Weerapong Phumratanaprapin

Mahidol University, Krung Thep, Bangkok, Thailand

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Publications (30)68.05 Total impact

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    ABSTRACT: The clinical manifestations of dengue infection in the adult are different from those in children, i.e. having less prevalence to bleeding, and more commonly, abnormal liver function tests. The primary objective is to describe the clinical manifestations of dengue infection in adult patients. The secondary objective is to compare the clinical manifestations of dengue infection between the groups of normal and abnormal liver function tests in adult patients. Retrospective study was done in adults (age 15 years) dengue patients admitted at the Hospital for Tropical Diseases from 2000-2002. Dengue infection diagnosed by WHO clinical criteria 1997 with serological tests confirmed by ELISA test or Rapid Immunochromatographic test. Liver function test was recorded by day of fever. There were 127 adult dengue patients with mean age 26.4 ± 11.5 years. Classifications of dengue infection by WHO criteria were DF 4.7%, DHF grade 126.0%, DHF grade 2 63.0% and DHF grade 3 6.3%. Mean duration of fever clearance time was 6.0 ± 1.9 days but the fever lasted longer in cases of high-level transaminases (> 10 folds). The common presenting symptoms and signs were myalgia (95.9%), nausea/vomiting (87.7%), positive tourniquet test (77.2%), abdominal pain (42.7%), hepatomegaly (34.6%), and bleeding (20.5%). The ratio of AST and ALTwas 1.8:1. Abnormal AST and ALT were found in 88.2% and 69.3% of the patients, respectively. Patients with nausea/vomiting, petechiae or duration of fever > 7 days more frequently had abnormal transaminases. Abnormal AST during the febrile stage was associated with bleeding. High-level AST and ALT occurred in 11.0% and 7.0%, respectively. Shock was associated with high-level ALT during the febrile stage. Adult dengue patients commonly showed abnormal liver function tests and accounted for at least two-thirds of them. High-level ALT during the febrile stage showed association with shock.
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    ABSTRACT: The number of travelers visiting Laos has more than doubled in the last 5 years. Little is known about their pre-travel preparations and the incidence of health problems during their trips. At three border posts between Laos and Thailand, travelers were invited to complete a study questionnaire. They were asked about their demographic profile, travel characteristics, pre-travel health preparations, and health problems during their stay in Laos. From September 2011 to April 2012, 1,205 questionnaires from Thais and 1,191 from foreigners were collected. Approximately 60% of the travelers were male; the overall median age among the Thais was 43 years, and among the foreigners was 32 years. Most foreign visitors were from Europe (66.8%), followed by other Asian countries (19.0%) and North America (7.1%). Almost half of the foreigners (47.8%) traveled as individual backpackers, whereas the majority of Thais traveled as package tourists. Foreigners were more likely to trek, cycle, and swim during their trips. There were also significant differences in the average length of stay between foreigners (16.1 days) and Thais (3.8 days, p < 0.001). Health problems were reported in 24.9% of foreigners, the most common being diarrhea, cough, animal exposure, and fever. Only 6.1% of Thais reported health problems, the most common being cough and diarrhea. The relative risk adjusted for duration of stay was 1.63 (95% confidence interval: 1.01-2.64). Occurrence of health problems was associated with younger age group, non-Asian nationality, length of stay, and participation in adventurous activities. Health problems are rather frequent among non-Thai travelers in contrast to Thais during their trips to Lao People's Democratic Republic. There were significant differences in terms of risk profile and prevalence of health problems between these two groups.
