Burden of malaria during pregnancy in perennial transmission settings of two densely forested and remote blocks (Baihar and Birsa) of district Balaghat, Madhya Pradesh, central India.

Background Malaria in pregnancy (MIP) is a major public health problem due to the vulnerability of pregnant women to infections, resulting in adverse maternal/foetal outcomes in endemic areas. Methods We did a field-based study to assess the burden of MIP (prevalence at the time of enrolment and follow-up) and to identify risk factors for MIP in the Birsa and Baihar blocks of district Balaghat in Madhya Pradesh, which have perennial malaria transmission. Malaria screening (during 2015-2017) was done by microscopy and bivalent rapid diagnostic test (SD Bioline RDT, malaria antigen Plasmodium falciparum/Plasmodium vivax Pf/Pv). Dried blood spots were used for haemoglobin estimation. Sociodemographic details with past and present pregnancy status were obtained. A subset of pregnant women were followed up for malaria during pregnancy. Women were also screened for malaria post delivery. Malaria treatment was given as per the National Guidelines of 2013. Multivariate analysis was done to assess independent risk factors for malaria. Results A total of 1728 pregnant women were screened, of which 1651 were included in the final analysis. Malaria prevalence at first screening was 23.4% (Pf 88%). Prevalence and Pf parasitaemia both were significantly higher among primigravid (G1) compared to multigravid (G>2; p value 0.012 and 0.019, respectively). Pregnant women of the Baiga ethnic group were more likely to have malaria compared to those belonging to the Gond group (OR [95% CI]; 2.4 [1.7-3.4]; p<0.00001) and non-indigenous group (OR [95% CI]; 8.3 [3.9-19.7]; p<0.00001). Primigravid status of women, first and second trimester of pregnancy, women belonging to indigenous ethnic tribal group and cash crop insufficiency for whole year (a socioeconomic indicator) in the family were the independent risk factors for malaria. Conclusion MIP is a major public health problem in forested tribal settlements of Birsa and Baihar blocks of Balaghat district in Madhya Pradesh and requires immediate intervention.

Sequential dysregulated plasma levels of angiopoietins (ANG-2 and ratios of ANG-2/ANG-1) are associated with malaria severity and mortality among hospital admitted cases in South Bastar Region of Chhattisgarh, Central India.

Cerebral malaria (CM) is one of the most severe forms of P. falciparum infection, with an associated high case-fatality rate. Angiopoietins (ANG-1 and ANG-2) are important biomarkers of endothelial activation and dysfunction. This study was carried out in Maharani Hospital and associated Medical College, Jagdalpur, CG, Central India from 2010 to 2014. Based on the treatment recovery patterns, cases (n = 65) were classified as mild malaria with rapid recovery (MM-RR), n= 14; non-cerebral severe malaria with moderately fast recovery (NCSM-MFR), n= 9; CM survivors with slow recovery (CMS-SR), n= 36 and deteriorated CM non-survivors (Det-CMNS), n= 6. Plasma levels (pg/ml) of ANG-1 and ANG-2 were measured by ELISA in all the samples at the time of hospital admission and 48 hours of treatment. Levels were also measured in available samples at the third time point (time of discharge for survivors or 72 hours post-treatment in fatal cases). Data analysis was done by appropriate statistical tests using Stata 11.0 and SPSS 25.0 software. At the time of admission, ANG-2 and ratios of ANG-2/ANG-1 significantly distinguished Det-CMNS cases from MM-RR and NCSM-MFR cases with good AUC scores (0.8-0.9). Further, Det-CMNS cases could also be distinguished from MM-RR, NCSM-MFR, and CMS-SR cases by ANG-2 (AUC scores 0.9) and ratios of ANG-2/ANG-1 (AUC: 0.8-0.9) at 48 hours of treatment. Paired analysis of sequential measurement of angiopoietins revealed that compared to admission levels, the ratios of ANG-2/ANG-1 significantly declined 48 hours after treatment in MM-RR (p= 0.041), NCSM-MFR (p= 0.050), and CMS-SR (p= 0.0002) cases but not in cases of Det-CMNS (p= 0.916). In conclusion, plasma levels of ANG-2 and ratios of ANG-2/ANG-1 may serve as good biomarkers to distinguish the malaria severity at the time of hospital admission and recovery patterns upon treatment in Central India.

