Efficacy of voriconazole in a murine model of acute Trypanosoma cruzi infection

OBJECTIVES

Antifungal triazole derivatives have been studied as possible alternatives for the treatment of Chagas' disease. Voriconazole has demonstrated in vitro activity against Trypanosoma cruzi, but its efficacy in vivo has not yet been tested. We aimed to determine the effect of voriconazole in a murine model of acute T. cruzi infection.

METHODS

Treatment efficacy was evaluated by comparing parasitaemia, mortality and organ involvement (by histological examination) of infected mice.

RESULTS

Treatment with voriconazole significantly lowered parasitaemia and mortality compared with controls, reduced the percentage of mice with amastigote nests in heart and skeletal muscle and moderately decreased myocardial inflammation.

CONCLUSIONS

Our findings support the potential of voriconazole for the treatment of acute Chagas' disease and motivate future animal studies using varying doses and treatment schemes. Further evaluation of voriconazole for clinical use in human Chagas' patients is warranted.

[Acute toxoplasmosis: clinical and laboratory data in eleven patients]

INTRODUCTION

The clinical and laboratory data of immunocompetent patients with acute toxoplasmosis (AT) are described.

PATIENTS AND METHODS

We performed a retrospective study of patients with AT attended between 1996 and 2004. Diagnostic criteria consisted of compatible clinical findings (generalized and cervical lymphadenopathies) and specific serology against Toxoplasma gondii (high IgG and IgM and/or reactive IgA). IgG and IgM determinations were performed by ELFA and IgA determinations by ELISA. IgM-CMV, heterophil antibodies, hemogram, hepatic chemistry were also determined and funduscopic examination was performed.

RESULTS

Eleven immunocompetent patients with AT were evaluated. The mean age was 8.8 years (95 % CI: 3.6-12.9). The patients were evaluated between the first and the third month after symptom onset. Of the 11 patients, hard elastic lymphadenopathies were found in 10, single cervical lymphadenectomy in three and generalized lymphadenectomy in seven. One patient showed no symptoms. In one patient, nodal histology showed the Piringer-Kuchinka triad. None of the patients showed alterations in the hemogram, hepatic chemistry or funduscopic examination. The mean IgG value was 4.143 UI/ml (95 % CI: 2.570 and 5.717). IgM was reactive in nine of the 11 patients (81.8 %) and IgA in seven out of 10 patients (70 %). In all patients, at least one of these two immunoglobulins was reactive. In all patients, clinical outcome was favorable without parasiticide treatment.

CONCLUSION

Except for one asymptomatic patient, all the patients had generalized lymphadenopathies and only 27.2 % showed cervical lymphadenopathies. A negative IgM or IgA result does not rule out a diagnosis of AT. Parasiticide treatment is unnecessary in this entity. Acute toxoplasmosis should be considered early in children with lymphadenopathies to avoid invasive procedures.

[Toxocariasis: clinical and laboratory features in 54 patients]

OBJECTIVE

To describe the clinical and laboratory findings in children with toxocariasis.

METHODS

Fifty-four children with reactive serology to Toxocara determined by ELISA were prospectively identified between January 1998 and September 2000. The patients were divided into three groups: asymptomatic children (n 24), those with visceral larva migrans (n 16) and those with ocular larva migrans (n 14). Age, serology titers, and eosinophil count at diagnosis were compared among the groups. The patients received treatment with albendazole 10-15 mg/kg/day for 15 days or thiabendazole 25 mg/kg/day in two series of 7 days.

RESULTS

The clinical features were as follows: 24 children (44.4 %) were asymptomatic, pneumonitis was found in 9 (16.7 %), hepatomegaly in 6 (11.1 %), acute posterior uveitis in 5 (9.3 %), strabismus in 5 (9.3 %), leukocoria in 4 (7.4 %), fever in 3 (5.6 %). There was 1 case of keratitis, 1 of cataracts, 1 of myocarditis and 1 case of pneumonia with pleural effusion. Some patients showed more than one clinical feature. Four children experienced loss of vision in the affected eye. No differences in age or serology titers were found among the groups. Eosinophil count was lower in the group with ocular larva migrans than in the other groups (p < 0.001). Children with active disease showed clinical improvement and a 70.4 % decrease in eosinophilic count one year after treatment. Serological titers showed an unpredictable pattern during the follow-up.

CONCLUSIONS

Most of the infected children were asymptomatic. In the post-treatment follow-up, clinical improvement and a decrease in eosinophilic count were observed. Further studies are needed to evaluate the efficacy of treatment, especially in asymptomatic children.

Neurosyphilis in an eight-year-old child: usefulness of the SPECT study

An 8-year-old boy with symptomatic late-onset congenital syphilis is reported. The child had been undertreated when he was 78 days of age, but his clinical and serologic follow-up did not occur until he was 3 years of age. At that time, he was asymptomatic, and cerebrospinal fluid disclosed not only hypercellularity but also a reactive Venereal Disease Research Laboratories test. Although he was then retreated at 4 years of age, he developed seizures. Cranial computed tomography and magnetic resonance imaging were normal, but two single photon emission computed tomography scans performed when he was 5 years of age and then 7 years of age demonstrated areas of hypoperfusion that closely agreed with the alterations on electroencephalograph. Brain single photon emission computed tomography was able to detect cerebral nervous system abnormalities in this young patient with neurosyphilis, whereas other image studies did not.

