Leukocyte Inclusions Research Articles

Absence of hearing loss in a mouse model for DFNA17 and MYH9-related disease: The use of public gene-targeted ES cell resources

Multiple mouse embryonic stem (ES) cell banks expand the capability to characterize functions of genes implicated in human disease and to develop mouse models for the further understanding of disease pathology. Genetic diseases that result in hearing loss can provide insight into causative molecular mechanisms for deafness. We utilized BayGenomics, the public mouse ES cell bank, to identify gene-trapped ES cell lines associated with hearing loss. We identified two gene-trapped ES cell lines specific for the non-muscle myosin heavy chain class IIA or myosin heavy chain IX (Myh9). Inherited mutations in the Myh9 gene have been linked to non-syndromic hereditary hearing impairment DFNA17 as well as ‘MYH9-related disease’ characterized by macrothrombocytopenia, leukocyte inclusions, and in some patients deafness. Mutant Myh9 mice were derived from one of these ES cell lines that underwent germline transmission for in-depth otological examination. No homozygous mice however were identified at birth, consistent with recently published data describing the embryonic lethality of homozygous mutations in Myh9. We provide evidence that adult heterozygous Myh9 mouse inner ears contain half wild-type levels of Myh9 mRNA. Hearing loss however was not observed in heterozygous Myh9 mice in contrast to human Myh9-related diseases. Aged heterozygous Myh9 mice also did not show signs of cochleosaccular degeneration common in DFNA17. Although inheritance of Myh9 mutations in humans is dominant, we conclude that heterozygous loss of Myh9 is not critical to hearing function in mice by itself.

Clinical Characteristics of Autosomal Dominant Giant Platelet Syndromes and Mutation Analysis of MYH9

Background: The autosomal dominant giant platelet syndromes (GPS), characterized by triads of giant platelets, thrombocytopenia, and Döhle-like leukocyte inclusions are caused by MYH9 mutation, a gene encoding the nonmuscle myosin heavy chain-IIA. This study was aimed to identify the Korean GPS patients and to define clinical findings and molecular characteristics on them. Methods: After taking a family history, platelets were counted using hematologic autoanalyzer and peripheral blood smear (PBS) was examined for platelet size and number, and the presence of leukocyte inclusions. Mutation of MYH9 was studied from mononuclear cells from PB by direct sequencing of previously known 8 exons after PCR amplification of genomic DNA. Results: Twenty patients from 5 unrelated families were diagnosed as GPS. Giant platelets, greater than red cells on PBS, were found to be 3.1% of platelet (range, 1～11%). The median platelet count was 61,000/μL. Inclusion bodies were found in 3 families. Two families had previously reported mutations. Family I had Arg1944Ter in exon 40, located in the tail portion of myosin, while Family IV had Lys373Asn in exon 10, located in the proximal portion of myosin head. The mutations were found only in affected patients, but not in normal siblings or unrelated families. Conclusion: In this study, we identified several families with autosomal dominant GPS. Two families had known MYH9 mutations, Arg1944Ter and Lys373Asn. The search for unknown mutations in the remaining families as well as study of protein structural and functional alteration seems to be necessary for further delineation of these rare genetic disorders.

Intracytoplasmic Inclusions in Circulating Leukocytes from an Eastern Box Turtle (Terrapene carolina carolina) with Iridoviral Infection

A free-ranging adult female eastern box turtle (Terrapene carolina carolina) was presented to the University of Tennessee in October 2003 because of suspected trauma and blindness. Physical examination revealed lethargy, clear ocular and nasal discharges, and white oral and laryngeal plaques. Intracytoplasmic inclusions within heterophils and large mononuclear leukocytes were observed on routine blood smear examination. Postmortem findings included necrosis of epithelial and parenchymal cells with intracytoplasmic inclusions. Ultrastructurally, the leukocyte inclusions consisted of variably electron-dense granular material and viral particles consistent with the Iridoviridae family of viruses. The virus shared 100% sequence identity to a 420-base pair sequence of frog virus 3 (family Iridoviridae, genus Ranavirus) as determined by polymerase chain reaction and gene sequencing targeting a portion of the Ranavirus major capsid protein gene.

