Pulmonary hypertension in patients with thalassemia major

To evaluate the pulmonary artery pressure in patients with thalassemia major, Doppler echocardiography was performed in 33 patients with thalassemia major (aged 2 to 24 years) and 33 normal controls. Pulmonary artery pressure was estimated by (1) measuring the systolic transtricuspid gradient from tricuspid regurgitation and adding it to the right atrial pressure, estimated by the response of the inferior vena cava to deep inspiration, and (2) measuring the time to peak velocity of pulmonary flow. The results showed that of 33 patients, 28 had tricuspid regurgitation with a pulmonary systolic pressure ranging from 18 to 94 mm Hg (47 +/- 15 mm Hg). Pulmonary systolic pressure was > 30 mm Hg in all 22 patients > 10 years old and in four of six patients < 10 years old. Pressure correlated with left ventricular ejection fraction (r = -0.74), the ratio of mitral peak early diastolic flow velocity and peak velocity during the atrial contraction (r = 0.52), age (r = 0.56), and total blood transfusion units (r = 0.59). The pulmonary time to peak velocity was shortened compared with controls (p < 0.05). We concluded that pulmonary hypertension, as another cardiovascular complication of multiple factors of cause, seems to occur more frequently and at an early stage of the cardiac involvement in patients with thalassemia major.

Urinary tract infection: is there a need for routine renal ultrasonography?

AIMS

To assess the yield of routine renal ultrasound (RUS) in the management of young children hospitalised with first uncomplicated febrile urinary tract infection (UTI).

METHODS

All children aged 0-5 years who had been hospitalised over a two year period with first uncomplicated febrile UTI in a medium size institutional regional medical centre were included. Children with known urinary abnormalities and/or who had been treated with antibacterial agents within seven days before admission were excluded. All included children underwent renal ultrasonography during hospitalisation and voiding cystouretrography (VCUG) within 2-6 months. The yield of RUS was measured by its ability to detect renal abnormalities, its sensitivity, specificity, and positive and negative predictive values for detecting vesicoureteral reflux (VUR), and by its impact on UTI management.

RESULTS

Of 255 children that were included in the study, 33 children had mild to moderate renal pelvis dilatation on RUS suggesting VUR, of whom only nine had VUR on VCUG. On the other hand, in 36 children with VUR on VCUG the RUS was normal. The sensitivity, specificity, positive predictive value, and negative predictive value of abnormal RUS for detecting VUR were 17.7%, 87.6%, 23.5%, and 83.2% respectively. In none of the patients with abnormal RUS was a change in the management at or following hospitalisation needed.

CONCLUSION

Results show that the yield of RUS to the management of children with first uncomplicated UTI is questionable.

Association between mitral annulus calcification and carotid atherosclerotic disease

BACKGROUND AND PURPOSE

It has been established that mitral annulus calcification (MAC) is an independent predictor of stroke, though a causative relationship was not proved, and that carotid artery atherosclerotic disease is also associated with stroke. The aim of this study was to determine whether there is an association between the presence of MAC and carotid artery atherosclerotic disease.

METHODS

Of the 805 patients in whom the diagnosis of MAC was made by transthoracic echocardiography between 1995 and 1997, 133 patients (60 men and 73 women; mean age, 74.3+/-8 years; range, 47 to 89 years) underwent carotid artery duplex ultrasound for various indications; the study group comprised these patients. They were compared with 129 age- and sex-matched patients without MAC (57 men and 72 women; mean age, 73.6+/-7 years; range, 61 to 96 years) who underwent carotid artery duplex ultrasound during the same period for the same indications. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet. MAC was considered severe when the thickness of the localized, highly reflective area was > or =5 mm on 2-dimensional echocardiography in the 4-chamber view. Carotid artery stenosis was graded as follows: 0%, 20%, 40%, 60%, 80%, and 100%.

