Machine Learning to Predict Interim Response in Pediatric Classical Hodgkin Lymphoma Using Affordable Blood Tests.

PURPOSE: Response assessment of classical Hodgkin lymphoma (cHL) with positron emission tomography-computerized tomography (PET-CT) is standard of care in well-resourced settings but unavailable in most African countries. We aimed to investigate correlations between changes in PET-CT findings at interim analysis with changes in blood test results in pediatric patients with cHL in 17 South African centers. METHODS: Changes in ferritin, lactate dehydrogenase (LDH), erythrocyte sedimentation rate (ESR), albumin, total white cell count (TWC), absolute lymphocyte count (ALC), and absolute eosinophil count were compared with PET-CT Deauville scores (DS) after two cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine in 84 pediatric patients with cHL. DS 1-3 denoted rapid early response (RER) while DS 4-5 denoted slow early response (SER). Missing values were imputed using the k-nearest neighbor algorithm. Baseline and follow-up blood test values were combined into a single difference variable. Data were split into training and testing sets for analysis using Python scikit-learn 1.2.2 with logistic regression, random forests, naïve Bayes, and support vector machine classifiers. RESULTS: Random forest analysis achieved the best validated test accuracy of 73% when predicting RER or SER from blood samples. When applied to the full data set, the optimal model had a predictive accuracy of 80% and a receiver operating characteristic AUC of 89%. The most predictive variable was the differences in ALC, contributing 21% to the model. Differences in ferritin, LDH, and TWC contributed 15%-16%. Differences in ESR, hemoglobin, and albumin contributed 11%-12%. CONCLUSION: Changes in low-cost, widely available blood tests may predict chemosensitivity for pediatric cHL without access to PET-CT, identifying patients who may not require radiotherapy. Changes in these nonspecific blood tests should be assessed in combination with clinical findings and available imaging to avoid undertreatment.

Outcome of Retinoblastoma After Implementation of National Retinoblastoma Treatment Guidelines in South Africa.

PURPOSE: Retinoblastoma, a curable childhood cancer, has been identified as a tracer cancer in the WHO Global Initiative for Childhood Cancer. To document the outcomes of children with retinoblastoma in South Africa, treated as per the first prospective standard national treatment guidelines for childhood cancer in South Africa. PATIENTS AND METHODS: All children diagnosed with retinoblastoma between 2012 and 2016 in five South African pediatric oncology units were treated with a standard treatment on the basis of the International Society of Pediatric Oncology-Pediatric Oncology in Developing Countries guidelines for high-income settings. Treatment included focal therapy with/without chemotherapy, or enucleation with/without chemotherapy, and orbital radiotherapy, depending on enucleated eye histology. The end point was survival at 24 months, using Kaplan-Meier curves with log-rank (Mantel-Cox) and chi-square (χ2) tests with respective P values reported. RESULTS: A total of 178 children were included in the study; 68% presented with unilateral disease. The median age was 27 months (range 0-118 months) with a male:female ratio of 1:0.75. The overall survival was 79% at 24 months with significant association with stage at diagnosis (P < .001) and older age over 2 years as opposed to younger than 2 years (P < .001). Causes of death were disease progression/relapses in 90% (34 of 38) and unknown in 2% (1 of 38), whereas treatment abandonment was 1.7% (3 of 178). CONCLUSION: Efficacy with national treatment guidelines was confirmed, and feasibility of implementing standard national childhood cancer treatment guidelines was documented, involving multidisciplinary teams in South Africa. Outcome was significantly associated with stage at diagnosis and age.

Implemented nutritional intervention algorithm in pediatric oncology compared to standard nutritional supportive care outcomes.