Pathologic Quiz Case: Twin Neonates With Thrombocytopenia

Pathologic Quiz Case: Twin Neonates With Thrombocytopenia

Perioperative management of a patient with May-Hegglin anomaly requiring craniotomy

May-Hegglin anomaly (MHA) is a rare type of autosomal dominant platelet disorder associated with mutations in the gene encoding nonmuscle myosin heavy chain 9 (MYH9). It is characterized by the presence of large platelets, leukocyte inclusions, and thrombocytopenia. The bleeding tendency is usually mild, but severe hemorrhages have been reported. This is the first reported case of a patient with MHA who underwent craniotomy for intractable seizure disorder of temporal lobe origin. Patients who have thrombocytopenia have a higher likelihood of developing intraoperative or postoperative intracranial hematoma and bleeding complications. The patient was administered desmopressin (DDAVP) prior to the neurosurgical procedure and had no complications. With this approach, the use of platelet concentrates could be avoided. We discuss the role of DDAVP in MHA and related platelet disorders and review the current literature.

Detection of unique neutrophil non‐muscle myosin heavy chain‐A localization by immunofluorescence analysis in MYH9 disorder presented with macrothrombocytopenia without leukocyte inclusions and deafness

MYH9 disorders are autosomal-dominant macrothrombocytopenias with leukocyte inclusions caused by mutations in the MYH9 gene, which encodes the non-muscle myosin heavy chain-A (NMMHCA). We report a patient with an MYH9 disorder who presented with macrothrombocytopenia without leukocyte inclusions and severe bilateral sensory deafness. Conventional May-Grunwald-Giemsa staining failed to detect granulocyte cytoplasmic inclusions, whereas immunofluorescence analysis clearly demonstrated abnormal neutrophil NMMHCA localization. Genetic analyses revealed a novel heterozygous 18 base deletion in MYH9, leading to a six-amino acid in-frame deletion (N76_S81del) in NMMHCA. These results further support the usefulness of immunofluorescence analysis in differential diagnosis of MYH9 disorders.

Congenital Macrothrombocytopenia and Defective Localization of the Nonmuscle Myosin Heavy Chain IIA in Leukocytes and Megakaryocytes with a Normal MYH9 Gene.

Autosomal dominant macrothrombocytopenias such as the May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome and Epstein syndrome are all characterized by mutations in the MYH9 gene. It has been proposed that these MYH9-related diseases are not distinct entities but represent a variable expression of a single disorder with a continuous clinical spectrum varying from mild macrothrombocytopenia with leukocyte inclusions to more severe conditions encompassing hearing loss, cataracts and renal failure. Mutations in the MYH9 gene cause abnormal expression and/or function of the 224 kDa nonmuscle myosin heavy chain IIA (NMMHC-IIA) protein. Class II myosins are hexameric complexes composed of 2 heavy chains and 2 pairs of light chains forming a structure containing 2 N-terminal globular domains and an elongated α-helical C-terminal tail. Since identical mutations in the MYH9 gene cause variable clinical presentations in different patients, other factors likely modulate the mutant phenotype. We describe a patient with congenital macrothrombocytopenia, mild bleeding problems, Döhle-like leukocyte inclusion bodies, normal hearing, normal renal function and absent cataracts. The patient has macrothrombocytes with an average manual platelet count of 100 x 109/L. Immunofluorescence confocal microscopy using an antibody specific for NMMHC-IIA revealed unique localization of NMMHC-IIA in the patient's leukocytes. Platelets and leukocytes from both parents and one sister are normal. Megakaryocytes cultured from the patient's and one parent's peripheral blood CD34+ cells also demonstrated abnormal distribution of NMMHC-IIA in only the patient's megakaryocytes. Ultrastructural analysis using electron microscopy revealed distinct inclusion bodies in the patient's leukocytes and megakaryocytes that were not observed in either parent. The patient's macrothrombocytopenia together with the abnormal distribution of NMMHC-IIA within leukocytes is highly suggestive of a MYH9-related disorder. The absence of these findings in either parent suggested a de novo MYH9 mutation. We therefore sought to identify the mutation via amplification and DNA sequencing of all MYH9 exons and intron/exon boundaries. Exons 1, 10, 16, 24, 25, 26, 30, 38 and 40 representing all of the previously described mutations in MYH9-related disorders were found to be normal. Surprisingly, the remaining MYH9 gene exons and intron/exon boundaries were also normal. This unexpected finding suggests that another factor is involved in the normal assembly and/or localization of NMMHC-IIA in human leukocytes and megakaryocytes. It also suggests that a deficiency of this factor may lead to congenital macrothrombocytopenia with features indistinguishable from those of MYH9-related disorders. Identification of this factor could enhance our understanding of NMMHC-IIA-related congenital macrothrombocytopenias and would allow us to gain insights into the normal assembly and/or function of NMMHC-IIA in human megakaryocytes and platelets.