Serum levels of total human Tau associated with axonal damage among severe malaria patients in Central India.

Tau is a microtubule-associated protein (MAP) that is abundant in the axonal part of neurons of the central nervous system. Previous studies among African children and Vietnamese adults suffering from cerebral malaria (CM) showed the pathological significance of measuring circulatory total Tau levels. A pilot investigation was carried out to better characterise neurological pathogenesis among severe malaria patients in Central India. Serum levels of total human Tau (pg/ml) were measured by ELISA following manufacturer guidelines among hospital admitted P. falciparum malaria patients classified with different degree of severity (mild malaria = MM, non-cerebral severe malaria = NCSM, cerebral malaria survivors = CM-S and cerebral malaria non-survivors = CM-NS) using WHO, 2000 definitions, including healthy controls (HC) enroled from the hospital's blood bank. Categorical and numerical variables were analysed by applying appropriate statistical test using Stata 11.0 software. A total of 139 subjects (14 HC, 25 MM, 29 NCSM, 44 CM-S and 27 CM-NS) were included in this preliminary investigation. Serum levels of total human Tau were detected in 0% HC, 4.0% MM, 20.7% NCSM, 43.2% CM-S and 48.2% CM-NS patients. Compared to MM, percent Tau detection was significantly higher among severe malaria patients (p = 0.001). Further, compared to NCSM,% Tau detection was significantly higher in CM-S patients (Chi2 = 3.9, p = 0.048) & CM-NS patients (Chi2 = 4.7, p = 0.030). Percent Tau detection was also significantly higher among severe malaria cases presenting with multiple complications compared to those without multiple complications (p = 0.006). ROC analysis of serum Tau levels (pg/ml) revealed a fair AUC value (0.75) to distinguish CM-NS group (but not CM-S) from NCSM group. In conclusion, serum percent detection of total human Tau is associated with axonal damage among patients with different degree of P. falciparum malaria severity in Central India.

Socio-economic & household risk factors of malaria in tribal areas of Madhya Pradesh, central India.

BACKGROUND & OBJECTIVES: Malaria is a major public health problem in many States of the country, particularly, in Madhya Pradesh where both Plasmodium vivax and P. falciparum are endemic. Although many studies have been conducted to investigate risk factors for malaria, but only a few have examined household and socio-economic risk factors. The present study was, therefore, undertaken to explore the relationship of different socio-demographic, socio-economic and behavioural risk factors with malaria prevalence in tribal areas of Madhya Pradesh, India. METHODS: This study was undertaken in all 62 villages of Bargi Primary Health Centre from May 2005 to June 2008. These villages comprised 7117 households with an average family size of five members. Fortnightly fever surveys were conducted in all villages to assess prevalence of malaria infection in the community. The distinct univariate and multivariate logistic regression models were fitted on the data set. RESULTS: The important socio-demographic risk factors like age of household head, social group, occupation and family size; socio-economic factors like type of walls of house, place of drinking water source, irrigated land, cash crop; and behavioural variables like place of sleeping, use of bed nets, etc. were found significantly associated with malaria in univariate analyses. In multivariate analyses only social groups, family size, type of walls of house, and place of sleeping had strong significant association with prevalence of malaria. INTERPRETATION & CONCLUSIONS: The study shows that in tribal areas where people are living in poor quality of houses with no proper use of preventive measures, malaria is firmly established. We conclude that community based interventions which bring improvement in standard of living, access to healthcare facilities and health awareness, will have a significant impact on malaria prevention in these areas.

Burden of complicated malaria in a densely forested Bastar region of Chhattisgarh State (Central India).