AIM: To implement a childhood cancer-specific nutritional algorithm adapted for the South African context for interventions at time-set intervals to evaluate differences in the nutritional status of newly diagnosed children with cancer. METHOD: Children with newly diagnosed cancer were assessed for stunting, underweight, wasting, and moderate to severe malnutrition (MUAC < -2SD and < - 3 SD) between October 2018 and December 2020 in a longitudinal nutritional assessment study with monthly assessments. Two pediatric oncology units (POUs) served as the intervention group that implemented the nutritional algorithm-directed intervention and three other POUs formed the control group that implemented standard supportive nutritional care. RESULTS: A total of 320 patients were enrolled with a median age of 6.1 years (range three months to 15.3 years) and a male-to-female ratio of 1.1:1. The malnourished patients in the intervention group showed significant improvement at six months after diagnosis for stunting (P = 0.028), underweight (P < 0.001), and wasting until month five (P = 0.014). The improvements in the control group were not significant. Moderate acute malnutrition (MAM) significantly improved over the first six months of cancer treatment in the intervention group (P < 0.001), while MAM improvement was only significant in the control group for the children under five years of age (P = 0.004). The difference in mean z-scores over time for the nutritional parameters between the intervention and control groups was insignificant. CONCLUSION: We established that the nutritional algorithm adapted for South Africa as an intervention tool for childhood cancer assisted in optimizing nutritional interventions and improved nutritional outcomes over the first six months of cancer treatment.

Prevalence of Poverty and Hunger at Cancer Diagnosis and Its Association with Malnutrition and Overall Survival in South Africa.

Many South African children live in poverty and food insecurity; therefore, malnutrition within the context of childhood cancer should be examined. Parents/caregivers completed the Poverty-Assessment Tool (divided into poverty risk groups) and the Household Hunger Scale questionnaire in five pediatric oncology units. Height, weight, and mid-upper arm circumference assessments classified malnutrition. Regression analysis evaluated the association of poverty and food insecurity with nutritional status, abandonment of treatment, and one-year overall survival (OS). Nearly a third (27.8%) of 320 patients had a high poverty risk, associated significantly with stunting (p = 0.009), food insecurity (p < 0.001) and residential province (p < 0.001) (multinomial regression). Stunting was independently and significantly associated with one-year OS on univariate analysis. The hunger scale was significant predictor of OS, as patients living with hunger at home had an increased odds ratio for treatment abandonment (OR 4.5; 95% CI 1.0; 19.4; p = 0.045) and hazard for death (HR 3.2; 95% CI 1.02, 9.9; p = 0.046) compared to those with food security. Evaluating sociodemographic factors such as poverty and food insecurity at diagnosis is essential among South African children to identify at-risk children and implement adequate nutritional support during cancer treatment.

SACCSG HL-2018. Barriers and enablers of a harmonized treatment protocol for childhood and adolescent Hodgkin lymphoma in South Africa.

Introduction: Collaborative studies have contributed to improved survival of pediatric Hodgkin lymphoma in well-resourced settings, but few are documented in resource-constrained countries. The South Africa Children's Cancer Study Group initiated harmonization of management protocols in 2015. This article analyzes barriers and enablers of the process. Methods: Clinician-researchers at 11 state-funded pediatric oncology units completed preparatory questionnaires in June 2018. Parameters included infrastructure, access to therapeutic modalities and clinician numbers. A reassessment of 13 sites (two new pediatric oncology unit) in February 2021 ascertained changes in resources and identified challenges to full participation. Questions investigated the presence and quality of diagnostic radiology, availability of surgeons, cytology/pathology options and hematology laboratory facilities. Results: The response rate was 11/11 to survey 1 and 13/13 to survey 2. The anticipated pre-study barriers to participation of pediatric oncology units included time constraints and understaffing. PET-CT was unavailable to two centers. The majority of pediatric oncology units met the minimum criteria to participate. The interim survey confirmed chemotherapy and radiotherapy availability nearly 100% of the time. One site reported improved access to radiotherapy while another reported improved access to PET-CT. Barriers to participation included excessive times to obtain regulatory approvals, time constraints and lack of dedicated research staff. Enablers include the simple management algorithm and communication tools. Conclusion: This study demonstrates that multicenter collaboration and harmonization of management protocols are achievable in a middle-income setting. Minimal funding is required but full participation to run high-quality studies requires more financial investment. Focused funding and increased prioritization of research may address systemic barriers to full participation.

The pre-surgical factors that determine the decision to proceed to resection in children diagnosed with high-risk neuroblastoma in a resource limited setting.

