Amphotericin B Deoxycholate Treatment of Post–Kala-Azar Dermal Leishmaniasis in India

ABSTRACT.

Post–kala-azar dermal leishmaniasis (PKDL) is widely prevalent in the endemic regions of India, but its treatment remains unsatisfactory. The WHO recommends a 12-week treatment with oral miltefosine, but its ocular toxicities are a serious concern. The late 1980s and early 1990s saw the use of sodium stibogluconate and amphotericin B (AmB) for a brief period. Both drugs had frequent adverse events and were expensive, and the duration of treatments was unacceptably long. This retrospective study evaluated, analyzed, and reported the outcomes of PKDL patients treated with a shorter course of AmB, the most effective antileishmanial drug. The hospital records of PKDL patients treated with AmB by 30 alternate-day infusions over 60 days (instead of conventional 60–80 infusions over 100–120 days) between September 2010 and August 2016 were reviewed. Only patients with confirmed parasitological diagnosis were included. Their records were studied for treatment-related adverse events, end-of-treatment parasitological status, and 12-month follow-up results. One hundred two patients were eligible for this study between September 2010 and August 2016. After therapy, 92/102 (90.2%) patients improved; 3 (2.9%) had to cease treatment owing to severe adverse effects, and one died of severe diarrhea unrelated to AmB. Six (5.9%) patients withdrew consent before the treatment was complete. At the 12-month evaluation, 89/102 (87.3%) patients attained a final cure. A 30-infusion regimen of AmB remains highly effective in PKDL. Without a shorter, safer, and more economical regimen for the treatment of PKDL, it should be used until a better regimen is available.

INTRODUCTION

Post–kala-azar dermal leishmaniasis (PKDL) is a dermal rash that occurs in 5–15% of patients several months to years after the cure of visceral leishmaniasis (VL) in the Indian subcontinent (ISC). In contrast, in East Africa, PKDL occurs either with VL or immediately after the episode of VL. In India, a spontaneous cure for PKDL does not occur, whereas in Africa, most patients have spontaneous healing within 3 months.¹ Post–kala-azar dermal leishmaniasis has been a neglected entity of a neglected tropical disease. Fortunately, with the launch of the Kala-Azar Elimination Program (KAEP), the incidence of VL has decreased steeply. Unfortunately, there are a significant number of untreated PKDL patients in the community, which presents serious epidemiological implications. These patients are reservoirs of the parasite Leishmania donovani and can sustain transmission or even initiate an outbreak of VL.^2,3

Sandflies pick up Leishmania infection from PKDL patients quite efficiently.^4,5 Thus, it is of paramount importance that these patients be treated effectively to remove the lurking threat of another epidemic, even after the goal of elimination of VL has been achieved. Furthermore, the only way to achieve this is early diagnosis and treatment of PKDL patients by active case detection to eliminate these human reservoirs. However, as far as the treatment of PKDL is concerned, the options are limited, and previously used regimens were toxic, long, and arduous (e.g.,120 daily injections of sodium stibogluconate [SSG] over 4 months or more^6,7 or 60–80 amphotericin B deoxycholate [AmB] infusions over 100–120 days).⁸ In 2002, miltefosine (MF), the first orally administrable antileishmanial drug, was approved in India for treating VL.⁹ A few years later, in 2010, the WHO recommended this drug for the treatment of PKDL in South Asia,¹⁰ and the drug was dispensed free of cost through public health facilities by the National Program. Unfortunately, recently several reports of ocular toxicities of MF have appeared in the literature, and many patients developed permanent partial or total vision loss.^11–13 Thus, no safe regimen is available for the treatment of PKDL, and there is a crisis in India.

At the Kala-Azar Medical Research Center (KAMRC), Muzaffarpur, between September 2010 and August 2016, a significant number of PKDL patients were treated with a modified AmB regimen with half the quantity of the drug delivered over a much shorter duration. In this retrospective, observational, in-depth study, an analysis of the findings and outcomes was done, looking at the possibility of using this treatment regimen for PKDL in India.

