Pratip Kumar Kundu

Age Associated Oxidative Damage in Lymphocytes

Lymphocytes are an important immunological cell and have been played a significant role in acquired immune system; hence, may play in pivotal role in immunosenescence. Oxidative stress has been reported to increase in elderly subjects, possibly arising from an uncontrolled production of free radicals with aging and decreased antioxidant defenses. This study was aimed to evaluate the level of lipid-protein damage and antioxidant status in lymphocytes of healthy individuals to correlate between oxidative damage with the aging process. Twenty healthy individuals of each age group (11–20; 21–30; 31–40; 41–50; and 51–60 years) were selected randomly. Blood samples were drawn by medical practitioner and lymphocytes were isolated from blood samples. Malondialdehyde (MDA), protein carbonyls (PC) level were evaluated to determine the lipid and protein damage in lymphocytes. Superoxide dismutase (SOD), catalase (CAT), glutathione and glutathione dependent enzymes were estimated to evaluate the antioxidant status in the lymphocytes. Increased MDA and PC levels strongly support the increased oxidative damage in elderly subject than young subjects. The results indicated that, balance of oxidant and antioxidant systems in lymphocytes shifts in favor of accelerated oxidative damage during aging. Thus oxidative stress in lymphocytes may particular interest in aging and may play important role in immunosenescence.

High Prevalence of Asymptomatic Malaria in a Tribal Population in Eastern India

ABSTRACT Asymptomatic infection by Plasmodium falciparum is an important obstacle to eliminating malaria. Asymptomatic carriers do not seek treatment for infection, and therefore they become a reservoir for the parasite. For this reason, these carriers pose a real public health risk. The systematic identification and treatment of asymptomatic infections should reduce the parasite reservoir. A large reduction in this pool will lower the chance of transmission of the disease. In this study, we screened a tribal population of 1,040 individuals in the Purulia district of West Bengal by using a dual-antigen rapid diagnostic kit (RDK), microscopy, and species-specific PCR. All positive individuals were treated with artemisinin-based combination therapy (ACT) (artesunate plus sulfadoxine-pyrimethamine) and followed for 42 days. Polymorphisms in candidate genes were screened by DNA sequencing. A significant proportion (8.4%) of the study population was infected with P. falciparum but showed no clinical manifestations. The PCR method was more sensitive in detecting infection than the RDK or microscopy. The efficacy of the ACT was 97%. In the pfcrt gene, the mutation K76T (the mutated amino acid is indicated by bold type) was found in 100% of the cases. In the pfmdr1 gene, the mutations N86Y and Y184F were noted in 55.5% and 11% of the cases, respectively. Six different haplotypes were identified in the pfdhfr-pfdhps genes. Most importantly, the quintuple mutant A16I51R59N108I164-S436G437E540A581A613 was found in 10% of the isolates, which is potentially important for the development of sulfadoxine-pyrimethamine resistance. A significant proportion of the study population harboring P. falciparum does not seek treatment and therefore serves as a reservoir for the parasite, maintaining the natural cycle. If the National Vector Borne Disease Control Programme (NVBDCP) of India is to eliminate malaria, then this hidden parasite burden needs to be addressed properly. Similar study in other parts of the country could help to determine the magnitude of the problem.

Comparative Efficacies of Artemisinin Combination Therapies in Plasmodium falciparum Malaria and Polymorphism of pfATPase6, pfcrt, pfdhfr, and pfdhps Genes in Tea Gardens of Jalpaiguri District, India

ABSTRACT In India, chloroquine has been replaced by a combination of artesunate and sulfadoxine-pyrimethamine (AS-SP) for uncomplicated P. falciparum malaria. Other available combinations, artemether-lumefantrine (AM-LF) and artesunate-mefloquine (AS-MQ), not included in the national program, are widely used by private practitioners. Little is known about the therapeutic efficacy of these artemisinin combinations and the prevalence of molecular markers associated with antimalarial drug resistance. A total of 157 patients with P. falciparum monoinfection were recruited and randomized into three study groups (AS-SP, AM-LF, and AS-MQ). All patients were followed up for 42 days to study the clinical and parasitological responses according to the WHO protocol (2009). We assessed the polymorphism of the pfATPase6, pfcrt, pfdhfr, and pfdhps genes by the DNA-sequencing method. The PCR-corrected therapeutic efficacies of AS-SP, AM-LF, and AS-MQ were 90.6% (95% confidence interval [CI], 0.793 to 0.969), 95.9% (95% CI, 0.860 to 0.995), and 100% (95% CI, 0.927 to 1.00), respectively. No specific mutational pattern was observed in the pfATPase6 gene. All isolates had a K76T mutation in the pfcrt gene. In the pfdhfr-pfdhps genotype, quadruple mutation was frequent, and quintuple mutation was documented in 6.3% of P. falciparum isolates. The significant failure rate of AS-SP (9.5%), although within the limit (10%) for drug policy change, was due to SP failure because of prevailing mutations in pfdhfr, I51R59N108, with pfdhps, G437 and/or E540. The efficacy of this ACT needs periodic monitoring. Artemether-lumefantrine and artesunate-mefloquine are effective alternatives to the artesunate-sulfadoxine-pyrimethamine combination.