Surgical control has prognostic value in neuroblastoma (NB). Advanced NB is common at diagnosis in South Africa. We investigated the pre-surgery factors that influenced decisions to perform surgical resections. We included 204 patients with high-risk NB from a national retrospective study, who completed induction chemotherapy between 2000 and 2016.The median age was 32.4 months (IQR 15.1 - 53.5 months). Primary tumor resection was achieved in 76.9% of patients between 0-18 months of age, 51.8% between 18-60 months and 51.7% older than 60 months (p < 0.001). Only 43.2% of patients with distant metastatic disease had surgery done (p < 0.001). LDH was >750 U/L in 46.8% and ferritin >120 g/dL in 53.1% of those who had surgery (p = 0.005). The majority (80.4%), who had achieved post-induction metastatic complete remission (mCR), were operated, while 28.7% without mCR had surgery (p < 0.001). The long-term overall survival in patients with mCR and primary tumor resection was 36.5% compared to those with mCR without primary tumor resection (25.4%) and without mCR (≤3.0%)(p < 0.001). Age (p < 0.001), stage (p < 0.001), mCR (p < 0.001) and treatment setting (p < 0.001) were of prognostic significance. The tumor site and MYCN-amplification did not significantly predict resection rates. Post-induction mCR and stage were associated with surgical resection and five-year OS (p < 0.001) on multivariate analysis.Patients with high-risk NB who achieved mCR and had primary tumor resections are curable in limited resourced settings. Stage and post-induction mCR were significant variables that led to surgery. These variables should be included as indications in the management of metastatic NB in resource limited settings.

High-risk neuroblastoma that achieved post-induction chemotherapy metastatic remission and have undergone resection, is curable, even in limited resource settings.Achieving metastatic complete remission was the only factor that significantly predicated if surgery was done.The age at diagnosis, stage and hospitals with expertise in neuroblastoma surgery were of prognostic significance in South Africa.If a patient with high-risk neuroblastoma achieves metastatic complete remission in a resource limited setting, it should be an indication for resection of the primary tumor.

The implementation of a national paediatric oncology protocol for neuroblastoma in South Africa.

PURPOSE: The aim of the World Health Organization-International Paediatric Oncology Society is to improve childhood cancer survival in low- and middle-income countries to 60% by 2030. This can be achieved using standardised evidence-based national treatment protocols for common childhood cancers. The aim of the study was to describe the development and implementation of the SACCSG NB-2017 neuroblastoma (NB) treatment protocol as part of the treatment harmonisation process of the South African Children's Cancer Study Group. METHODS: The Consolidated Framework for Implementation Research was used to identify factors that could influence the implementation of the national NB protocol as a health care intervention. The evaluation was done according to five interactive domains for implementation: intervention characteristics, inner setting, outer setting, individual or team characteristics and the implementation process. RESULTS: The protocol was developed over 26 months by 26 physicians involved in childhood cancer management. The process included an organisational phase, a resource identification phase, a development phase and a research ethics approval phase. Challenges included nationalised inertia, variable research ethical approval procedures with delays and uncoordinated clinical trial implementation. CONCLUSION: The implementation of the national NB protocol demonstrated the complexity of the implementation of a national childhood cancer treatment protocol. However, standardised paediatric cancer treatment protocols based on local expertise and resources in limited settings are feasible.

Sex Cord Stromal Tumors in Children and Adolescents: A First Report by The South African Children's Cancer Study Group (1990-2015).

OBJECTIVES: Pediatric sex cord stromal tumors (SCSTs) are extremely rare and there are no reported data from Africa. The authors evaluated the outcomes of children and adolescents with biopsy-proven SCSTs in preparation for the introduction of a national protocol. MATERIALS AND METHODS: Retrospective data were collated from 9 South African pediatric oncology units from January 1990 to December 2015. Kaplan-Meier analysis was performed to estimate overall survival (OS) and event-free survival. RESULTS: Twenty-three patients were diagnosed with SCSTs, 3 male and 20 female individuals, during the study period. Histologies included 1 thecoma, 9 Sertoli-Leydig cell tumors, and 13 juvenile granulosa cell tumors. Stage I tumors predominated (n=14; 60.9%), with 2 stage II (8.7%), 5 stage III (21.7%), and 2 stage IV tumors (8.7%). The upfront resection rate was 91.3% with no reported surgical morbidity or mortality and an OS of 82.1%. Chemotherapy approaches were not standardized. Most children (81.8%), except 2, had recognized platinum-based regimens. Chemotherapy-related toxicity was minimal and acceptable. Assessment of glomerular filtration rate and audiology assessments were infrequent and not standardized. Three patients were lost to follow-up. CONCLUSIONS: Although the numbers in this cohort are small, this study represents the first national cohort in Africa. The 5-year OS of 82.1% was encouraging. Standardized management of rare tumors like SCSTs is critical to improve ensure OS and address potential long-term sequelae.

