Combined transcriptomics and TMT-proteomics reveal abnormal complement and coagulation cascades in cow's milk protein allergy.

Cow's milk protein allergy (CMPA) is primarily due to the inability of the intestinal mucosa to establish typical immunological tolerance to proteins found in cow's milk, and the specific molecular mechanism is still unclear. In order to investigate molecular alterations in intestinal tissues during CMPA occurrence, this study analyzed the jejunal tissue of ß-lactoglobulin (BLG)-sensitized mice through transcriptomics and quantitative tandem mass tag (TMT)-labeled proteomics. A total of 475 differentially expressed genes (256 up-regulated, 219 down-regulated) and 94 differentially expressed proteins (65 up-regulated, 29 down-regulated) were identified. Comparing the KEGG pathways of the two groups, it was found that both were markedly enriched in the signaling pathways of complement and coagulation cascade. Among these, kallikrein B1 (KLKB1) in this pathway is speculated to be pivotal in CMPA. It may potentially enhance the release of bradykinin by activating the kallikrein-kinin system, leading to pro-inflammatory effects and exacerbating intestinal mucosal damage. This study suggests that the pathways of complement and coagulation cascades could be significant in the context of intestinal immunity in CMPA, and KLKB1 may be its potential therapeutic target.

Description of a Novel Pathogenic Variant in the ARPC1B and a Severe Allergy in Two Infants.

Actinrelated protein 2/3 complex subunit 1B (ARPC1B) deficiency is an inborn error of immunity (IEI) characterized by a combination of immunodeficiency and immune dysregulation and classified as an IEI with allergic manifestations. Here, we describe two patients with pathogenic variants in the ARPC1B gene. The first patient presented with eczema and bronchospasm at six months of age. The second patient presented with eczema and milk protein allergy at five months of age. The c.899_944 (p.Glu300Glyfs*7) pathogenic variant was previously described, whereas the c.863del (p.Pro288Leufs*9) variant was novel. ARPC1B deficiency should be considered because of the severe allergic manifestations at an early age.

Filaggrin loss-of-function mutations are associated with persistence of egg and milk allergy.

BACKGROUND: A genetic defect in the epidermal barrier protein filaggrin (FLG) plays a major role in the etiology of eczema and associated allergic airways diseases. However, it is still controversial to what extend loss-of-function (LOF) mutations in FLG contribute to the development and persistence of food allergies. OBJECTIVES: This study tested association of FLG LOF mutations with allergic reactions to diverse foods and investigated their potential effect on the persistence of early food allergies. METHODS: This study recruited 890 children with challenge-proven food allergy for the German Genetics of Food Allergy Study (GOFA). Longitudinal data were available for 684 children. All children were clinically characterized, including their allergic responses to specific foods, and genotyped for the 4 most common LOF mutations in FLG; R501X, 2282del4, R2447X, and S3247X. Associations between FLG mutations and food allergies were analyzed by logistic regression using the German Multicenter Allergy Study cohort as the control population. RESULTS: FLG mutations were associated with allergies to diverse foods including hen's egg (HE), cow's milk (CM), peanut, hazelnut, fish, soy, cashew, walnut, and sesame with similar risk estimates. Effects remained significant after adjusting for the eczema status. Interestingly, FLG mutations increased the risk of a persistent course of HE and CM allergy. CONCLUSIONS: Using the gold standard for food allergy diagnosis, this study demonstrates that FLG LOF mutations confer a risk of any food allergy independent of eczema. These mutations predispose to the persistence of HE and CM allergy and should be considered in the assessment of tolerance development.

Genetic susceptibility to cow's milk allergy in Chinese children.