BACKGROUND: A prospective study on severe and complicated malaria was undertaken in the tribal dominated area of Bastar division, Chhattisgarh (CG), Central India, with an objective to understand the clinical epidemiology of complicated malaria in patients attending at a referral hospital. METHODS: Blood smears, collected from the general medicine and pediatric wards of a government tertiary health care facility located in Jagdalpur, CG, were microscopically examined for malaria parasite from July 2010 to December 2013. The Plasmodium falciparum positive malaria cases who met enrollment criteria and provided written informed consent were enrolled under different malaria categories following WHO guidelines. PCR was performed to reconfirm the presence of P.falciparum mono infection among enrolled cases. Univariate and multivariate logistic regression analysis was done to identify different risk factors using STATA 11.0. RESULTS: A total of 40,924 cases were screened for malaria. The prevalence of malaria and P.falciparum associated complicated malaria (severe and cerebral both) in the hospital was 6% and 0.81%, respectively. P.falciparum malaria prevalence, severity and associated mortality in this region peaked at the age of > 4-5 years and declined with increasing age. P.falciparum malaria was significantly more prevalent in children than adults (P < 0.00001). Among adults, males had significantly more P.falciparum malaria than females (P < 0.00001). Case fatality rate due to cerebral malaria and severe malaria was, respectively, 32% and 9% among PCR confirmed mono P.falciparum cases. Coma was the only independent predictor of mortality in multivariate regression analysis. Mortality was significantly associated with multi-organ complication score (P = 0.0003). CONCLUSION: This study has revealed that the pattern of morbidity and mortality in this part of India is very different from earlier reported studies from India. We find that the peak morbidity and mortality in younger children regardless of seasonality. This suggests that this age group needs special care for control and clinical management.

CXCL10 gene promoter polymorphism -1447A>G correlates with plasma CXCL10 levels and is associated with male susceptibility to cerebral malaria.

The risk factors for cerebral malaria (CM) and the wide variation in clinical manifestations of malaria are poorly understood. Recent studies indicate that interferon gamma inducible chemokine, CXCL10, is a strong predictor of both human and experimental cerebral malaria. Increased plasma and cerebrospinal fluid levels of CXCL10 were tightly associated with fatal CM in Indian and Ghanaian patients. In the present study, we hypothesized that in a subset of malaria patients, CM susceptibility is associated with variation in CXCL10 expression. We determined whether polymorphisms in the CXCL10 gene promoter region played a role in the clinical status of malaria patients and addressed the genetic basis of CXCL10 expression during malaria infection. Following extensive bioinformatics analyses, two reported single nucleotide polymorphisms in the CXCL10 promoter (-135G>A [rs56061981] and -1447A>G [rs4508917]) were identified among 66 CM and 69 non-CM Indian patients using PCR-restriction fragment length polymorphism assay. Individuals with the -1447(A/G) genotype were susceptible to CM (adjusted odds ratio [AOR] = 2.60, 95% CI = 1.51-5.85, p = 0.021). In addition, individuals with the -1447(A/G) genotype had significantly higher plasma CXCL10 levels than individuals with the -1447(A/A) genotype. Stratifying patients according to gender, the observed association of CM with over expression of CXCL10 were more pronounced in males than in female patients (AOR = 5.47, 95% CI = 1.34-22.29, p = 0.018). Furthermore, -135G>A polymorphism conferred a decreased risk of CM among males (AOR = 0.19, 95% CI = 0.05-0.78, p = 0.021). Polymorphisms in the CXCL10 gene promoter sequence were associated with increased CXCL10 production, which is linked to severity of CM. These results suggest that the -1447A>G polymorphism in CXCL10 gene promoter could be partly responsible for the reported variation underlying severity of CM outcomes particularly in males.

Malaria in a tertiary health care facility of Central India with special reference to severe vivax: implications for malaria control.

Plasmodium vivax is now recognized as a cause of severe and fatal infection in many parts of the world. This prospective observational study was undertaken in a tertiary health setting to understand the spectrum of the disease burden and associated complications due to P. vivax malaria in central India. A malaria clinic under Regional Medical Research Centre for Tribals is operational at Netaji Subhash Chandra Bose Medical College and Hospital, Jabalpur in central India, where all fever cases and cases with history of fever were referred for screening of malaria parasite by microscopy and rapid diagnostic test kits. Confirmation of all the cases was done by PCR targeting 18s ribosomal RNA gene of the parasite to exclude mixed infection with P. falciparum. Severe vivax malaria was found in 22 (11·1%) out of 198 vivax patients. Cerebral malaria, seizures, severe malaria anaemia, and respiratory distress each were observed in 32% subjects. Multi-organ dysfunction syndrome was common (36%). Mortality was recorded in two patients and neurological sequelae were also observed in two patients at the time of discharge. This is the first report from Central India where P. vivax has been shown to be associated with severe signs of malaria. Severe vivax malaria is a relatively new clinical entity and further studies from different parts of the world are needed to understand clinical spectrum and burden of P. vivax not only for successful treatment, but also for designing and developing effective malaria control measures.