In Vivo Therapeutic Efficacy of Chloroquine Alone or in Combination with Primaquine against Vivax Malaria in Kolkata, West Bengal, India, and Polymorphism in pvmdr1 and pvcrt-o Genes

ABSTRACT Plasmodium vivax malaria, though benign, has now become a matter of concern due to recent reports of life-threatening severity and development of parasite resistance to different antimalarial drugs. The magnitude of the problem is still undetermined. The present study was undertaken to determine the in vivo efficacy of chloroquine (CQ) and chloroquine plus primaquine in P. vivax malaria in Kolkata and polymorphisms in the pvmdr1 and pvcrt-o genes. A total of 250 patients with P. vivax monoinfection were recruited and randomized into two groups, A and B; treated with chloroquine and chloroquine plus primaquine, respectively; and followed up for 42 days according to the WHO protocol of 2009. Data were analyzed using per-protocol analyses. We assessed polymorphisms of the pvmdr1 and pvcrt-o genes by a DNA-sequencing method. Out of the 250 patients recruited, 204 completed a 42-day follow-up period, 101 in group A and 103 in group B. In group A, the non-PCR-corrected efficacy of CQ was 99% (95% confidence interval [CI], 0.944 to 1.00), and in group B, all cases were classified as adequate clinical and parasitological response (ACPR). Day 3 positivity was observed in 11 (5.3%) cases. No specific mutation pattern was recorded in the pvcrt-o gene. Eight nonsynonymous mutations were found in the pvmdr1 gene, three of which were new. The Y976F mutation was not detected in any isolate. Chloroquine, either alone or in combination with primaquine, is still effective against P. vivax malaria in the study area. (The study protocol was registered in CTRI [Clinical Trial Registry-India] of the Indian council of Medical Research under registration no. CTRI/2011/09/002031.)

PKDL—A Silent Parasite Pool for Transmission of Leishmaniasis in Kala-azar Endemic Areas of Malda District, West Bengal, India

Post Kala-azar Dermal Leishmaniasis (PKDL) is a chronic but not life-threatening disease; patients generally do not demand treatment, deserve much more attention because PKDL is highly relevant in the context of Visceral Leishmaniasis (VL) elimination. There is no standard guideline for diagnosis and treatment for PKDL. A species-specific PCR on slit skin smear demonstrated a sensitivity of 93.8%, but it has not been applied for routine diagnostic purpose. The study was conducted to determine the actual disease burden in an endemic area of Malda district, West Bengal, comparison of the three diagnostic tools for PKDL case detection and pattern of lesion regression after treatment. The prevalence of PKDL was determined by active surveillance and confirmed by PCR based diagnosis. Patients were treated with either sodium stibogluconate (SSG) or oral miltefosine and followed up for two years to observe lesion regression period. Twenty six PKDL cases were detected with a prevalence rate of 27.5% among the antileishmanial antibody positive cases. Among three diagnostic methods used, PCR is highly sensitive (88.46%) for case confirmation. In majority of the cases skin lesions persisted after treatment completion which gradually disappeared during 6–12 months post treatment period. Reappearance of lesions noted in two cases after 1.5 years of miltefosine treatment. A significant number of PKDL patients would remain undiagnosed without active mass surveys. Such surveys are required in other endemic areas to attain the ultimate goal of eliminating Kala-azar. PCR-based method is helpful in confirming diagnosis of PKDL, referral laboratory at district or state level can achieve it. So a well-designed study with higher number of samples is essential to establish when/whether PKDL patients are free from parasite after treatment and to determine which PKDL patients need treatment for longer period.

Efficacy of Chloroquine and Sulphadoxine-Pyrimethamine either alone or in combination before introduction of ACT as first-line therapy in uncomplicated Plasmodium falciparum malaria in Jalpaiguri District, West Bengal, India

Objective  In India, till recently, Chloroquine was used as first‐line therapy in areas with Chloroquine sensitive Plasmodium falciparum malaria cases. The National Vector Borne Disease Control Programme (NVBDCP) has introduced artemisinin combination therapy (ACT) as first‐line option to treat all P. falciparum cases in the country. This study was carried out to ascertain the efficacy of Chloroquine and Sulphadoxine‐Pyrimethamine, either alone or in combination, before the launch of ACT by NVBDCP.

