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Journal of Clinical Neurophysiology :... Sep 2023The aim of this study was to investigate the subclinical involvement of the optic nerve in asymptomatic patients with vitamin B12 deficiency using visual evoked...
PURPOSE
The aim of this study was to investigate the subclinical involvement of the optic nerve in asymptomatic patients with vitamin B12 deficiency using visual evoked potentials.
METHODS
This study included 40 asymptomatic patients diagnosed with vitamin B12 deficiency (considered as serum levels below 150 pg/mL) and a control group of 40 healthy individuals. All participants underwent a visual evoked potential examination. Routine screening for homocysteine was performed for patients with vitamin B12 deficiency. The levels of vitamin B12 and homocysteine and the presence of megaloblastic anemia were analyzed statistically compared with P100, N75, and N135 latencies and amplitudes.
RESULTS
The mean vitamin B12 level was 96 pg/mL in the patient group and 374 pg/mL in the control group. In the patient group, 24 (60%) patients had hyperhomocysteinemia and 8 (20%) patients had megaloblastic anemia. The P100 wave latency of patients with vitamin B12 deficiency was significantly prolonged compared with the control group ( P < 0.01). There was no significant difference in the P100 amplitude between the patient group and the control group. P100 latencies were significantly longer in patients with hyperhomocysteinemia ( P = 0.002).
CONCLUSIONS
Our study showed that patients with vitamin B12 deficiency may have visual evoked potential abnormalities without visual symptoms or examination findings. In addition, high homocysteine levels led to a prolonged P100 latency in the patient group independent of vitamin B12 levels.
Topics: Humans; Evoked Potentials, Visual; Hyperhomocysteinemia; Vitamin B 12 Deficiency; Vitamin B 12; Anemia, Megaloblastic
PubMed: 35349545
DOI: 10.1097/WNP.0000000000000920 -
Endocrinology Jul 2024Thyroid hormone (TH) effects are mediated through TH receptors (TRs), TRα1, TRβ1, and TRβ2. The TRs bind to the DNA and regulate expression of TH target genes... (Comparative Study)
Comparative Study
Thyroid hormone (TH) effects are mediated through TH receptors (TRs), TRα1, TRβ1, and TRβ2. The TRs bind to the DNA and regulate expression of TH target genes (canonical signaling). In addition, they mediate activation of signaling pathways (noncanonical signaling). Whether noncanonical TR action contributes to the spectrum of TH effects is largely unknown. The aim of this study was to attribute physiological effects to the TR isoforms and their canonical and noncanonical signaling. We conducted multiparameter phenotyping in male and female TR knockout mice (TRαKO, TRβKO), mice with disrupted canonical signaling due to mutations in the TR DNA binding domain (TRαGS, TRβGS), and their wild-type littermates. Perturbations in senses, especially hearing (mainly TRβ with a lesser impact of TRα), visual acuity, retinal thickness (TRα and TRβ), and in muscle metabolism (TRα) highlighted the role of canonical TR action. Strikingly, selective abrogation of canonical TR action often had little phenotypic consequence, suggesting that noncanonical TR action sufficed to maintain the wild-type phenotype for specific effects. For instance, macrocytic anemia, reduced retinal vascularization, or increased anxiety-related behavior were only observed in TRαKO but not TRαGS mice. Noncanonical TRα action improved energy utilization and prevented hyperphagia observed in female TRαKO mice. In summary, by examining the phenotypes of TRα and TRβ knockout models alongside their DNA binding-deficient mutants and wild-type counterparts, we could establish that the noncanonical actions of TRα and TRβ play a crucial role in modulating sensory, behavioral, and metabolic functions and, thus, contribute to the spectrum of physiological TH effects.
Topics: Animals; Female; Mice, Knockout; Male; Phenotype; Thyroid Hormone Receptors alpha; Thyroid Hormone Receptors beta; Mice; Signal Transduction; Thyroid Hormones; Mice, Inbred C57BL
PubMed: 38889231
DOI: 10.1210/endocr/bqae067 -
Role of Cytokine-Inducible SH2 Domain-Containing (CISH) Protein in the Regulation of Erythropoiesis.Biomolecules Oct 2023The cytokine-inducible SH2 domain-containing (CISH) protein was the first member of the suppressor of cytokine signaling (SOCS) family of negative feedback regulators...
