Pancreatitis induced by pentavalent antimonial agents during treatment of leishmaniasis

Pentavalent antimony (Sbv), formulated as sodium stibogluconate or meglumine antimoniate, is the standard treatment for the leishmaniases. In 16 of 17 consecutive, prospectively observed patients in Washington D.C., serum levels of amylase and lipase rose to abnormal values after therapy with sodium stibogluconate was started; 12 of 17 had symptoms of pancreatitis. Sbv therapy was continued to completion in 7 of 17 patients and interrupted in 10 of 17. Pancreatitis improved in every patient after Sbv therapy was stopped. Sbv treatment was resumed after brief interruptions in 6 of 10 patients. All six of these patients had flares of pancreatitis, but each completed therapy. Subsequently, we measured amylase and lipase levels in stored sera from 32 patients treated in Peru with either sodium stibogluconate or meglumine antimoniate for mucosal leishmaniasis. In all 32 Peruvian patients, serum amylase and lipase rose to abnormal levels during Sbv therapy; 11 of 32 had symptoms of pancreatitis. Standard Sbv regimens induce pancreatitis in almost all patients, but continued therapy is often tolerated; pancreatitis subsides when therapy is stopped, and rechallenge may be tolerated after a brief halt in treatment.

Visceral infection caused by Leishmania tropica in veterans of Operation Desert Storm

BACKGROUND

Visceral leishmaniasis, usually caused by Leishmania donovani, has rarely been reported from eastern Saudi Arabia, so it was not expected to affect the soldiers of Operation Desert Storm.

METHODS

We evaluated eight soldiers with visceral leishmanial infection, examining their serum with an immunofluorescent-antibody assay, examining their marrow or biopsy tissue for amastigotes with an indirect immunofluorescent-monoclonal-antibody assay, and culturing the parasites. Cultured promastigotes were isolated and characterized by isoenzyme analysis.

RESULTS

None of the eight soldiers had classic signs or symptoms of visceral leishmaniasis (kala-azar). Seven soldiers had unexplained fever, chronic fatigue, malaise, cough, intermittent diarrhea, or abdominal pain that began up to seven months after they returned to the United States; one had no symptoms. Five had adenopathy or mild, transient hepatosplenomegaly. None had cutaneous manifestations. Diagnoses were made by bone marrow aspiration (seven patients) or lymph-node biopsy (one patient). Six isolates have been identified as L. tropica, which usually causes only cutaneous disease. Of the six patients treated with sodium stibogluconate, five improved and one remained symptomatic.

CONCLUSIONS

L. tropica can produce visceral infection that can cause unexplained systemic illness in persons returning from areas where this organism is endemic.

2-acetylpyridine thiosemicarbazones. 13. Derivatives with antifilarial activity

Several members of a series of 2-acetylpyridine thiosemicarbazones possess in vivo and in vitro macrofilaricidal properties. The most promising of the group tested is N4-(2-aminophenyl)-2-[1-(2-pyridinyl)ethylidene]-hydrazinecarbothioam ide (4), which suppressed 100% of the macrofilariae of Brugia pahangi and 94% of those of Acanthocheilonema viteae in the jird at a dose of 25 mg/kg per day x 5. Compounds 4 and 14 were also shown to inactivate or kill Onchocerca gutturosa and Onchocerca volvulus adult worms as measured by the loss of their motility or the inhibition of the conversion by the worms of the dye MTT to formazan.

Human cutaneous leishmaniasis in Ecuador: identification of parasites by enzyme electrophoresis

Twenty-six strains of Leishmania were isolated from cutaneous lesions in humans in 3 different geographical areas of Ecuador. The species were identified by enzyme electrophoresis as Leishmania braziliensis, L. panamensis, L. guyanensis, L. mexicana, and L. amazonensis.

