Etiology of nonresponsive celiac disease: results of a systematic approach

OBJECTIVES: Nonresponse or relapse of symptoms is common in patients with celiac disease treated with gluten free diet. Refractory sprue (RS) is defined as initial or subsequent failure of a strict gluten-free diet to restore normal intestinal architecture and function in patients who have celiac-like enteropathy. The aims of this study were: 1) to identify causes of persistent symptoms in patients referred with presumed diagnosis of nonresponsive celiac disease (NCD); and 2) to characterize patients with true RS. METHODS: Patients were identified who had been systematically evaluated for NCD between January 1997, and May 2001. Patient records and small bowel biopsy results were reviewed. RESULTS: A total of 55 patients were referred with a presumed diagnosis of NCD. Six did not have celiac disease and had other diseases responsible for their symptoms. Diarrhea, abdominal pain, and weight loss were the most common reasons for evaluation in cases of NCD, whereas weight loss, steatorrhea, and diarrhea were the most common presenting features of RS (nine patients). Of the 49 patients with celiac disease, 25 were identified as having gluten contamination. Additional diagnoses accounting for persistent symptoms included: pancreatic insufficiency, irritable bowel syndrome, bacterial overgrowth, lymphocytic colitis, collagenous colitis, ulcerative jejunitis, T-cell lymphoma, pancreatic cancer, fructose intolerance, protein losing enteropathy, cavitating lymphadenopathy syndrome, and tropical sprue. CONCLUSIONS: Based on this study, we conclude the following: 1) gluten contamination is the leading reason for NCD; 2) of NCD cases, 18% are due to RS; and 3) alternative diseases or those coexistent with celiac disease and gluten contamination should be ruled out before a diagnosis of RS is made.     

Age-dependent neurological phenotypes in a mouse model of PRRT2-related diseases

Paroxysmal kinesigenic dyskinesia is an episodic movement disorder caused by dominant mutations in the proline-rich transmembrane protein PRRT2, with onset in childhood and typically with improvement or resolution by middle age. Mutations in the same gene may also cause benign infantile seizures, which begin in the first year of life and typically remit by the age of 2 years. Many details of PRRT2 function at the synapse, and the effects of mutations on neuronal excitability in the pathophysiology of epilepsy and dyskinesia, have emerged through the work of several groups over the last decade. However, the age dependence of the phenotypes has not been explored in detail in transgenic models. Here, we report our findings in heterozygous and homozygous Prrt2 knockout mice that recapitulate the age dependence of dyskinesia seen in the human disease. We show that Prrt2 deletion reduces the levels of synaptic proteins in a dose-dependent manner that is most pronounced at postnatal day 5 (P5), attenuates at P60, and disappears by P180. In a test for foot slippage while crossing a balance beam, transient loss of coordination was most pronounced at P60 and less prominent at age extremes. Slower traverse time was noted in homozygous knockout mice only, consistent with the ataxia seen in rare individuals with biallelic loss of function mutations in Prrt2. We thus identify three age-dependent phenotypic windows in the mouse model, which recapitulate the pattern seen in humans with PRRT2-related diseases.

     

B-cell lymphoma after angioimmunoblastic lymphadenopathy: a case with oligoclonal gene rearrangements associated with Epstein-Barr virus

We describe a patient with angioimmunoblastic lymphadenopathy with dysproteinemia (AILD), who subsequently developed large-cell immunoblastic lymphoma of B-cell immunophenotype. At the time of the initial diagnosis, histologic examination of an inguinal lymph node showed typical features of AILD, and there was no evidence of a monoclonal B-cell population by immunohistochemical analysis. In situ hybridization and Southern blot analysis for Epstein-Barr virus (EBV) were negative. At autopsy 2 years later, the patient had widespread lymph node and organ involvement by large-cell immunoblastic lymphoma of B-cell immunophenotype. Southern blot analysis performed on DNA extracted from lymph nodes, liver, and spleen showed two patterns of Ig heavy chain and kappa light chain gene rearrangements. The T-cell receptor beta chain gene was in the germline configuration. Analysis with an EBV terminal repeat region probe showed two clonal populations that paralleled the Ig gene rearrangement studies. Double-labeling immunohistochemistry and in situ hybridization confirmed the presence of EBV within the neoplastic B cells. The data support the hypothesis that EBV was not etiologically related to AILD in this case, and that EBV proliferation may occur after the onset of the disease. Further, the data suggest that some B-cell lymphomas that arise in the setting of AILD resemble EBV-associated B-cell lymphomas that arise in other immunodeficiency states.     

Thrombopoietin stimulates megakaryocytopoiesis, myelopoiesis, and expansion of CD34+ progenitor cells from single CD34+Thy-1+Lin- primitive progenitor cells

