Luc L. Oligny

Dientamoeba fragilis masquerading as allergic colitis

BACKGROUND Dientamoeba fragilis is a rare cause of chronic infectious diarrhea and colitis in children. METHODS Review of the clinical manifestations, diagnostic methods, and clinical course of D. fragilis infection in our hospital. RESULTS Eleven pediatric patients are discussed, seven of whom had a history of recent travel. Clinical manifestations of infectious diarrhea included anorexia, intermittent vomiting, abdominal pain, and diarrhea, ranging from 1 to 100 weeks in duration. Peripheral eosinophilia was present in seven patients. One patient with well-documented bovine protein allergy had intermittent episodes of diarrhea and abdominal pain, despite an appropriate elimination diet. Eosinophilic colitis documented by colonoscopy, was due to D. fragilis. Metronidazole was effective in treating five patients, and iodoquinol was effective in treating four others. CONCLUSIONS D. fragilis should be included in the differential diagnosis of chronic diarrhea and eosinophilic colitis. The identification of this pathogen requires clinical awareness of epidemiologic risk factors and presenting complaints, as well as the laboratory staining procedures essential to its proper identification.

Human papillomavirus (HPV) study of 691 pathological specimens from Quebec by PCR-direct sequencing approach.

Human papillomaviruses (HPV) are etiological agents of cervical cancer. In order to address clinical demand for HPV detection and sequence typing, mostly in pre‐cancerous cervical lesions, we applied our two‐tier PCR‐direct sequencing (PCR‐DS) approach based on the use of both MY09/MY11 and GP5 + /GP6 + sets of primers. We tested 691 pathological specimens, all of which were biopsies, 75% of which were diagnosed histologically as cervical intraepithelial neoplasia (CIN) grades I–III. In total, 484 samples (70%) tested HPV‐positive, yielding 531 HPV sequences from 47 HPV types, including two novel types. Four most frequently found HPV types accounted for 52.9% of all isolates: HPV6, 16, 11, and 31 (21.5%, 20.0%, 7.0%, and 4.5%, respectively). Some interesting results are the following: all currently known high‐risk HPV (14 types) and low‐risk HPV (6 types) were detected; HPV18 was not the 1st or 2nd but rather the 4th–5th most frequent high‐risk HPV type; the highest detection rate for HPV (86%) among samples suspected to be HPV‐infected was found in the youngest age group (0–10 years old), including 70% (44/63) “genital” HPV types; HPV types of undetermined cervical cancer risk represented 19% and of the total HPV isolates but were strongly increased in co‐infections (36.5% of all isolates). To our knowledge, this is the largest sequencing‐based study of HPV. The HPV types of unknown cancer risk, representing the majority of the known HPV types, 27 of the 47 types detected in this study, are not likely to play a major role in cervical cancer because their prevalence in CIN‐I, II, and III declines from 16% to 8% to 2.5%. The two‐tier PCR‐DS method provides greater sensitivity than cycle sequencing using only one pair of primers. It could be used in a simple laboratory setting for quick and reliable typing of known and novel HPV from clinical specimens with fine sequence precision. It could also be applied to anti‐cancer vaccine development. J. Med. Virol. 63:284–292, 2001.