Age at diagnosis as a prognostic factor in South African children with neuroblastoma.

PURPOSE: Low- and middle-income countries (LMICs) reported a higher median age at diagnosis of neuroblastoma (NB) compared to high-income countries. The aim was to determine if the optimal age at diagnosis, which maximizes the difference in overall survival between younger versus older patients in the South African population was similar to the internationally validated 18 months age cut-point. METHODS: Four hundred sixty NB patients diagnosed between 2000 and 2016 were included. Receiver operating characteristic (ROC) curves were used to predict potential age cut-point values for overall survival in all risk group classifications. Risk ratios, sensitivity, specificity, and positive and negative predictive values at the specific cut-points were estimated with 95% confidence intervals, and time to mortality by age at the specific cut-points was shown with Kaplan-Meier curves and compared using log-rank tests. RESULTS: The median age at diagnosis for the total cohort was 31.9 months (range 0.2-204.7). For high-risk (HR), intermediate-risk, low-risk, and very low-risk patients, the median age at diagnosis was, respectively, 36 months (range 0.4-204.7), 16.8 months (range 0.7-145.1), 14.2 months (range 2.0-143.5), and 8.7 months (range 0.2-75.6). The ROC curves for the total NB cohort (area under the curve [AUC] 0.696; P < .001) and HR (AUC 0.682; P < .001) were analyzed further. The optimal cut-point value for the total cohort was at 19.1 months (sensitivity 59%; specificity 78%). The HR cohort had potential cut-point values identified at 18.4 months age at diagnosis (sensitivity 45%; specificity 87%) and 31.1 months (sensitivity 67%; specificity 62%). The 19.1 months cut-point value in the total cohort and the 18.4 months cut-point value in HR were as useful in predicting overall survival as 18 months age at diagnosis. CONCLUSION: The 18 months cut-point value appears to be the appropriate age for prognostic determination, despite the higher median age at diagnosis in South Africa.

The importance of local control management in high-risk neuroblastoma in South Africa.

PURPOSE: To investigate the impact of local therapies on high-risk neuroblastoma (HR-NB) outcomes in South Africa. METHODS: Data from 295 patients with HR-NB from nine pediatric oncology units between 2000 and 2014 were analysed. All patients received chemotherapy. Five-year overall (OS) and event free survival (EFS) were determined for patients who had received local therapy, either surgery or radiotherapy or both. RESULTS: Surgery was performed in only 35.9% (n = 106/295) patients. Surgical excision was done for 34.8% (n = 85/244) of abdominal primaries, 50.0% (n = 11/22) of thoracic primaries; 22.2% (n = 2/9) neck primaries and 66.7% (n = 8/12) of the paraspinal primaries. Only 15.9% (n = 47/295) of all patients received radiotherapy. Children, who had surgery, had an improved five-year OS of 32.1% versus 5.9% without surgery (p < 0.001). Completely resected disease had a five-year OS of 30.5%, incomplete resections 31.4% versus no surgery 6.0% (p < 0.001). Radiated patients had a five-year OS of 21.3% versus 14.2% without radiotherapy (p < 0.001). Patients who received radiotherapy without surgical interventions, had a marginally better five-year OS of 12.5% as opposed to 5.4% (p < 0.001). Patients who underwent surgery had a longer mean overall survival of 60.9 months, while patients, who were irradiated, had a longer mean overall survival of 7.9 months (p < 0.001). On multivariate analysis, complete metastatic remission (p < 0.001), surgical status (p = 0.027), and radiotherapy status (p = 0.040) were significant predictive factors in abdominal primaries. CONCLUSION: Surgery and radiotherapy significantly improve outcomes regardless of the primary tumor site, emphasizing the importance of local control in neuroblastoma.