BACKGROUND AND OBJECTIVES: Cow's milk allergy (CMA) is the most common food allergy in young children. Previous studies have reported that single-nucleotide polymorphisms (SNPs) are associated with CMA. The extent to which SNPs contribute to the occurrence of CMA is unknown. The purpose of this study was to investigate the independent relevance of genetic predisposition to CMA in Chinese children. METHODS AND STUDY DESIGN: 200 infants with CMA and 799 healthy controls aged 0-12 months were included. Five previously identified genetic variants (rs17616434, rs2069772, rs1800896, rs855791 and rs20541) were genotyped. Logistic regression was used to analyze the genetic associations or their interactions with a family history of allergy on CMA. RESULTS: Among the five SNPs, only IL10 rs1800896 was significantly associated with CMA (odds ratio (OR) 1.60, p=0.042). Each 1-risk allele increase in the genetic risk score (GRS) was suggestively associated with an 11% higher risk of CMA (1.11: 0.99-1.27, p=0.069) and a 45% increased risk of CMA in the GRS high-risk group compared to the GRS low-risk group (1.45: 1.02-2.06, p=0.037). Furthermore, parental allergy also increased the risk of CMA among children (1.87: 1.46-2.39, p<0.001). Importantly, parental allergy exacerbated the genetic effect on the risk of CMA. CONCLUSIONS: The rs1800896 variant in the IL-10 gene is associated with CMA in Chinese children. In addition, the GRS had an interaction with parental history of allergy, implying that genetic risk for CMA was exacerbated among those with parental history of allergy.

Effect of oral immunotherapy in children with milk allergy: The ORIMA study.

BACKGROUND: This study was aimed at evaluating the efficacy and safety of oral immunotherapy (OIT) in children with severe cow's milk allergy. METHODS: The subjects comprised 28 children (aged 3-12 years) with allergic symptoms that were induced by ≤ 10 mL of cow's milk in an oral food challenge test (OFC). The subjects were randomly allocated to the treatment group (n = 14) and control group (n = 14); the former received rush immunotherapy for 2 weeks, followed by a gradual increase of cow's milk volume to 100 mL for 1 year, and the latter completely eliminated cow's milk for 1 year. Both groups underwent an OFC with 100 mL of cow's milk after 1 year. RESULTS: The treatment group had significantly higher rates of a negative OFC [7/14 (50%) vs. 0/14 (0%), p < 0.01] compared with the control group. The cow's milk-specific IgE level significantly decreased in the treatment group (p < 0.01) but not in the control group (p = 0.63). During the study period, adrenaline was required in 6/14 patients (43%) of the treatment group and in 0/14 patients (0%) of the control group. Long follow-up data were available at the 2-year point after the study for 8 in the treatment group and 7 (87.5%) of these continued to ingest milk (>100 mL). CONCLUSIONS: The effect of immunotherapy was 50%, but the incidence of adverse events was not low. Further studies focusing on safety is necessary to standardize OIT for cow's milk allergy.

Analysis of altered miRNA profiling in the colon of a mouse model with Beta-lactoglobulin allergy

No disponible

Analysis of altered miRNA profiling in the colon of a mouse model with ß-lactoglobulin allergy.

OBJECTIVES: The differences in the expression profiles of colonic miRNAs between ß-lactoglobulin (ß-Lg) allergic mice and normal mice were analyzed to investigate the important role of the miRNA regulation mechanism in the pathogenesis of cow's milk allergy. METHODS: The present study performed Illumina sequencing to characterize the miRNA profile changes in mouse colon responding to ß-Lg challenge. Target genes were predicted by TargetScan 50 and miRanda 3.3a algorithms and assessed by GO and KEGG analysis. The expression levels of selected miRNAs and cytokine production were verified by cell transfection and quantitative RT-PCR. RESULTS: A total of 15 miRNAs were diversely expressed between the colon of the normal and ß-Lg-sensitized mice (P < 0.05, fold change of >1.50 or <0.67), including six up-regulated miRNAs and nine down-regulated miRNAs, among which seven miRNAs were validated using qRT-PCR. GO enrichment and KEGG pathway analyses further revealed that biological process, protein binding, cytoplasm and the pathways of cancer were significantly enriched, which were closely connected to the allergic inflammation development. Additionally, six key functional interaction pairs in ß-Lg allergy were identified in miRNA prediction algorithms and verified using qRT-PCR. CONCLUSIONS: We can conclude that our results suggested that the miRNAs regulation network participated in the pathogenesis of cow's milk allergy.