Therapeutic efficacy of artemisinin combination therapies and prevalence of S769N mutation in PfATPase6 gene of Plasmodium falciparum in Kolkata, India.

OBJECTIVE To study the in vivo efficacy of these two ACTs in the treatment of Plasmodium falciparum (P. falciparum malaria) in Kolkata and to determine the prevalence of mutant S769N codon of the PfATPase6 gene among field isolates of P. falciparum collected from the study area. METHODS A total of 207P. falciparum positive cases were enrolled randomly in two study arms and followed up for 42 days as per WHO (2009) protocol. A portion of PfATPase6 gene spanning codon S769N was amplified and sequenced by direct sequencing method. RESULTS It was observed that the efficacy of both the ACT regimens were highly effective in the study area and no mutant S769N was detected from any isolate. CONCLUSIONS The used, combination AS+SP is effective and the other combination AM+LF might be an alternative, if needed.

Age associated changes in antioxidant and antioxidative enzymes in human neutrophil of different aged people

Objective To evaluate the level of lipid-protein damage and antioxidant status in neutrophils of healthy individuals to correlate between oxidative damage with the aging process. Method: Twenty healthy individuals of each age group (11-20; 21-30; 31-40; 41-50; and 51-60 years) were selected randomly. Blood samples were drawn by medical practitioner and neutrophils were isolated from blood samples. Superoxide (O2.−) generation anion, malondialdehyde (MDA), protein carbonyls (PC) level were evaluated to determine the lipid and protein damage in neutrophils. Superoxide dismutase (SOD), catalase (CAT), glutathione and glutathione dependent enzymes were estimated to evaluate the antioxidant status in the neutrophils.

Asymptomatic leishmaniasis in kala-azar endemic areas of Malda district, West Bengal, India

Asymptomatic leishmaniasis may drive the epidemic and an important challenge to reach the goal of joint Visceral Leishmaniasis (VL) elimination initiative taken by three Asian countries. The role of these asymptomatic carriers in disease transmission, prognosis at individual level and rate of transformation to symptomatic VL/Post Kala-azar Dermal Leishmaniasis (PKDL) needs to be evaluated. Asymptomatic cases were diagnosed by active mass survey in eight tribal villages by detecting antileishmanial antibody using rK39 based rapid diagnostic kits and followed up for three years to observe the pattern of sero-conversion and disease transformation. Out of 2890 total population, 2603 were screened. Antileishmanial antibody was detected in 185 individuals of them 96 had a history of VL/PKDL and 89 without such history. Seventy nine such individuals were classified as asymptomatic leishmaniasis and ten as active VL with a ratio of 7.9:1. Out of 79 asymptomatic cases 2 were lost to follow up as they moved to other places. Amongst asymptomatically infected persons, disease transformation in 8/77 (10.39%) and sero-conversion in 62/77 (80.52%) cases were noted. Seven (9.09%) remained sero-positive even after three years. Progression to clinical disease among asymptomatic individuals was taking place at any time up to three years after the baseline survey. If there are no VL /PKDL cases for two or more years, it does not mean that the area is free from leishmaniasis as symptomatic VL or PKDL may appear even after three years, if there are such asymptomatic cases. So, asymptomatic infected individuals need much attention for VL elimination programme that has been initiated by three adjoining endemic countries.

Distribution of pfcrt haplotypes and in-vivo efficacy of chloroquine in treatment of uncomplicated P. falciparum malaria before deployment of Artemisinin Combination Therapies in urban population of Kolkata, India.

A total of 101 P. falciparum positive patients were enrolled from urban population of Kolkata, India to determine the therapeutic efficacy of chloroquine as per 28 days follow-up schedule of WHO, 2003. All parasite strains were analyzed for P. falciparum chloroquine resistance transporter (pfcrt) haplotypes using DNA sequencing methodology. The PCR corrected chloroquine resistant P. falciparum was very high (76.3%, 95% CI 0.642 – 0.832) of which early treatment failure was (10%), and late treatment failure was (66.3%). K76T mutation was found in all parasite strains irrespective of therapeutic outcomes. Both the Venezuelan (SVMNT) and Southeast Asian (CVIET) haplotypes were prevalent in the study population with predominance of South East Asian haplotype (87.1%). The present study showed that incidence of CQ resistant P. falciparum malaria in Kolkata was very high and well above the WHO recommended cut-off level for change of drug policy. Recently introduced Artimisinine Combination Therapy by the Government of India to treat all P. falciparum cases is an appropriate step.