Genetic variation in the Plasmodium falciparum circumsporozoite protein in India and its relevance to RTS,S malaria vaccine.

RTS,S is the most advanced malaria vaccine candidate, currently under phase-III clinical trials in Africa. This Plasmodium falciparum vaccine contains part of the central repeat region and the complete C-terminal T cell epitope region (Th2R and Th3R) of the circumsporozoite protein (CSP). Since naturally occurring polymorphisms at the vaccine candidate loci are critical determinants of the protective efficacy of the vaccines, it is imperative to investigate these polymorphisms in field isolates. In this study we have investigated the genetic diversity at the central repeat, C-terminal T cell epitope (Th2R and Th3R) and N-terminal T cell epitope regions of the CSP, in P. falciparum isolates from Madhya Pradesh state of India. These isolates were collected through a 5-year prospective study aimed to develop a well-characterized field-site for the future evaluation of malaria vaccine in India. Our results revealed that the central repeat (63 haplotypes, n = 161) and C-terminal Th2R/Th3R epitope (24 haplotypes, n = 179) regions were highly polymorphic, whereas N-terminal non-repeat region was less polymorphic (5 haplotypes, n = 161) in this population. We did not find any evidence of the role of positive natural selection in maintaining the genetic diversity at the Th2R/Th3R regions of CSP. Comparative analysis of the Th2R/Th3R sequences from this study to the global isolates (n = 1160) retrieved from the GenBank database revealed two important points. First, the majority of the sequences (~61%, n = 179) from this study were identical to the Dd2/Indochina type, which is also the predominant Th2R/Th3R haplotype in Asia (~59%, n = 974). Second, the Th2R/Th3R sequences in Asia, South America and Africa are geographically distinct with little allele sharing between continents. In conclusion, this study provides an insight on the existing polymorphisms in the CSP in a parasite population from India that could potentially influence the efficacy of RTS,S vaccine in this region.

Plasma levels of angiopoietin-1 and -2 predict cerebral malaria outcome in Central India.

BACKGROUND: The mechanisms underlying the pathogenesis of cerebral malaria (CM) syndrome are not well understood. Previous studies have shown a strong association of inflammatory chemokines, apoptotic markers and angiogenic molecules with CM associated mortality. Recognizing the importance of angiopoietins (ANG) in the pathogenesis of CM, a retrospective investigation was carried out in a hospital cohort of malaria patients with Plasmodium infection in central India to determine if these factors could be suitable markers of CM associated severity. METHODS: Patients enrolled in the study were clinically characterized as healthy controls (HC), mild malaria (MM), CM survivors (CMS) and CM non-survivors (CMNS) based on their malaria status and hospital treatment outcome. Plasma ANG-1 and ANG-2 levels were assessed using sandwich ELISA. Receiver operating characteristic (ROC) curve analysis was used to calculate area under the curve (AUC) for each biomarker in order to assess predictive accuracy of individual biomarkers. RESULTS: The plasma levels of ANG-1 were lower in CMS and CMNS compared to control groups (mild malaria and healthy controls) at the time of hospital admission. On the contrary, ANG-2 levels positively correlated with malaria severity and were significantly higher in CMNS. The ratio of ANG-2/ANG-1 was highest in CMNS compared to other groups. Receiver operating characteristic curves revealed that compared to ANG-1 (AUC = 0.35), ANG-2 (AUC = 0.95) and ratio of ANG-2/ANG-1 (AUC = 0.90) were better markers to discriminate CMNS from MM cases. However, they were less specific in predicting fatal outcome amongst CM cases at the time of hospital admission. CONCLUSION: These results suggest that at the time of admission plasma levels of ANG-2 and ratio of ANG-2/ANG-1 are clinically informative biomarkers to predict fatal CM from MM cases while they have limited usefulness in discriminating fatal CM outcomes in a pool of CM cases in endemic settings of Central India.

Potential serological biomarkers of cerebral malaria.

