Serum lipid metabolism characteristics and potential biomarkers in patients with unilateral sudden sensorineural hearing loss.

BACKGROUND: Glycerophospholipids (GPLs) are essential for cell membrane structure and function. Sphingomyelin and its metabolites regulate cell growth, apoptosis, and stress responses. This study aimed to investigate lipid metabolism in patients experiencing sudden sensorineural hearing loss across all frequencies (AF-SSNHL). METHODS: The study included 60 patients diagnosed with unilateral AF-SSNHL, among whom 30 patients had a level of hearing improvement ≥ 15 dB after 6 months of follow-up. A propensity score-matched (2:1) control group was used. Liquid chromatography‒mass spectrometry based untargeted lipidomics analysis combined with multivariate statistics was performed to investigate the lipids change. The "lipidome" R package and weighted gene co-expression network analysis (WGCNA) were utilised to assess the lipids' structural features and the association between lipids and hearing. RESULTS: Lipidomics successfully differentiated the AF-SSNHL group from the control group, identifying 17 risk factors, mainly including phosphatidylcholine (PC), phosphatidylethanolamine (PE), and related metabolites. The ratios of lysophosphatidylcholine/PC, lysophosphatidylethanolamine/PE, and lysodimethylphosphatidylethanolamine/PE were upregulated, while some glycerophospholipid (GPL)-plasmalogens were downregulated in the AF-SSNHL group, indicating abnormal metabolism of GPLs. Trihexosylceramide (d34:1), PE (18:1e_22:5), and sphingomyelin (d40:3) were significantly different between responders and nonresponders, and positively correlated with hearing improvement. Additionally, the results of the WGCNA also suggested that partial GPL-plasmalogens were positively associated with hearing improvement. CONCLUSION: AF-SSNHL patients exhibited abnormally high blood lipids and pronounced GPLs metabolic abnormalities. Sphingolipids and GPL-plasmalogens had an association with the level of hearing improvement. By understanding the lipid changes, clinicians may be able to predict the prognosis of hearing recovery and personalize treatment approaches.

Study on the correlation of C-reactive protein/albumin ratio with sudden sensorineural hearing loss complicated by hypertension: a prospective study.

BACKGROUND: Understanding the pathophysiology of sudden sensorineural hearing loss (SSNHL) and identifying its clinical symptoms and associated risk factors are crucial for doctors in order to create effective prevention and therapeutic methods for this prevalent otolaryngologic emergency. METHODS: This study focuses on investigating the correlation between the C-reactive protein/albumin ratio (CAR) and SSNHL complicated by hypertension. In this study, 120 patients diagnosed with SSNHL were divided into groups with and without hypertension, and propensity score matching was used to compare and analyze the severity, type, prognosis, and CAR levels in SSNHL. RESULTS: The results showed that the SSNHL group with hypertension had significantly higher CAR levels, age, hearing curve abnormalities, and more severe hearing loss compared to the control group with isolated SSNHL. These differences were statistically significant (p < 0.001). Among different subtypes of SSNHL, CAR levels increased progressively with the advancement of the condition, and these differences were also statistically significant (p < 0.001). CONCLUSION: In summary, in patients with SSNHL, those with hypertension had higher CAR levels than those without a history of hypertension, and they experienced more severe hearing loss. Moreover, there was a clear correlation between CAR levels and the extent of SSNHL, indicating that greater CAR levels in patients with SSNHL are connected to more severe hearing loss in various hearing patterns and perhaps indicative of a poorer prognosis.

A rare genomic duplication in 2p14 underlies autosomal dominant hearing loss DFNA58.

