The genomic profiling of high-risk smoldering myeloma patients treated with an intensive strategy unveils potential markers of resistance and progression

Smoldering multiple myeloma (SMM) precedes multiple myeloma (MM). The risk of progression of SMM patients is not uniform, thus different progression-risk models have been developed, although they are mainly based on clinical parameters. Recently, genomic predictors of progression have been defined for untreated SMM. However, the usefulness of such markers in the context of clinical trials evaluating upfront treatment in high-risk SMM (HR SMM) has not been explored yet, precluding the identification of baseline genomic alterations leading to drug resistance. For this reason, we carried out next-generation sequencing and fluorescent in-situ hybridization studies on 57 HR and ultra-high risk (UHR) SMM patients treated in the phase II GEM-CESAR clinical trial (NCT02415413). DIS3, FAM46C, and FGFR3 mutations, as well as t(4;14) and 1q alterations, were enriched in HR SMM. TRAF3 mutations were specifically associated with UHR SMM but identified cases with improved outcomes. Importantly, novel potential predictors of treatment resistance were identified: NRAS mutations and the co-occurrence of t(4;14) plus FGFR3 mutations were associated with an increased risk of biological progression. In conclusion, we have carried out for the first time a molecular characterization of HR SMM patients treated with an intensive regimen, identifying genomic predictors of poor outcomes in this setting.

Efficacy of bortezomib to intensify the conditioning regimen and the graft-versus-host disease prophylaxis for high-risk myeloma patients undergoing transplantation

This multicenter phase I trial was designed to evaluate the safety and efficacy of bortezomib (Bz) as part of both the conditioning regimen and the graft-versus-host disease (GvHD) prophylaxis. Patients received fludarabine, melphalan and Bz (days -9 and -2). GVHD prophylaxis consisted of Bz (days +1, +4, and +7), sirolimus (Siro) from day -5 and tacrolimus (Tk) from -3 (except the first five patients that did not receive Tk). Twenty-five patients with poor prognostic multiple myeloma were included. Eleven out of the 19 patients had high-risk features. Out of the 21 patients evaluable at day +100, 14 were in CR (67%) and 7 (33%) in PR. Cumulative incidence (CI) of nonrelapse mortality at 1 year was 24%. CI of grades 2-4 and 3-4 acute GvHD was 35% and 10%, respectively; CI of chronic GvHD was 35% and 55% at 1 and 2 years, respectively. Overall and event free survival at 2 years were 64% and 31%, respectively. Bz as part of the conditioning regimen and in the combination with Siro/tacrolimus for GvHD prophylaxis is safe and effective allowing an optimal disease control early after transplant and reducing the risk of GvHD.

Next generation flow for minimally-invasive blood characterization of MGUS and multiple myeloma at diagnosis based on circulating tumor plasma cells (CTPC)

Here, we investigated for the first time the frequency and number of circulating tumor plasma cells (CTPC) in peripheral blood (PB) of newly diagnosed patients with localized and systemic plasma cell neoplasms (PCN) using next-generation flow cytometry (NGF) and correlated our findings with the distinct diagnostic and prognostic categories of the disease. Overall, 508 samples from 264 newly diagnosed PCN patients, were studied. CTPC were detected in PB of all active multiple myeloma (MM; 100%), and smoldering MM (SMM) patients (100%), and in more than half (59%) monoclonal gammopathy of undetermined significance (MGUS) cases (p <0.0001); in contrast, CTPC were present in a small fraction of solitary plasmacytoma patients (18%). Higher numbers of CTPC in PB were associated with higher levels of BM infiltration and more adverse prognostic features, together with shorter time to progression from MGUS to MM (p <0.0001) and a shorter survival in MM patients with active disease requiring treatment (p ≤ 0.03). In summary, the presence of CTPC in PB as assessed by NGF at diagnosis, emerges as a hallmark of disseminated PCN, higher numbers of PB CTPC being strongly associated with a malignant disease behavior and a poorer outcome of both MGUS and MM.