Characterization and Distribution of Colonic Dendritic Cells in Crohn's Disease

Dendritic cells (DCs) are thought to play an important role in the pathogenesis of autoimmune inflammation, including Crohn’s disease (CD). We investigated the distribution and state of maturation of DCs in the colon in relation to the severity of inflammation and therapy. Using archival specimens from colonic resections in 19 pediatric patients with CD and 14 controls, we identified and characterized the DCs within the lamina propria, submucosa, and muscularis compartments using morphologic and quantitative immunohistochemical methods. The distribution of CD11c+CD83+CD68−DC-SIGN+ and immature CD11c+CD83−CD68−DC-SIGN+ DCs within the different compartments varied according to the presence or absence of CD as well as to the severity of inflammation and systemic corticoid treatment. Immature DCs were only found in non-inflamed control colonic tissue. Marked reductions (60% and 30%) in total CD11c+ and CD83+ DC numbers were observed in CD tissue samples compared with controls (P < 0.05). CD samples from patients on corticosteroid therapy were significantly more depleted than in tissue from untreated patients or those on other drugs. Colonic tissue with severe inflammation had reduced numbers of CD11c+ and CD83+ DCs in the lamina propria and submucosal compartments (80% and 76% for CD11c; 75% and 76% for CD83, respectively, P < 0.05), with a concomitant increase (525% for CD11c and 700% for CD83 P < 0.05) of DCs in the muscularis compartment, compared to moderately inflamed and non-inflamed CD tissue. Our data suggest that an imbalance in intestinal DC subpopulations may play a role in the initiation and/or the maintenance of chronic inflammation in CD. Corticosteroid therapy is associated with colonic DC depletion.

Searching for an intrinsic neuroendocrine cell in the kidney: An immunohistochemical study of the fetal, infantile and adult kidney

The pathogenesis of primary renal carcinoid tumor is unknown. One hypothesis has implied derivation from a yet unrecognized intrinsic neuroendocrine cell in the renal parenchyma/hilum either as a minute endocrineparacrine constituent or resulting from entrapped/misplaced progenitor cells of the so-called dispersed neuroendocrine system during organogenesis. Immunohistochemical staining for chromogranin and serotonin was systematically performed on a whole-mount and geographically mapped normal adult kidney, kidneys from 15 fetuses (age range: 15 to 38 weeks), and renal specimens from 18 infants/children (age range: 7 days to 123 months). Minute paraganglion nests (composed of chromogranin positive/serotonin negative chief cells and S-100 protein positive dendritic cells) were incidentally detected within the renal hilum primitive stroma (unilaterally) of two fetuses at 22 and 26 weeks. Sequestration and persistence of such paraganglion nests during renal growth and maturation would offer a basis for the rare occurrence of extra-adrenal paraganglioma involving the renal hilum/pedicle. Otherwise, no neuroendocrine cell was detected within the renal parenchyma or hilum, therefore not validating/sustaining the aforementioned hypothesis in the pathogenesis of renal carcinoid tumor.

Basal cells of second trimester fetal breasts: immunohistochemical study of myoepithelial precursors.

The molecular characterization of human mammary myoepithelial cells is incomplete, hindering our understanding of its importance in breast physiology and pathology. Because data on the precursors of this cell lineage remain scarce and often contradictory, basal epithelial cells of second trimester fetal breasts were studied by light microscopy (LM) and immunohistochemistry (IHC). Up to 20 wk of gestational age, the mammary rudiments only comprised roundish primary outgrowths, “primary buds,” more likely to represent immature nipples than true mammary tissue. At 21 wk secondary outgrowths, “projections,” extended from enlarged primary buds into well-vascularized layers of dense mesenchyme. Basal projection cells had a partial myoepithelial-like phenotype: they reacted with CD29, CD49f, CD104, keratin 14, vimentin, S100β protein, and p63; furthermore, many became positive for keratin 17, α-smooth muscle actin, and CD10 (but not for keratin 19) between wk 21 and 25. The continuous basement membrane associated with the fetal mammary rudiments was strongly positive for collagens type IV and VII, and for laminin 5. Consistently strong and basally polarized staining for hemidesmosomal components suggested that although incompletely differentiated, most second trimester myoepithelial precursors might already mediate local epithelial-mesenchymal interactions, i.e., complex signaling pathways which are crucial for both orderly growth during development and maintenance of homeostasis during adult life. Because they are likely implicated in the phenomenon of menstrual cycle-related growth spurts in the adult resting breast, the strategically positioned cells of the myoepithelial lineage might constitute critical protagonists in defective epithelial-mesenchymal signaling associated with cancer progression.

Fetal and perinatal autopsy in prenatally diagnosed fetal abnormalities with normal karyotype.

