Krishna Pandey

Comparison of short-course multidrug treatment with standard therapy for visceral leishmaniasis in India: an open-label, non-inferiority, randomised controlled trial

BACKGROUND Improved treatment approaches are needed for visceral leishmaniasis. We assessed the efficacy and safety of three potential short-course combination treatments compared with the standard monotherapy in India. METHODS Standard treatment (1 mg/kg amphotericin B infusion on alternate days for 30 days, total dose 15 mg/kg) was compared with three drug combinations (single injection of 5 mg/kg liposomal amphotericin B and 7-day 50 mg oral miltefosine or single 10-day 11 mg/kg intramuscular paromomycin; or 10 days each of miltefosine and paromomycin) in an open-label, parallel-group, non-inferiority, randomised controlled trial in two hospital sites in Bihar, India. Patients aged 5-60 years with parasitologically confirmed visceral leishmaniasis were randomly assigned one of the four treatments by the trial statistician by use of a computer-generated list. Clinical assessments were done at the end of treatment (15 days on combination treatment; 31 days for standard treatment) and after 45 days and 6 months. The primary endpoint was definitive cure (defined as no sign or symptom of visceral leishmaniasis and parasitologically cured to the last follow-up). Analyses were done both by intention to treat and per protocol. This trial is registered with ClinicalTrials.gov, number NCT00696969. FINDINGS Between June, 2008, and July, 2009, 634 patients were assigned amphotericin B (n=157), liposomal amphotericin B with miltefosine (n=160) or paromomycin (n=158), or miltefosine and paromomycin (n=159). 618 patients were in the per-protocol population. There were two relapses in each group. The numbers with definitive cure at 6 months for the intention-to-treat population were 146 (cure rate 93·0%; CI 87·5-96·3) for amphotericin B, 156 (97·5%; 93·3-99·2) for liposomal amphotericin B and miltefosine, 154 (97·5%; 93·24-99·2) for liposomal amphotericin B and paromomycin, and 157 (98·7%; 95·1-99·8) for miltefosine and paromomycin. All combinations were non-inferior to the standard treatment, in both the intention-to-treat and per-protocol populations. Patients in the combination groups had fewer adverse events than did those assigned standard treatment. INTERPRETATION Combination treatments for visceral leishmaniasis are efficacious and safe, and decrease the duration of therapy, thereby encouraging adherence and reducing emergence of drug-resistant parasites. FUNDING Drugs for Neglected Diseases initiative and the Indian Council of Medical Research.

Phase 4 Trial of Miltefosine for the Treatment of Indian Visceral Leishmaniasis

BACKGROUND Visceral leishmaniasis (VL) is a major public health problem in Bihar, accounting for 90% of all cases in India. Development of high levels of resistance to various existing drugs necessitated the search for alternative orally administered drugs. Hospital-based studies have shown that oral miltefosine is a highly effective treatment for VL both in adults and in children. METHODS An open, single-arm trial was designed to investigate the feasibility of treatment of VL patients with miltefosine in field conditions in 13 centers in Bihar. RESULTS The phase 4 study was conducted among 1132 adult and pediatric VL patients. Compliance was good, with 1084 (95.5%) patients completing the full 28-day treatment course. Nine hundred and seventy-one (85.8%) patients returned for the final cure assessment at 6 months after treatment. The final cure rate was 82% by intention to treat analysis and 95% by per protocol analysis (similar to the 94% cure rate in hospitalized patients). Treatment-related adverse events of common toxicity criteria grade 3 occurred in ~3% of patients, including gastrointestinal toxicity and rise in aspertate amino transferase, alanine amino transferase, or serum creatinine levels, similar to previous clinical experience. CONCLUSION This study supports the use of miltefosine in an outpatient setting in an area where VL is endemic.

Mechanism of Amphotericin B Resistance in Clinical Isolates of Leishmania donovani

