Comparison of Intralesional Two Percent Zinc Sulfate and Glucantime Injection in Treatment of Acute Cutaneous Leishmaniasis

Abstract

Introduction:

Cutaneous leishmaniasis is an endemic disease in developing countries caused by different species of leishmania parasite, and if left untreated, it will result in a deformed scar after a relatively long period. Although various systemic and topical treatments have been proposed for leishmaniasis, pentavalent Antimony compounds remain the first-line treatment for it. Considering the cases with treatment failure, potential side effects and reluctance of patients to receive the drug, there are continuing efforts to find better treatment alternatives.

Aim:

Comparison of the effect of intralesional 2% zinc sulfate injection with Glucantime in treatment of acute cutaneous leishmaniasis.

Materials and Methods:

In this clinical trial, 45 patients with clinical diagnosis of cutaneous leishmaniasis and positive direct smear for leishman body were treated by intralesional injection of either 2% zinc sulfate or Glucantime. After simple randomization, in one group the patients were treated with 2 bouts of intralesional 2% zinc sulfate with a 2-week interval, and in the other group they were treated with 6 weekly bouts of intralesional Glucantime. The patients were monitored in two week intervals for 8 weeks. Healing of the lesions was evaluated clinically and by direct smear, and the data were analyzed using SPSS (11.5) software, t-Student, Mann-Whitney and Analysis of covariance (ANCOVA) statistical tests.

Findings:

In the end of study, 34 patients completed the study, 10 of whom received intralesional Glucantime and 24 of whom received intralesional 2% zinc sulfate. The healing rate after 8 weeks was 80% in the group receiving intralesional Glucantime and 33.3% in the one receiving 2% zinc sulfate (P=0.009).

Conclusion:

Based on the results of this study, intralesional injection of 2% zinc sulfate was less effective in treatment of cutaneous leishmaniasis than intralesional Glucantime.

Introduction

Cutaneous leishmaniasis is a skin disease caused by different species of leishmania with specific inclination of each species to a particular geographical region. It is endemic in 88 countries including Iran, Iraq, Brazil, Afghanistan, Peru, Sudan and Syria. It has afflicted 12 million people with 1-1.5 million new cases each year putting 350 million people at risk. It is becoming a global problem with increasing incidence due to immigration and travel.[1] Hyperendemicity of leishmaniasis in Iran has made it an important health problem in this country demanding high annual expenses. Although cutaneous leishmaniasis is a self-limiting disease, its healing takes months to years and in some cases it becomes chronic. On the other hand, healing is associated with a deformed scar.[2] Despite multiple treatment suggestions for cutaneous leishmaniasis, pentavalent Antimony compounds are used as first-line treatment,[3] but regarding their serious potential side effects including cardiac, hepatic and blood toxicity and pancreatitis, increased cases of clinical response failure,[4] high prices, lack of production technology in many of the developing endemic countries and prolonged treatment period, there are still efforts for finding an effective treatment with less side effects acceptable for patients. In numerous studies, oral zinc sulfate has been reported effective in treatment of cutaneous leishmaniasis.[5–7] Efficacy of intralesional zinc sulfate is debated in various studies, so that in Sharquie study it has been very effective[8] while in that of Firooz its efficacy has been reported to be inferior to intralesional Glucantime.[9] Therefore, we decided to compare the effect of intralesional zinc sulfate in treatment of acute cutaneous leishmaniasis with therapeutic effects of Glucantime in this clinical trial study.

Materials and Methods

This randomized clinical trial was performed from March to September 2004 on patients with cutaneous leishmaniasis admitted to Imam Reza Hospital in Mashhad. Patients with clinical diagnosis of cutaneous leishmaniasis were included in the study according to the inclusion criteria after laboratory confirmation.

Inclusion criteria

1. Confirmation of cutaneous leishmaniasis based on direct smear

2. Number of lesions being less or equal to 3

3. Duration of the disease being shorter than 12 weeks

4. Minimum age being 7 and maximum 60 years old

5. Completion of informed consent form by patient or parents of minor patients

6. Dry cutaneous leishmaniasis

Exclusion criteria

1. Pregnant or breast feeding women, infants lower the age of 7

2. Lesions on ear, nose, joints and near the eye

3. Number of lesions more than 3

4. Application of any kind of treatment for cutaneous leishmaniasis

5. Duration of the disease longer than 12 weeks (to omit spontaneous healing cases during the follow-up period)

6. Recurrent infection

7. Wet cutaneous leishmaniasis

According to these criteria, 45 patients were studied in two groups of A (treated with intralesional zinc sulfate) and B (treated with intralesional Glucantime). Eleven patients were excluded from the study for various reasons including painful injections,[6] the emergence of new lesions,[1] the need for systemic therapy[2] or failure to complete treatment;[2] and finally, 34 patients (including 24 patients in group A and 10 patients in group B) completed the study.