OBJECTIVE To review the information on fetal and perinatal autopsies, the process of obtaining consent, and the alternative information-gathering options following a prenatal diagnosis of non-chromosomal malformations, and to assist clinicians in providing postnatal counselling regarding fetal diagnosis and recurrence risks. OUTCOMES To provide better counselling about fetal and perinatal autopsies for women and families who are dealing with a prenatally diagnosed non-chromosomal fetal anomaly. EVIDENCE Published literature was retrieved through searches of PubMed or Medline, CINAHL, and The Cochrane Library in 2009 and 2010, using appropriate key words (fetal autopsy, postmortem, autopsy, perinatal postmortem examination, autopsy protocol, postmortem magnetic resonance imaging, autopsy consent, tissue retention, autopsy evaluation). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Additional publications were identified from the bibliographies of these articles. There were no date or language restrictions. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. BENEFITS, HARMS, AND COSTS This update educates readers about (1) the benefits of a fetal perinatal autopsy, (2) the consent process, and (3) the alternatives when the family declines autopsy. It also provides a standardized approach to fetal and perinatal autopsies, emphasizing pertinent additional sampling when indicated. VALUES The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Recommendations 1. Standard autopsy should ideally be an essential part of fully investigating fetal loss, stillbirths, and neonatal deaths associated with non-chromosomal fetal malformations. (II-3A) 2. Clinicians and health care providers approaching parents for autopsy consent should discuss the options for a full, limited, or step-wise postmortem examination; the issue of retained fetal tissues; and the value of autopsy and the possibility that the information gained may not benefit them but may be of benefit to others. This information should be provided while respecting the personal and cultural values of the families. (III-A) 3. If parents are unwilling to give consent for a full autopsy, alternatives to full autopsy that provide additional clinical information must be presented in a manner that includes disclosure of limitations. (III-A) 4. External physical examination, medical photographs, and standard radiographic or computed tomography should be offered in all cases of fetal anomaly(ies) of non-chromosomal etiology. (II-2A) 5. Well-designed, large prospective studies are needed to evaluate the accuracy of postmortem magnetic resonance imaging. It cannot function as a substitute for standard full autopsy. (III-A) 6. The fetal and perinatal autopsies should be performed by trained perinatal or pediatric pathologists. (II-2A) 7. The need for additional sampling is guided by the results of previous prenatal and/or genetic investigations, as well as the type of anomalies identified in the fetus. Fibroblast cultures may allow future laboratory studies, particularly in the absence of previous karyotyping or if a biochemical disorder is suspected, and DNA analysis. (II-3A) 8. In cases requiring special evaluation, the most responsible health care provider should have direct communication with the fetopathologist to ensure that all necessary sampling is performed in a timely manner. (II-3A) 9. The most responsible health care providers must see the families in follow-up to share autopsy findings, plan for the management of future pregnancies, obtain consent for additional testing, and offer genetic counselling to other family members when appropriate. (III-A).

Multifocal, Nascent, and Invasive Myoepithelial Carcinoma (Malignant Myoepithelioma) of the Breast: An Immunohistochemical and Ultrastructural Study:

This report describes the light microscopic (LM), immunohistochemical (IHC), and electron microscopic (EM) features of a multifocal, nascent, and invasive myoepithelial carcinoma of the breast. By LM, the spindle cells disclosed fibrillar acidophilic cytoplasm, mild nuclear atypia, and a low mitotic index. Myoepithelial differentiation was established through IHC (single- and double-labeling techniques) and EM: periductal and infiltrating spindle cells coexpressed total muscle actin, a-smooth muscle actin, vimentin, cytokeratin 14, and pankeratin, and their EM features were characteristic of myoepithelial cells, i.e., perinuclear tonofilaments, subplasmalemmal bundles of microfilaments with dense bodies, intermediate junctions, poorly developed desmosomes, pinocytic vesicles, and fragmented external lamina. No invasive epithelial cells disclosed luminal differentiation (by LM, IHC, EM), identifying, thus, this neoplasm as a pure spindle cell myoepithelial carcinoma of the breast.