Biomarkers have been used to diagnose and prognosticate the progress and outcome of many chronic diseases such as neoplastic and non communicable diseases. However, only recently did the field of malaria research move in the direction of actively identifying biomarkers that can accurately discriminate the severe forms of malaria. Malaria continues to be a deadly disease, killing close to a million people (mostly children) every year. One life-threatening complication of malaria is cerebral malaria (CM). Studies carried out in Africa have demonstrated that even with the best treatment, as high as 15-30% of CM patients die and about 10-24% of CM survivors suffer short-or long-term neurological impairment. The transition from mild malaria to CM can be sudden and requires immediate intervention. Currently, there is no biological test available to confirm the diagnosis of CM and its complications. It is hoped that development of biomarkers to identify CM patients and potential risk for adverse outcomes would greatly enhance better intervention and clinical management to improve the outcomes. We review here what is currently known regarding biomarkers for CM outcomes. A Pub Med literature search was performed using the following search terms: "malaria," "cerebral malaria," "biomarkers," "mortality" and "neurological sequelae." This search revealed a paucity of usable biomarkers for CM management. We propose three main areas in which researchers can attempt to identify CM biomarkers: 1) early biomarkers, 2) diagnostic biomarkers and 3) prognostic biomarkers.

CXCL10/IP-10 in infectious diseases pathogenesis and potential therapeutic implications.

C-X-C motif chemokine 10 (CXCL10) also known as interferon γ-induced protein 10 kDa (IP-10) or small-inducible cytokine B10 is a cytokine belonging to the CXC chemokine family. CXCL10 binds CXCR3 receptor to induce chemotaxis, apoptosis, cell growth and angiostasis. Alterations in CXCL10 expression levels have been associated with inflammatory diseases including infectious diseases, immune dysfunction and tumor development. CXCL10 is also recognized as a biomarker that predicts severity of various diseases. A review of the emerging role of CXCL10 in pathogenesis of infectious diseases revealed diverse roles of CXCL10 in disease initiation and progression. The potential utilization of CXCL10 as a therapeutic target for infectious diseases is discussed.

CXCL4 and CXCL10 predict risk of fatal cerebral malaria.

Plasmodium falciparum in a subset of patients can lead to a diffuse encephalopathy known as cerebral malaria (CM). Despite treatment, mortality caused by CM can be as high as 30% while 10% of survivors of the disease may experience short- and long-term neurological complications. The pathogenesis of CM involves alterations in cytokine and chemokine expression, local inflammation, vascular injury and repair processes. These diverse factors have limited the rate of discovery of prognostic predictors of fatal CM. Identification of reliable early predictors of CM severity will enable clinicians to adjust this risk with appropriate management of CM. Recent studies revealed that elevated levels of CXCL10 expression in cerebrospinal fluid and peripheral blood plasma independently predicted severe and fatal CM. CXCR3, a promiscuous receptor of CXCL10, plays an important role in pathogenesis of mouse model of CM. In this study the role of corresponding CXCR3 ligands (CXCL11, CXCL10, CXCL9 & CXCL4) in fatal or severe CM was evaluated by comparing their levels in 16 healthy control (HC), 26 mild malaria (MM), 26 cerebral malaria survivors (CMS) and 12 non-survivors (CMNS) using enzyme linked immunosorbent assay (ELISA). Levels of CXCL4 and CXCL10 were significantly elevated in CMNS patients (p < 0.05) when compared with HC, MM and CMS. Elevated plasma levels of CXCL10 and CXCL4 were tightly associated with CM mortality. Receiver Operating Characteristic (ROC) curve analysis revealed that CXCL4 and CXCL10 can discriminate CMNS from MM (p < 0.0001) and CMS (p <0.0001) with an area under the curve (AUC)=1. These results suggest that CXCL4 and CXCL10 play a prominent role in pathogenesis of CM associated death and may be used as functional or surrogate biomarkers for predicting CM severity.

Evidence of selective sweeps in genes conferring resistance to chloroquine and pyrimethamine in Plasmodium falciparum isolates in India.