The cytokine-inducible SH2 domain-containing (CISH) protein was the first member of the suppressor of cytokine signaling (SOCS) family of negative feedback regulators discovered, being identified in vitro as an inducible inhibitor of erythropoietin (EPO) signaling. However, understanding of the physiological role played by CISH in erythropoiesis has remained limited. To directly assess the function of CISH in this context, mice deficient in CISH were characterized with respect to developmental, steady-state, and EPO-induced erythropoiesis. was strongly expressed in the fetal liver, but CISH knockout (KO) mice showed only minor disruption of primitive erythropoiesis. However, adults exhibited mild macrocytic anemia coincident with subtle perturbation particularly of bone marrow erythropoiesis, with EPO-induced erythropoiesis blunted in the bone marrow of KO mice but enhanced in the spleen. was expressed basally in the bone marrow with induction following EPO stimulation in bone marrow and spleen. Overall, this study indicates that CISH participates in the control of both basal and EPO-induced erythropoiesis in vivo.
Topics: Animals; Mice; Anemia; Cytokines; Erythropoiesis; Signal Transduction; src Homology Domains; Suppressor of Cytokine Signaling Proteins
PubMed: 37892192
DOI: 10.3390/biom13101510 -
Practical Laboratory Medicine Mar 2024To compare the laboratory tests conducted in real-life settings for patients with anemia with the expected prescriptions derived from an optimal checkup.
OBJECTIVE
To compare the laboratory tests conducted in real-life settings for patients with anemia with the expected prescriptions derived from an optimal checkup.
METHODS
A panel of experts formulated an "optimal laboratory test assessment" specific to each anemia profile. A retrospective analysis was done of the laboratory tests conducted according to the type of anemia (microcytic, normocytic or macrocytic). Using an algorithmic system, the laboratory tests performed in real-life practice were compared with the recommendations suggested in the "optimal laboratory test assessment" and with seemingly "unnecessary" laboratory tests.
RESULTS
In the analysis of the "optimal laboratory test assessment", of the 1179 patients with microcytic anemia, 269 (22.8%) had had one of the three tests recommended by the expert system, and only 33 (2.8%) had all three tests. For normocytic anemia, 1054 of 2313 patients (45.6%) had one of the eleven recommended tests, and none had all eleven. Of the 384 patients with macrocytic anemia, 196 (51%) had one of the four recommended tests, and none had all four. In the analysis of "unnecessary laboratory tests", one lab test was unnecessarily done in 727/3876 patients (18.8%), i.e. 339 of 1179 (28.8%) microcytic, 171 of 2313 (7.4%) normocytic, and 217 of 384 (56.5 %) macrocytic anemias.
CONCLUSION
Laboratory investigations of anemia remain imperfect as more than half of the cases did not receive the expected tests. Analyzing other diagnostic domains, the authors are currently developing an artificial intelligence system to assist physicians in enhancing the efficiency of their laboratory test prescriptions.
PubMed: 38404528
DOI: 10.1016/j.plabm.2024.e00357 -
Journal of Ayub Medical College,... 2023Thiamine-responsive megaloblastic anaemia (TRMA) is characterized by the classic trio of diabetes mellitus, sensorineural hearing loss, and megaloblastic anaemia,...