Here we define a ~200 Kb genomic duplication in 2p14 as the genetic signature that segregates with postlingual progressive sensorineural autosomal dominant hearing loss (HL) in 20 affected individuals from the DFNA58 family, first reported in 2009. The duplication includes two entire genes, PLEK and CNRIP1, and the first exon of PPP3R1 (protein coding), in addition to four uncharacterized long non-coding (lnc) RNA genes and part of a novel protein-coding gene. Quantitative analysis of mRNA expression in blood samples revealed selective overexpression of CNRIP1 and of two lncRNA genes (LOC107985892 and LOC102724389) in all affected members tested, but not in unaffected ones. Qualitative analysis of mRNA expression identified also fusion transcripts involving parts of PPP3R1, CNRIP1 and an intergenic region between PLEK and CNRIP1, in the blood of all carriers of the duplication, but were heterogeneous in nature. By in situ hybridization and immunofluorescence, we showed that Cnrip1, Plek and Ppp3r1 genes are all expressed in the adult mouse cochlea including the spiral ganglion neurons, suggesting changes in expression levels of these genes in the hearing organ could underlie the DFNA58 form of deafness. Our study highlights the value of studying rare genomic events leading to HL, such as copy number variations. Further studies will be required to determine which of these genes, either coding proteins or non-coding RNAs, is or are responsible for DFNA58 HL.

Identification of dyslipidemia as a risk factor for sudden sensorineural hearing loss: A multicenter case-control study.

BACKGROUND: Recently, several studies have reported an association between lipid profiles and sudden sensorineural hearing loss (SSNHL), yet there is considerable variability between the individual studies in defining the precise association between serum lipids levels and SSNHL. This study sought to identify a possible relationship between dyslipidemia and the prevalence and prognosis of SSNHL. METHODS: A case-control study was carried out at two independent medical centers, including 2,288 SSNHL patients and 2,288 healthy controls. Clinical characteristics and serum lipid parameters were assessed, including total cholesterol (CHOL), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglycerides (Trig), apolipoprotein AI (ApoAI), apolipoprotein B (ApoB), and lipoprotein a (Lpa). Multivariate logistic regression analysis was performed to assess the relationship between lipid profiles and SSNHL in the 4,576 subjects. RESULTS: Significant differences were identified in several conventional serum lipid markers including CHOL, Trig, HDL, LDL, ApoAI, ApoB, and Lpa, between SSNHL patients and healthy controls. Serum ApoAI levels were significantly lower in patients with bilateral SSNHL compared to unilateral SSNHL. Binary logistic regression analysis revealed that higher levels of ApoB, LDL, Trig, and lower levels of ApoAI and HDL were all associated with an increased risk of SSNHL. After clinical characterization, multivariate analysis showed that only low levels of ApoB predicted likelihood of a recovery of more than 30 dB among patients with SSNHL. CONCLUSIONS: Serum lipids are associated with the incidence and prognosis of SSNHL. Identification of dyslipidemia may improve early evaluation and management of SSNHL risks.

Differential Levels of Endoplasmic Reticulum Stress in Peripheral Blood Mononuclear Cells from Patients with Sudden Sensorineural Hearing Loss.

BACKGROUND Sudden sensorineural hearing loss (SSNHL) is currently treated with a combination of drugs, predominantly with glucocorticoids (GCs). However, the mechanisms of action of GCs in SSNHL are unknown. This study aimed to analyze the role of endoplasmic reticulum stress (ERS) in SSNHL pathogenesis and prognosis. MATERIAL AND METHODS In this study, we evaluated the expression and activation status of the protein kinase RNA-like endoplasmic reticulum kinase (PERK)-C/EBP homologous protein (CHOP) pathway in peripheral blood mononuclear cells (PBMCs) from patients with SSNHL and compared them with those in healthy controls. We also compared differences in expression of activating transcription factor 4 (ATF4) and CHOP before and after glucocorticoid treatment in patients with improved and unimproved SSNHL. RESULTS Treatment with GCs significantly improved hearing in 55% of patients with SSNHL. Levels of phosphorylated PERK (p-PERK) and phosphorylated eukaryotic initiation factor 2alpha were increased in PBMCs from patients with SSNHL compared with healthy controls. ATF4 and CHOP expression were also significantly elevated. After treatment, the amount of ATF4 and CHOP proteins in PBMCs in the patients whose SSNHL improved was significantly reduced compared with the levels measured before treatment in all patients with SSNHL. The expression of the ATF4 and CHOP proteins in PBMCs in the unimproved group, however, was not significantly changed relative to pretreatment levels. CONCLUSIONS ERS may play a significant role in the pathogenesis of SSNHL, and the responsiveness of the condition to GC-mediated mitigation of ERS may be one of the key factors that affect patient prognosis.

