Considerations for Use of Pharmacodynamic Biomarkers to Support Biosimilar Development - (III) A Randomized Trial with Interferon Beta-1a Products.

The US Food and Drug Administration (FDA) has taken steps to bring efficiency to the development of biosimilars, including establishing guidance for the use of pharmacokinetic and pharmacodynamic (PD) similarity study data without a comparative clinical study with efficacy end point(s). To better understand the potential role for PD biomarkers in biosimilar development and inform best practices for biomarker selection and analysis, we conducted a randomized, double-blinded, placebo-controlled, single-dose, parallel-arm clinical study in healthy participants. Eighty-four healthy participants (n = 12 per dose arm) received either placebo or one of three doses of either interferon ß-1a (7.5-30 µg) or pegylated interferon ß-1a (31.25-125 µg) to evaluate the maximum change from baseline and the baseline-adjusted area under the effect curve for the biomarkers neopterin in serum and myxovirus resistance protein 1 in blood. Both PD biomarkers increased following product administration with clear separation from baseline (neopterin: 3.4-fold and 3.9-fold increase for interferon ß-1a and pegylated interferon ß-1a, respectively; myxovirus resistance protein 1: 19.0-fold and 47.2-fold increase for interferon ß-1a and pegylated interferon ß-1a, respectively). The dose-response curves support that therapeutic doses were adequately sensitive to detect differences in both PD biomarkers for consideration in a PD similarity study design. Because baseline levels of both biomarkers are low compared with on-treatment values, there was little difference in using PD measures adjusted to baseline compared with the results without baseline adjustment. This study illustrates potential methodologies for evaluating PD biomarkers and an approach to address information gaps when limited information is publicly available for one or more PD biomarkers.

Considerations for Use of Pharmacodynamic Biomarkers to Support Biosimilar Development - (II) A Randomized Trial with IL-5 Antagonists.

The US Food and Drug Administration (FDA) guidance describes how pharmacodynamic (PD) biomarkers can be used to address residual uncertainty and demonstrate no clinically meaningful differences between a proposed biosimilar and its reference product without relying on clinical efficacy end point(s). Pilot studies and modeling can inform dosing for such PD studies. To that end, we conducted a randomized, double-blinded, placebo-controlled, single-dose, parallel-arm clinical study in healthy participants to evaluate approaches to address information gaps, inform best practices for analysis of biomarker samples and study results, and apply emerging technologies in biomarker characterization. Seventy-two healthy participants (n = 8 per arm) received either placebo or 1 of 4 doses of the interleukin-5 inhibitors mepolizumab (3-24 mg) or reslizumab (0.1-0.8 mg/kg). A clinical study using doses lower than approved therapeutic doses was combined with modeling and simulation to evaluate the dose-response relationship of the biomarker eosinophils. There was no dose-response relationship for eosinophil counts due to variability, although the mepolizumab 24 mg and reslizumab 0.8 mg/kg doses showed clear effects. Published indirect-response models were used to explore eosinophil data across doses from this study and the unstudied therapeutic doses. Simulations were used to calculate typical PD metrics, such as baseline-adjusted area under the effect curve and maximum change from baseline. The simulation results demonstrate sensitivity of eosinophils as a PD biomarker and indicate doses lower than the approved doses would have PD responses overlapping with variability in the placebo arm. The simulation results further highlight the utility of model-based approaches in supporting use of PD biomarkers in biosimilar development.

Effect of Oral Ranitidine on Urinary Excretion of N-Nitrosodimethylamine (NDMA): A Randomized Clinical Trial.