In order to prepare 2% solution of zinc sulfate, 2 g of dry zinc sulfate was dissolved per 100 ml double distilled water to make the transparent solution with pH=5. In order to sterilize the solution, first the solution was poured in serology glass and put for 20 minutes in 120C autoclave. In the next stage, the solution was passed by syringe through 0.2 μm color filter under laminar hood and transferred to vials of which the cap was sealed by paraffin.

To ensure a sterile solution, several culture samples were taken from vials for aerobic and anerobic bacteria with negative results. The solution was injected using insulin syringe needles in adjacent intact skin of the lesions with 45 degree angle so that the lesions were indurated and white. The average volume of injected solution per lesion was 0.2-0.5 ml. In group A, in each lesion injection of zinc sulfate was performed twice within 2 weeks. In group B, Glucantime was weekly injected in the lesions for 6 weeks using insulin syringe. The patients were monitored every 2 weeks for 8 weeks, and each patient completed a questionnaire including age, gender, lesion location, erythema size and induration of the lesions data. Rehabilitated lesions were assessed using clinical examination and determination of the induration size and erythema in the lesions. All the lesions were ultimately subject to direct smear. In conclusion, after 8 weeks the treatment response was recorded using the system of Sharquie:[10]

1. Slight: Partial reduction of erythema and edema

2. Mild: Reduction of lesion size up to 30%

3. Moderate: Reduction of lesion size between 30% and 60%

4. Marked: Reduction of lesion size more than 60% or negative smear

5. Total tolerance: Complete healing of the lesion with negative smear

Treatment response was calculated in each group, and then the analysis was performed using SPSS (11.5) software and t-Student, Mann-Whitney and ANCOVA statistical tests.

Results

From 35 patients in group A (treated with 2% zinc sulfate), 24 patients, and out of 15 patients in group B (treated with Glucantime), 10 patients completed the study. The level of changes in erythema and induration of the lesions in days 14, 28, 42 and 56 after treatment is summarized in Tables 1 and 2, respectively. The results indicate that reduction of erythema and induration of the lesions 42 days after starting the treatment was significantly higher in group treated with Glucantime than that treated with zinc sulfate.

Table 1.

Frequency distribution of units under study based on the type of drug and changes in erythema on days 14, 28, 42 and 56 after starting treatment

Table 2.

Frequency distribution of units under study based on the type of drug and changes in induration on days 14, 28, 42 and 56 after starting treatment

Comparing the mean average size of lesions in the two groups under study with adjustment relative to their size before treatment is shown in Table 3, indicating higher reduction of lesion size relative to that before the treatment in the group treated with Glucantime compared to group treated with intralesional zinc sulfate.

Table 3.

Comparison of the mean average size of lesions in the two groups under study with size adjustment relative to that before treatment

Complete cure rate in the group treated with intralesional Glucantime after 8 weeks was 80%, and it was 33.3% in the group treated with intralesional 2% zinc sulfate indicating significantly higher efficacy of Glucantime in treatment of cutaneous leishmaniasis lesions relative to intralesional zinc sulfate (P=0.009) [Table 4].

Table 4.

Frequency distribution of units under study for drug type and cure rate at the end of treatment period

The side effects seen in both groups were pain after injection and hyperpigmentation. Burning after injection and necrosis of the lesions were seen in all case in zinc sulfate group, and inflammation and swelling in only three patients who received zinc sulfate.

Photos of 2 of our patients in zinc sulfate group one with good response and another one without improvement are shown in Figures 1–5.

Figure 1.

Before treatment with zinc sulfate in a patient who responded to treatment

Figure 5.

After treatment of Figure 4 with zinc sulfate, without any response

Figure 2.

Necrosis and scar after treatment with zinc sulfate

Figure 3.

Improvement of Figure 1 with zinc sulfate

Figure 4.