Metabolic syndrome components and sudden sensorineural hearing loss: a case-control study.

PURPOSE: Cardiovascular risk factors, including metabolic syndrome (MetS) components, were reported as possible risk factors of sudden sensorineural hearing loss (SSNHL). The objective of this study was to evaluate the relationship between MetS (and its components) and SSNHL. METHODS: Eighty-one SSNHL patients and 243 sex-, aged-matched controls participated from January 2018 to July 2019. The participants included 176 (54.3%) men and 148 (45.7%) women. The correlation between Mets components, total cholesterol, low-density lipoprotein-cholesterol, and the onset of SSNHL was analyzed using used multivariate conditional logistic regression analysis. RESULTS: A total 12 patients (14.8%) with SSNHL and 27 subjects (11.1%) in control group had MetS (p > 0.05). The rate of low levels of high-density lipoprotein-cholesterol (HDL-C), hypertriglyceridemia, and hypertension was significantly higher in the SSNHL group than those in the control group (p < 0.05). A trend of odds SSNHL was observed with increasing the number of MetS components (p < 0.001). The multivariable analysis revealed that the rate of hypertriglyceridemia and low HDL-C concentration was significantly higher in the SSNHL groups compared to the controls. CONCLUSIONS: Hypertriglyceridemia and low levels of HDL-C may be important factors in the pathogenesis of SSNHL, and should be assessed during the investigation of patients with this condition.

Can miR-34a be suitable for monitoring sensorineural hearing loss in patients with mitochondrial disease? A case series.

Purpose: We aimed at evaluating the feasibility of using MicroRNA (miR)-34a and miR-29b to detect inner ear damage in patients with mitochondrial disease (MD) and sensorineural hearing loss (SNHL).Material and Methods: Three patients with MD and SNHL and seven healthy control subjects were included in this case series. MD patients underwent pure tone audiometry (PTA), distortion product otoacoustic emission (DPOAE) and auditory brain response tests to investigate the specific cochlear and retrocochlear functions; control patients underwent PTA. MiR-34a and miR-29b were extracted from blood in all subjects included in the study. The expression of miR-34a and miR-29b in MD patients and healthy controls were statistically compared, then the expression of these two miRs was compared with DPOAE values.Results: In MD patients, miR-34a was significantly up-regulated compared to healthy controls; miR-34a and DPOAEs were negatively correlated. Conversely, miR-29b was up-regulated only in the youngest patient who suffered from the mildest forms of MD and SNHL, and negatively correlated with DPOAEs.Conclusion: In MD patients, miR-34a and miR-29b might be a marker of inner ear damage and early damage, respectively. Additional studies on larger samples are necessary to confirm these preliminary results.

The atherogenic index (ATH index) as a potential predictive marker of idiopathic sudden sensorineural hearing loss: a case control study.

BACKGROUND: The importance of blood lipids in the pathogenesis of sudden sensorineural hearing loss (SSNHL) is widely discussed in the literature. However, the published results that hyperlipidaemia causes hearing problems are contradictory. The objective of this study was to establish whether increased lipid levels affect the risk of idiopathic SSNHL. METHODS: A case-controlled study was conducted of 27 patients with idiopathic SSNHL and 24 healthy control subjects. All of the subjects underwent complete audiological examination. The plasma levels of total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (apo) A-I, apoB and apoE were measured with commercially available kits (Chronolab Systems, Spain). Several clinical ratios and indices of lipid metabolism were calculated. RESULTS: Detailed analysis of lipid metabolism in patients with idiopathic SSNHL has shown that disturbances in auditory function are associated with increased atherogenicity of the lipid profile. However, there were no significant differences in the conventional parameters of lipid metabolism (TC, TG and HDL-C) between patients with idiopathic SSNHL and subjects in the control group. Higher values of the apoB/apoA-I ratio, atherogenic index of plasma (AIP) and atherogenic index (ATH index) in patients with SSNHL indicated increased atherogenicity of the lipid profile. Binary logistic regression analysis showed that of these three indices, only higher values of the ATH index were significantly associated with an increased risk of idiopathic SSNHL. CONCLUSIONS: The ATH index can be used as a marker indicating the risk of idiopathic SSNHL when the conventional lipid indices are still normal.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Patients with Sudden Sensorineural Hearing Loss.