Thiamine-responsive megaloblastic anaemia (TRMA) is characterized by the classic trio of diabetes mellitus, sensorineural hearing loss, and megaloblastic anaemia, typically emerging subtly between infancy and adolescence. Administration of high-dose thiamine often yields improvements in anaemia and occasionally in diabetes. Uncommon manifestations include optic atrophy, congenital heart defects, short stature, and stroke. In this specific case, a 5-year-old diagnosed with insulin-dependent diabetes mellitus (IDDM) since the age of one presented with symptoms such as polyuria, fever, and vomiting, revealing an HbA1c of 10.64. Further examinations disclosed compromised hearing and vision. A negative antibody workup and a thyroid profile indicating hypothyroidism prompted additional investigations, including Brainstem Evoked Response Audiometry (BERA) and retinal examination, confirming bilateral sensorineural hearing loss and maculopathy, respectively. A comprehensive blood count unveiled megaloblastic anaemia. Genetic profiling confirmed a homozygous mutation in the SLC19A2 gene, thus diagnosing TRMA. An early diagnosis, coupled with genetic confirmation, enables timely intervention, with patients responding positively to high-dose thiamine. Genetic counselling plays a pivotal role in enlightening families about the disease and its inheritance patterns, fostering awareness and understanding.
Topics: Humans; Child, Preschool; Thiamine Deficiency; Thiamine; Anemia, Megaloblastic; Hearing Loss, Sensorineural; Hypothyroidism; Diabetes Mellitus; Membrane Transport Proteins
PubMed: 38406914
DOI: 10.55519/JAMC-S4-12486 -
Clinical Laboratory Sep 2023Thiamine responsive megaloblastic anemia (TRMA) is a genetic disease caused by SLC19A2 gene mutation. This study aimed to preliminarily explore the relationship between...
BACKGROUND
Thiamine responsive megaloblastic anemia (TRMA) is a genetic disease caused by SLC19A2 gene mutation. This study aimed to preliminarily explore the relationship between endoplasmic reticulum stress (ERS)-PERK signaling pathway and the pathogenesis of hyperglycemia induced by TRMA.
METHODS
Islet β (INS.1 and β-TC-6) and HEK293T cell line models with stable overexpression of SLC19A2 and SLC19A2 (c.1409insT) were established. The cells were divided into empty virus group (control), wild-type group (overexpressed SLC19A2), and mutation group (overexpressed SLC19A2 (c.1409insT)). Quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and western blotting were used to detect the expression levels of ERS-PERK signaling pathway-related proteins, including glucose-regulated protein 78 (GRP78), protein kinase R-like ER kinase (PERK), and eukaryotic initiation factor 2 (eIF2α), activating transcription factor 4 (ATF4), and C/EBP homologous protein (CHOP) in islet β cells. Protein localization was assessed by immunofluorescence staining.
RESULTS
Compared with the control group, the mRNA expression levels of SLC19A2 in wild-type and mutant islet β cells (INS.1 and β-TC-6) and HEK293T cells were significantly upregulated (all p < 0.05). Compared with the control group and the wild-type group, the mRNA expression levels of GRP78, PERK, eIF2α, ATF4, and CHOP were increased (all p < 0.05) in the mutant islet β cells; the protein expression levels of PERK, GRP78, and eIF2α were elevated (all p < 0.05). In addition, the results of immunofluorescence staining showed that SLC19A2 (c.1409insT) mutation changed the localization of the proteins in the cells. Thus, they were not located on the cell surface, but in the cytoplasm and nuclei, and protein aggregation occurred in the cytoplasm.
CONCLUSIONS
1. Islet β and HEK293Tcell lines, stably overexpressing SLC19A2 and SLC19A2 (c.1409insT) mutations, were successfully constructed. 2. SLC19A2 (c.1409insT) mutation could raise the expression levels of ERS-PERK signaling pathway-related proteins (GRP78, PERK, eIF2α, ATF4, and CHOP), and activate apoptosis pathway. 3. SLC19A2 (c.1409insT) mutation could change the localization of proteins and produce protein aggregation in cells. It could lead to protein misfolding and ERS, which would participate in the pathological mechanism of hyperglycemia induced by TRMA.
Topics: Humans; Endoplasmic Reticulum Chaperone BiP; HEK293 Cells; Protein Aggregates; Hyperglycemia; Anemia, Pernicious; Endoplasmic Reticulum Stress; Thiamine; RNA, Messenger; Membrane Transport Proteins
PubMed: 37702666
DOI: 10.7754/Clin.Lab.2023.230324 -
Langenbeck's Archives of Surgery Jun 2024SASI (single anastomosis sleeve ileal) bypass can lead to nutritional deficiencies, including disorders of iron metabolism and anemia. This study aims to evaluate the...