Maroteaux-Lamy Syndrome

Mucopolysaccharidoses are a type of lysosomal storage disorders characterized by defect in the degradation of Mucopolysaccharides due to deficiency of specific lysosomal enzymes leading to their accumulation in various tissues. MPS -VI (Maroteaux-Lamy Syndrome) is an autosomal recessive syndrome due to deficiency of enzyme Aryl- Sulfatase -B, and is characterized by characteristic facies, normal intelligence, Dysostosis multiplex, organomegaly, joint stiffness, corneal clouding and striking inclusions in peripheral blood leucocytes. We present an 8-year-old male child with MPS-VI syndrome, confirmed by enzyme assay.

A Unique Immunofluorescence Method Promotes Accurate Diagnosis in MYH9 Disorders: A Case Report.

The identification of a mutation in the MYH9 gene in hereditary macrothrombocytopenia has established a distinct entity proposed as "MYH9 disorders," which previously have often been misdiagnosed as chronic immune thrombocytopenic purpura. The authors describe clinical and laboratory characterization of a family with the disorder demonstrating giant platelets, thrombocytopenia, and leukocyte inclusion bodies. The authors emphasize the efficacy of a unique immunofluorescence method for the nonmuscle myosin heavy chain A in the diagnosis, because it is more sensitive than May-Grünwald-Giemsa staining and more practical than electron microscopy or direct sequencing. MYH9 disorders may be much more common than previously realized if accurately diagnosed.

Hematological abnormalities in a patient with a 22q11.2 deletion

We report a case of a 28-year-old man carrying a 22q11.2 deletion and presenting with giant platelets, thrombocytopenia and leukocyte inclusion bodies. In our patient, platelet glycoproteins were normally expressed on membranes and platelet function was preserved. The May-Hegglin anomaly or Sebastian syndrome associated with the 22q11.2 deletion was suggested. Atypical features also included the lack of any cardiovascular defect, T cell deficit or palate anomaly, generally common with this deletion.

Identification and phenotyping of leukocytes in bovine bronchoalveolar lavage fluid.

A method is proposed to identify leukocyte subpopulations in bovine bronchoalveolar lavage fluid by dual-laser flow cytometry. The technique uses several parameters, i.e., exclusion of highly autofluorescent alveolar macrophages and inclusion of leukocytes on the basis of labeling by specific antibodies and light scatter characteristics.

Correlation between the clinical phenotype of MYH9-related disease and tissue distribution of class II nonmuscle myosin heavy chains

Nonmuscle myosin heavy chain II-A is responsible for MYH9-related disease, which is characterized by macrothrombocytopenia, granulocyte inclusions, deafness, cataracts, and renal failure. Since another two highly conserved nonmuscle myosins, II-B and II-C, are known, an analysis of their tissue distribution is fundamental for the understanding of their biological roles. In mouse, we found that all forms are ubiquitously expressed. However, megakaryocytic and granulocytic lineages express only II-A, suggesting that congenital features, macrothrombocytopenia, and leukocyte inclusions correlate with its exclusive presence. In kidney, eye, and ear, where clinical manifestations have a late onset, as well as in other tissues apparently not affected in patients, II-A and at least one of the other two isoforms are expressed, suggesting that II-B and II-C can partially compensate for each other. We hypothesize that cells expressing only II-A manifest the congenital defects, while tissues expressing additional myosin II isoforms show either late onset of abnormalities or no pathological sign.