Genomic sequences of HLA-A*68:169, HLA-B*07:298 and HLA-B*39:129

Three new HLA class I alleles were described in the Spanish population. HLA-A*68:169 and -B*39:129 show one amino acid replacement at the α1-domain, compared to A*68:02 (P47 > L47) and -B*39:06 (S11 > A11), respectively. HLA-B*07:298 presents one nucleotide mutation within exon 1, resulting in a new amino acid position -14, L>Q, which has not been previously described in any HLA protein. Prediction of the B*07:298 signal peptide cleavage did not show significant differences in comparison with that obtained for the rest of HLA-B genes.

Prognostic value of antigen expression in multiple myeloma: a PETHEMA/GEM study on 1265 patients enrolled in four consecutive clinical trials

Persistence of minimal residual disease (MRD) after treatment for myeloma predicts inferior outcomes, but within MRD-positive patients there is great heterogeneity with both early and very late relapses. Among different MRD techniques, flow cytometry provides additional information about antigen expression on tumor cells, which could potentially contribute to stratify MRD-positive patients. We investigated the prognostic value of those antigens required to monitor MRD in 1265 newly diagnosed patients enrolled in the GEM2000, GEM2005MENOS65, GEM2005MAS65 and GEM2010MAS65 protocols. Overall, CD19^pos, CD27^neg, CD38^lo, CD45^pos, CD81^pos, CD117^neg and CD138^lo expression predicted inferior outcomes. Through principal component analysis, we found that simultaneous CD38^lowCD81^posCD117^neg expression emerged as the most powerful combination with independent prognostic value for progression-free survival (HR:1.69; P=0.002). This unique phenotypic profile retained prognostic value among MRD-positive patients. We then used next-generation flow to determine antigen stability throughout the course of the disease, and found that the expression of antigens required to monitor MRD is mostly stable from diagnosis to MRD stages, except for CD81 whose expression progressively increased from baseline to chemoresistant tumor cells (14 vs 28%). Altogether, we showed that the phenotypic profile of tumor cells provides additional prognostic information, and could be used to further predict risk of relapse among MRD-positive patients.

Next Generation Flow for highly sensitive and standardized detection of minimal residual disease in multiple myeloma

Flow cytometry has become a highly valuable method to monitor minimal residual disease (MRD) and evaluate the depth of complete response (CR) in bone marrow (BM) of multiple myeloma (MM) after therapy. However, current flow-MRD has lower sensitivity than molecular methods and lacks standardization. Here we report on a novel next generation flow (NGF) approach for highly sensitive and standardized MRD detection in MM. An optimized 2-tube 8-color antibody panel was constructed in five cycles of design-evaluation-redesign. In addition, a bulk-lysis procedure was established for acquisition of ⩾10⁷ cells/sample, and novel software tools were constructed for automatic plasma cell gating. Multicenter evaluation of 110 follow-up BM from MM patients in very good partial response (VGPR) or CR showed a higher sensitivity for NGF-MRD vs conventional 8-color flow-MRD -MRD-positive rate of 47 vs 34% (P=0.003)-. Thus, 25% of patients classified as MRD-negative by conventional 8-color flow were MRD-positive by NGF, translating into a significantly longer progression-free survival for MRD-negative vs MRD-positive CR patients by NGF (75% progression-free survival not reached vs 7 months; P=0.02). This study establishes EuroFlow-based NGF as a highly sensitive, fully standardized approach for MRD detection in MM which overcomes the major limitations of conventional flow-MRD methods and is ready for implementation in routine diagnostics.