Decreased Histone Acetylation Levels at Th1 and Regulatory Loci after Induction of Food Allergy.

Immunoglobulin E (IgE)-mediated allergy against cow's milk protein fractions such as whey is one of the most common food-related allergic disorders of early childhood. Histone acetylation is an important epigenetic mechanism, shown to be involved in the pathogenesis of allergies. However, its role in food allergy remains unknown. IgE-mediated cow's milk allergy was successfully induced in a mouse model, as demonstrated by acute allergic symptoms, whey-specific IgE in serum, and the activation of mast cells upon a challenge with whey protein. The elicited allergic response coincided with reduced percentages of regulatory T (Treg) and T helper 17 (Th17) cells, matching decreased levels of H3 and/or H4 histone acetylation at pivotal Treg and Th17 loci, an epigenetic status favoring lower gene expression. In addition, histone acetylation levels at the crucial T helper 1 (Th1) loci were decreased, most probably preceding the expected reduction in Th1 cells after inducing an allergic response. No changes were observed for T helper 2 cells. However, increased histone acetylation levels, promoting gene expression, were observed at the signal transducer and activator of transcription 6 (Stat6) gene, a proallergic B cell locus, which was in line with the presence of whey-specific IgE. In conclusion, the observed histone acetylation changes are pathobiologically in line with the successful induction of cow's milk allergy, to which they might have also contributed mechanistically.

DL-propargylglycine administration inhibits TET2 and FOXP3 expression and alleviates symptoms of neonatal Cows' milk allergy in mouse model.

BACKGROUND: Cows' milk allergy (CMA) is a hypersensitivity immune reaction brought on by specific immunologic mechanisms to cow's milk proteins. As one of the most common food allergies in infants, the incidence of CMA during the first year of life is estimated to be nearly 7.5%. Due to the limitation in the knowledge of the pathological mechanism underlying CMA, however, the clinical interventions and therapies remain very unsatisfactory. AIM OF THE STUDY: The transcriptional factor FOXP3 possesses crucial roles in CMA, and increased FOXP3 mRNA expression has a predictive function in faster acquisition of tolerance in infants with CMA. But the exact mechanism remains not fully elucidated. METHODS: For PAG treatment, PAG (dissolved in saline 30 mg/mL, 0, 5, 10, 20 mg/kg BW) was administered daily intraperitoneally (ip) for one week at the time that 6 weeks after the CMP sensitisation. RESULTS: In the present study, we revealed that the expression of FOXP3 is significantly up-regulated in PBMCs from CMA patients and CMA mice on mRNA and protein level. Furthermore, a dramatic reduction in the FOXP3 TSDR methylation and a significant increase in the expression of TET2 are observed in CMA patients and CMA mice. More importantly, we found that propargylglycine (PAG) significantly alleviates symptoms of CMA in mice by suppressing the expression of FOXP3 through restoring TET2 expression. CONCLUSIONS: Our work revealed a novel function of PAG on CMA, which may provide a deeper insight into the pathomechanism of CMA and a novel therapy target for CMA clinical interventions.

Precision medicine in cow's milk allergy.