MATERIALS AND METHODS

Study design and setting.

In this retrospective observational study of PKDL, patients were treated with AmB between September 2010 and August 2016 at the KAMRC, Muzaffarpur, the field site of the Institute of Medical Sciences, Banaras Hindu University.

Eligibility criteria.

The study included all medical records of confirmed cases of PKDL of either age or sex. Patients with the following conditions were excluded from the study: patients with a hemoglobin level <5.0 g/dL; total leukocyte count <2.5 × 10⁹/L; platelet count <50 × 10⁹/L; liver diseases likely to influence the outcome of the study; serum creatinine value ≥1.5 times upper limit normal, which is 1.3 and 1.1 mg/dL for males and females, respectively; cardiac diseases; and any comorbid condition likely to affect the outcome of PKDL.

Data collection.

A team of physicians reviewed eligible patients’ files for general and systemic examination and investigations carried out for the diagnosis. A thorough medical history was recorded, including demographic information and a history of prior VL. Immunochromatographic rapid strip tests (InBios, Seattle, WA) were used to detect rK39 antigen antibodies in all patients. A slit-skin smear examination was done to demonstrate amastigotes of Leishmania infection. Patients with negative skin smears were further investigated for confirmation of the PKDL by polymerase chain reaction (PCR) in skin tissues. According to the manufacturer’s recommendations, the QIAamp Tissue and Blood DNA Extraction Mini Kit (Qiagen, Hilden, Germany) was used to isolate DNA from skin and blood. Leishmania donovani species-specific primers were used for parasite detection by PCR, and the procedure was carried out as described previously.¹⁴ Every patient underwent examinations for complete blood counts, blood glucose, serum electrolytes, and renal and liver functions. To ascertain the efficacy and safety of the therapy at baseline and follow-up, essential investigations (blood counts, electrocardiogram, serum electrolytes, liver and renal function tests) were conducted periodically in conjunction with the clinical assessment. After completion of treatment at day 60, a parasitological analysis was repeated as done at baseline.

Treatment.

All confirmed PKDL patients were treated with AmB at a dose of 1 mg/kg body weight diluted in 500 mL of 5% glucose for slow intravenous (IV) infusions over 3–4 hours on alternate days for a total of 30 doses over 60 days. Oral antipyretic (paracetamol) and antihistaminic (chlorpheniramine maleate) were given an hour before each infusion to minimize infusion reactions. Patients were hospitalized throughout the treatment period (60 days) and were closely observed for adverse events. Periodic laboratory evaluations were done at weekly intervals until the completion of treatment. Patients with laboratory abnormalities at the end of treatment remained hospitalized and were discharged only when their laboratory values had returned to normal. Patients were sent home with proper counseling for regular follow-ups at 3, 6, and 12 months. An increase in the number or size of lesions or the appearance of new lesions indicated treatment failure. At the end of treatment, patients with a negative slit-skin smear and PCR, flattening of nodules or papules, and significant repigmentation of macules in more than 70% of lesions at 12-month follow-up were considered finally cured.

STATISTICAL ANALYSES

Statistical analysis was performed using Statistical Package for the Social Sciences v. 23.0 (IBM Corp., Armonk, NY). Simple descriptive statistics were used (mean ± SD for quantitative variables and frequency with percentage distribution for categorized variables). The statistical analysis was carried out for various categorical parameters using the χ² and Fischer’s exact tests. Paired Student’s t-test and Wilcoxon signed rank test were used for paired samples. P-values less than 0.05 were considered significant.

RESULTS

The present study included 102 PKDL patients treated between September 2010 and August 2016. Ninety-two (90.2%) of 102 patients had a history of previous VL, and the most common treatment received by them for VL was SSG in 28 (27.45%) patients, followed by MF in 23 (22.54%) patients. Clinical and laboratory findings are described in Table 1. The rK39 rapid strip test was positive in all patients (102, 100%). Of 102 patients, 92 (90.2%) received all 30 AmB infusions, and of the remaining 10, six (5.9%) withdrew their consent after 3–22 infusions. One patient died owing to a cause unrelated to the study drug. In three patients, the treatment was stopped because one each developed severe vomiting, severe infusion reaction, and nephrotoxicity, which returned to normal after stoppage of the treatment (Figure 1). Ninety-two (90.2%) patients completed the treatment. Satisfactory improvement was observed in all of them.