Before treatment with zinc sulfate

Discussion

Pentavalent Antimony compounds (Glucantime and Pentostam) are currently used as first-line treatment of cutaneous leishmaniasis. Due to the side effects of these drugs, lack of cost effectiveness in economic terms, absence of production technology in many endemic developing countries and inadequate efficacy in some cases, the search for effective, risk free and inexpensive drugs is necessary. Considering the fact that Glucantime is the salt of the heavy metal Antimony and inhibits the amastigote growth by stopping glycolytic function and fatty acid oxidation, researchers have turned to consider other less toxic heavy metals such as zinc; and the hypothesis has been proposed that zinc may be effective against leishmania parasite. Zinc sulfate with concentration used in this study has the effect of immune-stimulation,[11] and the zinc ion has the ability of protein precipitation.[12] On the other hand, it has been shown that intralesional 2% zinc sulfate has a high capacity to inhibit leishmania amastigote, and possibly exerts this function through tissue damage and severe inflammatory changes.[13] Zinc also directly affects the enzymatic system of leishmania parasite.[14]

Zinc can boost Th1-mediated immune responses and help combat intracellular pathogens, and in this way it may be effective against leishmania.[15] Zinc is an intracellular signal molecule that plays an important role in improving the function of macrophages, dendrocytes and monocytes and cell -mediated immunity that are in turn effective in body defense against leishmania.[16,17] Zinc is involved in the determination of structural properties of molecules concerned with connection and entry of leishmania into white blood cells.[18] Several studies have shown that the serum zinc level in patients with leishmaniasis has been lower compared to control group;[19–21] and following treatment with Antimony compounds the serum zinc level has increased.[22] Regarding the above statements, several clinical trials have been conducted to evaluate the effects of oral and intralesional zinc sulfate in the treatment of cutaneous leishmaniasis.

Najim et al showed that oral zinc sulfate is effective on leishmania parasite both extracorporally and in animal body.[5] Sharquie et al evaluated the effect of different doses of oral zinc sulfate in treatment of cutaneous leishmaniasis. Their results showed that the rate of healing in the group receiving oral zinc sulfate with 2.5 mg/kg/day dose for 31.8±18 days was 89.3%, in the group receiving 5 mg/kg/day dose for 29.9±1.7 days 93.1%, and in the group with 10 mg/kg/day dose for 28.3±1.4 days 96.6%.[6] Sharquie introduced in 2004 a case of disseminated cutaneous leishmaniasis treated with oral zinc sulfate with 10 mg/kg/day dose divided to three bouts for 4 months.[7]

In a clinical trial conducted by Sharquie et al in 1997, cutaneous Leishmaniasis patients were subject to treatment by intralesional zinc sulfate, Glucantime and 7% sodium chloride solution. Based on the results of this study, 33 out of 38 (84.8%) lesions treated with intralesional 2% zinc sulfate showed complete healing following a bout of intralesional injection, and 94.7% of lesions were completely healed by two times injection within 10-15 days.[8]

Iraji et al in 2005 conducted a study to compare the effect of 2% zinc sulfate and intralesional Glucantime in the treatment of cutaneous leishmaniasis. The rate of healing after 6 weeks in 35 patients receiving Glucantime (6 weekly injections) was 60%, and it was 83.3% in 31 patients receiving 2% zinc sulfate (2 injections with 2-week interval). After weeks 2 and 4 post-treatment, the efficacy of treatment with zinc sulfate was higher than Glucantime (P<0.01), but after 6 weeks no difference between the two groups was observed (P>0.05). They concluded that treatment with intralesional zinc sulfate can be the alternative treatment for intralesional Glucantime.[23] In contrast, in the study by Firooz et al in 2005 in the form of a randomized double-blind controlled clinical trial, 31 cutaneous leishmaniasis lesions were treated with intralesional Glucantime and 19 lesions were treated with 2% zinc sulfate weekly for 6 weeks. A week after the end of treatment, complete healing was seen in 19 lesions (61.3%) in the first group and in two cases (10.5%) in the second group (P<0.05). It was shown that a 6-week treatment period with 2% intralesional zinc sulfate is less efficient in treatment of Old World leishmaniasis than intralesional Glucantime.[9]

In our study, like that of Firooz et al but more significantly, the rate of healing 8 weeks after starting the treatment in the group treated with intralesional Glucantime was 80%, and was significantly higher than the 33.3% rate of healing in the group treated with intralesional 2% zinc sulfate (P=0.009).

In justifying the differences observed between our study and investigations of other researchers in which zinc sulfate has been indicated the efficient treatment of cutaneous Leishmaniasis, the following points can be cited:

1. Difference in leishmania species causing cutaneous leishmaniasis in Mashhad, Isfahan and Iraq, and as a result difference in sensitivity of leishmania parasites to zinc sulfate.

2. Difference in the formulation of zinc sulfate.

3. Difference in method and frequency of zinc sulfate injection.

Generally, we must say that intralesional Glucantime injection compared with zinc sulfate is more effective in the healing of acute cutaneous leishmaniasis lesions, and pentavalent Antimony compounds make the first-line treatment of acute cutaneous leishmaniasis. In conclusion, we suggest that similar studies be performed with higher sample number, changing injection frequencies and zinc sulfate concentration, determining Leishmania subtype and its sensitivity to zinc sulfate for more precise conclusions.