OBJECTIVE: Sudden sensorineural hearing loss (SSNHL) is a common acute disease with an incidence of 0.5-2/10,000. This study aimed to determine whether the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) could be indicators for SSNHL. METHODS: A total of 60 confirmed cases of SSNHL and 60 healthy volunteers were included in this study. Peripheral blood NLRs and PLRs were compared between these groups. The SSNHL patients were divided into two groups, according to therapeutic effect: an effective group and an ineffective group. Peripheral blood NLRs and PLRs before and after treatment were compared between these two groups. RESULTS: The average NLRs and PLRs of these patients were both significantly higher than in controls. The average NLRs and PLRs of the ineffective group were both significantly higher than those of the effective group. CONCLUSION: Peripheral blood NLR and PLR could be used as a convenient, reliable, and cost-effective indicator to predict the prognosis of SSNHL.

Biallelic mutations in LARS2 can cause Perrault syndrome type 2 with neurologic symptoms.

Perrault syndrome represents a genetically heterogeneous disorder characterized by sensorineural hearing loss in males and females and ovarian dysfunction in females. Causative genes include HARS2, HSD17B4, CLPP, C10orf2, and LARS2. Some patients with Perrault syndrome exhibit neurologic features including learning disability, cerebellar ataxia, and peripheral neuropathy and are classified as type 2 and are clinically separate from those without neurological symptoms other than a hearing loss (type 1). To date, all reported patients with LARS2 mutations (15 patients in 8 families) have been classified as type 1. Here, we report female siblings with biallelic mutations in LARS2, p.Glu294Lys, and p.Thr519Met, who were classified as type 2. The proposita developed progressive sensorineural hearing loss at 18 months and pervasive developmental disorder at 8 years, with repetitive behavior, insistence on sameness, attention deficit, tic, irritability, and an ataxic gait. At age 15 years, she was diagnosed as having primary amenorrhea with elevated FSH and LH and a decreased estradiol; ultrasound and magnetic resonance imaging examinations revealed a small uterus and no detectable ovaries. The proposita's younger sister presented with neonatal sensorineural hearing loss and a mild delay in motor and speech development. She was diagnosed as having primary amenorrhea with endocrinologic and radiographic findings that were comparable to those of her sister. She had difficulty with reading comprehension, and had trouble with open-ended test questions at 12 years of age. We concluded that Perrault syndrome patients with LARS2 mutations are at risk for neurologic problems, despite previous notions otherwise.

Diagnosis and treatment of MYH9-RD in an Australasian cohort with thrombocytopenia.

MYH9-related disorders (MYH9-RDs) caused by mutation of the MYH9 gene which encodes non-muscle myosin heavy-chain-IIA (NMMHC-IIA), an important motor protein in hemopoietic cells, are the most commonly encountered cause of inherited macrothrombocytopenia. Despite distinguishing features including an autosomal dominant mode of inheritance, giant platelets on the peripheral blood film accompanied by leucocytes with cytoplasmic inclusion bodies (döhle-like bodies), these disorders remain generally under-recognized and often misdiagnosed as immune thrombocytopenia (ITP). This may result in inappropriate treatment with corticosteroids, immunosupressants and in some cases, splenectomy. We explored the efficacy of next generation sequencing (NGS) with a candidate gene panel to establish the aetiology of thrombocytopenia for individuals who had been referred to our center from hematologists in the Australasian region in whom the cause of thrombocytopenia was suspected to be secondary to an inherited condition but which remained uncharacterized despite phenotypic investigations. Pathogenic MYH9 variants were detected in 15 (15/121, 12.4%) individuals and the pathogenecity of a novel variant of uncertain significance was confirmed in a further two related individuals following immunofluorescence (IF) staining performed in our laboratory. Concerningly, only one (1/17) individual diagnosed with MYH9-RD had been referred with this as a presumptive diagnosis, in all other cases (16/17, 94.1%), a diagnosis was not suspected by referring clinicians, indicating a lack of awareness or a failing of our diagnostic approach to these conditions. We examined the mean platelet diameter (MPD) measurements as a means to better identify and quantify platelet size. MPDs in cases with MYH9-RDs were significantly larger than controls (p < 0.001) and in 91% were greater than a previously suggested threshold for platelets in cases of ITP. In addition, we undertook IF staining in a proportion of cases and confirm that this test and/or NGS are satisfactory diagnostic tests. We propose that fewer cases of MYH9-RDs would be missed if diagnostic algorithms prioritized IF and/or NGS in cases of thrombocytopenia associated with giant platelets, even if döhle-like bodies are not appreciated on the peripheral blood film. Finally, our report describes the long-term use of a thrombopoietin agonist in a case of MYH9-RD that had previously been diagnosed as ITP, and demonstrates that treatment with these agents may be possible, and is well tolerated, in this group of patients.

