The new WHO and ICC classification systems for myelodysplastic syndromes and their impact on the clinical laboratory.

The International Consensus Classification (ICC) and World Health Organization (WHO) proposed significant changes to the diagnostic criteria of myelodysplastic syndromes (MDS) in 2022. The impact of these criteria on hematopathology practice is uncertain. This study aims to evaluate the impact of the 2022 ICC and WHO 5th edition classifications on the diagnosis of cytopenias and MDS. Cases from 2021 performed for primary diagnosis of cytopenia(s)/MDS and their clinical, laboratory, and pathologic findings were reviewed and classified according to the new classification systems. The rate of major changes to the diagnosis was determined and potential pitfalls in the diagnostic approach, laboratory workflow, and clinical communication challenges were investigated. A total of 49 cases were recruited. Major changes to the diagnostic entities were made in 18/49 (37%) cases according to the WHO 5th edition, and 23/49 (47%) cases classified according to the ICC. The difference was accounted for by five cases of MDS-EB2 (revised WHO 4th edition) classified as MDS/AML (major change) in the ICC in contrast to no significant change (MDS-IB2) in the WHO 5th edition. MDS-SLD cases were not subject to major reclassification according to either system. The new molecularly defined categories of CCUS/CHIP, MDS-SF3B1, and MDS with biallelic TP53 mutations were almost identically represented in both systems in our cohort. A case of MDS-MLD was reclassified as CMML by both classification systems. There are few but important differences between the new MDS classification systems. A preimplementation assessment is helpful to identify diagnostic and potential clinical impacts of their adoption.

Classification of Monocytes, Promonocytes and Monoblasts Using Deep Neural Network Models: An Area of Unmet Need in Diagnostic Hematopathology.

The accurate diagnosis of chronic myelomonocytic leukemia (CMML) and acute myeloid leukemia (AML) subtypes with monocytic differentiation relies on the proper identification and quantitation of blast cells and blast-equivalent cells, including promonocytes. This distinction can be quite challenging given the cytomorphologic and immunophenotypic similarities among the monocytic cell precursors. The aim of this study was to assess the performance of convolutional neural networks (CNN) in separating monocytes from their precursors (i.e., promonocytes and monoblasts). We collected digital images of 935 monocytic cells that were blindly reviewed by five experienced morphologists and assigned into three subtypes: monocyte, promonocyte, and blast. The consensus between reviewers was considered as a ground truth reference label for each cell. In order to assess the performance of CNN models, we divided our data into training (70%), validation (10%), and test (20%) datasets, as well as applied fivefold cross validation. The CNN models did not perform well for predicting three monocytic subtypes, but their performance was significantly improved for two subtypes (monocyte vs. promonocytes + blasts). Our findings (1) support the concept that morphologic distinction between monocytic cells of various differentiation level is difficult; (2) suggest that combining blasts and promonocytes into a single category is desirable for improved accuracy; and (3) show that CNN models can reach accuracy comparable to human reviewers (0.78 ± 0.10 vs. 0.86 ± 0.05). As far as we know, this is the first study to separate monocytes from their precursors using CNN.

Ccl2 deficiency protects against chronic renal injury in murine renovascular hypertension.

Inflammation plays an important role in the pathogenesis of renal and cardiovascular disease in renovascular hypertension (RVH). Ccl2 is an important mediator of inflammation, and is induced within 24 hours following surgery to establish RVH in the murine 2 kidney 1 clip model, a time prior to onset of interstitial inflammation, fibrosis, or tubular atrophy. We tested the hypothesis that Ccl2 deficiency protects the stenotic kidney (STK) from development of chronic renal damage in mice with renovascular hypertension due to renal artery stenosis (RAS). RAS surgery was performed on wild type (WT) and Ccl2 knock out (KO) mice; animals were studied for four weeks. Renal blood flow was reduced to similar extent in both WT and Ccl2 KO mice with RVH. Perfusion of the stenotic kidney was significantly reduced in Ccl2 KO mice as assessed by magnetic resonance imaging (MRI). Stenotic kidney volume in WT, but not in Ccl2 KO mice, was significantly reduced following surgery. Cortical hypoxia was observed in the stenotic kidney of Ccl2 KO mice, as assessed by blood oxygen level-dependent MRI (BOLD-MRI). Ccl2 KO mice showed less cortical atrophy than WT RAS mice. Ccl2 deficiency reduced the number of infiltrating mononuclear cells and expression of Ccl5, Ccl7, Ccl8, Ccr2 and Cd206. We conclude that Ccl2 is a critical mediator of chronic renal injury in RVH.