Hematological abnormalities in a patient with a 22q11.2 deletion

We report a case of a 28-year-old man carrying a 22q11.2 deletion and presenting with giant platelets, thrombocytopenia and leukocyte inclusion bodies. In our patient, platelet glycoproteins were normally expressed on membranes and platelet function was preserved. The May-Hegglin anomaly or Sebastian syndrome associated with the 22q11.2 deletion was suggested. Atypical features also included the lack of any cardiovascular defect, T cell deficit or palate anomaly, generally common with this deletion.

MYH9-related disease: May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are not distinct entities but represent a variable expression of a single illness.

May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are autosomal dominant macrothrombocytopenias distinguished by different combinations of clinical and laboratory signs, such as sensorineural hearing loss, cataract, nephritis, and polymorphonuclear Döhle-like bodies. Mutations in the MYH9 gene encoding for the nonmuscle myosin heavy chain IIA (NMMHC-IIA) have been identified in all these syndromes. To understand the role of the MYH9 mutations, we report the molecular defects in 12 new cases, which together with our previous works represent a cohort of 19 families. Since no genotype-phenotype correlation was established, we performed an accurate clinical and biochemical re-evaluation of patients. In addition to macrothrombocytopenia, an abnormal distribution of NMMHC-IIA within leukocytes was observed in all individuals, including those without Döhle-like bodies. Selective, high-tone hearing deficiency and cataract was diagnosed in 83% and 23%, respectively, of patients initially referred as having May-Hegglin anomaly or Sebastian syndrome. Kidney abnormalities, such as hematuria and proteinuria, affected not only patients referred as Fechtner syndrome and Epstein syndrome but also those referred as May-Hegglin anomaly and Sebastian syndrome. These findings allowed us to conclude that May-Hegglin anomaly, Sebastian syndrome, Fechtner syndrome, and Epstein syndrome are not distinct entities but rather a single disorder with a continuous clinical spectrum varying from mild macrothrombocytopenia with leukocyte inclusions to a severe form complicated by hearing loss, cataracts, and renal failure. For this new nosologic entity, we propose the term "MHY9-related disease," which better interprets the recent knowledge in this field and identifies all patients at risk of developing renal, hearing, or visual defects.

Chronic prostatitis/chronic pelvic pain pyndrome): seminal markers of inflammation.

The new prostatitis classification proposes the inclusion of seminal leukocytes in the diagnosis of inflammatory chronic pelvic pain syndrome (CPPS). The present study has been performed to clarify the role of seminal leukocytes and inflammatory seminal plasma parameters in order to contribute to the differential diagnosis between inflammatory (category IIIA) and non-inflammatory (category IIIB) CPPS. A total of 112 consecutive symptomatic patients (mean age 37.3 years; range 21-64) attending our prostatitis outpatient clinic were investigated. Men with evidence for bacterial infection were excluded by prior standardized lower urinary tract localization studies. Men were categorized into inflammatory and non-inflammatory CPPS according to the leukocyte analysis in expressed prostatic secretions (EPS) and urine after prostatic massage (VB 3). Ejaculate analysis was performed after lower urinary tract localization studies. Inflammatory markers included peroxidase positive leukocytes (PPL) and PMN-elastase. Receiver operating characteristic curves were constructed to analyze cutpoints provided that the differences were significant. Increased leukocyte counts in EPS/VB 3 were found in 64 men, while in 48 this was not the case. No differences could be detected in relation to patients' age ( P>0.05). In men with category IIIA prostatitis, PPL and elastase in the seminal fluid were significantly increased ( P<0.001). For PPL and elastase, a cutpoint of 0.113 x 10(6)/ml and 280 ng/ml, respectively, were suggested. Increased PPL (>0.113 x 10(6)/ml) and elastase (>280 ng/ml) in the seminal fluid indicate inflammatory disease provided that the ejaculate analysis is performed on the same day after lower urinary tract localization studies.