RESULTS

Compared with the control group, the MAC group showed a significantly higher prevalence of carotid stenosis of > or =40% (45% versus 29%, P=0.006), which was associated with > or =2-vessel disease (23% versus 10%, P=0.006) and bilateral carotid artery atherosclerotic disease (21% versus 10%, P=0.011). Severe MAC was found in 48 patients. More significant differences were found for the severe MAC subgroup (for carotid stenosis of > or =40%) in rates of carotid artery atherosclerotic disease (58% versus 29%, P=0.001), and > or =2-vessel disease (31% versus 10%, P=0.001), in addition to bilateral carotid artery stenosis (27% versus 10%, P=0.004) and even bilateral proximal internal carotid artery stenosis (21% versus 8%, P=0.015). Furthermore, significant carotid artery atherosclerotic disease (stenosis of > or =60%) was significantly more common in the severe MAC subgroup than in the controls (42% versus 26%, P<0.05) and was associated with higher rates of > or =2-vessel disease (19% versus 7%, P=0.02) and bilateral carotid artery stenosis (17% versus 7%, P=0.05). On multivariate analysis, MAC and age but not traditional risk factors were the only independent predictors of carotid atherosclerotic disease (P=0.007 and P=0.04, respectively).

CONCLUSIONS

There is a significant association between the presence of MAC and carotid artery atherosclerotic disease. MAC may be an important marker for atherosclerotic disease of the carotid arteries. This association may explain the high prevalence of stroke in patients with MAC.

Heterogeneous glioblastoma cell cross-talk promotes phenotype alterations and enhanced drug resistance

Glioblastoma multiforme is the most lethal of brain cancer, and it comprises a heterogeneous mixture of functionally distinct cancer cells that affect tumor progression. We examined the U87, U251, and U373 malignant cell lines as in vitro models to determine the impact of cellular cross-talk on their phenotypic alterations in co-cultures. These cells were also studied at the transcriptome level, to define the mechanisms of their observed mutually affected genomic stability, proliferation, invasion and resistance to temozolomide. This is the first direct demonstration of the neural and mesenchymal molecular fingerprints of U87 and U373 cells, respectively. U87-cell conditioned medium lowered the genomic stability of U373 (U251) cells, without affecting cell proliferation. In contrast, upon exposure of U87 cells to U373 (U251) conditioned medium, U87 cells showed increased genomic stability, decreased proliferation rates and increased invasion, due to a plethora of produced cytokines identified in the co-culture media. This cross talk altered the expression 264 genes in U87 cells that are associated with proliferation, inflammation, migration, and adhesion, and 221 genes in U373 cells that are associated with apoptosis, the cell cycle, cell differentiation and migration. Indirect and direct co-culturing of U87 and U373 cells showed mutually opposite effects on temozolomide resistance. In conclusion, definition of transcriptional alterations of distinct glioblastoma cells upon co-culturing provides better understanding of the mechanisms of glioblastoma heterogeneity, which will provide the basis for more informed glioma treatment in the future.

Deleterious mutation in the FYB gene is associated with congenital autosomal recessive small-platelet thrombocytopenia

BACKGROUND

The FYB gene encodes adhesion and degranulation-promoting adaptor protein (ADAP), a hematopoietic-specific protein involved in platelet activation, cell motility and proliferation, and integrin-mediated cell adhesion. No ADAP-related diseases have been described in humans, but ADAP-deficient mice have mild thrombocytopenia and increased rebleeding from tail wounds.

PATIENTS AND METHODS

We studied a previously reported family of five children from two consanguineous sibships of Arab Christian descent affected with a novel autosomal recessive bleeding disorder with small-platelet thrombocytopenia. Homozygosity mapping and exome sequencing were used to identify the genetic lesion causing the disease phenotype on chromosome 5. Bone-marrow morphology and platelet function were analyzed. Platelets were characterized by scanning electron microscopy.

RESULTS

We identified a homozygous deleterious nonsense mutation, c.393G>A, in FYB. A reduced percentage of mature megakaryocytes was found in the bone marrow. Patients' platelets showed increased basal expression of P-selectin and PAC-1, and reduced increments of activation markers after stimulation with ADP, as detected by flow cytometry; they also showed reduced pseudopodium formation and the presence of trapped platelets between the fibrin fibers after thrombin addition, as observed on scanning electron microscopy.

CONCLUSIONS

This is the first report of a disease caused by an FYB defect in humans, manifested by remarkable small-platelet thrombocytopenia and a significant bleeding tendency. The described phenotype shows ADAP to be important for normal platelet production, morphologic changes, and function. It is suggested that mutation analysis of this gene be included in the diagnosis of inherited thrombocytopenia.