Cardiovascular phenotype in Smad3 deficient mice with renovascular hypertension.

Renovascular hypertension (RVH) has deleterious effects on both the kidney and the heart. TGF-ß signaling through Smad3 directs tissue fibrosis in chronic injury models. In the 2-kidney 1-clip (2K1C) model of RVH, employing mice on the 129 genetic background, Smad3 deficiency (KO) protects the stenotic kidney (STK) from development of interstitial fibrosis. However, these mice have an increased incidence of sudden cardiac death following 2K1C surgery. The purpose of this study was to characterize the cardiovascular phenotype of these mice. Renal artery stenosis (RAS) was established in Wild-type (WT) and Smad3 KO mice (129 genetic background) by placement of a polytetrafluoroethylene cuff on the right renal artery. Mortality was 25.5% for KO mice with RAS, 4.1% for KO sham mice, 1.2% for WT with RAS, and 1.8% for WT sham mice. Myocardial tissue of mice studied at 3 days following surgery showed extensive myocyte necrosis in KO but not WT mice. Myocyte necrosis was associated with a rapid induction of Ccl2 expression, macrophage influx, and increased MMP-9 activity. At later time points, both KO and WT mice developed myocardial fibrosis. No aortic aneurysms or dissections were observed at any time point. Smad3 KO mice were backcrossed to the C57BL/6J strain and subjected to RAS. Sudden death was observed at 10-14 days following surgery in 62.5% of mice; necropsy revealed aortic dissections as the cause of death. As observed in the 129 mice, the STK of Smad3 KO mice on the C57BL/6J background did not develop significant chronic renal damage. We conclude that the cardiovascular manifestations of Smad3 deficient mice are strain-specific, with myocyte necrosis in 129 mice and aortic rupture in C57BL/6J mice. Future studies will define mechanisms underlying this strain-specific effect on the cardiovascular system.

Cardiovascular manifestations of renovascular hypertension in diabetic mice.

Purpose. Type 2 diabetes is the leading cause of end stage renal disease in the United States. Atherosclerotic renal artery stenosis is commonly observed in diabetic patients and impacts the rate of renal and cardiovascular disease progression. We sought to test the hypothesis that renovascular hypertension, induced by unilateral renal artery stenosis, exacerbates cardiac remodeling in leptin-deficient (db/db) mice, which serves as a model of human type II diabetes. Methods. We employed a murine model of renovascular hypertension through placement of a polytetrafluoroethylene cuff on the right renal artery in db/db mice. We studied 109 wild-type (non-diabetic, WT) and 95 db/db mice subjected to renal artery stenosis (RAS) or sham surgery studied at 1, 2, 4, and 6+ weeks following surgery. Cardiac remodeling was assessed by quantitative analysis of the percent of myocardial surface area occupied by interstitial fibrosis tissue, as delineated by trichrome stained slides. Aortic pathology was assessed by histologic sampling of grossly apparent structural abnormalities or by section of ascending aorta of vessels without apparent abnormalities. Results. We noted an increased mortality in db/db mice subjected to RAS. The mortality rate of db/db RAS mice was about 23.5%, whereas the mortality rate of WT RAS mice was only 1.5%. Over 60% of mortality in the db/db mice occurred in the first two weeks following RAS surgery. Necropsy showed massive intrathoracic hemorrhage associated with aortic dissection, predominantly in the ascending aorta and proximal descending aorta. Aortas from db/db RAS mice showed more smooth muscle dropout, loss of alpha smooth muscle actin expression, medial disruption, and hemorrhage than aortas from WT mice with RAS. Cardiac tissue from db/db RAS mice had more fibrosis than did cardiac tissue from WT RAS mice. Conclusions. db/db mice subjected to RAS are prone to develop fatal aortic dissection, which is not observed in WT mice with RAS. The db/db RAS model provides the basis for future studies directed towards defining basic mechanisms underlying the interaction of hypertension and diabetes on the development of aortic lesions.

A novel mutation of IL1RN in the deficiency of interleukin-1 receptor antagonist syndrome: description of two unrelated cases from Brazil.