Bence Jones proteinuria in smoldering multiple myeloma as a predictor marker of progression to symptomatic multiple myeloma

The diagnosis of smoldering multiple myeloma (SMM) includes patients with a heterogeneous risk of progression to active multiple myeloma (MM): some patients will never progress, whereas others will have a high risk of progression within the first 2 years. Therefore, it is important to improve risk assessment at diagnosis. We conducted a retrospective study in a large cohort of SMM patients, in order to investigate the role of Bence Jones (BJ) proteinuria at diagnosis in the progression to active MM. We found that SMM patients presenting with BJ proteinuria had a significantly shorter median time to progression (TTP) to MM compared with patients without BJ proteinuria (22 vs 88 months, respectively; hazard ratio=2.3, 95% confidence interval=1.4-3.9, P=0.002). We also identified risk subgroups based on the amount of BJ proteinuria: ⩾500 mg/24 h, <500 mg/24 h and without it, with a significantly different median TTP (13, 37 and 88 months, P<0.001). Thus, BJ proteinuria at diagnosis is an independent variable of progression to MM that identifies a subgroup of high-risk SMM patients (51% risk of progression at 2 years) and ⩾500 mg of BJ proteinuria may allow, if validated in another series, to reclassify these patients to MM requiring therapy before the end-organ damage development.

Frequency of HLA-A, -B and -DRB1 specificities and haplotypic associations in the population of Castilla y León (northwest-central Spain)

The frequencies of human leukocyte antigen (HLA) class I and class II specificities and haplotypic associations were determined in 1940 unrelated donors from Castilla y León and compared with other Iberian, Mediterranean and European populations. Specificities were determined using polymerase chain reaction reverse sequence-specific oligonucleotide or polymerase chain reaction sequence-specific primer techniques. In the analysis, 19, 29 and 13 specificities were found for HLA-A, -B and -DRB1, respectively, with HLA-A*02 (26%), -A*01 (11%), -B*44 (16%), -B*35 (10%), -DRB1*07 (16%) and -DRB1*13 (14%) showing the highest frequencies. In addition, 10 common HLA-A-B-DRB1 haplotypic associations were observed, A*01-B*08-DRB1*03 (3%) and A*29-B*44-DRB1*07 (3%) being the most frequent ones. These findings indicate that the population of Castilla y León is genetically equidistant from the Portuguese and other Spanish populations and shares a common origin with other Iberian populations, in which European, Mediterranean and North African genetic components are present; this is in agreement with the historical and genetic background of the population. These data contribute to a better understanding of the genetic structure of the Iberian Peninsula and provide a healthy control population from our region that should be useful for the study of disease associations.

High-dose chemotherapy and auto-SCT in elderly patients with Hodgkin's lymphoma

Our purpose was to assess efficacy and toxicity of high-dose chemotherapy (HDCT) and ASCT in patients with relapsed and refractory Hodgkin's lymphoma (HL) aged 60 years and older and compare the results with a group of younger HL patients treated in a similar manner. We identified 15 consecutive patients, with HL aged 60 years and older who underwent HDCT (etoposide 60 mg/kg+ melphalan 160 mg/m(2)) and ASCT at our institution from May 2001 to March 2008. The results were compared with a cohort of 157 younger HL patients treated in a similar manner from January 1999 to December 2006. After a median follow-up of 2.5 years, PFS at 3 years after ASCT was 73% (95% confidence interval (CI) 37-90) for the older group and 56% (95% CI 46-64) for the younger group (P=0.45); OS after ASCT was 88% (95% CI 39-98) for the older group and 84% (95% CI 75-90) for the younger group (P=0.80). No transplant-related deaths were seen. Our study suggests that ASCT is feasible for selected elderly patients with HL, giving similar results to younger patients in terms of survival and toxicity.

Monoclonal free light chains can be found in heavy chain diseases

Heavy chain diseases (HCDs) are rare B-cell lymphoproliferative neoplasias characterized by the production of a monoclonal component consisting of a truncated monoclonal Ig heavy chain without the associated light chain. Among them, patients with gamma-HCD are so rare that no more than 150 cases can be found in the literature. In this paper, we report one additional case: an 83-year-old man with a gamma-HCD, in whom a kappa light chain component was detected in the serum by using the serum free light-chain assessment and in addition monoclonal kappa cytoplasmic expression was detected in bone marrow plasma cells by flow cytometric analysis. In the work-up of the patient, the underlying anatomopathological lymphoproliferative disease corresponded to a lymphoplasmacytic lymphoma, as it is stated in the current World Health Organization classification (2008), with both lymphadenopathic and bone marrow infiltration. As in other cases, several autoimmune manifestations (antiphospholipidic syndrome and immune thrombocytopenia) were present during the course of the disease in this patient. This case report illustrates a new case of gamma-HCD, in which serum free light-chain analysis and flow cytometry represented a valuable tool for diagnosis, a finding that could be very important for the future management of these patients.