Effect of hydroxyurea in sickle cell anemia: a clinical trial in children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia

This study evaluated the efficacy of hydroxyurea treatment in the prevention of vaso-occlusive crises among children and teenagers with severe sickle cell anemia and sickle cell beta-thalassemia. Nineteen children and young adults with severe sickle cell disease were enrolled to the hydroxyurea treatment trial. The incidence of vaso-occlusive crises, acute chest syndrome, hemolytic crises, splenic sequestration episodes, blood transfusions, and hospital days in the 2 years before hydroxyurea (HU) treatment were compared with the same parameters in the first 2 years of treatment. The patients received a mean dose of 21.3 mg/kg/day daily and were treated during a mean period of 40.3 +/- 14 months (range 20 to 68 months). Significant increases were observed after 1 month in the Hgb, MCV, MCH, and MCHC levels and were more notable after 3 months. The increase in the Hgb F level became important after 3 months of HU therapy and was highly significant (p < .001) beyond 6 months. No differences were observed in the RDW, reticulocyte count, Hgb S, and Hgb A2. Severe neutropenia was observed in one case. A decrease in the frequency of vaso-occlusive crises, acute chest syndrome, hemolytic crises, blood transfusions, and days spent in the hospital was demonstrated during the HU treatment period compared to the same period before. The clinical and laboratory response to HU was dramatic in severely affected sickle cell anemia (SCA) patients. The response to HU in children and teenagers with severe sickle cell anemia is similar to the response in adults, and no severe adverse effects were observed.

The prognostic value of whole blood SOX2, NANOG and OCT4 mRNA expression in advanced small-cell lung cancer

BACKGROUND

The data on expression and clinical impact of cancer stem cell markers SOX2, NANOG and OCT4 in lung cancer is still lacking. The aim of our study was to compare SOX2, NANOG and OCT4 mRNA expression levels in whole blood between advanced small-cell lung cancer (SCLC) patients and healthy controls, and to correlate mRNA expression with progression-free survival (PFS) after first-line chemotherapy and overall survival (OS) in advanced SCLC patients.

PATIENTS AND METHODS

50 advanced SCLC patients treated with standard chemotherapy and followed at University Clinic Golnik, Slovenia, between 2009 and 2013 were prospectively included. SOX2, NANOG and OCT4 mRNA expression levels were determined using TaqMan qPCR in whole blood collected prior to chemotherapy. Whole blood of 34 matched healthy individuals with no cancerous disease was also tested.

RESULTS

SOX2 mRNA expression was significantly higher in whole blood of SCLC patients compared to healthy controls (p = 0.006). Significant correlation between SOX2 mRNA expression levels and the number of distant metastatic sites was established (p = 0.027). In survival analysis, patients with high SOX2 expression had shorter OS (p = 0.017) and PFS (p = 0.046). In multivariate Cox analysis, an independent value of high SOX2 expression for shorter OS (p = 0.002), but not PFS was confirmed. No significant differences were observed for NANOG or OCT4 expression levels when comparing SCLC patients and healthy controls neither when analysing survival outcomes in SCLC patients.

CONCLUSIONS

SOX2 mRNA expression in whole blood might be a promising non-invasive marker for molecular screening of SCLC and important prognostic marker in advanced chemotherapy-treated SCLC patients, altogether indicating important role of cancer stem-like cell (CSC) regulators in cancer spread. Further evaluation of SOX2 as a possible screening/prognostic marker and a therapeutic target of SCLC is warranted.

The in vivo effect of recombinant human granulocyte-colony stimulating factor in neutropenic neonates with sepsis

The effects of recombinant granulocyte-colony stimulating factor (rhG-CSF) in neonatal neutropenia with presumed sepsis, which has a poor prognosis, were investigated. The study involved 14 neonates with presumed sepsis and neutropenia. Findings were compared with those from 24 historical controls. rhG-CSF (5 micrograms/ kg/day i.v. for 5 days) was administered immediately following diagnosis. Complete blood counts were obtained before and 24, 48, 72, 96 and 120 h after initiation of treatment. Neutrophil storage pool (NSP) was assessed (in 4 patients) before and after treatment. Statistical analysis was performed using one way analysis of variance. Treatment led to an increase in absolute neutrophil count (ANC) levels in 13/14 patients. At the end of treatment, the mean ANC was higher than that of controls (P = 0.007). There was a marked increase in the NSP of between 32% and 65% (P = 0.005). There were two clinical failures, one of whom was considered to have died from his underlying condition. There were no reports of clinical or haematological toxicity during treatment or follow up.