Importance: In 2019, the US Food and Drug Administration (FDA) received a citizen petition indicating that ranitidine contained the probable human carcinogen N-nitrosodimethylamine (NDMA). In addition, the petitioner proposed that ranitidine could convert to NDMA in humans; however, this was primarily based on a small clinical study that detected an increase in urinary excretion of NDMA after oral ranitidine consumption. Objective: To evaluate the 24-hour urinary excretion of NDMA after oral administration of ranitidine compared with placebo. Design, Setting, and Participants: Randomized, double-blind, placebo-controlled, crossover clinical trial at a clinical pharmacology unit (West Bend, Wisconsin) conducted in 18 healthy participants. The study began in June 2020, and the end of participant follow-up was July 1, 2020. Interventions: Participants were randomized to 1 of 4 treatment sequences and over 4 periods received ranitidine (300 mg) and placebo (randomized order) with a noncured-meats diet and then a cured-meats diet. The cured-meats diet was designed to have higher nitrites, nitrates (nitrate-reducing bacteria can convert nitrates to nitrites), and NDMA. Main Outcome and Measure: Twenty-four-hour urinary excretion of NDMA. Results: Among 18 randomized participants (median age, 33.0 [interquartile range {IQR}, 28.3 to 42.8] years; 9 women [50%]; 7 White [39%], 11 African American [61%]; and 3 Hispanic or Latino ethnicity [17%]), 17 (94%) completed the trial. The median 24-hour NDMA urinary excretion values for ranitidine and placebo were 0.6 ng (IQR, 0 to 29.7) and 10.5 ng (IQR, 0 to 17.8), respectively, with a noncured-meats diet and 11.9 ng (IQR, 5.6 to 48.6) and 23.4 ng (IQR, 8.6 to 36.7), respectively, with a cured-meats diet. There was no statistically significant difference between ranitidine and placebo in 24-hour urinary excretion of NDMA with a noncured-meats diet (median of the paired differences, 0 [IQR, -6.9 to 0] ng; P = .54) or a cured-meats diet (median of the paired differences, -1.1 [IQR, -9.1 to 11.5] ng; P = .71). No drug-related serious adverse events were reported. Conclusions and Relevance: In this trial that included 18 healthy participants, oral ranitidine (300 mg), compared with placebo, did not significantly increase 24-hour urinary excretion of NDMA when participants consumed noncured-meats or cured-meats diets. The findings do not support that ranitidine is converted to NDMA in a general, healthy population. Trial Registration: ClinicalTrials.gov Identifier: NCT04397445.

Sensitive and rapid UHPLC-MS/MS assay for simultaneous quantifications of calcipotriol and paclitaxel in rat whole blood and plasma samples.

Vitamin-D analogues have emerged as potential stroma-modulating agents for the treatment of pancreatic ductal adenocarcinoma (PDAC). One such agent, calcipotriol (Cal) has shown significant activity in in vitro and in vivo models of pancreatic ductal adenocarcinoma. Attempts in our lab have been focused on establishing the therapeutic merits of co-formulating this agent with the chemotherapeutic drug paclitaxel (PTX) in animal models. Accurate and reliable quantifications of these agents is critical to successful pharmacokinetic/pharmacodynamic (PK/PD) projections from animals into humans. Herein, we developed a LC-MS/MS assay for measuring Cal and PTX in whole blood and plasma. A liquid-liquid analyte extraction procedure, using a mixture of water-MeOH (50:50, v/v) and hexane-dichloromethane- isopropyl alcohol (150:15:5, v/v/v) was used. Chromatographic separation was carried out on Kinetex C18 column (1.7 µm, 100 × 2.10 mm) under an isocratic elution at a flow rate of 0.4 mL/min with a total runtime of 3.5 min. The mobile phase was composed of ammonium acetate (pH 6.51; 5 mM)-methanol (15:85, v/v). The analytes were ionized by positive electrospray ionization using API 5500-Qtrap triple quadrupole mass spectrometer (Applied Biosystem/AB SCIEX). The linearity of calibration curves for both analytes were established at 0.5 (LLOQ)-500 ng/mL with correlation coefficients exceeding 0.99. Spiked whole blood and plasma samples were used as surrogates for matrix validation. For both analytes, the intra-day and inter-day accuracies were 90.5-105 % and 96.6-106 %, respectively, while the corresponding precisions were 3.09-10.7 % and 5.20-12.9 %. No carryover was observed for the analytes which also remained acceptably stable in the surrogate matrices under relevant conditions. The assay is robust, reliable and sensitive in rat whole blood and plasma. The analytes extraction procedure performs acceptably well in both matrices with high recoveries and minimal matrix effects. Additionally, only 20 µL of rat whole blood or plasma is required and the total run time per sample is 3.5 min. PK studies enabled by the assay revealed that when co-administered, PTX AUC0→∞ and Cmax increased while those of Cal decreased. This finding alerts a potential drug-drug interaction and warrants further investigation in studies using this combination regimen.

Doxorubicin-loaded hollow gold nanospheres for dual photothermal ablation and chemoembolization therapy.