Antigens of the major histocompatibility system in ischemic heart disease and idiopathic dilated cardiomyopathy

BACKGROUND

Although dilated cardiomyopathy (DCM) is a disease of unknown and probably multifactorial etiology, a change in immune mechanisms is presumably significant, with many abnormalities in humoral and cellular responses having been reported. The heart thus becomes the target organ for an initial episode of myocardial damage that triggers an autoimmune response.

HYPOTHESIS

The purpose of this study was to analyze the frequency of different human leukocyte antigens in patients with a diagnosis of well-advanced DCM and ischemic heart failure, comparing them with a control group of presumably healthy subjects.

METHODS

The group with dilated cardiomyopathy consisted of 50 patients (7 women and 43 men), aged from 14 to 64 years. The group with ischemic heart disease included 76 patients (4 women and 72 men), with ages ranging from 34 to 64. The control group, consisting of 1,337 presumably healthy subjects from the Spanish Mediterranean area, was recruited based on paternity studies.

RESULTS

Compared with the control group, we found in DCM a greater incidence of B15 (20 vs. 6%) and DQ3 (83 vs. 50%) antigens. In ischemic heart disease we found a lower incidence of A1 (3 vs. 22%), B8 (5 vs. 12%), and DQ2 (16 vs. 50%) in comparison with the control group.

CONCLUSIONS

In the Spanish Mediterranean area, the presence of antigens B-15 and DQ3 would be associated with advanced DCM. The absence of antigens A1, B8, and DQ2 would be associated with the occurrence of severe ischemic heart disease.

Autoimmune hemolytic anemia following allogeneic hematopoietic stem cell transplantation in adult patients

Autoimmune hemolytic anemia (AIHA) after allogeneic hematopoietic stem cell transplantation (HSCT) is still not well characterized. The aim of this study was to analyze the incidence and risk factors for the development of AIHA, as well as its prognosis and response to treatment in a series of patients undergoing allogeneic HSCT at a single institution. Between 1996 and 2004, 272 adult patients with a variety of malignant hematopoietic disorders underwent allogeneic HSCT. Direct antiglobulin testing was performed in routine pretransfusion compatibility testing or after clinical suspicion of AIHA. Twelve patients developed AIHA after HSCT at a median time of 147 days (range, 41-170). The 3-year cumulative incidence of AIHA was 4.44%. Eight cold antibodies and four warm antibodies were detected. Multivariate analysis shows that HSCT from unrelated donors (P=0.02) and the development of chronic extensive graft-versus-host disease (GVHD) (P=0.0004) were the only independent factors associated with AIHA. Two patients are still alive. AIHA was never the primary cause of death but added morbidity in patients with other concomitant complications. Patients undergoing HSCT from unrelated donors and those who develop chronic extensive GVHD are especially predisposed for this complication.

[Stress, hemodynamic and immunological responses to inhaled and intravenous anesthetic techniques for video-assisted laparoscopic cholecystectomy]

OBJECTIVE

Given the immunomodulatory effects of anesthesia and surgery, 2 anesthetic regimens in clinical use were compared to evaluate hemodynamic, stress, and immunologic response in patients undergoing laparoscopic cholecystectomy.

PATIENTS AND METHODS

Randomized controlled trial in patients classified ASA I and scheduled for laparoscopic cholecystectomy. Patients were randomly assigned to the inhaled anesthetic group (13 anesthetized with propofol-fentanyl-isoflurane) or the total intravenous anesthesia (TIVA) group (14 patients anesthetized with propofol-remifentanil). Patients in both groups received the muscle relaxant vecuronium. We assessed hemodynamic variables, cortisol levels, prolactin, interleukin 6, white cell and lymphocyte counts before, during (1 hour after induction) and after (24 hours and 7 days) surgery.