Bone infarction in children with sickle cell disease: early diagnosis and differentiation from osteomyelitis

An early differential diagnosis between bone infarction and osteomyelitis in sickle cell patients is practically impossible using routine laboratory methods. Twenty radioisotope studies in sickle cell patients during vaso-occlusive crises, were analyzed. A three stage process can be described. In the first stage a decreased uptake can be demonstrated by Tc 99m methylene diphosphonate (MDP) bone scanning. In osteomyelitis, an increased uptake area is usually seen at this early stage, corresponding to increased uptake in Ga-67 citrate scanning. At the second stage, approximately a week later, normal uptake can be seen. Two to four weeks later an area of increased uptake is recorded that corresponds to the healing process, stage three. We recommend therefore Tc 99m MDP bone scanning in the early stages if clinical signs and symptoms suggest a vaso occlusive crisis or osteomyelitis in a sickle cell patient. This study can be followed by a Ga-67 citrate scintigraphy in doubtful cases. Later studies should be used for the assessment of the healing process. Two illustrative case reports are included.

Free radicals in tetanic activity of isolated skeletal muscle

1. The concentration of the free radicals in muscle tissue mitochondria changes with the phase of muscle contraction. 2. Potassium cyanide (KCN) influences the shape of the isotonic tetani mechanograms; the contraction is still strong and qualitatively comparable in amplitude to untreated controls. 3. On the other hand, the correlation between the free radical concentration and muscle contraction is lost. 4. The free radical concentration in isolated mitochondria is influenced by KCN and potassium ferricyanide. 5. The free radical concentration changes due to the electron flow in the respiratory chain. 6. Inhibition of the respiratory phosphorylation by KCN could affect the free radical level.

Relation of nonobstructive aortic valve calcium to carotid arterial atherosclerosis

Recently it was shown that subjects with aortic valve calcium (AVC) are at increased risk for future cardiovascular disease including stroke. We hypothesized that the increased risk of stroke may be due to an association with carotid artery atherosclerotic disease. Between 1995 and 1999 our laboratory made a diagnosis of AVC without significant stenosis in 3,949 patients. Of those, 279 patients without other cardiac structural exclusion criteria (148 men and 131 women; mean age 73 +/- 9 years, range 45 to 90) underwent carotid artery duplex ultrasound for various indications, and formed the study group. Age- and sex-matched patients without AVC (n = 277), who underwent carotid artery duplex ultrasound during the same period and for the same indications, served as the control group. Compared with the control group, the AVC group had a significantly higher prevalence of carotid stenosis (> 40% to 60%, 89% vs 78% [p < 0.001]; >60% to 80%, 43% vs 23% [p <0.001];and > 80% to 100%, 32%vs 14% [p < 0.001]). The AVC group had a similar, significantly higher prevalence of > or = 2-vessel disease and bilateral carotid stenosis (stenosis levels of > 20% to 40%, >40% to 60%, > 60% to 80%, and > 80% to 100%). In multivariate analysis, AVC, but not traditional risk factors, was the only independent predictor of severe carotid atherosclerotic disease (stenosis > 80% to 100%; p = 0.0001). Thus, there is a significant association between the presence of AVC and carotid atherosclerotic disease.

Rapid Antibody Response after Vaccination with a Virosomal Hepatitis A Vaccine

BACKGROUND

This study was designed to assess the early antibody kinetics after a priming dose, and the extent of the antibody increase after a booster dose of an inactivated virosomal hepatitis A virus (HAV) vaccine (Epaxal).

PATIENTS AND METHODS

This was an open, uncontrolled study in 30 healthy subjects. The vaccine was injected intramuscularly on day 1 and month 12. Serum antibody titers were measured by ELISA on day 1 (pre dose) and at various time points thereafter until month 12 (pre-booster dose). After the booster dose, antibody titers were measured at various intervals until month 24. Neutralizing antibody titers were measured in 12 subjects a number of times during the 1st month by an antibody neutralization assay. Titers > or = 10 mIU/ml were considered seroprotective.

RESULTS

ELISA antibody titers showed a rapid increase post vaccination. By day 15, 96% of subjects were seroprotected, which increased to 100% by day 22 (n = 27 evaluable subjects, aged 18-43 years; 13 male, 14 female). All subjects achieved seroprotective HAV-neutralizing antibody titers by day 11 (n = 12). The booster vaccination at month 12 resulted in a strong response in all subjects, with a sustained anti-HAV antibody titer (1,155 mIU/ml) at month 24. Both the priming and booster doses were well tolerated.