Immunofluorescence Analysis of Neutrophil Nonmuscle Myosin Heavy Chain-A in MYH9 Disorders: Association of Subcellular Localization with MYH9 Mutations

The autosomal dominant macrothrombocytopenia with leukocyte inclusions, May-Hegglin anomaly, Sebastian syndrome, and Fechtner syndrome, are rare human disorders characterized by a triad of giant platelets, thrombocytopenia, and characteristic Döhle body-like cytoplasmic inclusions in granulocytes. Epstein syndrome is another autosomal dominant macrothrombocytopenia associated with Alport syndrome but without leukocyte inclusions. These disorders are caused by mutations in the same gene, the MYH9, which encodes the nonmuscle myosin heavy chain-A (NMMHCA). The term, MYH9 disorders, has been proposed, but the clinicopathologic basis of MYH9 mutations has been poorly investigated. In this study, a total of 24 cases with MYH9 disorders and suspected cases were subjected to immunofluorescence analysis by a polyclonal antibody against human platelet NMMHCA. Abnormal subcellular localization of NMMHCA was observed in every neutrophil from individuals with MYH9 mutations. Comparison with May-Grünwald-Giemsa staining revealed that the NMMHCA always coexisted with the neutrophil inclusion bodies, suggesting that NMMHCA is associated with such bodies. In three cases, neutrophil inclusions were not detected on conventional May-Grünwald-Giemsa-stained blood smears but immunofluorescence analysis revealed the abnormal NMMHCA localization. In contrast, cases with Epstein syndrome and the isolated macrothrombocytopenia with normal NMMHCA localization had no MYH9 mutations. An antibody that recognizes the C-terminal 12 mer peptides showed similar immunoreactivity from the patients heterozygous for truncated mutations that abolished the C-terminal epitope, suggesting that normal NMMHCA dimerizes with abnormal NMMHCA to form inclusion bodies. We further propose that the localization pattern can be classified into three groups according to the number, size, and shape of the fluorescence-labeled NMMHCA granule. Immunofluorescence analysis of neutrophil NMMHCA is useful as a screening test for the clear hematopathologic classification of MYH9 disorders.

Genetics, clinical and pathological features of glomerulonephrites associated with mutations of nonmuscle myosin IIA (Fechtner syndrome)

Background: Fechtner syndrome (FTNS), also known as Alport-like syndrome, is a rare inherited condition characterized by progressive nephritis, macrothrombocytopenia, Döhle-like leukocyte inclusions, deafness, and cataract. Although it recently was shown that FTNS derives from mutation of MYH9, the gene for the heavy chain of nonmuscle myosin IIA (NMMHC-IIA), its pathophysiological characteristics remain unknown. Methods: We studied a large FTNS family in which 10 components carried a missense mutation of MYH9 determining the D1424H substitution. Results: All affected subjects presented with macrothrombocytopenia and leukocyte Döhle-like bodies consisting of macroaggregates of NMMHC-IIA, but only two subjects had major renal problems characterized by proteinuria and renal failure. Electron microscopy showed focal and segmental effacement of podocytes and loss of the interpodocyte slit diaphragm. Immunohistochemistry showed apical localization of NMMHC-IIA in tubular epithelia and less podocyte staining in the two patients, whereas it was diffuse in normal epithelia. Three patients presented with stable microhematuria, and another five patients had no renal lesions, although they carried the same mutation of MYH9. Therefore, MYH9 mutation per se was responsible for platelet and leukocyte abnormalities, whereas additional predisposing conditions and/or environmental factors are necessary for nephropathy, cataract, and deafness. Looking at podocyte components conferring permselectivity properties to the kidney, we characterized the haplotype of podocin and found cosegregation of one specific allele in the two patients with nephrotic syndrome, suggesting a relationship between podocin features and proteinuria. Conclusion: Our study indicates a major role for the NMMHC-IIA abnormality in the pathogenesis of leukocyte, platelet, and kidney defects in FTNS. The basic feature in all cases is aggregation and compartmentation of NMMHC-IIA. However, proteinuria and podocyte lesions are the hallmark of nephropathy in patients who develop renal failure, and podocin may have some function in this setting. Am J Kidney Dis 41:95-104. © 2003 by the National Kidney Foundation, Inc.

