Spleen histology in children with sickle cell disease and hereditary spherocytosis: Hints on the disease pathophysiology

open2Hereditary spherocytosis (HS) and sickle cell disease (SCD) are associated with splenomegaly and spleen dysfunction in pediatric patients. Scant data exist on possible correlations between spleen morphology and function in HS and SCD. This study aimed to assess the histological and morphometric features of HS and SCD spleens, in order to get possible correlations with disease pathophysiology. In a large series of spleens from SCD, HS and control patients the following parameters were considered: (i) macroscopic features; (ii) lymphoid follicle (LF) density; (iii) presence of peri-follicular marginal zones (MZs); (iv) presence of Gamna-Gandy bodies; (v) density of CD8-positive sinusoids; (vi) density of CD34-positive microvessels; (vii) presence/distribution of fibrosis and SMA-positive myoid cells; (viii) density of CD68-positive macrophages. SCD and HS spleens have similar macroscopic features. SCD spleens had lower LF density and fewer MZs than HS spleens and controls. SCD also showed lower CD8-positive sinusoid density, increased CD34-positive microvessel density and SMA-positive myoid cells, and higher prevalence of fibrosis and Gamna-Gandy bodies. HS had lower LF and CD8-positive sinusoid density than controls. No significant differences were noted in red pulp macrophages. By multivariate analysis, the majority of HS spleens clustered with controls, while SCD grouped separately. A multi-parametric score could predict the degree of spleen changes irrespective of the underlying disease. In conclusion, SCD spleens display greater histologic effacement than HS and SCD-related changes suggest impaired function due to vascular damage. These observations may contribute to guide the clinical management of patients.embargoed_20161128Alaggio, RitaAlaggio, Rita; Gamba, Piergiorgi

Arterial oxygen content is precisely maintained by graded erythrocytotic responses in settings of high/normal serum iron levels, and predicts exercise capacity: an observational study of hypoxaemic patients with pulmonary arteriovenous malformations.

Oxygen, haemoglobin and cardiac output are integrated components of oxygen transport: each gram of haemoglobin transports 1.34 mls of oxygen in the blood. Low arterial partial pressure of oxygen (PaO2), and haemoglobin saturation (SaO2), are the indices used in clinical assessments, and usually result from low inspired oxygen concentrations, or alveolar/airways disease. Our objective was to examine low blood oxygen/haemoglobin relationships in chronically compensated states without concurrent hypoxic pulmonary vasoreactivity.165 consecutive unselected patients with pulmonary arteriovenous malformations were studied, in 98 cases, pre/post embolisation treatment. 159 (96%) had hereditary haemorrhagic telangiectasia. Arterial oxygen content was calculated by SaO2 x haemoglobin x 1.34/100.There was wide variation in SaO2 on air (78.5-99, median 95)% but due to secondary erythrocytosis and resultant polycythaemia, SaO2 explained only 0.1% of the variance in arterial oxygen content per unit blood volume. Secondary erythrocytosis was achievable with low iron stores, but only if serum iron was high-normal: Low serum iron levels were associated with reduced haemoglobin per erythrocyte, and overall arterial oxygen content was lower in iron deficient patients (median 16.0 [IQR 14.9, 17.4]mls/dL compared to 18.8 [IQR 17.4, 20.1]mls/dL, p<0.0001). Exercise tolerance appeared unrelated to SaO2 but was significantly worse in patients with lower oxygen content (p<0.0001). A pre-defined athletic group had higher Hb:SaO2 and serum iron:ferritin ratios than non-athletes with normal exercise capacity. PAVM embolisation increased SaO2, but arterial oxygen content was precisely restored by a subsequent fall in haemoglobin: 86 (87.8%) patients reported no change in exercise tolerance at post-embolisation follow-up.Haemoglobin and oxygen measurements in isolation do not indicate the more physiologically relevant oxygen content per unit blood volume. This can be maintained for SaO2 ≥78.5%, and resets to the same arterial oxygen content after correction of hypoxaemia. Serum iron concentrations, not ferritin, seem to predict more successful polycythaemic responses

Increased age and male sex are independently associated with higher frequency of blood–cerebrospinal fluid barrier dysfunction using the albumin quotient