OBJECTIVE: Monogenic autoinflammatory diseases are disorders of Mendelian inheritance that are characterized by mutations in genes that regulate innate immunity and whose typical features are systemic inflammation without high-titer autoantibodies or antigen-specific T cells. Skin and bone inflammation in the newborn period have been described in 3 of these autoinflammatory disorders: neonatal-onset multisystem inflammatory disease, Majeed syndrome, and deficiency of interleukin-1 (IL-1) receptor antagonist (DIRA) syndrome. This study was undertaken to present the characteristics of the DIRA syndrome in 2 cases from Brazil, and describe a novel mutation in IL1RN. METHODS: Two unrelated Brazilian patients were evaluated for the clinical signs and symptoms of these 3 disorders, and peripheral blood samples were assessed for mutations in NLRP3, LPIN2, and IL1RN by DNA resequencing analysis. A mutation in IL1RN that encodes a mutant protein was identified, and the expression and function of this mutant protein were compared to those of the wild-type protein. RESULTS: Both patients presented with pustular dermatitis resembling generalized pustular psoriasis, recurrent multifocal aseptic osteomyelitis, and elevation in the levels of acute-phase reactants, all of which are features most consistent with the DIRA syndrome. Chronic lung disease was observed in 1 of the patients, and jugular venous thrombosis was observed in the other patient. Both patients showed a partial response to corticosteroid therapy, and 1 patient experienced an initial improvement of dermatitis with the use of acitretin. Both patients were homozygous for a novel 15-bp (in-frame) deletion on the IL1RN gene. The mutated protein expressed in vitro had no affinity with the IL-1 receptor, and stimulation of the patients' cells with recombinant human IL-1α or IL-1ß led to oversecretion of proinflammatory cytokines, similar to the findings obtained in previously reported patients. CONCLUSION: The presence of the same homozygous novel mutation in IL1RN in 2 unrelated Brazilian patients suggests that this genetic variant may be a founder mutation that has been introduced in the Brazilian population.

Glutathione S-transferase M1 and T1 polymorphisms in Arab glaucoma patients.

PURPOSE: Glutathione S-transferases (GSTs) are a family of enzymes that inactivate xenobiotics and endogenous end products formed as secondary metabolites during oxidative stress. In humans, GSTT1 and GSTM1 deletion genotypes (T0M1, T1M0, and T0M0) are associated with a variety of pathologic processes including certain ophthalmologic diseases. METHODS: We compared the prevalence of GSTT1 and GSTM1 deletion genotypes, which were determined by multiplex polymerase chain reaction, in 107 Arab patients with glaucoma (49 with primary open-angle glaucoma, 29 with pseudoexfoliation glaucoma, and 29 with primary angle-closure glaucoma) to 120 age, sex, and ethnically matched controls. RESULTS: All three GST polymorphisms were significantly more common in the entire glaucoma group (p<0.0167) than in controls. However, when patients were stratified by glaucoma type, the deletion genotype, T0M0, was not particularly associated with any type of glaucoma tested. The T1MO genotype was more common among patients with each type of glaucoma than among controls whereas T0M1 genotype was more common among pseudoexfoliation glaucoma (PEG) and primary open-angle glaucoma (POAG) patients than controls. CONCLUSIONS: The overall results indicate a possible variable association between various GSTT1 and GSTM1 genotypes and glaucoma in this population. Decreased GST function might interfere with the metabolism of oxidative intermediates and exacerbate the direct or indirect damaging effects of oxidative stress on the optic nerve. It is possible that these GST polymorphisms may be risk factors for glaucoma.

Nuclear and mitochondrial analysis of patients with primary angle-closure glaucoma.

PURPOSE: Certain types of glaucoma are linked to nuclear genetic mutations or to mitochondrial disturbances. In this study, patients with primary angle-closure glaucoma (PACG) were examined for mutations in nuclear genes reported to be associated with glaucoma and for possible mitochondrial abnormalities. METHODS: In patients with PACG, the nuclear genes MYOC, OPTN, CYP1B1, WDR36, OPA1, and OPA3 were sequenced, the entire mitochondrial (mt)DNA coding region was sequenced, relative mtDNA content was measured, and mitochondrial respiratory activity (MRA) was assessed. RESULTS: No novel or previously reported mutations were present in the nuclear genes MYOC, OPTN, CYP1B1, WDR36, OPA1, and OPA3 in 29 patients with PACG. Four (13.8%) patients had potentially pathologic mtDNA nucleotide changes not found in control subjects. The patients with PACG did not differ significantly from the control subjects in relative mitochondrial content and had only a small decrease in MRA (2.4%) of indeterminate significance. CONCLUSIONS: These Middle Eastern patients with PACG had no mutations in nuclear genes associated with other types of glaucoma or inherited optic neuropathies. Mitochondrial abnormalities were minimal, and the overall pattern of those abnormalities was distinctly different from that of Leber hereditary optic neuropathy, nonarteritic ischemic optic neuropathy, primary open-angle glaucoma, and optic neuritis. These results are consistent with the hypothesis that anatomic factors may be more important determinants for PACG than the genetic and mitochondrial factors evaluated here.