Circulating Serum miRNA-205 as a Diagnostic Biomarker for Ototoxicity in Mice Treated with Aminoglycoside Antibiotics.

BACKGROUND: To confirm levels and detection timing of circulating microRNAs (miRNAs) in the serum of a mouse model for diagnosis of ototoxicity, circulating miR-205 in the serum was evaluated to reflect damages in the cochlear microstructure and compared to a kidney injury model. METHOD: A microarray for miRNAs in the serum was performed to assess the ototoxic effects of kanamycin-furosemide. Changes in the levels for the selected miRNAs (miR-205, miR-183, and miR-103) were compared in the serum and microstructures of the cochlea (stria vascularis, organ of Corti, and modiolus) between the ototoxicity and normal mouse groups. An acute kidney injury (AKI) mouse model was used to assess changes in miR-205 levels in the kidney by ototoxic drugs. RESULTS: In the mouse model for ototoxicity, the serum levels of circulating miR-205 peaked on day 3 and were sustained from days 7⁻14. Furthermore, miR-205 expression was highly expressed in the organ of Corti at day 5, continued to be expressed in the modiolus at high levels until day 14, and was finally also in the stria vascularis. The serum miR-205 in the AKI mice did not change significantly compared to the normal group. Conclusions Circulating miR-205 from the cochlea, after ototoxic damage, migrates through the blood vessels to organs, which is then finally found in blood. In conditions of hearing impairment with ototoxic medications, detection of circulating miR-205 in the blood can be used to determine the extent of hearing loss. In the future, inner ear damage can be identified by simply performing a blood test before the hearing impairment due to ototoxic drugs.

Newborn Dried Blood Spot Polymerase Chain Reaction to Identify Infants with Congenital Cytomegalovirus-Associated Sensorineural Hearing Loss.

OBJECTIVE: To determine the utility of dried blood spot (DBS) polymerase chain reaction (PCR) in identifying infants with cytomegalovirus (CMV) infection-associated sensorineural hearing loss (SNHL). STUDY DESIGN: Newborns at 7 US hospitals between March 2007 and March 2012 were screened for CMV by saliva rapid culture and/or PCR. Infected infants were monitored for SNHL during the first 4 years of life to determine sensitivity, specificity, and positive and negative likelihood ratios of DBS PCR for identifying CMV-associated SNHL. RESULTS: DBS at birth was positive in 11 of 26 children (42%) with SNHL at age 4 years and in 72 of 270 children (27%) with normal hearing (P = .11). The sensitivity (42.3%; 95% CI, 23.4%-63.1%) and specificity (73.3%; 95% CI, 67.6%-78.5%) was low for DBS PCR in identifying children with SNHL at age 4 years. The positive and negative likelihood ratios of DBS PCR positivity to detect CMV-associated SNHL at age 4 years were 1.6 (95% CI, 0.97-2.6) and 0.8 (95% CI, 0.6-1.1), respectively. There was no difference in DBS viral loads between children with SNHL and those without SNHL. CONCLUSIONS: DBS PCR for CMV has low sensitivity and specificity for identifying infants with CMV-associated hearing loss. These findings, together with previous reports, demonstrate that DBS PCR does not identify either the majority of CMV-infected newborns or those with CMV-associated SNHL early in life.