    Journal of Travel Medicine 03/2014; 21(3). DOI:10.1111/jtm.12107 · 1.53 Impact Factor
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    Biochemical and Biophysical Research Communications 03/2013; 432(1):200–201. DOI:10.1016/j.bbrc.2013.01.107 · 2.28 Impact Factor
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    ABSTRACT: Each year millions of travelers visit Southeast Asia where rabies is still prevalent. This study aimed to assess the risk of rabies exposure, i.e., by being bitten or licked by an animal, among travelers in Southeast Asia. The secondary objective was to assess their attitudes and practices related to rabies. Foreign travelers departing to the destination outside Southeast Asia were invited to fill out the study questionnaire in the departure hall of Bangkok International Airport. They were asked about their demographic profile, travel characteristics, pre-travel health preparations, their possible exposure and their practices related to rabies during this trip. From June 2010 to February 2011, 7,681 completed questionnaires were collected. Sixty-two percent of the travelers were male, and the median age was 32 years. 34.0% of the participants were from Western/Central Europe, while 32.1% were from East Asia. Up to 59.3% had sought health information before this trip. Travel clinics were the source of information for 23.6% of travelers. Overall, only 11.6% of the participants had completed their rabies pre-exposure prophylaxis, and 15.3% had received only 1-2 shots, while 73.1% had not been vaccinated at all. In this study, the risk of being bitten was 1.11 per 100 travelers per month and the risk of being licked was 3.12 per 100 travelers per month. Among those who were bitten, only 37.1% went to the hospital to get post exposure treatment. Travelers with East Asian nationalities and longer duration of stay were significantly related to higher risk of animal exposure. Reason for travel was not related to the risk of animal exposure. Travelers were at risk of being exposed to potentially rabid animals while traveling in Southeast Asia. Many were inadequately informed and unprepared for this life-threatening risk. Rabies prevention advice should be included in every pre-travel visit.
    PLoS Neglected Tropical Diseases 09/2012; 6(9):e1852. DOI:10.1371/journal.pntd.0001852 · 4.49 Impact Factor
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    ABSTRACT: The global spread of the four dengue virus serotypes (DENV-1 to -4) has made this virus a major and growing public health concern. Generally, pre-existing neutralizing antibodies derived from primary infection play a significant role in protecting against subsequent infection with the same serotype. By contrast, these pre-existing antibodies are believed to mediate a non-protective response to subsequent heterotypic DENV infections, leading to the onset of dengue illness. In this study, we prepared hybridomas producing human monoclonal antibodies (HuMAbs) against DENV using peripheral blood mononuclear cells (PBMCs) from patients in the acute phase (around 1 week after the onset of illness) or the convalescent phase (around 2weeks after the onset of illness) of secondary infection. Interestingly, a larger number of hybridoma clones was obtained from patients in the acute phase than from those in the convalescent phase. Most HuMAbs from acute-phase infections were cross-reactive with all four DENV serotypes and showed significant neutralization activity to all four DENV serotypes. Thus, secondary DENV infection plays a significant role in stimulating memory cells to transiently increase the number of antibody-secreting plasma cells in patients in the early phase after the secondary infection. These HuMAbs will enable us to better understand the protective and pathogenic effects of DENV infection, which could vary greatly among secondarily-infected individuals.
    Biochemical and Biophysical Research Communications 06/2012; 423(4):867-72. DOI:10.1016/j.bbrc.2012.06.057 · 2.28 Impact Factor
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    ABSTRACT: To identify factors associated with acute renal failure among patients with severe falciparum malaria (MARF), we studied 189 severe malaria patients admitted to the Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University, in Bangkok, Thailand. Among these, 63 had MARF, and 126 did not. Baseline clinical demographics and laboratory variables were evaluated with univariate analysis. Logistic regression was used to ascertain adjusted odds ratios. By univariate analysis, factors associated with MARF included male gender, fever duration > 4 days, patients who lived in a non-endemic area prior to malaria infection, body mass index > 18.5 kg/m(2), oliguria, abdominal pain, impaired consciousness, jaundice, anemia, liver enlargement, total white blood cell count > 10x10(9)/1, total bilirubin > 3 mg/dl, aspartate aminotransferase > 120 U/l, alanine aminotransferase > 120 U/l, albumin < 3 g/dl, fever clearance time >72 hours, and parasite clearance time > 72 hours. A hemoglobin > 10 g/dl, patients living in a malaria endemic area, non-oliguria on the day of admission, and splenomegaly were negatively associated with MARF. After multivariate logistic regression, oliguria during the first 24 hours of admission and a history of living in a nonendemic area prior to malarial infection were factors associated with MARF. We conclude the most significant factors associated with MARF were oliguria on the day of admission and living in a non-endemic area prior to malaria infection.