Table 1.

Demographic, baseline, and post-treatment laboratory data

Variable	Day 0	Day 60	P-Value
Age in Years (mean ± SD)	22.98 ± 12.45	–	–
Male Sex	56 (54.9%)	–	–
History of Kala-Azar	92 (90.2%)	–	–
Type of Lesions	No. (%)	–	–
Macular	59 (57.8%)	…	–
Nodular	23 (22.5%)	…	–
Polymorphic	20 (19.7%)	–	–
Weight (kg)	42.63 ± 16.81	43.31 ± 16.22	0.01
Total leukocyte count (× 109 cells/L)	10.6 ± 4.2	9.3 ± 3.1	0.001
Hemoglobin (g/dL)	12.29 ± 1.81	9.49 ± 1.17	<0.001
Potassium (mmol/L)	3.96 ± 0.20	3.95 ± 0.31	0.731
Creatinine (mg/dL)	0.96 ± 1.33	1.37 ± 0.57	<0.001
AST (units/L)	70.74 ± 41.04	42.96 ± 38.30	<0.001
ALT (units/L)	45.05 ± 52.38	27.58 ± 22.34	<0.001

Figure 1.

Patient flow and disposition.

Amphotericin B deoxycholate–induced infusion reactions were common; fever with rigors was seen in 65.7% of patients (67/102), only fever was observed in 12.8% (13/102), and in the remaining 21.6% (22/102), no infusion reactions occurred. At enrollment, hepatic enzymes were raised in a significant number of patients (aspartate transaminase [AST] in 52 [51.0%] and alanine aminotransferase [ALT] in 30 [29.4%]). At the end of treatment, there was a significant decline in the levels of both enzymes (Table 1). Hypokalemia was recorded in only one (1%) patient at the end of treatment on day 60. At baseline, none of the patients had a raised serum creatinine value. However, 42 (41.2%) patients experienced a mild grade 2 rise in creatinine levels during therapy; in all of these, the creatinine values returned to normal within 10 days after the treatment was completed. However, in one patient with normal serum creatinine level at baseline, there was a significant increase in serum creatinine levels to grade 3 (4.31 mg/dL),¹⁵ and the AmB infusion was discontinued.

Relevant laboratory tests listed on case sheets were analyzed, and the results are shown in Table 1. By per-protocol calculations, the cure rate at 12-month follow-up was 96.8% of patients (89/92; 95% CI = 90.85–98.88%), and relapse was noted in two (2%) patients (Figure 1). However, with the intention-to-treat analysis, the final cure rate at 12 months was 87.3% (89/102; 95% CI = 79.41–92.4%).

DISCUSSION

The WHO suggested a road map for ending the neglect of neglected tropical diseases in 2021 − 2030. The road map sets global targets and milestones to prevent, control, eliminate, or eradicate 20 diseases and disease groups.¹⁶ According to the WHO’s road map, India has achieved the target of KAEP, and now the focus should be to maintain this status and aim to eradicate the disease by 2030. However, PKDL is an important player in the transmission of VL in India, being a human reservoir. In one of our studies, 15 (94%) of 16 patients with nodular PKDL and eight (80%) of 10 patients with macular PKDL transmitted L. donovani to at least one sandfly as determined by quantitative PCR.⁵ In the past, VL outbreaks have been attributed to PKDL.^2,3 Post–kala-azar dermal leishmaniasis needs to be eliminated to prevent future VL outbreaks and achieve the 2030 target of eradicating VL and PKDL.

