The gut microbiome: a clinically significant player in transplantation?

The intestinal microbiome is critical to digestion, metabolism and protection from pathogenic organisms. Dysbiosis, or alteration of this microbiome, can result in Clostridium difficile infection and may play a role in other conditions. Patients undergoing solid organ transplantation (e.g., kidney, lung, liver, small bowel) and hematopoietic stem cell transplantation have a shift in the gut microbiome with a decrease in predominant organisms, a loss of bacterial diversity and emergence of a new dominant population. This translates into increased morbidity and mortality with risk of infection and rejection. We discuss the changes seen in the microbiome and its possible consequences. It may be important to develop strategies to restore the normal microbiome in such patients.     

Atypical parakeratosis: A marker of dysplasia?

The Bethesda System categorizes atypical parakeratosis (APK) as “ASCUS or SIL depending on the degree of cellular abnormalities.” APK, however, is not well-defined. We retrospectively reviewed 68 cervicovaginal specimens with follow-up material to identify specific criteria and clinical significance of APK. APK cells were small cells, 2–3 times the diameter of a neutrophil, with dense, orangeophilic cytoplasm, high nuclear cytoplasmic ratio, dense, often uneven chromatin, and irregular nuclear contour. Of 62 cases with APK, 37 had accompanying dysplastic cells. Of 25 cases with APK alone, follow-up revealed 12 with squamous intraepithelial lesion (5 HSIL and 7 LSIL) and 13 with benign changes. A major diagnostic pitfall of APK was inflammation with degeneration. Abundant APK cells, minimal inflammation and degeneration, and previous history of dysplasia frequently were associated with follow-up SIL. The findings of this study identify APK as an important marker for dysplasia that warrants careful evaluation and follow-up. Diagn Cytopathol 1996;15:288–291. © Wiley-Liss, Inc.     

Prenatal antidepressant exposures and gastrointestinal complaints in childhood: A gut–brain axis connection?

Selective serotonin/norepinephrine reuptake inhibitors (collectively, SRIs) are the most commonly prescribed antidepressant agents for the treatment of depression in pregnancy. SRIs affect maternal and placental serotonin signaling, which might impact fetal brain development. Alterations in serotonin signaling might also impact the developing gut–brain axis (GBA) via alterations in the fetal enteric nervous system (ENS). Emerging evidence suggests that gestational SRI exposure may be associated with offspring gastrointestinal problems. However, prospective human studies of the effects of fetal SRI exposure on the ENS and function are absent in the literature. In this paper we present data demonstrating significant associations between prenatal SRI exposure and children's gastrointestinal (GI) problems in two well-characterized, prospective cohorts of preschool and later childhood individuals. The results support the hypothesis that prenatal SRI exposure can increase the risk for childhood GI difficulties. Further research is warranted on the potential SRI-induced changes to the child gut including the role of the microbiome and the GBA in the development of GI problems.     

The “Atypical” Mycobacteria: Recognition and Disease Association

Abstract

Current advances in the understanding of the pathogenicity of the agents of diarrheal infections, Vibrio cholerae, diarrheagenic E. coli, Shigella, Salmonella, and enteropathogenic Yersinia, have, to a great extent, become possible due to morphological studies of host-pathogen interactions in natural and experimental infections. Despite a multigenic nature and a diversity of pathogenic features in the bacterial species and even in serogroups of the same species, it is now possible to delineate four major patterns of interaction of enteric pathogens with their cellular targets, the enterocytes, and with the immune apparatus of the gut. These patterns, epicellular cytotonic, epicellular restructuring cytotonic, invasive intraepithelial cytotonic and cytotoxic, and invasive transcellular cytotonic and cytotoxic bacteremic, underlie early pathogenesis and clinical manifestations in the respective diarrheal diseases. In this review, the results of the morphological analyses of these patterns over the last 3 decades as well as some methodological problems encountered in the interpretation of morphological observations are discussed.     

Atypical depression: a variant of bipolar II or a bridge between unipolar and bipolar II?