Treatment of Plasmodium falciparum is complicated by the emergence and spread of parasite resistance to many of the first-line drugs used to treat malaria. Antimalarial drug resistance has been associated with specific point mutations in several genes, suggesting that these single nucleotide polymorphisms can be useful in tracking the emergence of drug resistance. In India, P. falciparum infection can manifest itself as asymptomatic, mild, or severe malaria, with or without cerebral involvement. We tested whether chloroquine- and antifolate drug-resistant genotypes would be more commonly associated with cases of cerebral malaria than with cases of mild malaria in the province of Jabalpur, India, by genotyping the dhps, dhfr, pfmdr-1, and pfcrt genes using pyrosequencing, direct sequencing, and real-time PCR. Further, we used microsatellites surrounding the genes to determine the origins and spread of the drug-resistant genotypes in this area. Resistance to chloroquine was essentially fixed, with 95% of the isolates harboring the pfcrt K76T mutation. Resistant genotypes of dhfr, dhps, and pfmdr-1 were found in 94%, 17%, and 77% of the isolates, respectively. Drug-resistant genotypes were equally likely to be associated with cerebral malaria as with mild malaria. We found evidence of a selective sweep in pfcrt and, to a lesser degree, in dhfr, indicating high levels of resistance to chloroquine and evolving resistance to pyrimethamine. Microsatellites surrounding pfcrt indicate that the resistant genotypes (SVMNT) were most similar to those found in Papua New Guinea.

A preliminary study on pro- and anti-inflammatory cytokine profiles in Plasmodium vivax malaria patients from central zone of India.

The aim of this preliminary study was to investigate the plasma cytokine profiles in a group of patients suffering from Plasmodium vivax malaria during the peak of its transmission season. Plasma samples of 173 P. vivax patients and 34 healthy individuals were analyzed for IFN-gamma, TNF-alpha, IL-10 and IP-10 levels by ELISA. Levels of both pro- and anti-inflammatory cytokines were significantly higher in P. vivax patients compared to controls. Children with P. vivax infection had significantly higher levels of IFN-gamma than adults (P=0.017). Asexual parasitaemia versus TNF-alpha (r=-0.31, P=0.01), IL-10 (r=-0.30, P=0.015) and gametocytaemia versus IFN-gamma (r=-0.26; P=0.034) levels showed significant negative correlation in children compared to adults. The median concentrations of IFN-gamma (P=0.001), IL-10 (P=0.032) and IP-10 (P

Macrophage migration inhibitory factor is associated with mortality in cerebral malaria patients in India.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine implicated in the pathogenesis of a number of human diseases including inflammatory neurological diseases. Its role in the pathogenesis of cerebral malaria is unknown. Cerebral malaria is a life-threatening complication of falciparum malaria with approximately 20%-30% of patients dying despite appropriate anti-malarial treatment. The reason for this cerebral malaria mortality is still unknown although host proinflammatory factors have been shown to be evidently important. The current study investigated the role of circulating MIF in the pathogenesis and outcomes of cerebral malaria. FINDINGS: Three categories of subjects contributed to this study: healthy controls subjects, mild malaria patients, and cerebral malaria patients. The cerebral malaria patients were further grouped into cerebral malaria survivors and cerebral malaria non-survivors. MIF levels in the peripheral blood plasma, obtained at the time of enrollment, were measured using standard ELISA methods. In logistic regression on cerebral malaria patients, log MIF levels were found to be significantly associated with fatal outcome (odds ratio 4.0; 95%CI 1.6, 9.8; p = 0.003). In multinomial logistic regression log MIF levels were found to be significantly associated with patient category (p = 0.004). CONCLUSION: This study suggests that elevated levels of MIF in the peripheral blood of cerebral malaria patients may be associated with fatal outcomes.

Burden of cerebral malaria in central India (2004-2007).

A study on the clinicoepidemiology of cerebral malaria (CM) and mild malaria (MM) among adults and children attending NSCB medical college hospital Jabalpur and civil hospital Maihar, Satna, in central India was undertaken. Of 1,633 patients, 401 were Plasmodium falciparum and 18 P. vivax. Of 401, 199 CM patients and 112 MM patients were enrolled. Severe complications among CM patients were jaundice (26%), acute renal failure (22%), respiratory distress (22%), severe malaria anemia (18%), hypotension (17%), hepatic encephalopathy (7.0%), and hematuria (5%). Among CM cases, seizures and severe malaria anemia were significantly higher in children (P < 0.0001) compared with adults, whereas jaundice (P < 0.0025), acute renal failure (P < 0.0001), and hematuria (P

Antibody responses to the merozoite surface protein-1 complex in cerebral malaria patients in India.

