic cranial changes in children with acute lymphoblastic leukemia]. / Langzeitbeobachtung der therapiebedingten cranialen computertomographischen Veränderungen bei Kindern mit akuter lymphoblastischer Leukämie.

PURPOSE: Long-term follow-up of cranial CT scans of children with acute lymphoblastic leukemia and evaluation of the influence of chemo- and radiotherapy on the CCT changes. PATIENTS AND METHODS: CCT scans of 68 children with non-B-ALL were analyzed retrospectively for signs of atrophy and changes in density. Patients were treated between 1981 and 1990 at the St. Anna Childrens Hospital Vienna according to the ALL-BFM protocols. Children were examined with CCT in defined periods from diagnosis until 3 years after cessation of treatment. As a control group served 69 patients with solid tumors who had not received corticoids or cranial irradiation. RESULTS: At the initial examination 56% of the ALL-patients showed CCT changes, 85% of these patients had already received corticoids. In the control group only 20% of the CCTs were found abnormal (p = 0.005). In both groups an age-dependence was found: 64% of the ALL-patients under five years of age and 22% of the patients above 5 years had initial CCT changes (p = 0.001). In the control group 39% of the patients under five years of age and 7% of the older patients showed CCT changes at the beginning of treatment (p = 0.003). The highest incidence of abnormal CCT scans (68%) was seen during intensive chemo- and radiotherapy. Until the end of therapy the incidence of abnormal CCTs decreased to 32%. After cessation of antileukemic therapy 35% of the patients whose CNS-prophylaxis included cranial irradiation, and 12% of the non-irradiated patients had abnormal CCT scans. CONCLUSION: Corticoids can cause reversible signs of cerebral atrophy. In the assessment of CCTs a physiological age-dependence of the volume of the CSF compartment has to be taken into consideration. The main reason for non-reversible CCT changes is the CNS- prophylaxis, above all the cranial irradiation, whereby younger children seem to be particular vulnerable.

Does expression of different EWS chimeric transcripts define clinically distinct risk groups of Ewing tumor patients?

PURPOSE: Because of the high heterogeneity of EWS gene fusions with FLI1 and ERG genes due to variable chromosomal breakpoint locations in Ewing tumors (ET) (14 different chimeric transcripts identified so far), we evaluated the clinical impact of the expression of diverse fusion transcripts in ET patients. PATIENTS AND METHODS: In a European multicenter study, 147 ET were analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR) and the molecular data statistically compared with all clinical data available. RESULTS: Most tumors expressed chimeric transcripts with fusion of EWS exon 7 to FLI1 exon 6 (75 of 147) (type I) or five (39 of 147) and EWS exon 10 to FLI1 exon 5 (eight of 147) or 6 (five of 147). In five cases, chimerism between EWS exon 9 and FLI1 exons 4 and EWS exon 7 and FLI1 exon 7 or 8 was observed. Fifteen cases of EWS-ERG rearrangement were identified. In 85 of these patients treated in the European Cooperative Ewing Sarcoma Studies, molecular results were analyzed in comparison to age, sex, tumor localization, tumor volume, and disease extension. No significant correlation between the various fusion types and these features were observed. Relapse-free survival (RFS) for the 31 patients with localized disease and fusion type I tended to be longer compared with the 24 patients with localized tumors bearing other chimeric transcripts (P = .04). CONCLUSION: Results suggest a possible advantage in PFS for patients with localized disease and fusion type I transcripts, although this will require prospective validation with a larger number of patients and longer follow-up periods.

Influence of fractionated total body irradiation on mucosal toxicity in intensified conditioning regimens for autologous bone marrow transplantation in pediatric cancer patients.