Leishmania spp.: development of pentostam-resistant clones in vitro by discontinuous drug exposure

Antimony unresponsiveness in mucocutaneous and visceral leishmaniasis is a serious clinical problem. Information on the mechanisms and characteristics of drug resistance in parasites that suggest chemotherapeutic strategies to overcome resistance is of practical importance. We developed nine lines of Leishmania resistant to drugs, the major emphasis being on pentavalent antimony (Sb) complexed to carbohydrate in the form of sodium stibogluconate (Pentostam), one of the only two antileishmanial agents with a clearly favorable therapeutic index. Resistance to Pentostam (33- to 212-fold increase) was obtained in promastigotes of Leishmania in vitro by exposure to gradually increasing concentrations of drug over several passages. Resistance to Sb was found to be either stable or unstable. Stable resistance to Sb required (greater than 3) exposures of the initial sensitive clones to Pentostam and tended to stabilize with increased time under pressure. In general, resistance obtained in a clone after only a few (less than or equal to 3) step treatments was low and unstable. Differences in the susceptibility to Pentostam were found between strains isolated from patients with American cutaneous leishmaniasis. In addition, natural isolates of Leishmania from patients represented a heterogeneous population of parasites as demonstrated by a biphasic concentration response to Sb (typical of mixed population dynamics) and by marked differences in susceptibility to Pentostam among clones prepared from single isolates. These results suggest that the emergence of parasite resistance to antimonial treatment is a potential risk of inadequate dose therapy.

IgG antibody subclasses in human filariasis. Differential subclass recognition of parasite antigens correlates with different clinical manifestations of infection

The four subclasses of IgG are distinct in structure, function, and degree of participation in the antibody response to complex antigens. Looking for differential responsiveness of potential pathogenetic significance, we have analyzed both quantitatively and qualitatively the filaria-specific IgG subclass responses of 20 patients with lymphatic filariasis presenting either with chronic lymphatic obstructive pathology and elephantiasis (CP) or with asymptomatic microfilaremia (MF). Subclass-specific monoclonal antibodies were used in an enzyme-linked immunosorbent assay to study IgG filarial antibodies quantitatively and in immunoblot analyses to determine qualitatively the subclass antibody specificities. Quantitatively, the most significant differences among patient groups were in levels of IgG4, which were more than 17 times higher in MF patients (geometric mean, 64.7 micrograms/ml) than in those with CP (mean, 3.7 micrograms/ml). When qualitative analyses were done on the same sera, major differences were noted, particularly in the recognition profiles of the IgG1, IgG3, and IgG4 responses. IgG1 and IgG3 responses to antigens were seen especially to antigens with m.w. greater than 68,000 in all patients with elephantiasis, whereas MF patients showed most of their reactivity to antigens less than 68,000. For IgG4, the MF patients showed prominent recognition of antigens throughout the entire range of m.w., whereas those with CP had very little IgG4 recognition of antigens of any m.w. Interestingly, this relationship was essentially reversed in the IgG3 antibody responses (especially to antigens greater than 68,000) and, to a lesser extent, the IgG1 responses. These findings demonstrate correlations of potential cause/effect significance between IgG4 antibody responsiveness and the immunomodulated asymptomatic MF form of clinical filariasis and between IgG3/IgG1 antibody responsiveness and the clinical presentation of CP.

IgG antibody subclasses in human filariasis. Differential subclass recognition of parasite antigens correlates with different clinical manifestations of infection

The four subclasses of IgG are distinct in structure, function, and degree of participation in the antibody response to complex antigens. Looking for differential responsiveness of potential pathogenetic significance, we have analyzed both quantitatively and qualitatively the filaria-specific IgG subclass responses of 20 patients with lymphatic filariasis presenting either with chronic lymphatic obstructive pathology and elephantiasis (CP) or with asymptomatic microfilaremia (MF). Subclass-specific monoclonal antibodies were used in an enzyme-linked immunosorbent assay to study IgG filarial antibodies quantitatively and in immunoblot analyses to determine qualitatively the subclass antibody specificities. Quantitatively, the most significant differences among patient groups were in levels of IgG4, which were more than 17 times higher in MF patients (geometric mean, 64.7 micrograms/ml) than in those with CP (mean, 3.7 micrograms/ml). When qualitative analyses were done on the same sera, major differences were noted, particularly in the recognition profiles of the IgG1, IgG3, and IgG4 responses. IgG1 and IgG3 responses to antigens were seen especially to antigens with m.w. greater than 68,000 in all patients with elephantiasis, whereas MF patients showed most of their reactivity to antigens less than 68,000. For IgG4, the MF patients showed prominent recognition of antigens throughout the entire range of m.w., whereas those with CP had very little IgG4 recognition of antigens of any m.w. Interestingly, this relationship was essentially reversed in the IgG3 antibody responses (especially to antigens greater than 68,000) and, to a lesser extent, the IgG1 responses. These findings demonstrate correlations of potential cause/effect significance between IgG4 antibody responsiveness and the immunomodulated asymptomatic MF form of clinical filariasis and between IgG3/IgG1 antibody responsiveness and the clinical presentation of CP.