Background: The cerebrospinal fluid (CSF)/serum quotient of albumin (QAlb) is the most used biomarker for the evaluation of blood–cerebrospinal fluid barrier (B-CSF-B) permeability. For years QAlb was considered only as an age-related parameter but recently it has also been associated to sex. The aim of the present study was to explore the impact of sex in the determination of B-CSF-B dysfunction. Methods: The analysis was retrospectively conducted on subjects consecutively admitted to the neurological ward. CSF and serum albumin levels were measured by immunonephelometry and pathological QAlb thresholds were considered: 6.5 under 40 years, 8.0 in the age 40–60 and 9.0 over 60 years. Results: 1209 subjects were included in the study. 718 females and 491 males (age: 15–88 years): 24.6% of patients had a diagnosis of multiple sclerosis, 23.2% suffered from other inflammatory neurological diseases, 24.6% were affected by non-inflammatory neurological diseases, and for 27.6% of patients the final neurological diagnosis could not be traced. Dysfunctional B-CSF-B was detected more frequently (44 vs. 20.1%, p &lt; 0.0001) and median QAlb value were higher (7.18 vs. 4.87, p &lt; 0.0001) in males than in females in the overall study population and in all disease sub- groups. QAlb and age were positively correlated both in female (p &lt; 0.0001) and male (p &lt; 0.0001) patients, however the slopes of the two regression lines were not significantly different (p = 0.7149), while the difference between the elevations was extremely significant (p &lt; 0.0001) with a gap of 2.2 units between the two sexes. Finally, in a multivari- able linear regression analysis increased age and male sex were independently associated with higher QAlb in the overall study population (both p &lt; 0.001) and after stratification by age and disease group. Conclusions: Accordingly, identification and validation of sex-targeted QAlb thresholds should be considered as a novel tool in an effort to achieve more precision in the medical approach

Retinoblastoma: Identifying the Diagnostic Signs for Early Treatment

Retinoblastoma is a rare but significant cause of childhood eye cancer world-wide. The prognosis depends upon early diagnosis and treatment but also upon accurate classification of the tumours. Unilateral incidence is normally non-hereditary compared with bilateral incidence where secondary tumours are more common. Survivorship is much better for unilateral compared with bilateral and trilateral retinoblastoma. Early signs are important to detect and photography can assist in identifying no return of “red-eye” during flash photography and yellow appearance of the tumour. Treatment options are discussed together with new psycho-oncology approaches that address potential trauma in the survivor as well as in the family of the survivor

Genetic, epigenetic and exogenetic information

We describe an approach to measuring biological information where ‘information’ is understood in the sense found in Francis Crick’s foundational contributions to molecular biology. Genes contain information in this sense, but so do epigenetic factors, as many biologists have recognized. The term ‘epigenetic’ is ambiguous, and we introduce a distinction between epigenetic and exogenetic inheritance to clarify one aspect of this ambiguity. These three heredity systems play complementary roles in supplying information for development. We then consider the evolutionary significance of the three inheritance systems. Whilst the genetic inheritance system was the key innovation in the evolution of heredity, in modern organisms the three systems each play important and complementary roles in heredity and evolution. Our focus in the earlier part of the paper is on ‘proximate biology’, where information is a substantial causal factor that causes organisms to develop and causes offspring to resemble their parents. But much philosophical work has focused on information in ‘ultimate biology’. Ultimate information is a way of talking about the evolutionary design of the mechanisms of development and inheritance. We conclude by clarifying the relationship between the two. Ultimate information is not a causal factor that acts in development or heredity, but it can help to explain the evolution of proximate information, which is

Phenotypic heterogeneity and genetic modification of P102L inherited prion disease in an international series

The largest kindred with inherited prion disease P102L, historically Gerstmann-Sträussler-Scheinker syndrome, originates from central England, with émigrés now resident in various parts of the English-speaking world. We have collected data from 84 patients in the large UK kindred and numerous small unrelated pedigrees to investigate phenotypic heterogeneity and modifying factors. This collection represents by far the largest series of P102L patients so far reported. Microsatellite and genealogical analyses of eight separate European kindreds support multiple distinct mutational events at a cytosine-phosphate diester-guanidine dinucleotide mutation hot spot. All of the smaller P102L kindreds were linked to polymorphic human prion protein gene codon 129M and were not connected by genealogy or microsatellite haplotype background to the large kindred or each other. While many present with classical Gerstmann-Sträussler-Scheinker syndrome, a slowly progressive cerebellar ataxia with later onset cognitive impairment, there is remarkable heterogeneity. A subset of patients present with prominent cognitive and psychiatric features and some have met diagnostic criteria for sporadic Creutzfeldt-Jakob disease. We show that polymorphic human prion protein gene codon 129 modifies age at onset: the earliest eight clinical onsets were all MM homozygotes and overall age at onset was 7 years earlier for MM compared with MV heterozygotes (P = 0.02). Unexpectedly, apolipoprotein E4 carriers have a delayed age of onset by 10 years (P = 0.02). We found a preponderance of female patients compared with males (54 females versus 30 males, P = 0.01), which probably relates to ascertainment bias. However, these modifiers had no impact on a semi-quantitative pathological phenotype in 10 autopsied patients. These data allow an appreciation of the range of clinical phenotype, modern imaging and molecular investigation and should inform genetic counselling of at-risk individuals, with the identification of two genetic modifiers