CONCLUSION

Primary vaccination with this virosomal HAV vaccine is well tolerated and induces a rapid HAV-neutralizing antibody response resulting in seroprotection in all subjects within 10 days. In addition, the booster vaccination results in prolonged seroprotective antibody levels.

Chemokines during anaphylaxis: the importance of CCL2 and CCL2-dependent chemotactic activity for basophils

Background

The role of chemokines in anaphylaxis is unclear.

Methods

We prospectively recruited 49 patients presenting to the emergency department with an acute episode of anaphylaxis and 28 healthy subjects. We measured serum levels of the chemokines CCL2, CCL5, CCL7, CCL8, CCL11, CCL13, CCL17, CCL21, CCL22, CCL24, and CCL26, tryptase, the absolute number of circulating basophils, monocytes, lymphocytes, and PMNs, and whole blood FCER1A, CPA3 and HDC gene expression at two time points: during the anaphylactic episode and in convalescent samples collected approximately 3 months later. We then investigated the in vitro chemotactic activity of chemokines induced during anaphylaxis for the in vitro migration of the corresponding cells.

Results

Only CCL2 chemokine levels were significantly increased in anaphylaxis samples (median 514 pg/ml) compared to convalescent samples (284 pg/ml, P < 0.0001) and healthy subjects (279 pg/ml, P < 0.0001); there was no significant difference in any of the other chemokines. There was a significant positive correlation between the rates of increase of serum CCL2 (median [range]: 106.0% [− 44.7% to 557.4%]) and tryptase (133.8% [− 6.6% to 893.4%]; r = 0.68, P < 0.0001) and between the acute concentration of serum CCL2 and the acute concentration of serum tryptase (r = 0.77, P < 0.0001). The number of circulating basophils, but not other blood cells, significantly decreased during anaphylaxis (median 5.0 vs. 19.1 cells/µl in convalescent samples; P < 0.0001); a decrease in whole-blood gene expression of basophil markers (P ≤ 0.0018) confirmed these changes. Anaphylactic serum enhances the in vitro migration of basophils via CCL2-dependent chemotactic activity; in contrast, no CCL2-dependent chemotactic activity was observed for convalescent samples.

Conclusions

Our findings imply an important and specific role for CCL2-mediated chemotactic activity in the pathophysiology of human anaphylaxis.

Venous thromboembolism, factor V Leiden, and methylenetetrahydrofolate reductase in a sickle cell anemia patient

Vaso-occlusive crisis is the most common cause of morbidity in patients with sickle cell anemia (SCA). Central nervous system involvement that leads to hemiplegia is the most frequent neurological complication in those patients. Peripheral deep venous thromboembolism was not reported in SCA patients. Activated protein C resistance is associated with an increased risk of thrombophilia. The authors report an SCA patient with recurrent cerebrovascular accident and deep venous thrombosis. Activated protein C resistance due to factor V Leiden heterozygous and heterozygocity for the methylenetetrahydrofolate reductase were diagnosed and suspected to be the risk factors that contribute to the development of the deep vein thrombosis in this SCA patient.

Campylobacter bacteremia and pneumonia in two splenectomized patients

Two patients with beta thalassemia who had undergone splenectomy for hypersplenism were admitted to the hospital with high fever and lobar pneumonia. Neither patient had gastrointestinal symptoms. Campylobacter bacteremia was diagnosed in both patients. Campylobacter jejuni was identified in the first patient and Campylobacter fetus in the second. Both patients were treated with broad-spectrum antibiotics and recovered fully.

An αIIb mutation in patients with Glanzmann thrombasthenia located in the N-terminus of blade 1 of the β-propeller (Asn2Asp) disrupts a calcium binding site in blade 6

BACKGROUND

Studies of Glanzmann thrombasthenia (GT)-causing mutations has generated invaluable information on the formation and function of integrin αIIbβ(3).

OBJECTIVE

To characterize the mutation in four siblings of an Israeli Arab family affected by GT, and to analyze the relationships between the mutant protein structure and its function using artificial mutations.