High Serum Folate Values in Lambs Experimentally Infected with Anaplasma phagocytophilum

Folates are involved in nucleic acid, protein and amino acid synthesis. In human serum, it has been estimated that 60% to 70% of folates are bound to proteins (Wagner 1985). Folate binding proteins (FBPs) are therefore crucial to the assimilation, distribution and retention of the vitamin folic acid and have been identified in various cells, extracellular fluids and tissues from humans and several animal species. FBPs have different functions based on their biochemical properties and can be divided into 3 classes: high-affinity folate binding proteins (HFBP), membrane-associated folate-binding proteins, which function in the transport of folate compounds across cell membranes, and cytoplasmic-binding proteins with a high affinity for specific reduced-folate compounds (Henderson 1990). Tick-borne fever (TBF) caused by the rickettsia Anaplasma phagocytophilum (formerly Ehrlichia phagocytophila) is a common disease in domestic ruminants on Ixodes ricinus infested pastures in Norway (Stuen 1997, Stuen & Bergstrom 2001). During the acute infection, A. phagocytophilum are found in cytoplasmatic inclusions in blood leucocytes, mainly neutrophils. Up to 95% of the neutrophils can be infected. The rickettsemia is followed by a severe neutropenia lasting for 1-2 weeks (Foggie

A novel model of autosomal dominant Alport syndrome in Dalmatian dogs.

Autosomal dominant Alport syndrome is a rare inherited disease characterized clinically by haematuria, renal failure and deafness, and ultrastructurally by a lamellated glomerular basement membrane (GBM). It is usually caused by mutations in the COL4A3 or COL4A4 genes which code for the alpha3 and alpha4 chains of type IV collagen. We describe here a novel spontaneous model of autosomal dominant Alport syndrome in Dalmatian dogs. Affected dogs were identified by a urinary protein creatinine >/=0.3. A total of 10 affected adult Dalmatians and eight unaffected age- and sex-matched dogs from breeds other than Dalmatians were examined. In addition, kidneys from five Dalmatian fetuses from affected mothers were examined histologically and ultrastructurally. All affected dogs were purebred Dalmatians and had a common progenitor. Successive generations were affected, and males and females were affected equally often and equally severely, consistent with autosomal dominant inheritance. The median age at onset of renal failure was 18 months (range 8 months to 7 years). Affected dogs were not clinically deaf, and did not have the ocular abnormalities seen in human X-linked or autosomal recessive Alport syndrome. In addition, they did not have the leucocyte inclusions, low platelet counts or large platelets seen in autosomal dominant hereditary nephritis due to MYH9 mutations. The renal histology and ultrastructural appearance of the GBM appeared to be normal in utero. However, affected adult kidneys demonstrated segmental glomerular hyalinosis and sclerosis with tubulo-interstitial inflammation and fibrosis, and on ultrastructural examination the GBM was lamellated with subepithelial frilling, vacuolation and occasional intramembranous deposits. All alpha1(IV)-alpha5(IV) type IV collagen chains were present in the affected GBM and Bowman's capsule. Autosomal dominant Alport syndrome in Dalmatians resembles the disease in Bull terriers but has arisen independently. These models will enable us to determine how genetic mutations affect the corresponding proteins and overall membrane structure in autosomal dominant Alport syndrome.

Mutations in Human Nonmuscle Myosin IIA Found in Patients with May-Hegglin Anomaly and Fechtner Syndrome Result in Impaired Enzymatic Function

A family of autosomal-dominant diseases including May-Hegglin anomaly, Fechtner syndrome, Sebastian syndrome, Alport syndrome, and Epstein syndrome are commonly characterized by giant platelets and thrombocytopenia. In addition, there may be leukocyte inclusions, deafness, cataracts, and nephritis, depending on the syndrome. Mutations in the human nonmuscle myosin IIA heavy chain gene (MYH9) have been linked to these diseases. Two of the recently described mutations, N93K and R702C, are conserved in smooth and nonmuscle myosins from vertebrates and lie in the head domain of myosin. Interestingly, the two mutations lie within close proximity in the three-dimensional structure of myosin. These two mutations were engineered into a heavy meromyosin-like recombinant fragment of nonmuscle myosin IIA, which was expressed in baculovirus along with the appropriate light chains. The R702C mutant displays 25% of the maximal MgATPase activity of wild type heavy meromyosin and moves actin filaments at half the wild type rate. The effects of the N93K mutation are more dramatic. This heavy meromyosin has only 4% of the maximal MgATPase activity of wild type and does not translocate actin filaments in an in vitro motility assay. Biochemical characterization of the mutant is consistent with this mutant being unable to fully adopt the "on" conformation.