BACKGROUND: Doxorubicin-loaded hollow gold nanospheres (Dox@HAuNS) are a promising technology for simultaneous trans-arterial tumor-targeted chemotherapy delivery and thermal ablation. We evaluated the efficacy of intra-arterial delivery of Dox@HAuNS followed by photothermal ablation (PTA) in a rabbit model of liver cancer. Adult New Zealand white rabbits (N=25) were inoculated with VX2 tumors into the left lobe of the liver. The animals were then randomized to sham surgery (N=5), PTA only (N=3), Dox@HAuNS only (N=5), HAuNS + PTA (N=5), and Dox@HAuNS + PTA (N=7). Nanoparticles were delivered as an emulsion with Lipiodol (Guerbet, France) via a trans-arterial approach. Following nanoparticle delivery, PTA was performed using an 808nm fibered laser at 1.5W for 3 minutes. Thermography during PTA demonstrated a sustained elevation in tumoral temperature in both HAuNS + laser and Dox@HAuNS + laser treatment groups relative to animals that underwent laser treatment without prior nanoparticle delivery. RESULTS: There was a significant decrease in tumor volumes in all three treatment arms relative to control arms (P = 0.004). Concentrations of intratumoral doxorubicin were significantly greater in animals treated with laser compared to those that were not treated with laser (P< 0.01). CONCLUSIONS: Doxorubicin-loaded HAuNS is a promising therapeutic agent for dual ablation/chemoembolization treatment of liver cancer.

Sustained delivery of a camptothecin prodrug - CZ48 by nanosuspensions with improved pharmacokinetics and enhanced anticancer activity.

Background and aim: We have synthesized a novel lactone-stabilized camptothecin (CPT) analog named CZ48 and demonstrated its potent anticancer effects via bioconversion to the active CPT in earlier studies. Herein, we aimed to develop, optimize and characterize CZ48 nanosuspensions, for a sustained delivery of this drug in humans with an intravenous (i.v.) administration. Methods and materials: A three-factor, five-level central composite design (CCD) was employed to establish the impacts of the critical influencing factors (concentrations (wt%) of CZ48, polysorbate 80 (Tween-80), and Pluronic® F-108 (F-108)) on the responses (particle size and zeta potential). Based on the quantitative influencing factor-response relationships, two optimized CZ48 nanosuspensions of 197.22 ± 7.12 nm (NS-S) and 589.35 ± 23.27 nm (NS-L) were developed with the zeta potential values of -26.5 mV and -27.9 mV, respectively. Results: CZ48 released from the nanosuspensions in a sustained manner in contrast to the rapid release from cosolvent in both PBS and human plasma. Moreover, NS-S exhibited more favored pharmacokinetic properties than NS-L, with a 31-fold prolonged elimination half-life of CPT, and a 2.4-fold enhanced CPT exposure over cosolvent. In efficacy study, NS-S exhibited significant tumor suppression and an improved survival rate with a higher tolerable dose, compared to CZ48 cosolvent. Conclusion: We have successfully developed CZ48 nanosuspensions with significantly favorable pharmacokinetics and improved efficacy using CCD approach. The formulation offers potential merits as a preferred candidate for clinical trials with the prolonged CPT exposure, which is known to correlate with the clinical efficacy.

Development and validation of a rapid and sensitive UPLC-MS/MS assay for simultaneous quantification of paclitaxel and cyclopamine in mouse whole blood and tissue samples.

The prominent stromal compartment surrounds pancreatic ductal adenocarcinoma and protects the tumor cells from chemo- or radiotherapy. We hypothesized that our nano formulation carrying cyclopamine (CPA, stroma modulator) and paclitaxel (PTX, antitumor agent) could increase the permeation of PTX through the stromal compartment and improve the intratumoral delivery of PTX. In the present study a sensitive, reliable UPLC-MS/MS method was developed and validated to quantify PTX and CPA simultaneously in mouse whole blood, pancreas, liver and spleen samples. Docetaxel was used as the internal standard. The method demonstrated a linear range of 0.5-2000 ng/mL for whole blood and tissue homogenates for both PTX and CPA. The accuracy and precision of the assay were all within ±15%. Matrix effects for both analytes were within 15%. Recoveries from whole blood, liver, spleen and pancreas homogenates were 92.7-105.2% for PTX and 72.8-99.7% for CPA. The stability was within ±15% in all test biomatrices. The validated method met the acceptance criteria according to US Food and Drug Administration regulatory guidelines. The method was successfully applied to support a pharmacokinetic and biodistribution study for PTX and CPA in mice biomatrices.