Cytokine Tissue Levels as Markers of Disease Activity in Pediatric Crohn Disease

The mucosal immune system is overactivated in Crohn disease (CD) and viral infections have been associated with clinical exacerbations. To investigate the potential association between mucosal inflammation and the cytokines involved in the early response to viruses, we analyzed colonic tissue levels of IL-2Rα, interferon-α, and IL-15 in CD. Patients undergoing diagnostic colonoscopy were classified into controls (n = 22) and three CD groups based on the histologic severity of inflammation and clinical activity: a) severely active CD (n = 3); b) mild to moderately active CD (n = 14); and c) quiescent CD (n = 23). Rectal biopsies (two per patient) were homogenized and cytokine levels determined by ELISA kits. Statistical analysis was performed by ANOVA with Tukey and Scheffé tests. IL-2Rα levels were increased in the active CD group compared with the quiescent CD group: a) 405 ± 87, b) 159 ± 31, and c) 33 ± 15 pg/mg DNA (p < 0.001). The latter group was similar to controls (39 ± 20 pg/mg DNA). Furthermore, a linear correlation (r = 0.98) between IL-2Rα and disease activity (Van Hees index) was observed. IL-15 levels were also higher in active compared with quiescent CD and controls: a) 0.69 ± 0.23 and b) 0.72 ± 0.31 versus c) 0.28 ± 0.21 and 0.28 ± 0.14 pg/mg DNA for controls (p < 0.05). Interferon-α levels were undetectable in all samples. Our data suggest that IL-2Rα tissue levels correlate with CD activity. IL-15 is also overproduced in inflamed CD tissue. The lack of a parallel elevation of interferon-α does not support a role for viral induction of IL-15 in inflamed CD samples.

Assessment of correlation between p16INK4a staining, specific subtype of human papillomavirus, and progression of LSIL/CIN1 lesions: first comparative study.

OBJECTIVES To study and compare the effectiveness of p16(INK4a) staining and specific human papillomavirus (HPV) subtypes as a prognostic marker in cervical intraepithelial neoplasia grade 1 (CIN1; low-grade squamous intraepithelial lesions). METHODS Sixty-four cervical samples diagnosed as CIN1 and stained with p16(INK4a), with HPV status assessed by polymerase chain reaction-direct sequencing. RESULTS Of the 34 p16(INK4a)-negative biopsy specimens, 26 regressed, seven persisted, and one progressed. Of the 20 p16(INK4a) diffusely positive biopsy specimens, seven regressed, eight persisted, and five progressed. Ten biopsy specimens stained positive only in the lower one-third of the sample, of which seven regressed and three persisted. p16(INK4a) diffusely positive CIN1 lesions were associated with only high-risk HPV subtypes, with the exception of one HPV-negative biopsy specimen. Three different high-risk HPV subtypes and one low-risk HPV subtype (HPV66) were identified in the six CIN1 lesions that progressed. CONCLUSIONS There is a significant relationship between p16(INK4a) immunostaining and follow-up (P = .002). p16(INK4a)-negative specimens or positivity in the lower one-third of CIN1 lesions seldom progress to a CIN2-3 lesion.

Collapsing glomerulopathy in Galloway-Mowat syndrome : A case report and review of the literature

The Galloway-Mowat syndrome (GMS) (MIM251300) is described as an autosomal recessive disorder, the gene of which has not yet been identified. We report the case of a boy presenting with an early nephrotic syndrome, microcephaly, seizures, and psychomotor retardation. He died at 3 years and 11 months in a context of end-stage renal function consistent with a GMS. He was the second child of a non-consanguineous marriage. There was no family history of nephrotic syndrome or end-stage renal failure, but his mother had a moderate mental retardation complicated by seizures. He presented dysmorphologic features, including micrognathia and large and floppy ears. Renal biopsy showed a focal segmental glomerulosclerosis with a collapsing glomerulopathy and abundant visceral epithelial cell proliferation. The majority of the glomeruli were sclerotic. We report the first case of GMS associated with a collapsing glomerulopathy.