BACKGROUND: Plasmodium falciparum infection causes cerebral malaria (CM) in a subset of patients with anti-malarial treatment protecting only about 70% to 80% of patients. Why a subset of malaria patients develops CM complications, including neurological sequelae or death, is still not well understood. It is believed that host immune factors may modulate CM outcomes and there is substantial evidence that cellular immune factors, such as cytokines, play an important role in this process. In this study, the potential relationship between the antibody responses to the merozoite surface protein (MSP)-1 complex (which consists of four fragments namely: MSP-1(83), MSP-1(30), MSP-1(38) and MSP-1(42)), MSP-6(36) and MSP-7(22) and CM was investigated. METHODS: Peripheral blood antibody responses to recombinant antigens of the two major allelic forms of MSP-1 complex, MSP-6(36) and MSP-7(22) were compared between healthy subjects, mild malaria patients (MM) and CM patients residing in a malaria endemic region of central India. Total IgG and IgG subclass antibody responses were determined using ELISA method. RESULTS: The prevalence and levels of IgG and its subclasses in the plasma varied for each antigen. In general, the prevalence of total IgG, IgG1 and IgG3 was higher in the MM patients and lower in CM patients compared to healthy controls. Significantly lower levels of total IgG antibodies to the MSP-1(f38), IgG1 levels to MSP-1(d83), MSP-1(19) and MSP-6(36) and IgG3 levels to MSP-1(f42) and MSP-7(22) were observed in CM patients as compared to MM patients. CONCLUSION: These results suggest that there may be some dysregulation in the generation of antibody responses to some MSP antigens in CM patients and it is worth investigating further whether perturbations of antibody responses in CM patients contribute to pathogenesis.

Plasma IP-10, apoptotic and angiogenic factors associated with fatal cerebral malaria in India.

BACKGROUND: Plasmodium falciparum in a subset of patients can lead to cerebral malaria (CM), a major contributor to malaria-associated mortality. Despite treatment, CM mortality can be as high as 30%, while 10% of survivors of the disease may experience short- and long-term neurological complications. The pathogenesis of CM is mediated by alterations in cytokine and chemokine homeostasis, inflammation as well as vascular injury and repair processes although their roles are not fully understood. The hypothesis for this study is that CM-induced changes in inflammatory, apoptotic and angiogenic factors mediate severity of CM and that their identification will enable development of new prognostic markers and adjunctive therapies for preventing CM mortalities. METHODS: Plasma samples (133) were obtained from healthy controls (HC, 25), mild malaria (MM, 48), cerebral malaria survivors (CMS, 48), and cerebral malaria non-survivors (CMNS, 12) at admission to the hospital in Jabalpur, India. Plasma levels of 30 biomarkers ((IL-1beta, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-8, IL-9, IL-10, IL-12 (p70), IL-13, IL-15, IL-17, Eotaxin, FGF basic protein, G-CSF, GM-CSF, IFN-gamma, IP-10, MCP-1 (MCAF), MIP-1alpha, MIP-1beta, RANTES, TNF-alpha, Fas-ligand (Fas-L), soluble Fas (sFas), soluble TNF receptor 1 (sTNF-R1) and soluble TNF receptor 2 (sTNFR-2), PDGF bb and VEGF)) were simultaneously measured in an initial subset of ten samples from each group. Only those biomarkers which showed significant differences in the pilot analysis were chosen for testing on all remaining samples. The results were then compared between the four groups to determine their role in CM severity. RESULTS: IP-10, sTNF-R2 and sFas were independently associated with increased risk of CM associated mortality. CMNS patients had a significantly lower level of the neuroprotective factor VEGF when compared to other groups (P < 0.0045). The ratios of VEGF to IP-10, sTNF-R2, and sFas distinguished CM survivors from non survivors (P < 0.0001). CONCLUSION: The results suggest that plasma levels of IP-10, sTNF-R2 and sFas may be potential biomarkers of CM severity and mortality. VEGF was found to be protective against CM associated mortality and may be considered for adjunctive therapy to improve the treatment outcome in CM patients.