ABSTRACT The clinical value of amphotericin B, the mainstay therapy for visceral leishmaniasis in sodium antimony gluconate-nonresponsive zones of Bihar, India, is now threatened by the emergence of acquired drug resistance, and a comprehensive understanding of the underlying mechanisms is the need of the hour. We have selected an amphotericin B-resistant clinical isolate which demonstrated 8-fold-higher 50% lethal doses (LD50) than an amphotericin B-sensitive strain to explore the mechanism of amphotericin B resistance. Fluorimetric analysis demonstrated lower anisotropy in the motion of the diphenylhexatriene fluorescent probe in the resistant strain, which indicated a higher fluidity of the membrane for the resistant strain than for the sensitive strain. The expression patterns of the two transcripts of S-adenosyl-l-methionine:C-24-Δ-sterol methyltransferase and the absence of ergosterol, replaced by cholesta-5,7,24-trien-3β-ol in the membrane of the resistant parasite, indicate a decreased amphotericin B affinity, which is evidenced by decreased amphotericin B uptake. The expression level of MDR1 is found to be higher in the resistant strain, suggesting a higher rate of efflux of amphotericin B. The resistant parasite also possesses an upregulated tryparedoxin cascade and a more-reduced intracellular thiol level, which helps in better scavenging of reactive oxygen species produced by amphotericin B. The resistance to amphotericin B was partially reverted by the thiol metabolic pathway and ABC transporter inhibitors. Thus, it can be concluded that altered membrane composition, ATP-binding cassette transporters, and an upregulated thiol metabolic pathway have a role in conferring amphotericin B resistance in clinical isolates of Leishmania donovani.

Inhibition of ABC Transporters Abolishes Antimony Resistance in Leishmania Infection

ABSTRACT The emergence of antimony (Sb) resistance has jeopardized the treatment of visceral leishmaniasis in various countries. Previous studies have considered the part played by leishmanial parasites in antimony resistance, but the involvement of host factors in the clinical scenario remained to be investigated. Here we show that unlike infection with Sb-sensitive (Sbs) Leishmania donovani, infection with Sb-resistant (Sbr) L. donovani induces the upregulation of multidrug resistance-associated protein 1 (MRP1) and permeability glycoprotein (P-gp) in host cells, resulting in a nonaccumulation of intracellular Sb following treatment with sodium antimony gluconate (SAG) favoring parasite replication. The inhibition of MRP1 and P-gp with resistance-modifying agents such as lovastatin allows Sb accumulation and parasite killing within macrophages and offers protection in an animal model in which infection with SbrL. donovani is otherwise lethal. The occurrence of a similar scenario in clinical cases is supported by the findings that unlike monocytes from SAG-sensitive kala-azar (KA) patients, monocytes from SAG-unresponsive KA patients overexpress P-gp and MRP1 and fail to accumulate Sb following in vitro SAG treatment unless pretreated with inhibitors of ABC transporters. Thus, the expression status of MRP1 and P-gp in blood monocytes may be used as a diagnostic marker for Sb resistance and the treatment strategy can be designed accordingly. Our results also indicate that lovastatin, which can inhibit both P-gp and MRP1, might be beneficial for reverting Sb resistance in leishmaniasis as well as drug resistance in other clinical situations, including cancer.

Liposomal Amphotericin B for Visceral Leishmaniasis in Human Immunodeficiency Virus-Coinfected Patients: 2-Year Treatment Outcomes in Bihar, India

BACKGROUND Reports on treatment outcomes of visceral leishmaniasis (VL)-human immunodeficiency virus (HIV) coinfection in India are lacking. To our knowledge, none have studied the efficacy of liposomal amphotericin B in VL-HIV coinfection. We report the 2-year treatment outcomes of VL-HIV-coinfected patients treated with liposomal amphotericin B followed by combination antiretroviral treatment (cART) in Bihar, India. METHODS The study included all patients with newly diagnosed VL-HIV coinfection and initiating treatment with liposomal amphotericin B (20-25 mg/kg in 4-15 days) between July 2007 and September 2010. Kaplan-Meier estimates of the cumulative incidence of death/treatment failure were calculated. RESULTS Fifty-five patients were included (83.6% male; median age, 35 years; 62% migrant laborers; median follow-up, 1 year). The median CD4 cell count at VL diagnosis was 66 cells/μL (interquartile range, 38-112). Twenty-seven patients (49.1%) presented with VL relapse of VL. The overall tolerance of liposomal amphotericin B was excellent, with no interrupted treatment. Survival by 1 and 2 years after VL treatment was estimated at 85.5%. No patients had initial treatment failure. The probabilities of VL relapse were 0%, 8.1%, and 26.5% at 0.5, 1, and 2 years after VL treatment, respectively; relapse rates were similar for primary VL and VL relapse. CD4 counts <200 cells/μL at 6 months after cART initiation were predictive of subsequent relapse. The mean CD4 cell counts at 6 and 24 months after cART initiation were 187 and 261 cells/μL, respectively. The rate for retention in HIV care was 83.6%. CONCLUSIONS Good long-term survival and retention rates were obtained for VL-HIV-coinfected patients treated with liposomal amphotericin B and cART. Although the initial VL treatment response was excellent, VL relapse within 2 years remained frequent.