    The Southeast Asian journal of tropical medicine and public health 11/2011; 42(6):1305-12. · 0.55 Impact Factor
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    ABSTRACT: A new fixed-dose artesunate (AS)-mefloquine (MQ) was assessed in adults hospitalized for 28 days with uncomplicated drug-resistant falciparum malaria. The patients (n = 25/arm) were treated with (i) two fixed-dose tablets (AS-MQ arm; 100 mg AS-200 mg MQ/tablet) daily for 3 days (days 0, 1, and 2) or (ii) nonfixed AS (AS-plus-MQ arm; 4 mg/kg of body weight/day for 3 days) plus MQ (15 mg/kg on day 1 and 10 mg/kg on day 2), dosed by weight. Clinical laboratory electrocardiogram (ECG), adverse events (AEs), efficacy, and pharmacokinetic parameters were assessed over 28 days. Both regimens were well tolerated. No AEs were drug related. Two serious AEs of malaria-induced hypotension occurring in the AS-MQ arm necessitated rescue treatment. There were no significant changes in hematology, biochemistry, or PR and QRS intervals. For all patients, mean Fridericia-corrected QT intervals were significantly (P < or = 0.0027) prolonged on day 3 (407 ms) and day 7 (399 ms) versus day 0 (389 ms), in parallel with significant (P < or = 0.0003) falls in heart rates (67 [day 3], 73 [day 7], and 83 [day 0] beats/minute). Fixed-nonfixed formulations were bioequivalent for MQ, but not for AS and dihydroartemisinin (DHA). One AS-MQ patient developed a new infection on day 28; his day 28 plasma MQ concentration was 503.8 ng/ml. Fixed-dose AS-MQ was well tolerated, had pharmacokinetic (PK) profiles broadly similar to those of nonfixed AS plus MQ, and is a suitable replacement.
    Antimicrobial Agents and Chemotherapy 09/2010; 54(9):3730-7. DOI:10.1128/AAC.01187-09 · 4.45 Impact Factor
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    ABSTRACT: Rabies remains a problem in Southeast Asia where large numbers of backpackers visit each year. During May-June 2008, a survey study was conducted of foreign backpackers in Bangkok, Thailand to assess their risk of rabies exposure. Eight hundred seventy (870) questionnaires were collected and analyzed. The median age of the backpackers was 25.5 years. Most of them were European (68.4%), followed by North American (13.2%). Although 80.7% had sought health information before traveling, only 55.6% had received information about rabies. Only 18.1% had completed pre-exposure rabies vaccination (3 shots) before travel, whereas 70.9% had not been vaccinated for rabies at all. In this study, the incidence of being licked was 3.56%, and of being bitten 0.69%, on average stays of 30.06 days in Southeast Asia. More than a half (54%) of exposures occurred in the first 10 days after arrival in Southeast Asia.
    The American journal of tropical medicine and hygiene 06/2010; 82(6):1168-71. DOI:10.4269/ajtmh.2010.09-0699 · 2.74 Impact Factor
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    ABSTRACT: Cerebral venous sinus thrombosis has been reported to be associated with various systemic illnesses and infections, including severe malaria. We report here a 43 year-old Thai male presenting with fever and seizures. He was diagnosed as and treated for severe falciparum malaria. After gaining consciousness he developed focal neurological signs and evidence of increased intracranial pressure. Magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) of the brain revealed a mid-superior sagittal sinus thrombosis with venous infarction. Investigations for other infections and thrombophilia were negative. The patient denied anticoagulant treatment. The clinical status and radiologic findings improved gradually. Physicians who care for malaria patients need to be aware of this rare complication when a malaria patient presents with focal neurological signs.