PURPOSE
SASI (single anastomosis sleeve ileal) bypass can lead to nutritional deficiencies, including disorders of iron metabolism and anemia. This study aims to evaluate the effect of SASI bypass on weight loss, anemia, and iron deficiency in patients with obesity during the follow-up period.
METHODS
This study is a retrospective analysis of prospectively collected data from patients who underwent SASI bypass at our hospital between January 2020 and February 2022.
RESULTS
The mean age of the patients was 42 years (range 22-58). The average duration of the follow-up period was 26 months. The mean percentage of excess weight loss (%EWL) was 90.1%, and total weight loss (%TWL) was 30.5%. During the postoperative observation period, anemia was identified in ten patients (25%), comprising 70% with normocytic anemia, 10% with microcytic anemia, and two macrocytic anemia cases (20%). Iron deficiency was observed in two patients (5%).
CONCLUSION
SASI bypass is an effective bariatric procedure in weight loss outcomes. However, there may be an increased risk of anemia and iron metabolism disruptions associated with this procedure. The common limb length (250 vs. 300 cm) did not significantly impact hemoglobin, iron, TIBC, ferritin levels, or anemia incidence among patients undergoing SASI bypass. The decrease in postoperative ferritin levels signifies a depletion in tissue iron reserves, thereby emphasizing the necessity for surveillance of iron homeostasis parameters following SASI bypass.
Topics: Humans; Adult; Female; Male; Middle Aged; Retrospective Studies; Ileum; Weight Loss; Postoperative Complications; Obesity, Morbid; Anemia; Anastomosis, Surgical; Bariatric Surgery; Young Adult; Anemia, Iron-Deficiency; Iron
PubMed: 38904793
DOI: 10.1007/s00423-024-03384-y -
Journal of Community Hospital Internal... 2023Vitamin B12 is a water-soluble vitamin cofactor for many enzymatic reactions in the body. It plays a vital role in the normal maturation of red blood cells and in...
Vitamin B12 is a water-soluble vitamin cofactor for many enzymatic reactions in the body. It plays a vital role in the normal maturation of red blood cells and in producing proteins needed for normal neurological function. The most common presentations of vitamin B12 deficiency are hematological abnormalities and neurological manifestations. Pseudo-thrombotic microangiopathy, a syndrome of hemolysis and thrombocytopenia, may mimic the presentation of thrombotic microangiopathies such as thrombotic thrombocytopenic purpura, an uncommon presentation of vitamin B12 deficiency. We present the case of a 58-year-old male with no significant past medical history who presented with severe macrocytic anemia and thrombocytopenia with laboratory findings suggestive of hemolytic anemia. He was found to have vitamin B12 deficiency with positive serological markers suggesting pernicious anemia is the underlying cause. Our case demonstrates that vitamin B12 deficiency should be considered in cases of suspected thrombotic microangiopathy, especially in the setting of significantly elevated lactate dehydrogenase levels and low reticulocyte count to avoid the initiation of unnecessary and expensive treatment modalities such as plasmapheresis.
PubMed: 38596564
DOI: 10.55729/2000-9666.1263 -
Clinical Endocrinology Mar 2024The hypothyroid phenotype associated with resistance to thyroid hormone alpha (RTH-α) is associated with a diverse clinical picture. On the other hand,...
BACKGROUND
The hypothyroid phenotype associated with resistance to thyroid hormone alpha (RTH-α) is associated with a diverse clinical picture. On the other hand, thyroid-stimulating hormone (TSH) levels are normal. Free triiodothyronine (fT3) and free thyroxine (fT4) levels can also be normal; however, normo- or macrocytic anaemia is usually present in reported cases. Diagnosis is challenging and there is limited data regarding screening methods.
OBJECTIVE
The study aimed to assess the efficiency of a screening strategy for RTH-α.