The evaluation of induction chemotherapy regimens for high-risk neuroblastoma in South African children.

Achieving remission after induction therapy in high-risk neuroblastoma (HR-NB) is of significant prognostic importance. This study investigated remission after induction-chemotherapy using three standard neuroblastoma protocols in the South African (SA) setting. Retrospective data of 261 patients with HR-NB diagnosed between January 2000 and December 2016, who completed induction chemotherapy with standard treatment protocols were evaluated. The treatment protocols were either OPEC/OJEC or the St Jude NB84 protocol (NB84) or rapid COJEC (rCOJEC). The postinduction metastatic complete remission (mCR) rate, 2-year overall survival (OS) and 2-year event free survival (EFS) were determined as comparative denominators. The majority (48.3%; n = 126) received OPEC/OJEC, while 70 patients received (26.8%) rCOJEC and 65 (24.9%) NB84. Treatment with NB84 had the best mCR rate (36.9%), followed by OPEC/OJEC (32.5%) and rCOJEC (21.4%). The 2-year OS of treatment with NB84 was 41% compared to OPEC/OJEC (35%) and rCOJEC (24%) (p = 0.010). The 2-year EFS of treatment with NB84 was 37% compared to OPEC/OJEC (35%) and rCOJEC (18%) (p = 0.008). OPEC/OJEC had the least treatment-related deaths (1.6%) compared to rCOJEC (7.1%) and NB84 (7.5%) (p = 0.037). On multivariate analysis LDH (p = 0.023), ferritin (p = 0.002) and INSS stage (p = 0.006) were identified as significant prognostic factors for OS. The induction chemotherapy was not significant for OS (p = 0.18), but significant for EFS (p = 0.08) Treatment with NB84 achieved better mCR, OS and EFS, while OPEC/OJEC had the least treatment-related deaths. In resource-constrained settings, OPEC/OJEC is advised as induction chemotherapy in HR-NB due to less toxicity as reflected in less treatment-related deaths.

Overall survival for neuroblastoma in South Africa between 2000 and 2014.

BACKGROUND: Outcome data for neuroblastoma in sub-Saharan Africa are minimal, whereas poor outcome is reported in low- and middle-income countries. A multi-institutional retrospective study across South Africa was undertaken to determine outcome. METHODS: Patients treated between January 2000 and December 2014 in nine South African pediatric oncology units were included. Kaplan-Meier curves and Cox regression models were employed to determine two-year survival rates and to identify prognostic factors. RESULTS: Data from 390 patients were analyzed. The median age was 39.9 months (range, 0-201 months). The majority presented with stage 4 disease (70%). The main chemotherapy regimens were OPEC/OJEC (44.8%), St Jude NB84 protocol (28.96%), and Rapid COJEC (22.17%). Only 44.4% had surgery across all risk groups, whereas only 16.5% of high-risk patients received radiotherapy. The two-year overall survival (OS) for the whole cohort was 37.6%: 94.1%, 81.6%, and 66.7%, respectively, for the very-low-risk, low-risk, and intermediate-risk groups and 27.6% for the high-risk group (P < 0.001, 95% CI). The median survival time for the whole group was 13 months (mean, 41.9 months; range, 0.1-209 months). MYCN-nonamplified patients had a superior two-year OS of 51.3% in comparison with MYCN-amplified patients at 37.3% (P = 0.002, 95% CI). CONCLUSIONS: Limited disease had an OS comparable with high-income countries, but advanced disease had a poor OS. South Africa should focus on early diagnosis and implementation of a national protocol with equitable access to treatment.

The development and use of a drug-induced immunosuppressed rat-model to screen Phela for mechanism of immune stimulation.