RESULTS

Hemodynamic variables were stable in both groups. Significant changes in prolactin levels and markers of immune and inflammatory responses between baseline and later measurements occurred in both groups. Patients who received TIVA had no change in cortisol levels at any time during the study. The TIVA group had lower levels of cortisol than did the inhaled anesthesia group (TIVA, 207 [SD, 100] ng/mL; inhaled 293 [97] ng/mL; P<0.05)), higher neutrophil counts (TIVA, 75 [12.5]%; inhaled: 62 [20]%; P<0.05) and higher CD4+ T lymphocyte counts (TIVA, 53 [11.6]%; inhaled: 42 [17.6]%; P<0.001).

CONCLUSION

Although both techniques afford hemodynamic stability, lower cortisol levels were observed with the application of TIVA with propofol-remifentanil. That would be the technique of choice for patients with compromised immune response.

HLA antigens and anti-neutrophil cytoplasmic antibodies (ANCA) in inflammatory bowel disease

HYPOTHESIS AND OBJECTIVES

the hypothesis of this study is that genes involved in the regulation of the immune system, expressed by HLA antigens and anti-neutrophil cytoplasmic antibodies (ANCA), could be determinants of disease susceptibility and behavior in inflammatory bowel disease (IBD).

MATERIAL AND METHOD

seventy patients with a diagnosis of inflammatory bowel disease, 46 with ulcerative colitis and 24 with Crohn"s disease were included. HLA class I (A and B) and II (DR) antigens were studied by serological techniques. Detection of ANCA was carried out in all patients by an indirect immunofluorescence method. The relative frequencies of HLA antigens were compared with a control group made up of 156 blood donors. The control group for the ANCA study was made up of 100 individuals.

RESULTS

we found a significant increased frequency of HLA-DR2 in patients with ulcerative colitis. No significant differences were found between patients with Crohn"s disease and controls regarding HLA typing. We detected a significant increase of HLA-DR3 in extensive forms of ulcerative colitis. Detection of ANCA was positive in 46% of the patients with ulcerative colitis and in 12% of the patients with Crohn"s disease (p <0.05). We observed an increased frequency of ANCA in patients with UC and HLA-DR2 (p = 0.15).

CONCLUSIONS

the association found between HLA-DR3 and extensive forms of ulcerative colitis provides evidence of genetic heterogeneity. The relationship between ANCA and HLA phenotype (although not significant) supports this concept.

Glutamate N-methyl-d-aspartate receptor blockade prevents induction of GAP-43 after focal ischemia in rats

Growth associated protein-43 (GAP-43) gene induction may be involved in reactive events that follow cerebral ischemic damage. Antagonists of the N-methyl-D-aspartate (NMDA) subclass of glutamate receptors are thought to ameliorate functional outcome after ischemic injury. To assess whether glutamate NMDA receptor blockade could alter GAP-43 postischemic induction we performed immunocytochemistry in rat brains that had been subjected to middle cerebral artery occlusion. Cortical cells did not constitutively express GAP-43, yet focal ischemia induced its expression, with an intense signal generated in cells over the lesioned area at 6 h, increasing at 24 h postischemia. This signal was effectively decreased by pretreatment with the NMDA receptor antagonist (5R,10S)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine hydrogen maleate (0.1 mg/kg s.c.), but not by the glutamate release blocker riluzole (8 mg/kg i.v.), suggesting that overactivation of NMDA receptor during ischemia is linked to GAP-43 expression.

Serum amino acid levels after permanent middle cerebral artery occlusion in the rat

BACKGROUND AND PURPOSE

High levels of glutamate in plasma and cerebrospinal fluid (CSF) have been demonstrated in patients with acute ischemic stroke. Whereas this glutamate increase in CSF is only evidenced during the first 6 h in stable ischemic stroke, it is sustained for 24 h in progressing stroke. The aim of this investigation was to study the evolution of serum glutamate levels after stroke in a rat model of permanent cerebral artery occlusion.