Unfortunately, PKDL has not received the attention needed from academia and the pharmaceutical industry. Publications on the treatment of PKDL are uncommon from the ISC. The significance of PKDL has only been recognized in the past 10–12 years. As these PKDL patients have no physical limitations except aesthetic issues, most of them do not come forward on their own for treatment; active case detection and complete treatment are required. The attrition rate is quite high, and a lot of persuasion is required to enroll and successfully treat affected patients.

If one looks back at the availability of therapeutic options for patients with PKDL, they are extremely limited in the ISC. As stated previously, all three regimens for SSG, AmB, and MF have serious issues with the length of treatment and toxic events. Prolonged (120-day) parenteral treatment with SSG frequently leads to serious cardiotoxicities, which can be fatal; the second option is 60–80 AmB infusions over 100 days or more, and the third currently recommended regimen is 12 weeks of MF, which often leads to serious ocular toxicities. In several studies, MF has been tested in patients with PKDL as a solo drug. Ramesh et al¹⁷ reported its dwindling efficacy and a relapse rate of 15%; similarly, in another small MF study, the inadequacy of the recommended 12-week treatment was noticed, and the authors proposed a 16-week treatment.¹⁸ In the wake of these reports, high cost, irregular availability, noncompliance resulting from prolonged therapy, frequent gastrointestinal adverse events, and most importantly, its ocular toxicity make MF unsuitable for use in the control program.¹¹ Because of its long half-life with the potential of teratogenicity, it entails contraception for the duration of treatment and another 5 months,¹⁹ Thus, there is a dire need for an acceptable regimen for this disease that is economical, shorter, and safe.

There have been attempts to use short liposomal amphotericin B (LAmB) courses in Bangladesh and India. In a study from Bangladesh, a total dose of 15 mg/kg given over 2 weeks achieved a cure rate of 78%.²⁰ In a small (16 patients in each arm) study from India, LAmB plus MF was compared with MF alone, and a 100% cure rate was reported with the combination.²¹ In another, just completed, multicenter trial from India and Bangladesh, a combination of LAmB (20 mg/kg) and MF (duration of 3 weeks) was compared with LAmB alone (20 mg/kg), and the results are awaited.²²

In the current study, 87.3% of PKDL patients were cured with the shorter regimen of AmB. Feasibility is better, and the cost of treatment is lower by 50%. The duration is also halved compared with the earlier suggested 100-day AmB regimen. The costs of hospital stay, laboratory monitoring, and wages lost for the patient and companion (caregiver, usually family member) is also significantly reduced. As expected, noncompliance, withdrawal of consent, cardiotoxicity, and other toxic events are higher with the longer regimens. Another important advantage is the doubling of the hospital’s capacity to treat these patients.

Notwithstanding the high incidence of infusion reactions, AmB has been the only drug used widely for several decades in different fungal diseases and leishmaniasis. Our experience with AmB treatment of more than 5,000 patients with VL has been very satisfactory, and renal failure, hypokalemia, and drug-related deaths were rare.

There is an urgent need to have an acceptable treatment regimen for PKDL in South Asia. Amphotericin B deoxycholate, though associated with frequent (mostly mild) adverse events, is the only drug that can be used to treat PKDL. From India or elsewhere, very few publications (with small sample sizes) describing the safety profile of AmB in the treatment of PKDL in India are available.²³ In the current study, experience with AmB in PKDL treatment was very satisfactory, and with 2 months of hospitalization using 30 AmB infusions on alternate days, high cure rates were observed.

There are certain limitations associated with this regimen (e.g., the necessity of 30 infusions remains challenging). Although the duration of treatment has been reduced significantly, 2 months of hospitalization are still needed. Periodic laboratory monitoring is required. So, the regimen used in this study should be used until a better alternative is available.

Although the introduction of single-dose IV infusion of LAmB for VL has boosted the capacity of primary health centers to provide IV infusions in VL-endemic regions, the high cost of LAmB makes this drug unaffordable for most low- or middle-income countries such as India. Although it is now available to the control program as a donation, it is meant only for patients with VL.²⁴ Antileishmanial treatment by the control program in India is heavily dependent on donations. We need to have PKDL treatment regimens that are cheap and can be carried out with India’s resources.