ETHNOPHARMACOLOGY RELEVANCY: Phela, is code name for a medicinal product made from four South African traditional medicinal plants (Clerodendrum glabrum E. Mey, Polianthes tuberosa (Linn.), Rotheca myricoides (Hochst.) Steane & Mabb. and Senna occidentalis (L.) Link). All these plants have established traditional use in a wide spectrum of diseases. Phela is under development for use as an immune booster in immunocompromised patients, which includes patients with the human immunodeficiency virus (HIV). Already several studies, both pre-clinical and clinical, have shown that Phela is a safe and effective immune booster. Despite some studies on the action of Phela, the mechanism of action by Phela is still not known. Understanding the mechanism of action will enable safer and effective use of the drug for the right indications. Unfortunately, there is no well characterized test-system for screening products for immune stimulant activity. Therefore, the objective of this study was to use Phela as the test article, to develop and validate a rat-model (test system) by which to screen medicines for immune stimulant activity. MATERIAL AND METHODS: First, the batch of Phela used was authenticated by high performance liquid chromatography (HPLC) techniques; analytical methods for the immunosuppressant drugs, cyclosporine A (CsA), cyclophosphamide (CP) and dexamethasone (Dex) were developed and validated; and a slide-A-Lyzer dialysis was used to test for potential interactions in rat plasma of Phela with CsA, CP and Dex. Thereafter, using Sprague Dawley (SD) rats and in separate experiments, the effective dose of Phela in the study animals was determined in a dose ranging study with levamisole, a known immune stimulant as the positive control; the appropriate doses for immunosuppression by CsA, CP and Dex were determined; the time to reach 'established immunosuppression' with each drug was determined (it was also the time for intervention with Phela); and eventually, the effect of Phela on the immune system was tested separately for each drug induced immunosuppression. The immune system was monitored by observing for changes in plasma profiles of IL-2, IL-10, IgG, IgM, CD4 and CD8 cell counts at appropriate intervals, while in addition to function tests, the kidneys, liver, spleen, thymus, were weighed and examined for any pathology. RESULTS: The chromatographic fingerprint certified this batch of Phela as similar to the authentic Phela. There was no significant interaction between Phela and CsA, CP and Dex. The effective dose of Phela was determined to be 15.4mg/kg/day. Phela led to a moderate increase in the immune parameters in the normal rats. Co-administration of Phela 15mg/kg/day orally for 21 days with CsA led to stoppage and reversal of the immunosppressive effects of CsA that were exhibited as increased IL-2, IL-10, CD4 and CD8 counts, implying that Phela stimulates the cell mediate immunity (CMI). For CP, Phela led to stoppage and reversal, though moderate, of CP-induced suppression of IL-10, IgM and IgG only, implying that Phela stimulates the humoral immunity (HI) too. Phela had no effect on Dex induced immunosuppression. Stimulation of the CMI means that Phela clinical testing programme should focus on diseases or disorders that compromise the CMI, e.g., HIV and TB. The stimulation of the HI immunity means that Phela may stimulate existing memory cells to produce antibodies. CONCLUSION: The present study has revealed Phela's mechanism of action as mainly by stimulation of the CMI, implying that the use of Phela as immune booster in HIV patients is appropriate; and that using Phela as the test product, a rat model for screening medicinal products for immune stimulation has been successfully developed and validated, with a hope that it will lead to the testing of other related medicinal products.

Changes in IL-2 and IL-10 during Chronic Administration of Isoniazid, Nevirapine, and Paracetamol in Rats.

The aim of this study was to illustrate the initial subclinical drug-induced liver injury and the associated adaptive immune response by monitoring for the changes in plasma IL-2, IL-10, and some cytochrome P450 activity during chronic administration of nevirapine (NVP), isoniazid (INH), and paracetamol (PAR) in rats without clinical hepatotoxicity. Male Sprague-Dawley (SD) rats were divided into four groups (saline (S), NVP, INH, and PAR) of 25 animals each. The drugs were administered daily for 42 days at therapeutic doses (NVP 200 mg/kg, PAR 500 mg/kg, and INH 20 mg/kg) to the respective groups by oral gavage and five rats per group were sacrificed weekly. All the three drugs induced a subclinical liver injury in the first 2-3 weeks followed by healing, indicating adaption. The liver injury was pathologically similar and was associated with immune stimulation and increased cytochrome P450 activity. NVP- and PAR-induced liver injury lasted up to 14 days while that for INH lasted for 28 days. NVP-induced liver injury was associated with increased IL-2, CD4 count, and CYP3A2 activity, followed by increased IL-10 during the healing phase. In conclusion, the initial drug-induced subclinical liver injury, its spontaneous healing, and the associated adaptive immune response have been demonstrated.