BACKGROUND: Although increasing data link atypical depression (AD) to the bipolar spectrum, controversies abound about the extent of the overlap. In particular, the Columbia group, which has pioneered in providing data on operational clarity and pharmacological specificity of atypical depressions, has nonetheless consistently avoided studying its discriminatory validity from bipolar II (BP-II). Accordingly, we undertook a full scale validation of such a link in a large clinical sample of BP-II and unipolar (UP) major depressive disorder (MDD). METHODS: Consecutive 348 BP-II and 254 MDD outpatients presenting with major depressive episodes (MDE) were interviewed off psychoactive drugs with a modified Structured Clinical Interview for DSM-IV, the structured Family History Screen and the Hypomania Interview Guide. We used the DSM-IV criteria for "atypical features" specifier. Depressive mixed state was defined as > or =3 concurrent hypomanic signs and symptoms during MDE. Bipolar validators were age at onset, high depressive recurrence, depressive mixed state and bipolar family history (types I and II). Univariate and multivariate logistic regression were used to examine associations and control for confounding variables. RESULTS: Frequency of AD was 43.0% in the combined BP-II and MDD sample. AD, versus non-AD, had significantly higher rates of BP-II. AD was significantly associated with all bipolar validators, among which family history was the most robust. A dose-response relationship was found between number of atypical symptoms during MDE and bipolar family history loading. The association between bipolar family history and number of atypical symptoms remained significant after controlling for the confounding effect of BP-II. Bipolar family history was strongly associated with the atypical symptoms of leaden paralysis and hypersomnia. CONCLUSION: These results confirm a strong link between AD and bipolar validators along psychopathologic and familial grounds. From a practical standpoint, AD is best viewed as a variant of BP-II. Clinicians confronted with MDE patients presenting with atypical features should strongly consider a BP-II diagnosis. In a more hypothetical vein, atypicality-or some associated features thereof-might serve as a nosologic bridge between UP and BP-II.     

Atypical fibroxanthoma and pleomorphic dermal sarcoma: Is superficial infiltration in subcutaneous tissue acceptable in AFX?

BackgroundAtypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS) are rare cutaneous neoplasms forming a spectrum. Case reports with recurrences and metastasis have been published despite the current view that AFX is benign. The aim of this study was to identify clinical and histopathological features that predict tumor recurrence.MethodsA retrospective review of AFX and PDS cases was performed. Clinical characteristics were obtained from patient records.ResultsA total of 29 AFX and 23 PDS cases were identified. Review led to re-classification of 12 cases (18%). In 14/50 (26.9%) cases a recurrence occurred. Recurrences were significantly more likely to occur when the tumor showed any infiltration in the subcutaneous fat (100% vs 43.2%, p = 0.000) or when the tumor diameter exceeded 2 cm (46.2% vs 16.2%, p = 0.030).ConclusionsThis study shows that histopathological distinction between AFX and PDS remains difficult with reclassification in 12 out of 52 (18%) cases upon review. All AFX cases solely confined to the dermis behaved benign. We therefore advocate to classify all cases with any form of subcutaneous extension as PDS, and only lesions without as AFX. This contrasts with the current general opinion in which superficial subcutaneous invasion is still accepted in AFX.     

Gender bias in lupus: does immune response initiated in the gut mucosa have a role?

The risk of developing systemic lupus erythematosus (SLE) is approximately nine times higher among women compared to men. However, very little is understood concerning the underlying mechanisms that contribute to this gender bias. Further, whether there is a link between immune response initiated in the gut mucosa, the progression of SLE and the associated gender bias has never been investigated. In this report, we show a potential link between the immune response of the gut mucosa and SLE and the gender bias of lupus for the first time, to our knowledge. Both plasma cell‐ and gut‐imprinted‐ α4β7 T cell frequencies were significantly higher in the spleen and gut mucosa of female (SWR × NZB)F₁ (SNF₁) mice compared to that of their male counterparts. Importantly, female SNF₁ mice not only showed profoundly higher CD45⁺ immune cell densities, but also carried large numbers of interleukin (IL)‐17‐, IL‐22‐ and IL‐9‐producing cells in the lamina propria (LP) compared to their male counterparts. Intestinal mucosa of female SNF₁ mice expressed higher levels of a large array of proinflammatory molecules, including type 1 interferons and Toll‐like receptors 7 and 8 (TLR‐7 and TLR‐8), even before puberty. Our work, therefore, indicates that the gut immune system may play a role in the initiation and progression of disease in SLE and the associated gender bias.     

Atypical hematologic and renal manifestations in Neurofibromatosis type I: Coincidence or pathophysiological link?

Neurofibromatosis type 1 (NF1) is an autosomal dominant, multi-system, neurocutaneous disorder that predisposes to the development of benign and malignant tumors with a birth incidence rate of 1 in 2500–3000. 50% of cases are sporadic. The diagnosis is exclusively based on clinical assessment with clinical diagnostic criteria such as café-au-lait spots, neurofibromas, axillary or groin freckling, Lisch nodules, optic pathway glioma, bony dysplasia and first-degree relative with NF1. We report a family with NF1 in which two members presented atypical clinical features in addition to the classical diagnostic criteria. Three relatives affected by NF1, a father and two of his three sons, are described.The clinical diagnosis was originally worn in all three cases, with the association many spots café-au –lait over the entire body and some axillary freckling as well as first-degree relative. One case presented an Acute Myeloid Leukemia (AML) type 2 at 10 years of age diagnosed before the revelation of bicytopenia associated pallor and isolated asthenia. A second case presented a nephrotic syndrome at 4 years of age due to the association of hydrops with headache and asthenia. Direct sequencing of NF1 led to identify the familial mutation, a previously unreported heterozygous missense mutation c.3443C > A, p.Ala1148Glu in exon 20 which segregated with all three affected patients. The family described in this report confirms the high clinical variability of NF1, even intrafamilial, and raises the question as to whether rare features such as AML and nephrotic syndrome are associated with NF1. Some NF1 patients presenting glomerular diseases or AML have rarely been reported, but due to the small number of cases described the mechanisms underlying these associations are poorly understood. However, it seems important to be aware of the possible occurrence of nephritic syndrome and/or malignant blood diseases in NF1 patients.     