PURPOSE OF REVIEW: The aim of this review is to describe the role of precision medicine in the diagnosis, treatment, and monitoring of cow's milk allergy. RECENT FINDINGS: The development of 'omics' sciences in the field of food allergy has led to a better understanding of the allergenicity of cow's milk proteins and significant advances in the knowledge of the pathogenesis and mechanisms of cow's milk allergy. Omics-based technologies allow the practitioner to better differentiate cow's milk allergy subtypes and to predict cow's milk allergy (CMA) persistence over time. Precision medicine extends the role of the oral food challenge, to determine the individual's threshold doses, and to establish tolerance to baked milk products. Other than symptom relief, dietary strategies are currently being investigated for the potential to induce tolerance. Oral immunotherapy offers a treatment option for patients with severe and persistent IgE-mediated CMA. Individual baseline-immune profiles may be predictive of cow's milk oral immunotherapy safety and efficacy.Patient data derived from current technology, in combination with the patient's history, can be translated into treatments targeted at patient-tailored interventions. SUMMARY: The identification of novel biomarkers may improve diagnostic accuracy and also predict patient responsiveness to treatments. Integration of patient data will become increasingly important as omics technologies become more widely used in the clinical setting.

Role of FOXP3 expression and serum vitamin D and C concentrations when predicting acquisition of tolerance in infants with cow's milk allergy

BACKGROUND: Treg cells and dietetic factors may play a significant role in the natural acquisition of tolerance in children with cow's milk allergy (CMA). The best marker for Treg lymphocytes is the transcription factor forkhead boxP3 (FOXP3). OBJECTIVE: We examine the relationship between FOXP3 mRNA expression and serum concentrations of vitamins D and C and the development of different phenotypes of tolerance in children with CMA. MATERIAL AND METHODS: The study group comprised 138 infants with CMA and 101 healthy infants. All children underwent oral food challenge, first with an extensively heated milk product and then with unheated products. FOXP3 mRNA expression and serum vitamin C and D concentrations were evaluated. RESULTS: At 2 years of life, 54 children (39.1%) still had CMA, 43 (31.2%) were unheated milk-reactive and heated milk-tolerant, while 41 (29.7%) had outgrown their allergy. The mean (SD) level of FOXP3 expression in the study group was 2.07 (1.23), which was lower than the control group value of 2.98 (1.52) (P<.001). A value below 1.45 indicated allergy. The mean serum level of vitamin D in the study group was lower than in the control group (29.67 [7.09] vs 33.35 [4.13] ng/mL; P<.001). No significant differences were found in mean serum vitamin C content. CONCLUSIONS: Increased FOXP3 mRNA expression can predict faster acquisition of tolerance in infants with CMA. These children have lower serum vitamin D levels than healthy children. No relationship was found between the natural history of CMA and serum vitamin C concentration

ANTECEDENTES: Las células Treg y los factores dietéticos pueden desempeñar un papel importante en la adquisición natural de tolerancia en niños con alergia a la leche de vaca (CMA). El mejor marcador de linfocitos Treg es el factor de transcripción Forkhead box P3 (FOXP3). OBJETIVOS: El artículo examina la relación entre la expresión de mRNA específico para FOXP3 y la concentración sérica de vitaminas D y C, así como el desarrollo de diferentes fenotipos de tolerancia en niños con CMA. Material y métodos: El grupo de estudio estaba compuesto por 138 bebés con CMA y 101 sanos. Todos los niños tomaron primero un producto lácteo hervido vía oral, y posteriormente productos lácteos sin calentar. Se evaluó la expresión de ARNm para FOXP3 y la concentración sérica de vitamina C y D. RESULTADOS: A los dos años de vida, 54 (39,1%) de los niños aún mostraban CMA, 43 (31,2%) eran reactivos a la leche sin calentar y tolerantes a la leche caliente, mientras que 41 (29,7%) habían superado la alergia. El nivel medio de expresión de FOXP3 en el grupo CMA fue de 2,07 ± 1,23; inferior al obtenido en el grupo control de 2,98 ± 1,52 (p < 0,001). Un valor por debajo de 1,45 indica alergia. El nivel sérico medio de vitamina D en el grupo de estudio (29,67 ± 7,09 ng/ml) fue más bajo que en el grupo control, 33,35 ± 4,13 ng/ml (p < 0,001). No se encontraron diferencias significativas en el contenido medio de vitamina C en suero. CONCLUSIONES: El aumento de la expresión de FOXP3 mRNA puede predecir la adquisición de tolerancia más rápida en los bebés con CMA. Estos niños tienen niveles séricos más bajos de vitamina D que los niños sanos. No se encontró relación entre la historia natural de CMA y la concentración de vitamina C en suero

Trajectories of class-switching-related egg and cow's milk allergen-specific immunoglobulin isotype formation and its modification by eczema with low- and high-affinity immunoglobulin E during early infancy.