Co-administration of fresh grape fruit juice (GFJ) and bergamottin prevented paracetamol induced hepatotoxicity after paracetamol overdose in rats.

The aim of this study was to evaluate small doses of known cytochrome P450 enzyme inhibitors, grapefruit juice (GFJ) and one of its components, bergamottin (BGT), for the prevention of paracetamol (PAR)-induced hepatotoxicity after overdose in rats. Six groups of 15 Sprague Dawley (SD) rats each were treated with single oral doses of either saline, PAR only 1725 mg/kg, PAR + GFJ low dose (2 ml) and PAR + GFJ high dose (3 ml), PAR + BGT 0.05 mg/kg (BGT-low) and PAR + BGT 0.22 mg/kg (BGT-high). Thereafter, 5 rats from each group were sacrificed after 24, 48 and 72 h and, on each occasion, blood samples were collected for determination of liver and renal function, full blood count (FBC) and PAR concentration. A piece of liver was sent for histopathology. By 48 h the liver enzymes in the PAR-only group were significantly (P < 0.05) higher than in the PAR + GFJ and PAR + BGT groups, i.e., alanine transaminase (ALT) 837 ± 268 u/L and aspertate transaminase (AST) 1359 ± 405 for PAR only; versus ALT 34 ± 48.8 u/L and AST 238 ± 221 for PAR + GFJ-high; ALT 22 ± 13.9 and AST168 ± 49.6 for PAR + BGT-high; and ALT 52 ± 7.2 u/L and AST 147 ± 153 for the control group. The results correlated with the histopathology findings where livers of the PAR-only group exhibited severe centrilobular and hepatocyte necrosis. In conclusion, GFJ and BGT prevented PAR-induced hepatotoxicity after PAR overdose in rats, and this calls for appropriate observation studies in humans.

The role of the immune system in nevirapine-induced subclinical liver injury of a rat model.

In this study, the role of the immune system in nevirapine- (NVP-) induced subclinical liver injury was investigated by observing for changes of some immune parameters during the initial stages of NVP-induced hepatotoxicity in a rat model. In the acute phase, two test-groups of 10 Sprague-Dawley rats each were administered with bacterial lipopolysaccharide (LPS) or saline (S) intraperitoneally, followed by oral NVP, after which 5 rats from each group were sacrificed at 6 and 24 hours. For the chronic phase, two groups of 15 rats each received daily NVP, and on days 7, 14, and 21, five rats from each group were administered with either LPS or S, followed by that day's NVP dose, and were sacrificed 24 hours later. NVP caused liver injury up to seven days and progressively increased IL-2 and IFN-γ levels and lymphocyte count over the 21 days. NVP-induced liver injury was characterized by apoptosis and degeneration changes, while, for LPS, it was cell swelling, leukostasis, and portal inflammation. Coadministration of NVP and LPS attenuated NVP-induced liver injury. In conclusion, the immune system is involved in NVP toxicity, and the LPS effects may lay the clue to development of therapeutic strategies against NVP-induced hepatotoxicity.

Evaluation of traditional medicines I: identification of PHELA using different chromatographic techniques.

PHELA is a herbal mixture of four African traditional medicinal plants that has been used for decades in wasting conditions and is now being developed by the Medical Research Council (MRC) as an immune booster for patients with compromised immune system. A chromatographic fingerprint of PHELA was needed for quality control purposes. Here, a comprehensive method for fingerprinting of PHELA using different chromatographic techniques is described. It involved extraction of the PHELA by either acidic or a simple 'salting-out' method, followed by Thin Layer Chromatography (TLC) analysis and/or preparative Column Chromatography (CC). The products were thereafter analyzed by High Performance Liquid Chromatography with UV-detector (HPLC-UV), HPLC with fluorescence-detector (HPLC-FL) and Gas-Chromatography with a Mass Selective Detector spectrometer (GC-MSD). The fingerprints were successfully used to differentiate PHELA from another common herbal product made from Hypericum perforatum (St. John's Wort), thereby illustrating its high potential for use in fingerprinting of PHELA and in differentiating it from other herbal medicines. By validating the different chromatographic techniques on the standardized extraction methods, this approach will enable wide application in quality control of PHELA using acceptable procedures, thereby promoting effective monitoring of the finished product in all countries where it will be used.