From April 1988 to March 1991 28 children with generalized solid tumors (N = 15) or hematologic malignancies (N = 13) received intensified myelotoxic regimens followed by autologous stem cell rescue (ABMT). These intensified regimens consisted of 12 Gy fractionated total body irradiation (FTBI) and 2 (or 3) cytotoxic drugs (group A, n = 19) or a combination of 3 cytotoxic drugs (group B, n = 9). FTBI-containing regimens produced more severe mucositis > = WHO grade 3 (p = 0.01) and a longer duration of severe mucositis. The mucositis had a median duration of 8 days (range 0-28) in group A compared with median 0 days (range 0-7) in group B (p < 0.01). Acute renal and liver toxicity were not different. The probability of overall survival at day +100 was 89% in all patients. In terms of long-term survival FTBI containing regimen did not prove superior: 5 out of 19 patients in group A and 6 out of 9 patients in group B have been survivors for a minimum of 3 years. In conclusion, severe gastrointestinal toxicity of such intensive regimens is avoidable if FTBI is omitted.

Treatment strategy for disseminated Langerhans cell histiocytosis. DAL HX-83 Study Group.

Treatment of Langerhans cell histiocytosis (LCH) remains problematic. To test the hypothesis that rapid initiation and long-term continuation of chemotherapy can improve survival and reduce recurrence and late consequences of disseminated LCH, we have completed a prospective clinical trial (DAL HX-83). One hundred six newly diagnosed patients were stratified into three risk groups (A: multifocal bone disease [n = 28]; B: soft tissue involvement without organ dysfunction [n = 57]; C: organ dysfunction [n = 21]). All patients received an identical initial 6-week treatment (etoposide [VP-16], prednisone, and vinblastine), and continuation treatment for 1 year, slightly adapted according to stratification at diagnosis. It included oral 6-mercaptopurine and eight pulses of vinblastine and prednisone for all patients, plus VP-16 in group B and VP-16 and methotrexate in group C. Eighty-nine percent and 91% of patients in groups A and B and 67% of the most severely affected group C, achieved complete resolution of disease. The speed of resolution was rapid (median 4 months) and independent of disease severity. The frequency of recurrence after initial resolution was low (12%, 23%, and 42% in groups A, B and C); overall fully 77% of patients have remained free of recurrence. Permanent consequences developed after diagnosis in 20% of the patients. Diabetes insipidus after initiation of treatment occurred in only 10% of patients. Mortality (9%) was limited to patients of groups B (two patients) and C (eight patients). Finally, among the 106 patients treated by DAL HX-83 none have developed a malignancy (median follow-up 6 years, 9 months). The shorter duration of active disease, low rate of recurrence and permanent consequences, and improved survival among patients with poor prognosis support the strategy of rapid initiation of a predefined prolonged treatment upon the diagnosis of disseminated LCH.

Prognostic significance of myeloid-associated antigen expression on blast cells in children with acute lymphoblastic leukemia. The Austrian Pediatric Oncology Group.

The prognostic significance of expression of myeloid-associated antigens in childhood acute lymphoblastic leukemia (myA+ALL) was evaluated. From 1984 to 1990, 251 children with immunologically verified ALL were treated in two prospective consecutive Austrian studies. Complete immunophenotyping was performed in 206 cases (82%). Out of these 175 cases were classified as B-cell precursor ALL, 31 cases as T-ALL. Expression of myeloid-associated antigens was demonstrated in 23 cases (13.1%) of childhood B-cell precursor ALL, particularly in immature (CD10 negative) forms (P < .0001), and in 1 case (3.2%) of T-ALL. CDw65 was expressed most frequently (12 cases), followed by CD13 and CD15 (5 cases each), CD33 (4 cases), and blood-group H (3 cases). Compared to myA- ALL prognosis of children with myA+ B-cell precursor ALL was poor, despite intensive multiagent chemotherapy according to BFM protocols. Remission rates were not impaired, but pEFS was 74.6% for myA- ALL, and only 37.8% for myA+ ALL (P = .0001). As demonstrated by multivariate analysis the expression of myeloid-associated antigens was the most important prognostic variable for EFS in B-cell precursor ALL, whether or not CD10 was expressed.