INTRODUCTION: Allergen-specific immunoglobulin isotype formation associated with immunoglobulin class-switching during the lactation period is the immunological background for food allergy in infants. We analyzed the serial changes in the production of feeding type-related egg- and milk-specific immunoglobulin isotypes from birth to 6 months of age with or without eczema in 84 infants. METHODS: Allergen-specific immunoglobulin G1 (IgG1), IgG2, IgG3, IgG4, IgA, and IgE levels of hen's egg and bovine milk were measured in cord blood and blood samples from infants at 2, 4, and 6 months of age by the densely carboxylated protein microarray. RESULTS: Formula and mixed feeding were associated with a rapid increase in cow's milk allergen-specific immunoglobulins and feeding type-related significant differences in casein-specific immunoglobulin levels were detected. Breast and mixed feeding were associated with slow but significant increase in ovalbumin-specific IgG1 and IgE levels, but not other immunoglobulins. We found two different immunoglobulin isotype formation at 6 months of age with low- or high-affinity IgE against ovalbumin. One isotype formation pattern had relatively high ovalbumin-specific IgG1 levels, detectable IgG2, and low-affinity IgE, while the other had low ovalbumin-specific IgG1 levels, undetectable IgG2, and high levels of high-affinity IgE. The incidence of eczema was significantly higher in the latter pattern (84.6%), compared with the remaining infants (42.2%). CONCLUSIONS: Feeding practice-related allergen sensitization and immunoglobulin isotype formation were identified during the lactation period. The development of eczema during the lactation period could potentially modify the immunoglobulin isotype formation with high levels of high-affinity IgE.

Randomized controlled trial on the influence of dietary intervention on epigenetic mechanisms in children with cow's milk allergy: the EPICMA study.

Epigenetic mechanisms could drive the disease course of cow's milk allergy (CMA) and formula choice could modulate these pathways. We compared the effect of two different dietary approaches on epigenetic mechanisms in CMA children. Randomized controlled trial on IgE-mediated CMA children receiving a 12-month treatment with extensively hydrolyzed casein formula containing the probiotic L.rhamnosus GG (EHCF + LGG) or with soy formula (SF). At the baseline, after 6 and 12 months of treatment FoxP3 methylation rate and its expression in CD4+ T cells were assessed. At same study points IL-4, IL-5, IL-10, and IFN-γ methylation rate, expression and serum concentration, miRNAs expression were also investigated. 20 children (10/group) were evaluated. Baseline demographic, clinical and epigenetic features were similar in the two study groups. At 6 and 12 months, EHCF + LGG group showed a significant increase in FoxP3 demethylation rate compared to SF group. At the same study points, EHCF + LGG group presented a higher increase in IL-4 and IL-5 and a higher reduction in IL-10 and IFN-γ DNA methylation rate compared to SF group. A different modulation of miR-155, -146a, -128 and -193a expression was observed in EHCF + LGG vs. SF. Dietary intervention could exert a different epigenetic modulation on the immune system in CMA children.

Higher Polygenetic Predisposition for Asthma in Cow's Milk Allergic Children.