Stromal Modulation Reverses Primary Resistance to Immune Checkpoint Blockade in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most difficult cancers to treat. It is refractory to most existing therapies, including immunotherapies, due to the presence of an excessive desmoplastic stroma, which restricts penetration of drugs and cytotoxic CD8+ T cells. Stromal modulation has shown promising results in the enhancement of immune checkpoint blockade treatment in PDAC. We demonstrate here effective stromal modulation by a polymeric micelle-based nanoformulation to codeliver a sonic hedgehog inhibitor (cyclopamine, abbreviated as CPA) and a cytotoxic chemotherapy drug (paclitaxel, abbreviated as PTX). The formulation, M-CPA/PTX, modulated the PDAC stroma by increasing the intratumoral vasculature density, which then promoted the tumor infiltration by cytotoxic CD8+ T cells without depletion of tumor-restraining α-smooth muscle action-positive fibroblasts and type I collage in the stroma. The combination of M-CPA/PTX and the PD-1 checkpoint blockade significantly prolonged animal survival in an orthotopic murine PDAC model as well as a genetically engineered mouse model of PDAC. The superior antitumor efficacy was mediated by enhanced tumor infiltration of CD8+ T cells without concomitant infiltration of suppressive regulatory T cells or myeloid-derived suppressor cells and by the coordinated action of PTX and interferon-gamma. Our results demonstrate that stroma-modulating nanoformulations are a promising approach to potentiate immune checkpoint blockade therapy of pancreatic cancer.

Simultaneous inhibition of hedgehog signaling and tumor proliferation remodels stroma and enhances pancreatic cancer therapy.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers. It has an excessive desmoplastic stroma that can limit the intratumoral delivery of chemotherapy drugs, and protect tumor cells against radiotherapy. Therefore, both stromal and tumor compartments need to be addressed in order to effectively treat PDAC. We hereby co-deliver a sonic hedgehog inhibitor, cyclopamine (CPA), and a cytotoxic chemotherapy drug paclitaxel (PTX) with a polymeric micelle formulation (M-CPA/PTX). CPA can deplete the stroma-producing cancer-associated fibroblasts (CAFs), while PTX can inhibit tumor proliferation. Here we show that in clinically relevant PDAC models, M-CPA effectively modulates stroma by increasing microvessel density, alleviating hypoxia, reducing matrix stiffness while maintaining the tumor-restraining function of extracellular matrix. M-CPA/PTX also significantly extends animal survival by suppressing tumor growth and lowering the percentages of poorly to moderately differentiated tumor phenotypes. Our study suggests that using multifunctional nanoparticles to simultaneously target stromal and tumor compartments is a promising strategy for PDAC therapy.

Development of PLGA-based itraconazole injectable nanospheres for sustained release.

PURPOSE: Itraconazole (ITZ) is a synthetic triazole antifungal agent, which is widely used for treatment and prevention of fungal infections. The purpose of this study is to develop ITZ-loaded poly(lactic-co-glycolic acid) (PLGA) nanospheres (PLGA-ITZ-NS) as a new sustained-release formulation for intravenous ITZ administration. MATERIALS AND METHODS: PLGA-ITZ-NS were prepared by a nanoprecipitation method and optimized by modifying the surfactant poloxamer 188 concentration and PLGA:ITZ ratio. Their physicochemical properties, including size, zeta potential, external morphology and encapsulation efficiency, were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM) and high performance liquid chromatography (HPLC). The effect of the different selected lyoprotectants with various concentrations on NS particles size and surface charge were also assessed. Rapid and sensitive HPLC and liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods were developed to determine ITZ concentrations in formulation and in rat plasma, respectively. Pharmacokinetics of the optimum PLGA-ITZ-NS formulation was compared with the former commercial Sporanox® injection formulation using rats as the animal model. Noncompartmental pharmacokinetic parameters were obtained by WinNonlin® software. RESULTS: Optimal PLGA-ITZ-NS had a mean particle size of about 200 nm with a high homogeneity (polydispersity index ≈0.2), favorable zeta potential (approximately -20 to -30 mV) and encapsulation efficiency (72%). In addition, 2% w/v sucrose was selected as a lyoprotectant for NS freeze-drying. The newly developed LC-MS/MS assay was validated and found to be accurate and precise. The in vivo study showed that the NS formulation has a similar systemic bioavailability to Sporanox® while providing a sustained plasma level (> 100 ng/mL) for up to 24 hours after intravenous administration. CONCLUSION: Our newly developed PLGA-ITZ-NS has shown great sustained release and comparable bioavailability with Sporanox®, therefore having the potential to be an alternative injectable formulation of ITZ.