A sustained increase of plasma fibrinogen in sudden sensorineural hearing loss predicts worse outcome independently.

OBJECTIVES: A number of etiologies of idiopathic sudden sensorineural hearing loss (ISSNHL) have been proposed. Vascular disturbance is one cause of ISSNHL and has been reported to be associated with fibrinogen. We aimed to determine whether hyperfibrinogenemia is associated with poor outcome and whether a serial change in fibrinogen level is associated with outcome. METHODS: Twenty-two patients with ISSNHL were enrolled. We compared the levels of fibrinogen in ISSNHL groups classified as improved and non-improved according to improvement of hearing. Blood samples were also collected from patients who visited the emergency room with coronary heart disease (CHD) as the control group. RESULTS: Initial fibrinogen level was significantly different between the non-improved and improved ISSNHL group (350.63±87.20 vs. 310.71±81.06. The improved ISSNHL group showed a "surge phenomenon", in which fibrinogen started to decrease at day 5 and increased at day 26. In the non-improved group, fibrinogen remained elevated throughout the course of therapy. CONCLUSION: It is important to measure not only the initial fibrinogen level but also to monitor its change throughout the course of therapy in order to predict the outcome of ISSNHL.

Sudden sensorineural hearing loss: is there a relationship between routine haematological parameters and audiogram shapes?

OBJECTIVE: To investigate the relationship between haematological routine parameters and audiogram shapes in patients affected by sudden sensorineural hearing loss (SSNHL). DESIGN: A retrospective study. All patients were divided into four groups according to the audiometric curve and mean values of haematological parameters (haemoglobin, white blood cell, neutrophils and lymphocytes relative count, platelet count, haematocrit, prothrombin time, activated partial thromboplastin time, fibrinogen and neutrophil-to-lymphocite ratio) of each group were statistically compared. The prognostic role of blood profile and coagulation test was also examined. STUDY SAMPLE: A cohort of 183 SSNHL patients without comorbidities. RESULTS: With a 48.78% of complete hearing recovery, individuals affected by upsloping hearing loss presented a better prognosis instead of flat (18.36%), downsloping (19.23%) and anacusis (2.45%) groups (p = 0.0001). The multivariate analysis of complete blood count values revealed lower mean percentage of lymphocytes (p = 0.041) and higher platelet levels (p = 0.015) in case of downsloping hearing loss; with the exception of fibrinogen (p = 0.041), none of the main haematological parameters studied resulted associated with poorer prognosis. CONCLUSIONS: Our work suggested a lack of association between haematological parameters and a defined audiometric picture in SSNHL patients; furthermore, only fibrinogen seems to influence the prognosis of this disease.

Osteoporosis in Stickler syndrome. A new family case with bone histology study.

The Stickler syndrome (SS) has been described as a "hereditary progressive arthro-ophtalmopathy" by Stickler in 1965, due to mutations on the collagen genes. Currently about 40 different genes have been identified which encode for at least 27 different collagens. The majority of mutations occur in the COL2A1 gene on chromosome 12q13 (SS type I). Mutations in COL11A1 are less frequent (SS type II). More recently, mutations in COL11A2 and in the COL9A1 gene have been reported with particular phenotypes. The main features of this autosomal inherited disease are ocular, auditory with orofacial abnormalities and early-onset osteoarthritis. We report the clinical presentation of an adult and his son, with a particular focus on the bone status of the father, radiography, bone densitometry and transiliac bone biopsy showing that he was suffering from osteoporosis. The lumbar bone mineral density was low with a Z-score at -2.9. Transiliac bone biopsy showed a dramatic decrease of trabecular bone volume (8.6%; Nl: 19.5±4.9%), thin trabeculae and a disorganized trabecular network. A slight increase of osteoid parameters was observed. Bone resorption was markedly increased with an excessive number of active (TRAcP+) osteoclasts. The cortical width was normal, but a slight increase of cortical porosity was found. Osteoporosis has been rarely described in the SS. It might be useful to systematically perform a bone densitometry in all patients with SS and to discuss the indication of a transiliac bone biopsy in severe cases.

Platelet diameters in inherited thrombocytopenias: analysis of 376 patients with all known disorders.