Cow's milk allergy (CMA) is an early-onset allergy of which the underlying genetic factors remain largely undiscovered. CMA has been found to co-occur with other allergies and immunological hypersensitivity disorders, suggesting a shared genetic etiology. We aimed to (1) investigate and (2) validate whether CMA children carry a higher genetic susceptibility for other immunological hypersensitivity disorders using polygenic risk score analysis (PRS) and prospective phenotypic data. Twenty-two CMA patients of the Dutch EuroPrevall birth cohort study and 307 reference subjects were genotyped using single nucleotide polymorphism (SNP) array. Differentially genetic susceptibility was estimated using PRS, based on multiple P-value thresholds for SNP inclusion of previously reported genome-wide association studies (GWAS) on asthma, autism spectrum disorder, atopic dermatitis, inflammatory bowel disease and rheumatoid arthritis. These associations were validated with prospective data outcomes during a six-year follow-up in 19 patients. We observed robust and significantly higher PRSs of asthma in CMA children compared to the reference set. Association analyses using the prospective data indicated significant higher PRSs in former CMA patients suffering from asthma and related traits. Our results suggest a shared genetic etiology between CMA and asthma and a considerable predictive sensitivity potential for subsequent onset of asthma which indicates a potential use for early clinical asthma intervention programs.

[Association of FokI rs2228570 and TMPRSS6 rs855791 polymorphisms with cow's milk protein allergy in children].

OBJECTIVE: To study the association of polymorphisms of FokI rs2228570 in the vitamin D receptor (VDR) gene and TMPRSS6 rs855791 with cow's milk protein allergy (CMPA) in children. METHODS: Quantitative real-time PCR was used to analyze the single nucleotide polymorphisms of FokI rs2228570 in the VDR gene and TMPRSS6 rs855791 in 100 children with CMPA and 100 healthy children (control group). The multivariate logistic regression model was used to identify the risk factors for CMPA. RESULTS: There were significant differences in the frequencies of CC, CT, and TT genotypes of TMPRSS6 rs855791 between the CMPA and control groups (P=0.008), and the CMPA group had a significantly higher frequency of TT genotype. The multivariate logistic regression analysis showed that the children with TT genotype of rs855791 had an increased risk of CMPA (OR=3.473, P=0.011). However, there was no significant difference in the genotype distribution of FokI rs2228570 in the VDR gene between the two groups (P=0.686). CONCLUSIONS: TMPRSS6 rs855791 polymorphism is associated with CMPA in children, and TT genotype may be the susceptible genotype of CMPA. FokI rs2228570 polymorphism is not associated with CMPA.

Effect of Lactobacillus acidophilus KLDS 1.0738 on miRNA expression in in vitro and in vivo models of ß-lactoglobulin allergy.

This study aims to investigate the correlation between the ability of L. acidophilus to modulate miRNA expression and prevent Th17-dominated ß-lactoglobulin (ß-Lg) allergy. In vitro immunomodulation was evaluated by measuring splenocyte proliferation, Th17-related immune response and miRNA expression in ß-Lg-sensitized splenocytes cultured with live L. acidophilus. Next, the allergic mouse model was used to evaluate anti-allergy capability of lactobacilli. The ß-Lg challenge led to induction of up-regulation of miR-146a, miR-155, miR-21 and miR-9 expression in both in vivo and in vitro, along with increased Th17-related cytokine levels and mRNA expression of RORγt and IL-17. However, treatment of live L. acidophilus significantly suppressed hypersensitivity responses and Th17 cell differentiation. Moreover, administration of live L. acidophilus reduced expression of four miRNAs, especially miR-146a and miR-155. In addition, the decreased expression of the miRNAs in the spleen of the L. acidophilus-treated group was closely associated with decrease of IL-17 and RORγt mRNA expression.

Association of REL Polymorphism with Cow's Milk Proteins Allergy in Pediatric Algerian Population.