    The Southeast Asian journal of tropical medicine and public health 09/2009; 40(5):893-7. · 0.55 Impact Factor
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    ABSTRACT: A 54-year-old male Thai patient from Prachin Buri Province presented with a history of chronic watery diarrhea for many years. He passed stool five to ten times per day with occasionally colicky pain, abdominal distension, nausea and vomiting. He had visited hospitals and private clinics and received treatment but with no improvement. He presented to the Hospital for Tropical Diseases, Bangkok, Thailand, where on physical examination, he had moderate dehydration, weakness, abdominal distension and a gurgling abdomen. The eggs, larvae and adult worms of Capillaria philippinensis were found on stool examination. The patient was admitted and treated with Mebendazole for 20 days, whereupon his symptoms resolved. Two months previously, he had ingested a raw small fresh-water fish dish called "Phra-Pla Siw/Soi". Small fresh-water fish near the patient's home were collected and examined for Capillaria philippinensis larva. The results were negative for parasitic organisms.
    The Southeast Asian journal of tropical medicine and public health 12/2008; 39(6):1000-4. · 0.55 Impact Factor
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    ABSTRACT: In a retrospective study of 1415 patients aged 15 and over, we determined the incidence of clinically important hyponatraemia and hypokalaemia in adults with uncomplicated malaria. On admission, serum concentrations of sodium (135-145 mmol/L) and potassium (3.5-5.0 mmol/L) were found outside these reference ranges in 81% of patients. Severe hypokalaemia (K+ <3.0 mmol/L) and severe hyponatraemia (Na+ <125 mmol/L occurred in 4.4% and 0.6% of the patients, respectively. For hypokalaemia (43%) and hyponatraemia (37%), hypovolaemia, blood urea to creatinine ratio and high serum glucose (>100 mg/dL) were all independent factors (P < 0.001). Other independent predictors for hypokalaemia were Plasmodium vivax infection, female gender; and for hyponatraemia, P. falciparum infection, male gender, concentrations of G-6-PD and serum bicarbonate.
    Tropical Doctor 07/2008; 38(3):155-7. DOI:10.1258/td.2007.070112 · 0.53 Impact Factor
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    ABSTRACT: Patients on dialysis are at high risk of acquiring viral hepatitis infections. However, there were only few data from Thailand. The aim of the present study was to assess the prevalence, incidence and associated risk factors of viral hepatitis infections among dialysis patients. A retrospective study was conducted to evaluate 5179 medical records of dialysis patients from the Thailand Renal Replacement Therapy Registry. In 2002, the seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were 6.3% (n = 2454) and 4.8% (n = 2167), respectively. HBV and HCV seroprevalence became 6.5% (n = 2585) and 4.3% (n = 2399) in 2003. The incidence of HBV and HCV infections were 1.5 and 2.4 cases per 1000 patient-years, respectively. Logistic regression analysis showed that age and gender were significant risk factors for HBV infection, but not for HCV infection. In Thailand, it was not uncommon for dialysis patients to acquire viral hepatitis infections. However, our prevalence is similar to reports from some other South-East Asian countries.
    Nephrology 09/2007; 12(4):399-405. DOI:10.1111/j.1440-1797.2007.00815.x · 1.86 Impact Factor
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    ABSTRACT: Serological testing of paired (i.e. admission and convalescent) sera from 103 fever patients in Kathmandu, Nepal, was performed to estimate the prevalence rates of scrub typhus, murine typhus, Leptospira and dengue virus antibodies and to determine their role in the cause of active infections. Blood cultures from 15 patients grew Salmonella enterica serovar Typhi, 8 grew S. Paratyphi A and 6 grew other bacteria. Diagnostic antibody levels were detected against murine typhus (27/103; 26%), scrub typhus (23/103; 22%), Leptospira (10/103; 10%) and dengue virus (8/103; 8%). Nineteen patients (18%) had diagnostically raised antibodies to more than one infectious agent. Seven S. Typhi (7/15; 47%) and two S. Paratyphi A (2/8; 25%) patients had significant scrub typhus, murine typhus, Leptospira or dengue virus IgM antibody titres. This study confirms the presence of leptospiral, rickettsial and dengue infections in Kathmandu as well as evidence for mixed infections with S. Typhi and Orientia tsutsugamushi or Rickettsia typhi. These infections should be kept in mind when considering the differential diagnoses of fever and empirical treatment options in Nepal. Many patients demonstrated static IgM antibody results between paired serum collections, suggesting recent rather than acutely active infections.