Abnormalities of platelet size are one of the distinguishing features of inherited thrombocytopenias (ITs), and evaluation of blood films is recommended as an essential step for differential diagnosis of these disorders. Nevertheless, what we presently know about this subject is derived mainly from anecdotal evidence. To improve knowledge in this field, we evaluated platelet size on blood films obtained from 376 patients with all 19 forms of IT identified so far and found that these conditions differ not only in mean platelet diameter, but also in platelet diameter distribution width and the percentage of platelets with increased or reduced diameters. On the basis of these findings, we propose a new classification of ITs according to platelet size. It distinguishes forms with giant platelets, with large platelets, with normal or slightly increased platelet size, and with normal or slightly decreased platelet size. We also measured platelet diameters in 87 patients with immune thrombocytopenia and identified cutoff values for mean platelet diameter and the percentage of platelets with increased or reduced size that have good diagnostic accuracy in differentiating ITs with giant platelets and with normal or slightly decreased platelet size from immune thrombocytopenia and all other forms of IT.

Preoperative use of platelets in a 6-year-old with acute appendicitis and a myosin heavy chain 9-related disorder: a case report and review of literature.

BACKGROUND: Mutations of nonmuscle myosin heavy chain 9 (MYH9) gene are an autosomal dominant cause of inherited thrombocytopenia in children. MYH9 spectrum disorders include May-Hegglin anomaly and Sebastian, Fechtner, and Epstein syndromes. Patients with these disorders often present with macroplatelets and thrombocytopenia and have a mild bleeding tendency; extrahematologic manifestations (nephropathy, deafness, and cataracts) correlate with specific mutations. No definitive guidelines exist for preoperative prophylactic platelet (PLT) transfusion in these patients. STUDY DESIGN AND METHODS: This was a case study and literature review. RESULTS: A 6-year-old male presented with appendicitis. Review of records revealed that he and his siblings had thrombocytopenia; polymerase chain reaction amplification with DNA sequence analysis showed a variation in the MYH9 gene previously reported as a known cause of MYH9-related disorders. Involvement of other organ systems was not found on initial work-up. The patient's PLT count on admission was 20 × 10(9) /L. The degree of thrombocytopenia prompted transfusion of apheresis PLTs and he had good response (73 × 10(9) /L). After infusion he developed hives, rash, itching, and nausea, which resolved after administration of epinephrine and hydrocortisone. Transfusion reaction work-up was negative and symptoms were interpreted as an allergic reaction. The appendectomy was uneventful. CONCLUSION: This patient's PLT count was within guidelines to warrant transfusion; however, some patients with MYH9 mutations have counts above the transfusion threshold. To the authors' knowledge, there are no set guidelines for preoperative prophylaxis in a patient with an MYH9 deficiency. The management of the bleeding diathesis in these patients, especially in the setting of invasive procedures, is uncertain.

Thrombin generation in two families with MYH9-related platelet disorder.

MYH9-related platelet disorders are inherited macrothrombocytopenias with additional clinical manifestations including renal failure, hearing loss, pre-senile cataract, and inclusion bodies in leucocytes that are present in different combinations. The MYH9 gene codes for the cytoplasmic contractile protein non-muscular myosin heavy chain IIA, present in several tissues. The bleeding tendency is usually mild to moderate but rarely, thrombotic complications are also seen. We report on the thrombin generation potential (ETP) in patients with MYH9-related disease with and without arterial thrombosis. In family A, four affected members [c.5521G>A mutation causing p.(Glu1841Lys)] were evaluated. Three of them had a moderate bleeding tendency and in two renal insufficiency and hearing loss were already present. These two patients had an arterial thrombosis (myocardial infarction and pons infarction, respectively) before 50 years of age. In family B, two members were affected [c.4679T>G, resulting in p.(Val1560Gly)]. Their bleeding tendency was mild (bleeding scores 4 and 3, respectively). Thrombelastography (ROTEM) was normal in all six individuals. ETP was below the normal range in family B. However, in family A, the two members affected by thrombosis had a normal ETP, indicating that other factors compensated for the low platelet count and might have contributed to the arterial thrombosis.