INTRODUCTION: Cow's milk proteins allergy (CMPA) pathogenesis involves complex immunological mechanisms with the participation of several cells and molecules involved in food allergy. The association of polymorphisms in the interleukin 4, Forkhead box P3 and the avian reticuloendotheliosis genes was investigated in an infant population with CMPA of Western Algeria. MATERIALS AND METHODS: We obtained DNA and clinical data from milk allergic subjects during active phase and from a group of non-atopic control subjects. RESULTS: Our findings showed that the allele G of the cRel gene intronic polymorphism at +7883 positions was significantly higher among cow's milk proteins allergic patients compared to control subjects. CONCLUSION: The results of this study suggest a possible association of CMPA with cRel G+7883T polymorphism.

Identificación de población de riesgo para alergia a la leche de vaca / Identification of population at risk for allergy to cow's milk

ANTECEDENTES: Los genotipos asociados con la alergia a la leche de vaca (ALV) son desconocidos. Aún no han podido ser replicados en poblaciones independientes, y podrían ser responsables de la marcada variabilidad de la respuesta clínica individual a las proteínas lácteas. OBJETIVO: Caracterizar haplogrupos, de la Región D-Loop del ADN mitocondrial, en un grupo de niños ALV, con el fin de arribar a un mejor conocimiento de la herencia biológica y genética en la etiología de la enfermedad. POBLACION Y METODO: Diseño: Análisis de mutaciones o variantes de la región D-loop del genoma mitocondrial. Población: 41 niños de ambos sexos de 0-2 años, 11 alérgicos ALV y 30 controles. (Río Cuarto, Córdoba, Argentina) Los pacientes ALV se dividieron, según la sintomatología que presentaban en 6 casos con Dermatitis Atópica (DA) + Enfermedad Gastrointestinal (EGI) y en 5 casos con Rinitis y Asma (RA). La Región D-Loop del genoma mitocondrial se amplificó por PCR. El análisis filogenético fue calculado usando el programa CLUSTAL OMEGA, the Neighbor-Joining, BLOSUM62, con los datos estudiados y grabados por Jukes-Cantor y luego con Kimura-2, programas específicos disponibles (software). RESULTADOS: Se encontró una mutación o variante nucleotídica no descripta T16519C en la transición de haplogrupos asociada a pacientes ALV con DA+EGI en 6/6 casos, comparados con 5/5 casos con RA que no la presentaron, mientras que en los controles se la observó solo en 6/30, p=0,0312; RR 2,900. CONCLUSIONES: Estos hallazgos sugieren que esta mutación probablemente aumente la posibilidad de padecer ALV asociada con DA+EGI. (AU)

BACKGROUND: Genotypes associated to cow's milk allergy (CMA) are unknown. They have not been replicated in independent populations, and could be responsible for the marked variability in individual clinical response to milk proteins. OBJECTIVE: To characterize haplogroups of the D-Loop region of mitochondrial DNA in a group of children allergic to cow's milk in order to arrive at a better understanding of biological and genetic heritability in the etiology of the disease. POPULATION AND METHOD: Design: Analysis of mutations or variants of the D-loop of mitochondrial genome region. Population: 41 children of both sexes from 0-2 years, 11 with CMA and 30 healthy subjects (controls). (Río Cuarto, Córdoba, Argentina). The CMA patients were divided according to the symptoms presenting in: 6 cases with Atopic Dermatitis (AD) + Gastrointestinal disease (GID) and in 5 cases with Rhinitis and Asthma (RA). The D-Loop Region of mitochondrial genome was amplified by PCR. Phylogenetic analysis was calculated using the program CLUSTAL OMEGA, the Neighbor-Joining, BLOSUM62, with studied and recorded by Jukes-Cantor data and then with Kimura-2, available specific programs (software). RESULTS: We found a non-descript mutation or variant nucleotide T16519C in the transition of haplogroups associated with CMA patients with AD+ GID in 6/6 cases, compared with 5/5 cases with RA that failed it, whereas in controls was observed it only in 6/30, p = 0, 0312 RR 2,900. CONCLUSIONS: These features suggest that this mutation probably increases the possibility of suffering CMA associated with AD + GID. (AU)