Detection and characterization of antigens in urine of patients with acute, congenital, and chronic Chagas' disease

Monoclonal antibodies raised against purified Trypanosoma cruzi urinary antigens were used in an enzyme-linked immunosorbent assay (ELISA) capture test for parasite antigens present in urine specimens of Argentinean and Brazilian patients with Chagas' disease. At diagnosis, antigenuria was demonstrated by ELISA in all acutely and congenitally infected infants studied. Moreover, T. cruzi urinary antigens were detected in samples from three of five patients with acute infections and four of five patients with congenital infections following chemotherapy. At least one ELISA-positive urine specimen from each individual was recorded in a longitudinal survey of 12 chronic chagasic patients. The same parasitic antigens (90 to 80 kDa, pI 5.7 to 6.0; 70 to 65 kDa, pI 4.9 to 4.5; 50 to 45 kDa, pI 5.3 to 5.1; and 40 to 35 kDa, pI 4.8 to 4.5) were identified by immunoprecipitation and two-dimensional polyacrylamide gel electrophoresis analysis of urine samples from patients with different forms of chagasic infection. The 90- to 80-kDa urinary protein resembles a trypomastigote-shed antigen. Determination of antigenuria proved valuable for early diagnosis of Chagas' disease and also for diagnosis of chronic cases with conflicting serology.

Congenital Chagas' disease: diagnostic and clinical aspects

The diagnostic and clinical aspects of congenital Chagas' disease were studied in 71 children in Buenos Aires. The children's ages ranged from 2 days to 10 years. In infants < 6 months old, the disease was diagnosed by detection of Trypanosoma cruzi in the blood; the microhematocrit test was positive in 38 (97.4%) of 39 cases. This test was the fastest and most reliable diagnostic method in this group, whereas two conventional serological methods were useful in children > or = 6 months of age. Forty-six (64.8%) of the 71 children had no clinical signs of infection. The clinical sign most frequently documented was hepatomegaly (18.3%). Three children were coinfected with human immunodeficiency virus; the latter infection was severe in two instances. Nifurtimox (10-15 mg/[kg.d] for 2 months) was used for parasiticidal treatment, and use of this drug resulted in mild adverse effects.

Acute CNS infection by Trypanosoma cruzi (Chagas' disease) in immunosuppressed patients

Acute CNS involvement by Trypanosoma cruzi is uncommon. We report 2 immunosuppressed patients, 1 adult who developed an acute meningoencephalitis, and 1 child who presented with the tumor-like form of the disease. Both patients acquired the disease through blood transfusion. Blood donors migrating from endemic areas can transmit the disease in nonendemic countries if they are not routinely screened for antibodies to T cruzi.

Rapid determination of Trypanosoma cruzi urinary antigens in human chronic Chagas disease by agglutination test

Detection of Trypanosoma cruzi in man becomes particularly difficult during the chronic stage of Chagas disease because of the low parasitemia. We were able to develop a simple and straightforward method for determining the concentration of T. cruzi antigens in urine using nitrocellulose micellar suspension (Nitrocell-Mr, Polychaco Argentina) and for their subsequent detection through a "latex" type agglutination test. The latex used was an esferocell nitrocellulose suspension (Esferocell-Mr, Polychaco). Specific antigens for T. cruzi were detected in 54 of 58 urine samples from chronic chagasic patients. The antigens characterized by affinity chromatography and SDS-PAGE were glycoproteins with apparent molecular weights (and pIs) of 100 kDa (pI 5 to 5.5), 80 kDa (pI 6.0), and 50 kDa (pI 6.5 to 7.0). This method is practical and fulfills the requirement of large-scale epidemiological studies. It is also helpful in cases of conflictive serology.

Specific circulating immune complexes in acute Chagas' disease

The presence of circulating immune complexes formed by IgM and IgG (CIC-IgM and CIC-IgG) was investigated, using antigen-specific enzyme-immunoassays (ELISA), in 30 patients with acute Chagas' disease who showed parasitemia and inoculation chagoma. Control population consisted of patients with chronic T. cruzi infection (30), acute toxoplasmosis 10), leishmaniasis (8), rheumatoid arthritis (3) and healthy individuals with negative serology for Chagas* disease (30). Acute chagasic patients were 100% CIC-IgG and 96.66% CIC-IgM positive whereas immunofluorescence tests yielded 90% and 86.66% of positivity for specific IgG and IgM antibodies, respectively. Chronic patients were 68% CIC-IgG and 0% CIC-IgM positive. The 30 negative and the 21 cross-reaction controls proved negative for ELISA (CIC-IgM and CIC-IgG). The high sensitivity of ELISA assays would allow early immunologic diagnosis, as well as prompt treatment, of acute T. cruzi infection, thus eliminating the problem of the false-positive and false-negative results which affects traditional methods for detection of circulating antibodies.

Two brothers with Martsolf's syndrome

Two brothers affected by a syndrome consisting of short stature, hypogonadism, and severe mental retardation are reported. The syndrome shares the features of that described by Martsolf et al in two brothers born to a consanguineous Polish Jewish couple. Although our patients' parents are Sephardic Jews, they deny consanguinity. These observations and personal knowledge of another affected Jewish boy raise the question of whether Martsolf's syndrome is a new entity that should be included in the group of those that affect mainly Jewish people, and whether its pattern of inheritance is X linked recessive or autosomal recessive limited to males.