METHODS

Glutamate, glycine, aspartate, taurine and tryptophan were measured by high-performance liquid chromatography from serum samples taken before and at different times after permanent middle cerebral artery occlusion (MCAO) and from sham-operated rats.

RESULTS

After MCAO, a 3-fold increase in glutamate and a 2-fold increase in glycine and aspartate were observed in rat serum. The onset of this amino acid increase began 4-6 h after ischemic induction, reached peak values at 8-24 h and returned to preischemic values by 48-72 h. Serum concentrations of taurine and tryptophan were not modified after MCAO. Sham-operated rats did not exhibit changes of basal amino acid concentrations in serum.

CONCLUSIONS

The serum excitatory amino acid profile in this experimental model confirms that the early detection of increased concentrations of glutamate and glycine at systemic circulation observed in patients with acute stroke is a consequence of the cerebral ischemic process.

HLA-DQA, -DQB and -DRB allele contribution to narcolepsy susceptibility

The association of narcolepsy with HLA class I antigens and HLA class II alleles was studies in a series of Spanish narcoleptic patients. The haplotype DRB1*1501-DRB5*0101-DQA1*0102-DQB1*0602 was found to be significantly associated with the disease, while the haplotype DRB1*0701-DRB4*01-DQA1*0201-DQB1*02 might confer a slight protective effect against narcolepsy. Gene dose-effect was not seen in any of the involved alleles, and linkage disequilibrium between the positively associated alleles was found to be stronger in patients than in controls. Statistical analysis applied to identify the HLA allele truly responsible for the association did not clearly discriminate between the contribution of DRB1*1501 and that of DQB1*0602, but it proved that the association with DQA1*0102 is secondary to that with DRB1*1501/DQB1*0602. Analysis of the diagnostic value of typing for the narcolepsy-associated alleles demonstrated a very high negative predictive value and revealed that this test can be convenient for exclusion of narcolepsy in cases when the diagnosis is not evident after clinical evaluation and the marker haplotype is absent. Finally, a family study indicated that narcolepsy is a multifactorial disorder that involves HLA genes under an incomplete penetrance model, with possible influences from environmental factors or other genes different to HLA genes.

A monolayer coagglutination microplate technique for typing red blood cells

BACKGROUND AND OBJECTIVES

Serologic agglutination tests have the disadvantage of lack of an objective endpoint that can be easily read and quantitated. We have developed a new method for ABO and Rh typing based on producing a red blood cell (RBC) monolayer on microplates and the mixed hemagglutination reaction.

MATERIALS AND METHODS

We have employed a new red cell fixation buffer to prepare the RBC monolayer. As the technique for grouping, we used a mixed agglutination reaction between the RBC monolayer and the RBCs to be typed.

RESULTS

Compared with an automated hemagglutination system in 34,519 samples, the method is shown to be more sensitive, free of false positive reactions, and cost-effective.

CONCLUSIONS

The microplate coagglutination method is accurate and lower in cost than conventional methods.

A new, fast, and simple DNA extraction method for HLA and VNTR genotyping by PCR amplification

In the present study a new DNA extraction method is described. The new protocol, which uses caprylic acid for isolating DNA, is technically simple and very fast, as it enables us to obtain DNA from peripheral blood in only 10 minutes. Moreover, DNA preparations obtained with this procedure can be effectively used for HLA class II and variable number tandem repeat genotyping by polymerase chain reaction, so the new method is well suited for routine clinical use in any type of analysis requiring DNA typing for individual characterization.

[The incidence of major histocompatibility system antigens in dilated and ischemic myocardiopathies]

AIM

The purpose of this study was to analyze the frequency of the different antigens of HLA in patients with diagnosis of very advanced dilated cardiomyopathy and ischemic heart disease by comparing them with a control group of supposedly healthy subjects.