Implication of QRS prolongation and its relation to mechanical dyssynchrony in idiopathic dilated cardiomyopathy in childhood.

We explored the role of QRS prolongation (>or=120 ms) and its relation to mechanical dyssynchrony and outcomes in childhood idiopathic dilated cardiomyopathy (IDC). A total of 89 patients 32.6 ms was used to define intra-LV dyssynchrony. The 1- and 5-year survivals were 70% and 53%, respectively. Requirement of intravenous inotropes at follow-up (hazard ratio 3.10) and initial LV ejection fraction (hazard ratio 0.95) were major prognostic factors. QRS prolongation, primarily left bundle branch block, was identified in 16 patients (18%) and tended to increase the risk of requiring inotropes. Moreover, none of those with QRS prolongation regained normal cardiac function at follow-up. Two patients with QRS prolongation showed marked improvement in cardiac function after cardiac resynchronization therapy. Mechanical dyssynchrony was noted in all patients with QRS prolongation and in 8% (interventricular) or 38% (intra-LV) of those without. In conclusion, QRS prolongation was common in childhood IDC and was possibly associated with persistent LV dysfunction and worse cardiac outcome. Mechanical (inter- and intraventricular) dyssynchrony was highly prevalent in those with QRS prolongation and was still often observed in those without.

Universal screening for biliary atresia using an infant stool color card in Taiwan.

UNLABELLED: Biliary atresia is the most common cause of death from liver disease in children. Although the Kasai operation before 60 days of age can significantly improve prognosis, delay in referral and surgery remains a formidable problem worldwide because of difficulties in differentiating it from benign prolonged neonatal jaundice. We established a universal screening system using an infant stool color card to promote the early diagnosis and treatment of biliary atresia. After a pilot regional study in 2002-2003, a national stool color screening system was established by integrating the infant stool color card into the child health booklet given to every neonate in Taiwan since 2004. Within 24 hours of the discovery of an abnormal stool color, this event is reported to the registry center. The annual incidence of biliary atresia per 10,000 live births in 2004 and 2005 was 1.85 (40/216,419) and 1.70 (35/205,854), respectively. The sensitivity of detecting biliary atresia using stool cards before 60 days of age was 72.5% in 2004, which improved to 97.1% in 2005. The national rate of the Kasai operation before 60 days of age increased from 60% in 2004 to 74.3% in 2005. The jaundice-free rate (<2 mg/dL) at 3 months after the Kasai operation among infants with biliary atresia in 2004-2005 was 59.5% (44 of 74), significantly higher than the historical data of 37.0% in 1976-2000 before the stool card screening program (P = 0.002). CONCLUSION: Universal screening using the stool color cards can enhance earlier referral, which may ultimately lead to timely performance of the Kasai operation and better postoperative outcome in infants with biliary atresia.

Pediatric Crohn disease: clinical and genetic characteristics in Taiwan.

OBJECTIVES: Crohn disease (CD) is a heterogeneous disorder. The nucleotide oligomerization domain 2/caspase activating recruitment domain 15 (NOD2/CARD15) gene located at 16q12 is strongly associated with susceptibility to CD in white people but is absent in adult Asian patients, whereas the role of Toll-like receptor 4 (TLR4) polymorphisms has also been reported. Because clinical and genetic data in Asian children with CD are lacking, the aim of this study was to elucidate the clinical and genetic characteristics of Taiwanese children with CD. PATIENTS AND METHODS: All of the children hospitalized at the National Taiwan University Hospital between January 2000 and July 2005 who fulfilled the diagnostic criteria for CD were enrolled. Their clinical characteristics were recorded, and genomic DNA was extracted from their white blood cells. After polymerase chain reaction was performed, direct sequencing was done to detect the 4 NOD2 hotspot mutations (P268S, R702W, G908R, 1007fs) and TLR4 polymorphisms (Asp299Gly, Thr399Ile). RESULTS: CD was diagnosed in 10 children (6 boys and 4 girls; age range at diagnosis, 14 months to 13 years; median age, 11.1 years). There were 5 children with ileocolonic region involvement, 3 with colonic region involvement, 2 with ileal region involvement, 4 with additional upper gastrointestinal tract involvement, and 2 with additional perianal fistula. Half of the children had growth retardation at diagnosis. Neither NOD2/CARD15 mutations nor TLR4 polymorphisms were found in the 10 patients. CONCLUSIONS: Ileocolonic location and inflammatory behavior constitute the most frequent phenotype of CD in Taiwan. Mutations in the NOD2/CARD15 and TLR4 genes that are common in the West are not associated with CD in Taiwanese children.