    Transactions of the Royal Society of Tropical Medicine and Hygiene 08/2007; 101(7):686-90. DOI:10.1016/j.trstmh.2007.02.015 · 1.93 Impact Factor
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    ABSTRACT: Peripheral gangrene, characterized by distal ischemia of the extremities, is a rare complication in patients with falciparum malaria. Patients with this complication have generally undergone early amputation of the affected areas. In this report, we describe 3 adult Thai patients presented at the Hospital for Tropical Diseases, Bangkok, with high grade of fever ranged 6-9 days, jaundice, acute renal failure, respiratory failure, alteration of consciousness and shock. Two patients had gangrene developed at the lower extremities on day 1 of hospitalization and 1 patient had gangrene developed on day 3. Blood smears revealed hyperparasitemia with Plasmodium falciparum. These patients were diagnosed as having severe malaria with peripheral gangrene. The resolution of gangrene was successfully achieved by treatment with artesunate and conservative treatment in 2 of 3 cases.
    The Korean Journal of Parasitology 07/2006; 44(2):139-43. DOI:10.3347/kjp.2006.44.2.139 · 0.97 Impact Factor
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    ABSTRACT: The etiology of bloodstream infections in febrile patients remain poorly characterized in Nepal. A retrospective study of febrile patients presenting to Dhulikhel Hospital Kathmandu University Teaching Hospital from July 2002 to June 2004 was performed to evaluate the etiology of bloodstream infections and the drug sensitivity patterns of cultured organisms. The medical and laboratory records of all febrile patients with an axillary temperature > or = 38 degrees C who had a blood culture taken (n = 1,774) were retrieved and analyzed. Of these, 122 (6.9%) patients had positive blood cultures, of which 40.1% were age 11 to 20 years. The male to female ratio was 1.7:1. Antibiotics had been taken prior to hospital presentation by 39 (32%) patients. Salmonella enterica serovar Typhi and serovar Paratyphi A were isolated in 50 (41.0%) and 13 (10.7%) cases, respectively. All S. Typhi and S. Paratyphi isolates were susceptible to ceftriaxone, while susceptibility to ciprofloxacin and chloramphenicol was recorded in 94.8% and 94.5% of cases, respectively. Cephalexin and amoxicillin had the lowest rates of susceptibility (64.2% and 54.1%, respectively). Salmonella spp were usually sensitive to chloramphenicol. These findings provide clinicians in this region of Nepal with a better understanding of the spectrum of pathogens causing bloodstream infections and will help guide empiric antibiotic choice.
    The Southeast Asian journal of tropical medicine and public health 04/2006; 37(2):351-6. · 0.55 Impact Factor
  • Annals of Tropical Medicine and Parasitology 10/2005; 99(6):623-5. · 1.20 Impact Factor
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    ABSTRACT: To study the risk factors for Plasmodium vivax gametocyte carriage, the presence or absence of gametocytes was determined in 2,125 patients with P. vivax malaria participating in clinical trials at the Hospital for Tropical Diseases in Bangkok, Thailand. Stepwise logistic regression models were used to determine which variables were significantly related to gametocyte carriage. On admission, 615 patients (29%) had detectable gametocytes (before treatment). After treatment had started, an additional 245 patients (11%) developed patent gametocytemia. The variables retained by multivariate analysis were highest observed temperature (adjusted odds ratio [AOR] per degrees C increase = 0.82, 95% confidence interval [CI] = 0.71-0.94, P = 0.006), asexual parasitemia > 9,200/muL (AOR = 2.8, 95% CI = 1.9-4.2, P < 0.0001), erythrocyte counts (AOR = 0.8/million/muL increase, 95% CI = 0.67-0.95, P = 0.01), monocyte percentage (AOR = 0.93 per % increase, 95% CI = 0.89-0.96, P < 0.0001), lymphocyte percentage (AOR = 0.98 per % increase, 95% CI = 0.97-0.99, P = 0.006), albumin (AOR = 0.67 per 10 g/mL increase, 95% CI = 0.5-0.9, P = 0.007), and anion gap (AOR = 1.1 per unit increase, 95% CI = 1.02-1.14, P = 0.009). The possible significance of these observations is discussed.