Resveratrol: A “miracle” drug in neuropsychiatry or a cognitive enhancer for mice only? A systematic review and meta-analysis

BackgroundOver the last decade resveratrol has been trialled for the prevention and treatment of cognitive decline; however, the results have shown a conflict between human studies compared with animal studies, especially on cognition, blood pressure, neuroimaging, and mood.MethodsHuman clinical trials and animal studies published prior to January 2020, were identified searching across major electronic databases. PRISMA guidelines were used for data extraction, which was independently performed by two authors. Pooled standard mean difference (SMD, random effect model) and odds ratios (ORs) were calculated.ResultsMost publications on animal models reported positive outcomes on cognition and brain function following exposure to resveratrol or grape seed extracts. By contrast, 11 meta-analyses of data from human placebo vs resveratrol, grape or wine treatment trials identified no statistically significant effect on a variety of measures, including cognitive and mood assessments, grey matter volume and blood pressure.ConclusionsBased on currently available data, the promising effects of resveratrol in animal models is not replicated in human clinical trials. The effects, if any, of resveratrol on human cognition are likely to be small. This work may be useful for the design and implementation of future pre-clinical and clinical studies using resveratrol in a neurological setting.     

Bacterial superantigens: provocateurs of gut dysfunction and inflammation?

Inflammatory bowel diseases (IBDs) are chronic debilitating conditions, which impair the patient's quality of life significantly. Among them, Crohn's disease and ulcerative colitis are idiopathic disorders for which an infective etiology has long been sought. Here, we present an opinion in support of the hypothesis that bacterial superantigens can participate in the initiation, exaggeration or reactivation of enteric inflammatory disease, at least in some patients. Although the identification of a specific pathogen responsible for IBD remains a worthy pursuit, an awareness of the response to bacterial products per se will be of value in providing a comprehensive understanding of enteric pathophysiological mechanisms and their potential role in IBDs.     

Pros and cons: Is faecal microbiota transplantation a safe and efficient treatment option for gut dysbiosis?

Faecal Microbiota Transplantation (FMT) is well established as an effective treatment for Clostridioides difficile infection (CDI), restoring gut microbiome diversity and function. The utility of FMT is currently being explored in relation to other immune-mediated pathologies, such as allergic disease, inflammatory bowel diseases and autoimmune diseases. Clinical trials in these areas are ongoing, and the altered gut microbiota (dysbiosis) that is often observed in these pathologies provides a rationale for the application of FMT to restore the microbiome. However, there is controversy on the risk-benefit ratio as it relates to the use of FMTs in pathologies other than CDI. In this Pro and Con article, we present the arguments for and against the use of FMT in immune-mediated pathologies, such as allergic disease. We further identify research gaps and recommend how these may be addressed in future studies.     

Atypical amyoplasia congenita in an infant with Leigh syndrome: A mitochondrial cause of severe contractures?

Amyoplasia congenita is a distinct form of arthrogryposis with characteristic features including internally rotated and adducted shoulders, extended elbows, flexion, and ulnar deviation of the wrists, and adducted thumbs. Fetal hypokinesia, secondary to a variety of genetic conditions, neuromuscular disorders, and environmental agents, is associated with contractures. In order to increase our understanding of the phenotypic spectrum associated with SURF 1 deficiency, a common cause of mitochondrial respiratory chain complex IV deficiency and Leigh syndrome, we describe a now 6-year-old boy who presented in the neonatal period with amyoplasia congenita. His development was normal until age 10.5 months, at which time he developed severe hypotonia and choreoathetosis following an episode of viral gastroenteritis. Following the onset of neurological symptoms, he gradually developed severe kyphosis and lower limb contractures. Blood and cerebrospinal fluid lactate levels were elevated and head imaging showed characteristic features of Leigh syndrome. He was found to harbor two pathogenic heterozygous mutations in the SURF 1 gene. In this case, mitochondrial dysfunction and the resultant energy deficiency may have played a role in causing abnormal neuronal development during embryogenesis, causing arthrogryposis. A variety of mitochondrial respiratory chain complex deficiencies have been associated with contractures of varying severity. Therefore, mitochondrial disorders should be considered in the differential diagnosis of neonatal arthrogryposis, especially if other characteristic findings such as lactic acidemia or basal ganglia abnormalities are present. ? 2012 Wiley Periodicals, Inc.