Estimation of Under-Reporting of Visceral Leishmaniasis Cases in Bihar, India

We estimated the level of under-reporting of visceral leishmaniasis (VL) cases by comparing the actual reported cases with those expected as estimated using age- and sex-stratified incidence proportions obtained in a cohort of 31,324 persons. The average incidence proportion of VL cases in study population was 5.7/1,000 (95% confidence interval [CI] = 4.88-6.54) and 1.09/1,000 persons (95% CI = 0.99-1.20) based on the reported cases in two primary health centers. The overall magnitude of VL cases not reported to the government agencies was higher by a factor 4.17 (95% CI = 3.75-4.63) than for reported cases. The levels of under-reporting were 4.74 (95% CI = 4.11-5.47) in males and 3.51 (95% CI = 2.99-4.11) in females with no significant difference (P > 0.05). It was significantly higher in persons >or= 30 years of age than in persons 30 years of age (P < 0.05).

Asymptomatic infection with visceral leishmaniasis in a disease-endemic area in bihar, India.

A prospective study was carried out in a cohort of 355 persons in a leishmaniasis-endemic village of the Patna District in Bihar, India, to determine the prevalence of asymptomatic persons and rate of progression to symptomatic visceral leishmaniasis (VL) cases. At baseline screening, 50 persons were positive for leishmaniasis by any of the three tests (rK39 strip test, direct agglutination test, and polymerase chain reaction) used. Point prevalence of asymptomatic VL was 110 per 1,000 persons and the rate of progression to symptomatic cases was 17.85 per 1,000 person-months. The incidence rate ratio of progression to symptomatic case was 3.36 (95% confidence interval [CI] = 0.75-15.01, P = 0.09) among case-contacts of VL compared with neighbors. High prevalence of asymptomatic persons and clinical VL cases and high density of Phlebotomus argentipes sand flies can lead to transmission of VL in VL-endemic areas.

Asymptomatic infection of visceral leishmaniasis in hyperendemic areas of Vaishali district, Bihar, India: a challenge to kala-azar elimination programmes

A cohort of 91 asymptomatic individuals with visceral leishmaniasis (VL) were identified during base line screening using recombinant 39-aminoacid antigen (rk-39) and polymerase chain reaction (PCR) conducted from December 2005 to June 2006 involving 997 individuals of two highly endemic villages of Vaishali district, Bihar. The point prevalence of asymptomatic infection was 98 per 1000 persons at baseline. There was no statistically significant difference between rk-39 and PCR positivity rate (P>0.05), even though PCR positivity alone was found significantly higher (4.2%) than rk-39 positivity alone (2.6%). The monthly follow-up of the asymptomatic cohort revealed a disease conversion rate of 23.1 per 100 persons within a year. There was a statistically significant difference in conversion of disease when individuals were positive by both tests as compared to single tests by rk-39 and PCR (P<0.01). Disease conversion rate in the subjects residing in households with a history of VL (62%, 13/21) was higher than those residing in the households without a history of VL (38%, 8/21). Most of the identified asymptomatic individuals were from low socio-economic strata similar to that of VL cases in general. Apart from rk-39, PCR may be considered for screening of asymptomatic Leishmania donovani infection in large-scale epidemiological studies. Screening of asymptomatic cases and their close follow-up to ascertain early detection and treatment of VL may be considered in addition to the existing VL control strategies.

Effectiveness and safety of liposomal amphotericin B for visceral leishmaniasis under routine program conditions in Bihar, India.

We evaluated, through the prospective monitoring of 251 patients at Sadar Hospital in Bihar, India, the effectiveness and safety of 20 mg/kg body weight of liposomal amphotericin B for the treatment of visceral leishmaniasis. The treatment success rates for the intention-to-treat, per protocol, and intention-to-treat worse-case scenario analyses were 98.8%, 99.6%, and 81.3%, respectively. Nearly one-half of patients experienced mild adverse events, but only 1% developed serious but non-life-threatening lips swelling. The lost to follow-up rate was 17.5%. Our findings indicate that the 20 mg/kg body weight treatment dosage is effective and safe under routine program conditions. Given that the exorbitant cost of liposomal amphotericin B is a barrier to its widespread use, we recommend further study to monitor and evaluate a lowered dosage and a shorter treatment course.

Oral miltefosine for Indian post-kala-azar dermal leishmaniasis: a randomised trial

Standard treatment of Indian post‐kala‐azar dermal leishmaniasis (PKDL) is unsatisfactory because to achieve therapeutic effectiveness, heroic courses of parenteral and toxic agents have to be administered. Our objective was to evaluate oral miltefosine for its potential to provide effective as well as tolerable treatment for this disease.