Evaluation of traditional medicines III: the mechanism of immune modulation by PHELA.

PHELA is a herbal traditional medicine that is under development for use as an immune booster in immune compromised individuals. Therefore, the aim of this study was to determine PHELA's mechanism of action by observing for changes in cytokine profiles. Four groups of Sprague Dawley rats (n = 8) were treated daily and separately with normal-saline, cyclosporine-A, PHELA-only and PHELA+ cyclosporine-A. Thereafter, 4 animals from each group were sacrificed after 7 and 14 days of treatment. Serum Th1 cytokines (IL-2, IFN-γ and TNF-α) and Th2 cytokines (IL-4 and IL-10) were measured by ELISA. The concentrations of Th1 cytokines in the PHELA-only treated group were similar to the control group on days 7 and 14. However, the Th1 cytokines were higher in the PHELA+cyclosporine-A treated group compared to cyclosporine-A group, and cyclosporine-A concentrations were similar in both groups. These results show that PHELA did not stimulate Th1 cytokines of a normal immune system but stimulated them when the immune system was suppressed by cyclosporine-A. In conclusion, PHELA is an immune-stimulant to a compromised immune system.

Evaluation of traditional medicines II: the use of metabolite peak-kinetics to monitor PHELA in rat plasma.

PHELA is a herbal mixture of four African traditional medicinal plants that is under development by the Medical Research Council (MRC) for use as an immune stimulant in immune compromised individuals. Before major in vivo investigations could be conducted, there was a need to establish a plasma marker for concentration monitoring of PHELA. Chromatographic separation was achieved using a C18 RP column (250 mm × 4.6 mm × 5 µm), 70% acetonitrile in water and fluorescent detection. Three groups of rats (n=5) were administered with PHELA (15.4 mg/kg) and one rat from each group was sacrificed at 1, 2, 4, 6 and 8 hours. Surprisingly, on the HPLC analysis, none of the marker peaks of spiked plasma were detectable in the plasma of treated animals. Instead, a new peak was observed at 9.2 minutes, which implied that it was a metabolite of PHELA. Using peak area per unit plasma volume (PK-area/L), the relevant pharmacokinetic parameters were derived. The metabolite's half-life was 3.47±0.35 hours and reached maximum concentration at 4.67 ± 1.15 hrs. It was estimated that with once daily dosing of PHELA, the concentration at steady state (Css) would be 47.52 ± 5.94 PK-area/L with no drug accumulation (Acc index =.009 ± 0.004). In conclusion, the use of peak area per unit volume to derive pharmacokinetics of unknown compounds (Peak-kinetics) and to confirm ingestion of PHELA were demonstrated with a hope that they may appeal to those experiencing similar problems with monitoring of herbal products of which little is known.

Interaction between valproic acid and acyclovir after intravenous and oral administration in a rabbit model.

This study was undertaken to investigate the effect of co-administration of valproic acid and acyclovir on the pharmacokinetic parameters of each other. Fifteen white New Zealand rabbits were divided into three groups: A, B and C. Group A received acyclovir only, group B received valproic acid only and group C received a combination of acyclovir and valproic acid. In a cross-over design, the intravenous route was studied first, followed by the oral route after a 2-week wash-out period. Blood samples were drawn over 10 hr and the pharmacokinetic parameters were derived from the concentrations. After intravenous administration, the area under the plasma concentration time curve and plasma concentrations of acyclovir in group C were higher than in group A, while the volume of distribution and plasma clearance of acyclovir in group C were only 12.8% and 10.36% of those of group A, respectively. A similar trend was observed after oral administration. However, the bioavailability (F) of acyclovir was 8.4% in group A versus 1.5% in group C. In addition, the concentrations and kinetic parameters of valproic acid between the two groups after oral and intravenous administration were not different. In conclusion, co-administration of single doses of acyclovir and valproic acid led to reduced oral bioavailability of acyclovir, but increased concentrations of acyclovir due to reduced volume of distribution and clearance. These observations call for a cautious approach to the concomitant use of the two drugs until human studies are done.