MATERIAL AND METHOD

The group of dilated cardiomyopathy consisted of 35 patients (8 women and 27 men) aged between 14 and 60 years. The group of ischemic heart disease included 32 patients (4 women and 28 men) aged between 34 and 64 years. The control group comprised 1337 subjects of the Spanish Mediterranean area, supposedly healthy and recruited from paternity studies.

RESULTS

In dilated cardiomyopathy we found a higher incidence in comparison with the control group of the A-2 (62.86% vs 46.22%), B-12 (60.00% vs 32.38%) and DQ-3 (82.86 vs 49.96%) antigens, and a lower incidence of B-51 (0.00% vs 12.49%). In ischemic heart disease we found, when comparing to the control group, a higher incidence of A-11 (31.25% vs 13.08%) and A-29 (34.38% vs 14.58%) antigens and a lower incidence of DQ-2 (15.63% vs 49.88%).

CONCLUSIONS

In the Spanish Mediterranean area, the presence of A-2, B-12 and DQ-3 antigens, as well as the absence of B-51 would favour the appearance of advanced dilated cardiomyopathy. The presence of the A-11 and A-29 antigens would predispose to ischemic cardiomyopathy while the presence of DQ-2 would have a protective effect on the appearance of this cardiopathy.

Isoimmune neonatal neutropenia caused by Fc gamma RIIIb antibodies in a Spanish child

BACKGROUND

Fc gamma RIIIb deficiency is a rare defect in which neutrophils do not express Fc gamma RIIIb and therefore the individuals with this defect have an NA null phenotype. Soluble Fc gamma RIII in plasma is severely decreased and almost undetectable. During pregnancy, Fc gamma RIIIb deficiency may cause the formation of maternal Fc gamma RIIIb antibodies, which leads to an isoimmune neonatal neutropenia. The first known case of isoimmune neonatal neutropenia caused by these antibodies in a Spanish child was identified.

CASE REPORT

A newborn infant was severely affected by omphalitis; analysis of his blood showed an absolute neutropenia, but he responded well on intravenous immunoglobulin therapy. The maternal antiserum reacted strongly with all tested Fc gamma RIIIb-positive neutrophils. A family study showed that the infant's mother, one of the mother's sisters, and her mother were Fc gamma RIIIb deficient. No neutrophil antibodies were found in the plasma from these other Fc gamma RIIIb-negative women, although both had had numerous pregnancies. The three women were healthy, but one had recurrent otitis. DNA analysis of the family showed the absence of both Fc gamma RIIIB genes in the three Fc gamma RIIIb-negative women. The father of the child and all the children of the Fc gamma RIIIB gene-deficient women were shown to lack one of the Fc gamma RIIIB genes.

CONCLUSION

A new case of isoimmune neonatal neutropenia caused by anti-Fc gamma RIIIb is identified. The family study indicates that the Fc gamma RIIIb deficiency is a hereditary genetic defect. In accordance with the location of Fc gamma RIIIB on chromosome 1, an autosomal pattern of inheritance of the Fc gamma RIIIB-deficient allele was observed.

[Alloimmune neonatal neutropenia: flow cytometry study of the 1st patient described in Spain with identification of an anti-NA1]

A strong antibody was found in a mother (first pregnancy) who had a severe neutropenic baby. The father's granulocytes were typed by flow cytometry as NA1+, NA2+, NB1+, ND1+ and the mother as NA1-, NA2+, NB1+ and ND1+. The antibody was identified as anti-NA1 by us, and confirmed later by a reference laboratory. The serum reacted with 54.8% of the 31 donors tested. The same antibody was found in the child's serum 35 days after birth, and the reactivity was stronger than in the mother's serum. The HLA-DR, DQ from the mother was DR3, DR7; DR52, DR53; DQ2. The baby's granulocytes were recovered slowly over a four-month period, but the course was benign without any specific treatment. Five months after birth, with recovery, the child's serum became negative and his granulocytes were confirmed as NA1+. Due to the difficulties in fully diagnosing and working with granulocytes we suspect that there are undetected cases; only one case has been recorded in Spain before.