Thrombopoietin (TPO) or MpI ligand is known to stimulate megakaryocyte (MK) proliferation and differentiation. To identify the earliest human hematopoietic cells on which TPO acts, we cultured single CD34+Thy- 1+Lin- adult bone marrow cells in the presence of TPO alone, with TPO and interleukin-3 (IL-3), or with TPO and c-kit ligand (KL) in the presence of a murine stromal cell line (Sys1). Two distinct growth morphologies were observed: expansion of up to 200 blast cells with subsequent differentiation to large refractile CD41b+ MKs within 3 weeks or expansion to 200-10,000 blast cells, up to 25% of which expressed CD34. The latter blast cell expansions occurred over a 3- to 6-week period without obvious MK differentiation. Morphological staining, analysis of surface marker expression, and colony formation analysis revealed that these populations consisted predominantly of cells committed to the myelomonocytic lineage. The addition of IL-3 to TPO-containing cultures increased the extent of proliferation of single cells, whereas addition of KL increased the percentage of CD34+ cells among the expanding cell populations. Production of multiple colony- forming unit-MK from single CD34+Thy-1+Lin- cells in the presence of TPO was also demonstrated. In limiting dilution assays of CD34+Lin- cells, TPO was found to increase the size and frequency of cobblestone areas at 4 weeks in stromal cultures in the presence of leukemia inhibitory factor and IL-6. In stroma-free cultures, TPO activated a quiescent CD34+Lin-Rhodamine 123lo subset of primitive hematopoietic progenitor cells into cycle, without loss of CD34 expression. These data demonstrate that TPO acts directly on and supports division of cells more primitive than those committed to the MK lineage.     

Long-term protection of hematopoiesis against the cytotoxic effects of multiple doses of nitrosourea by retrovirus-mediated expression of human O6-alkylguanine-DNA-alkyltransferase

A human O6-alkylguanine-DNA-alkyltransferase (ATase) cDNA-containing retrovirus was used to infect murine long-term primary bone marrow cultures. High levels of ATase expression were obtained, and colony- forming cells of the granulocyte-macrophage lineage from the cultures transduced with the human ATase retrovirus were three times more resistant to the alkylating agent, N-methyl-N-nitrosourea (MNU), than control cultures. Furthermore, expression of the human ATase protected long-term hematopoiesis, measured as the output of progenitor cells to the nonadherent fraction of the culture, against the cytotoxic effects of repeated exposures to MNU. These results clearly show that a human ATase cDNA-containing retrovirus can be used to infect long-term primary bone marrow cultures and that this attenuates their sensitivity to nitrosoureas.     

Imaging Surveillance of Hypervascular Liver Lesions in Non-Cirrhotic Patients

A consensus surveillance protocol is lacking for non-cirrhotic patients with hypervascular liver lesions presumed to represent hepatocellular adenomas. Patients with hypervascular liver lesions <5 cm not meeting criteria for focal nodular hyperplasia or hepatocellular carcinoma underwent surveillance with contrast-enhanced magnetic resonance imaging (MRI) 6, 12, and 24 months after baseline imaging. If lesions remained stable or decreased in size, then surveillance imaging was discontinued. Between 2011 and 2014, 116 patients with hypervascular liver lesions were evaluated. Seventy-nine patients were eligible for the surveillance protocol. Median follow-up was 24 months (range, 1–144 months). One patient (1 %) continued oral contraceptive pill (OCP) use and presented with hemorrhage requiring embolization 5 months after initial diagnosis. Ten patients (13 %) underwent elective embolization or surgical resection for size ≥5 cm. The remaining 68 patients (86 %) continued surveillance without hemorrhage or malignant transformation. Risk factors for requiring intervention during the surveillance period included younger age, larger lesion size, and estrogen use (all p?<?0.05). Patients with hepatocellular adenomas <5 cm can safely be observed after discontinuing OCP with serial imaging 6, 12, and 24 months after diagnosis. If lesions remain stable or decrease in size, then longer-term surveillance is unlikely to identify patients at risk for complications.     

Long-Term Survival After Local Excision for T1 Carcinoma of the Rectum

PURPOSE Many authors have reported high rates of local recurrence after local excision for early carcinoma of the rectum, which raises the question of whether oncologic resection gives better results. This study was designed to compare the long-term recurrence rate, long-term survival, and risk factors for T1 adenocarcinoma of the rectum treated with local excision or oncologic resection.METHODS We identified 144 patients who had T1 sessile adenocarcinoma in the lower third or middle third of the rectum. Patients who received adjuvant therapy or who had pedunculated lesions were excluded. Data included age, gender, size of lesion, histologic type of carcinoma, grade, presence of lymphovascular invasion, and depth of invasion. Outcomes were defined as five-year and ten-year cumulative probabilities of local recurrence, distant metastasis, overall survival, and cancer-free survival. The mean follow-up was 9.2 years; median follow-up was 8.1 years.RESULTS We compared 70 patients who underwent local excision with 74 patients who underwent oncologic resection. Among patients with lesions in the middle or lower third of the rectum, 1) the five-year and ten-year outcomes were significantly better for overall survival and cancer-free survival in the oncologic resection group, but there were no significant differences in local recurrence or distant metastasis; 2) the multivariate risk factors for long-term, cancer-free survival were invasion into the lower third of the submucosa, local excision, and older than aged 68 years; and 3) for lesions with invasion into the lower third of the submucosa, the oncologic resection group had lower rates of distant metastasis and better survival. Among patients with lesions in the lower third of the rectum, 1) the five-year and ten-year outcomes showed no significant differences in survival, local recurrence, or distant metastasis between the two groups; and 2) for lesions with invasion into the lower third of the submucosa, the oncologic resection group showed a trend of improved survival, which was not statistically significant, possibly because of low statistical power from the small sample size.CONCLUSIONS Patients who undergo local excision or oncologic resection for T1 carcinoma in the lower two-thirds of the rectum have a high incidence of local recurrence and distant metastasis. To improve the cure rate, the rate of recurrence must decrease. A randomized, controlled study is needed to determine whether adjuvant therapy may be beneficial.Read at the meeting of The American Society of Colon and Rectal Surgery, New Orleans, Louisiana, June 21 to 26, 2003.