Leishmania braziliensis: protein, carbohydrate, and antigen differences between log phase and stationary phase promastigotes in vitro

When Leishmania species are grown in vitro, parasites from the stationary phase differ from those in log phase growth in being more infective and more resistant to complement and macrophage mediated killing. In the present study, log phase and stationary phase promastigotes of Leishmania braziliensis panamensis were compared at the molecular level. Differences in polypeptide and glycoprotein composition and antigenicity between log and stationary phase promastigotes of L. b. panamensis were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting; the former showed that two polypeptides were unique to log phase promastigotes and one was unique to stationary phase promastigotes. There were also differences in surface lectin binding characteristics of log and stationary phase promastigotes. Live stationary phase promastigotes bound more concanavalin and lentil lectin than log phase promastigotes, indicating a greater number of mannose residues on their surfaces.

Identification of antigens of Trypanosoma cruzi which induce antibodies during experimental Chagas' disease

Experiments were conducted to identify antigens of Trypanosoma cruzi (Brazil strain) to which antibodies are directed during the course of experimental Chagas' disease in C3H(He) (susceptible) and C57BL/6J (resistant) female mice. An extract of culture forms of the parasite was subjected to SDS-polyacrylamide gel electrophoresis, transferred to a solid phase matrix of nitrocellulose and used as antigens to detect antibodies in the sera of infected mice. Reactive antibodies were detected using an avidin-biotin peroxidase test. Two antigens were consistently detected with sera of normal, uninfected C57BL/6 and C3H(He) mice (51,000 and 44,000; and 53,000 and 46,000 daltons, respectively). A total of 32 antigens with m.w. of 230,000 to 25,000 daltons reacted with antibodies in sera of C3H mice infected for 25 days. Both the number of antigens detected and intensity of reactions increased with time of infection in C3H mice. An early (day 5), rapid, although weak response was observed to antigens of 85,000, 56,000, 53,000, 46,000 and 41,000 daltons. Throughout infection intense responses to antigens of 75,000, 67,000, 45,000, 41,000 and 36,000 daltons were detected. A similar number of components (a total of 34) with m.w. of 210,000 to 20,000 daltons were detected as being antigenic during the course of T. cruzi infection of C57BL/6 mice. A high number of antigens (25) was observed early in infection of C57BL/6 mice by day 10, including components with m.w. of 90,000, 85,000 and 70,000 daltons. Only minor changes were detected, however, after day 20 until day 120, when increases in the number of antigens and the intensity of certain reactions (e.g., antigens of 75,000, 46,000 and 26,000 daltons) were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnosis of Chagas' disease in humans using a biotin-3H-avidin radioimmunoassay

A radioimmunoassay (RIA) originally designed to measure antibody responses to Trypanosoma cruzi in mice was adapted for use in the immunodiagnosis of Chagas' disease in humans. The assay utilizes biotinylated antibodies and 3H-avidin as the tracer molecules, and has proven to be both safe and sensitive. Results using the RIA and those from direct agglutination and indirect fluorescent antibody tests were comparable in most cases. Using the RIA, we were able to discriminate between mice infected with T. cruzi and Trypanosoma rangeli. Also, sera from Leishmania-infected individuals do not have detectable levels of antibodies capable of binding to T. cruzi. Intact, fixed epimastigotes of T. cruzi are used as the detecting antigen in the RIA and give results comparable to those obtained with intact trypomastigotes.

Trypanosoma magdalenae sp. n (Protozoa: Kinetoplastida) from a freshwater teleost, Petenia kraussii, in Colombia

A new, monomorphic trypanosome, Trypanosoma magdalenae sp. n. was found in five of 38 fish, Petenia kraussii, from the Río Magdalena in Colombia, South America. It is the first trypanosome species designated from freshwater teleosts in Colombia. The trypomastigotes measured in 42.4 micron +/- 2.05 SD (range, 39.8 - 45.6) by 2.1 micron +/- 0.20 (2.0 - 2.5). Their nuclear index was 1.6 micron +/- 0.22 (1.25 - 1.84) and their kinetoplastic index equaled 1.1 micron +/- 0.02 (1.08 - 1.15). Infection intensity was usually limited to two or three flagellates per 40 microliter of packed blood cells.