SUBJECTS AND METHODS
Out of a total of 6540 children evaluated at the outpatient clinics of paediatric neurology over 2 years and who underwent complete blood count and thyroid function tests, 432 were found to have anaemia. Within this group, we identified 42 children without an underlying specific neurological aetiology who exhibited normo- or macrocytic anaemia, normal TSH levels, fT3 levels in the upper half of the normal range or high, and fT4 levels in the lower half of the normal range or low. We excluded one patient who had already been diagnosed with RTH-α and nine patients could not be reached. Subsequently, clinical evaluation, biochemical assessment, and THRA sequencing analysis were conducted on 32 children. The findings were compared with those of the known RTH-α patients in our unit.
RESULTS
The median age of the patients was 5.7 (5.1-7.4) years, and 22 of them were males (69%). The main reasons for assessment in paediatric neurology clinics were autism spectrum disorder (n = 12, 38%), epilepsy (n = 11, 34%), and delay in developmental stages (n = 8, 25%). Constipation was present in five of the cases (16%), while the closure of the anterior fontanelle and tooth eruption were delayed in two cases (6%) and one case (3%), respectively. The median length/height and weight standard deviation (SD) scores were 0.3 [(-0.8)-(1.1)] and -0.1 [(-0.8)-(0.3)], respectively. The median fT3, fT4, and TSH levels were 4.6 (4.2-5.0) pg/mL, 0.9 (0.8-1.0) ng/dL, and 2.2 (1.8-3.1) uIU/mL, respectively. Thirteen of the patients (41%) had high fT3 levels, while none of them had low fT4 levels. The normo- or macrocytic anaemia rate was 47% (normocytic/macrocytic, n = 8/7) at the time of reassessment. Serum creatine kinase (CK) was elevated in five patients (16%; one had anaemia). None of the subjects had a pathological variant in THRA. Known RTH-α patients had significantly lower median height SD score, higher rates of delayed tooth eruption and closure of the anterior fontanelle, lower haemoglobin levels, and higher mean corpuscular volume (MCV) and CK levels as compared to those found without RTH-α.
CONCLUSIONS
This approach found one known patient with RTH-α but did not reveal any new cases. Notably, normo- or macrocytic anaemia did not persist in nearly half of the screened patients. A screening strategy that takes clinical findings and prominent laboratory features suggestive of RTH-α into account could lower unnecessary genetic analysis of THRA in patients presenting with neurological problems.
Topics: Male; Child; Humans; Child, Preschool; Female; Thyroxine; Autism Spectrum Disorder; Triiodothyronine; Thyroid Hormones; Thyroid Function Tests; Thyrotropin; Anemia, Macrocytic
PubMed: 38148509
DOI: 10.1111/cen.15007 -
Clinical Laboratory Oct 2023Vitamin B12, or cobalamin deficiency, an infrequent clinical entity in pediatric age, is found almost solely in breastfed infants whose mothers are purely vegetarian,...
BACKGROUND
Vitamin B12, or cobalamin deficiency, an infrequent clinical entity in pediatric age, is found almost solely in breastfed infants whose mothers are purely vegetarian, non-supplemented or with pernicious anemia. Megaloblastic anemia in infants presents with generalized weakness or irritability.
METHODS
Diagnosis is usually centered on complete blood count, vitamin dosing, and peripheral smear, which may show macrocytes, hypersegmented neutrophils, reticulocytopenia and a raised mean corpuscular volume (MCV ˃ 100 fL). Pancytopenia has also been noted.
RESULTS
We report an exclusive breastfed nine-month-old female child who presented with irritability, developmental delay, and difficulties in introducing new foods. Her initial blood count revealed pancytopenia. Vitamin B12 levels were found to be reduced. Maternal levels of Vitamin B12 were also found to be borderline low. The child was treated as per protocols, and improvement was evidenced with the return of hematological parameters to the regular and gradual advancement of milestones.
CONCLUSIONS
We aim to underscore the importance of megaloblastic anemia as an important and rare cause of anemia in infancy.
Topics: Humans; Infant; Child; Female; Pancytopenia; Anemia, Megaloblastic; Vitamin B 12 Deficiency; Vitamin B 12; Anemia, Pernicious
PubMed: 37844051
DOI: 10.7754/Clin.Lab.2023.230420