METHODS AND RESULTS

Sequencing disclosed a new A97G transversion in the αIIb gene predicting Asn2Asp substitution at blade 1 of the β-propeller. Alignment with other integrin α subunits revealed that Asn2 is highly conserved. No surface expression of αIIbβ(3) was found in patients' platelets and baby hamster kidney (BHK) cells transfected with mutated αIIb and WT β(3). Although the αIIbβ(3) was formed, the mutation impaired its intracellular trafficking. Molecular dynamics simulations and modeling of the αIIbβ(3) crystal indicated that the Asn2Asp mutation disrupts a hydrogen bond between Asn2 and Leu366 of a calcium binding domain in blade 6, thereby impairing calcium binding that is essential for intracellular trafficking of αIIbβ(3). Substitution of Asn2 to uncharged Ala or Gln partially decreased αIIbβ(3) surface expression, while substitution by negatively or positively charged residues completely abolished surface expression. Unlike αIIbβ(3), αVβ(3) harboring the Asn2Asp mutation was surface expressed by transfected BHK cells, which is consistent with the known lower sensitivity of αVβ(3) to calcium chelation compared with αIIbβ(3).

CONCLUSION

The new GT causing mutation highlights the importance of calcium binding domains in the β-propeller for intracellular trafficking of αIIbβ(3). The mechanism by which the mutation exerts its deleterious effect was elucidated by molecular dynamics.

Frontal and orbital bone infarctions causing periorbital swelling in patients with sickle cell anemia

Two cases of unilateral and bilateral periorbital hematomas occurred in patients with sickle cell anemia. The cause of periorbital swelling in these cases was found to be orbital and frontal bone infarctions, respectively, diagnosed by technetium Tc 99m medronate bone scintigraphy. To our knowledge, periorbital bone infarction, as a part of the differential diagnosis of periorbital hematoma and as part of the possible ocular manifestations in patients with sickle cell anemia, has not previously been described.

Uncommon sites of bone infarction in a sickle cell anemia patient

Unusual sites of bone infarction, in the skull and sternum, were observed in a patient suffering from sickle cell anemia. A 99mTc-MDP scan was performed and demonstrated foci of decreased activity in the symptomatic regions. The differentiation of bone infarction from osteomyelitis in sickle cell anemia patients is illustrated.

Acute chest syndrome in children with sickle cell anemia

Vaso-occlusive crisis is the most common cause of morbidity in patients with sickle cell anemia (SCA). Those patients are frequently admitted with chest signs and symptoms suggesting an infective process. The term acute chest syndrome (ACS) is used to describe those chest episodes in SCA patients, and it is postulated that a primary bone vaso-occlusive crisis may be the cause of the acute chest syndrome in SCA patients. In this study we report 52 episodes of ACS in a group of 22 children with SCA. Chest pain, fever, and leukocytosis were a constant clinical finding. The hematological, radiological, and bacteriological studies are reported. There is a constant and significant fall in hemoglobin levels from 88 +/- 10 g/L (8.8 +/- 1.0 g/dl) to 68 +/- 15 g/L (6.8 +/- 5 g/dl). Unilateral or bilateral pulmonary basal infiltrations were found in 50 episodes. Pleural effusion was noticed in 60 episodes, and it was bilateral in three. No significant bacteriological findings were present.

Congenital dysgranulopoietic neutropenia in two siblings: clinical, ultrastructural, and in vitro bone marrow culture studies

Two siblings with congenital neutropenia are reported. The first patient, female, died after Pseudomonas sepsis. The second patient male, suffered from recurrent pyogenic infections, with a more benign course. Bone Marrow (BM) and Peripheral Blood (PB) analysis in the second patient revealed a reduced number of granules and myelin bodies in the PB neutrophils, suggesting a developmental defect of primary and secondary granules. BM promyelocytes were almost normal, but the myelocytes and metamyelocytes showed defective granulogenesis. The BM in vitro granulocyte-macrophage-colony-forming cell (GM-CFC) growth and the PB white blood cells (WBC) granulocyte-macrophage-colony-stimulating factor (GM-CSF) production, which were analyzed in the second patient, showed normal numbers of GM-CFC, with differentiation mostly toward monocytes and a defect in the GM-CSF production capacity. The second patient's PB mononuclear cells or serum did not inhibit normal GM-CFC when added to control BM cells. We suggest that in this specific form of congenital neutropenia, which is probably an autosomal recessive disorder, the abnormal neutrophil granule production and the defective provision of GM-CSF by PB WBC are unique pathognomonic characteristics, possibly associated with the overt neutropenia.