Mechanism for fetal hemoglobin induction by histone deacetylase inhibitors involves gamma-globin activation by CREB1 and ATF-2.

The histone deacetylase inhibitors (HDA-CIs) butyrate and trichostatin A activate gamma-globin expression via a p38 mitogen-activating protein kinase (MAPK)-dependent mechanism. We hypothesized that down-stream effectors of p38 MAPK, namely activating transcription factor-2 (ATF-2) and cyclic AMP response element (CRE) binding protein (CREB), are intimately involved in fetal hemoglobin induction by these agents. In this study, we observed increased ATF-2 and CREB1 phosphorylation mediated by the HDACIs in K562 cells, in conjunction with histone H4 hyperacetylation. Moreover, enhanced DNA-protein interactions occurred in the CRE in the (G)gamma-globin promoter (G-CRE) in vitro after drug treatments; subsequent chromatin immunoprecipitation assay confirmed ATF-2 and CREB1 binding to the G-CRE in vivo. Enforced expression of ATF-2 and CREB produced (G)gamma-promoter trans-activation which was abolished by a 2-base pair mutation in the putative G-CRE. The data presented herein demonstrate that gamma-gene induction by butyrate and trichostatin A involves ATF-2 and CREB1 activation via p38 MAPK signaling.

Fetal hemoglobin induction by histone deacetylase inhibitors involves generation of reactive oxygen species.

OBJECTIVE: Several compounds, including butyrate and trichostatin A, have been shown to activate gamma-gene expression via p38 mitogen-activated protein kinase (MAPK) signaling. In eukaryotic cells, reactive oxygen species (ROS) act as signaling molecules to mediate phosphorylation of tyrosine kinases such as p38 MAPK to regulate gene expression. Therefore, we determined the role of the reactive oxygen species hydrogen peroxide (H(2)O(2)) in drug-mediated fetal hemoglobin (HbF) induction. METHODS: H(2)O(2) levels were measured using 2',7'-dichlorofluorescein-diacetate in K562 cells after drug treatments. To confirm a role for H(2)O(2) in HbF induction, studies were completed with the mitochondrial respiratory chain inhibitor myxothiazole, which prevents ROS generation. The ability of myxothiazole to block gamma-globin mRNA accumulation and HbF induction was measured in K562 cells and burst-forming unit-erythroid colonies respectively using quantitative real-time PCR and alkaline denaturation. RESULTS: Butyrate and trichostastin A stimulated p38 MAPK phosphorylation via a H(2)O(2)-dependent mechanism. Pretreatment with myxothiazole to inhibit ROS formation or SB203580 to impede p38 MAPK signaling attenuated gamma-gene activation in K562 cells and HbF induction in erythroid progenitors. However, myxothiazole had no effect on the ability of hydroxyurea to induce HbF. CONCLUSION: The findings presented herein support a ROS-p38 MAPK cell signaling mechanism for HbF induction by butyrate and trichostatin A.

Spinal Burkitt's lymphoma manifesting as nocturnal abdominal pain and constipation: a case report.

A 3-year-old boy presented at the Taiwan Adventist Hospital in Taipei with nocturnal epigastric pain and constipation. Abdominal X-ray showed colonic faecal impaction. Abdominal sonography showed gastric stasis with thickened pyloric wall and dilated rectosigmoid colons. The mouth-to-anus transit time (MATT) was prolonged. Endoscopy showed pale gastric mucosa, atony of pylorus and widening of the duodenal bulb. Three weeks after the onset of abdominal pain, he developed urinary incontinence and rapidly deteriorating paraplegia of lower limbs. Magnetic resonance imaging (MRI) showed an extradural intraspinal mass of T5-T8 and a soft tissue mass in the right superior mediastinum. After a laminectomy and tumour excision, the patient's symptoms improved quickly. The pathology revealed Burkitt's lymphoma. This is the first report of nocturnal abdominal pain and constipation as the initial manifestation of spinal Burkitt's lymphoma.