    The American journal of tropical medicine and hygiene 12/2004; 71(6):693-5. · 2.74 Impact Factor
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    ABSTRACT: Tafenoquine is an 8-aminoquinoline developed as a more effective replacement for primaquine. In a previous dose-ranging study in Thailand, 3 tafenoquine regimens with total doses ranging from 500 mg to 3000 mg prevented relapse of Plasmodium vivax malaria in most patients when administered 2 days after receipt of a blood schizonticidal dose of chloroquine. To improve convenience and to begin comparison of tafenoquine with primaquine, 80 patients with P. vivax infection were randomized to receive 1 of the following 5 treatments 1 day after receiving a blood schizonticidal dose of chloroquine: (A) tafenoquine, 300 mg per day for 7 days (n=18); (B) tafenoquine, 600 mg per day for 3 days (n=19); (C) tafenoquine, 600 mg as a single dose (n=18); (D) no further treatment (n=13); or (E) primaquine base, 15 mg per day for 14 days (n=12). The minimum duration of protocol follow-up was 8 weeks, with additional follow-up to 24 weeks. Forty-six of 55 tafenoquine recipients, 10 of 13 recipients of chloroquine only, and 12 of 12 recipients of chloroquine plus primaquine completed at least 8 weeks of follow-up (or had relapse). There was 1 relapse among recipients of chloroquine plus tafenoquine, 8 among recipients of chloroquine only, and 3 among recipients of chloroquine plus primaquine. The rate of protective efficacy (determined on the basis of reduction in incidence density) for all recipients of chloroquine plus tafenoquine, compared with recipients of chloroquine plus primaquine, was 92.6% (95% confidence interval, 7.3%-99.9%; P=.042, by Fisher's exact test). Tafenoquine doses as low as a single 600-mg dose may be useful for prevention of relapse of P. vivax malaria in Thailand.
    Clinical Infectious Diseases 11/2004; 39(8):1095-103. DOI:10.1086/424508 · 9.42 Impact Factor
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    ABSTRACT: The gametocidal activities of chloroquine and artesunate were compared. The relative risk (RR) of having detectable gametocytes appear after treatment initiation was lower in artesunate-treated patients (n = 792) than in chloroquine-treated patients (n = 695) (RR = 0.29; 95% CI = 0.2 to 0.40; P < 0.0001). The duration and magnitude of gametocyte carriage were also lower for artesunate than chloroquine. By reducing the transmission of Plasmodium vivax to the vector, artesunate could therefore reduce the incidence of P. vivax malaria.
    Antimicrobial Agents and Chemotherapy 07/2004; 48(7):2751-2. DOI:10.1128/AAC.48.7.2751-2752.2004 · 4.45 Impact Factor
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    ABSTRACT: To determine if intestinal helminths and the CD23/nitric oxide pathway had an influence on liver size, we conducted a cross-sectional study on 438 patients with confirmed P. falciparum malaria admitted at the Hospital for Tropical Diseases in Bangkok. For all patients the liver size was measured as number of centimeters below the rib cage, a stool examination was conducted, and CD23 and reactive nitrogen intermediates were measured. The median liver size was smaller in helminth-infected patients than in helminth-free patients (chi2 for trend = 9.1, p = 0.003). Liver size significantly increased with the concentration of sCD23 (p < 0.0001). The median sCD23 concentration (OD) was significantly lower in helminth-infected patients than in helminth-free patients, respectively 0.33 (quartiles 0.24-0.57) and 0.45 (quartiles 0.27-0.59), (p = 0.01). There was a negative correlation between sCD23 concentrations and RNI (Spearman's rho = -0.40, p < 0.0001). All the above results remained significant after controlling for potential confounders. These results are compatible with a CD23/NO-mediated decrease in liver size in helminth-infected patients.
    The Southeast Asian journal of tropical medicine and public health 04/2004; 35(1):31-4. · 0.55 Impact Factor