Sunflower (Helianthus annuus) Seed Allergy.

BACKGROUND AND OBJECTIVE: Sunflower seed is one of the most common edible seeds and its consumption is growing. Case reports of sunflower seed allergy have been described since the 1970s. However, there are few data on the prevalence and clinical manifestations of sunflower seed allergy. To improve understanding of sunflower seed allergy. METHODS: We evaluated the clinical and immunological features of patients with sunflower seed allergy diagnosed in the Allergy Department of a tertiary hospital in Madrid over a 5-years period. RESULTS: Forty-seven patients reported adverse reactions after ingestion of sunflower seed and had specific sensitization to sunflower seed determined by skin prick test (median 8 mm) or specific IgE (median 1.10 kUA/L). Most had an adult-onset reaction to sunflower seed preceded by a history of atopy and other food allergies, predominantly to peach, peanut and nuts. Clinical presentation of sunflower seed allergy ranged from mild to severe, with a high proportion of patients suffering severe reactions, often undertreated. A variability in the severity of symptoms was seen on repeated exposures to sunflower seed on a same patient. Levels of sunflower seed IgE were strongly correlated with levels of IgE to non-specific lipid transfer proteins, while no significant differences were found in the severity of the reactions according to sensitization to those proteins. CONCLUSION: Our findings reveal a variability of clinical presentations of sunflower seed allergy on repeated exposures and an underuse of epinephrine in anaphylaxis. We highlight the importance of strict avoidance of sunflower seed and accurate prescription and administration of epinephrine in allergic patients.

Hypersensitivity Reactions to Cancer Chemotherapy: Practical Recommendations of ARADyAL for Diagnosis and Desensitization.

Rapid drug desensitization has enabled first-line therapies in patients with drug hypersensitivity reactions to chemotherapeutic drugs including monoclonal antibodies. Desensitization is a safe and highly effective procedure, not only for IgE-mediated reactions, but also for those mediated by non-IgE mechanisms. The likelihood of breakthrough reactions during desensitization is low, and most are mild; in fact, moderate-to-severe reactions are infrequent. In this document, 16 allergy departments belonging to the Spanish research network ARADyAL present a review of the available scientific evidence and provide general guidelines for the diagnosis and management of drug hypersensitivity reactions to chemotherapeutic drugs and monoclonal antibodies. Emphasis is placed on the desensitization procedure.

IgE-Mediated Sensitization to Galactose-α-1,3- Galactose (α-Gal) in Urticaria and Anaphylaxis in Spain: Geographical Variations and Risk Factors.

BACKGROUND: The objectives of this study were to investigate the prevalence of sIgE to galactose-α-1,3-galactose (α-gal) in individuals with acute urticaria or anaphylaxis from different geographical areas of Spain and to evaluate the relevance of demographics and lifestyle as risk factors for this immune response. METHODS: Participants were recruited from allergy departments at 14 Spanish hospitals. Patients aged 18 years or older presenting with urticaria or anaphylaxis were enrolled into one of 2 arms: cases and controls. An interviewer-administered questionnaire collecting demographic data, lifestyle habits, and the presence of cofactors was obtained from each participant. sIgE to α-gal and total IgE were determined using ImmunoCAP. sIgE levels ≥0.35 kU/L were considered a positive result. RESULTS: The study population comprised 160 cases and 126 controls. The median age was 44 years. The overall prevalence of a positive result of sIgE to α-gal was 15.7%; this was higher in cases (26.3%) than in controls (2.4%). The sIgE anti-α-gal positivity rate ranged from 37.68% (rural) to 15.38% (semiurban), and 7.85% (urban). The rates of positivity were 46.32%, (Northern), 0.72% (Center), and 0% (Mediterranean). A positive result for sIgE to α-gal was associated with a history of tick bites, participation in outdoor activities, pet ownership, and ingestion of mammalian meats or innards before the onset of symptoms. Only alcohol consumption could be implicated as a cofactor. CONCLUSION: Sensitization to α-gal in patients with urticaria or anaphylaxis differs considerably between the 3 geographical areas studied and is related to tick bites.

Validation of the Spanish Version of the Food Allergy Quality of Life Questionnaire-Parent Form (S-FAQLQ-PF).

BACKGROUND: Food allergy is an emerging health problem. Several questionnaires can be used to establish health-related quality of life (HRQOL) in food allergy patients. Current questionnaires should be translated in such a way that they take account of the culture of the country in which they are to be used. Objective: To translate and perform a cross-sectional validation of the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF). METHODS: The parents of 54 children diagnosed with food allergy were recruited to assess the Spanish version of the FAQLQ-PF (S-FQLQ-PF). RESULTS: The S-FQLQ-PF was translated into Spanish according to WHO guidelines (including a forward-backward translation). The statistical analysis showed that feasibility, reliability, and internal consistency were very good for the global S-FAQLQ-PF score and for the different domains. Assessment of construct validity indicated that S-FAQLQ-PF has reduced capacity for measurement of HRQOL in younger children. Cross-sectional validation of the S-FAQLQ-PF demonstrated that HRQOL of a Spanish pediatric population was affected by patient age, severity of symptoms, and number of reactions. HRQOL was not affected by sex, food implicated, number of foods implicated, ingestion of the implicated food, or presence of anaphylaxis. CONCLUSIONS: Translation into Spanish and cultural validation of the FAQLQ-PF demonstrated the influence of factors, such as patient age, severity of symptoms, and number of reactions on the HRQOL of a pediatric Spanish population.

Virulence Characterization and Identification of Maize Lines Resistant to Puccinia sorghi Schwein. Present in the Argentine Corn Belt Region.

Puccinia sorghi Schwein., the causal agent of maize common rust, is an endemic disease in the Argentine Corn Belt region. Virulence surveys of the pathogen population within the region have not been performed; thus, the understanding of the pathogen population is low and it is difficult to deploy resistance genes that could be effective at controlling the disease. In total, 58 single-uredinial isolates derived from infected maize leaves collected in different locations throughout the Argentine Corn Belt region during 2010 to 2012 were tested on a set of 25 maize lines carrying different Rp genes. Maize lines Rp3-A and PIO19802 showed the lowest virulence frequencies (3.4 and 1.7%, respectively) for all tested isolates. Moreover, the combination in a single genotype of the resistance genes carried by lines Rp3-A and PIO19802 or either of these lines combined with the resistance genes from PIO12345 would confer resistance to all isolates tested. Virulent isolates on maize lines Rp-G, Rp1-K, and Rp-GI were most frequent in 2012. Twenty-four virulence phenotypes were identified, with phenotypes TCCG (17.2%), TTBB (15.5%), and TCFG (10.3%) being the most common throughout the region. Adult plant resistance associated with hypersensitive response was identified at vegetative stage 6 in maize lines PIO68752, PIO28427, and PIO36420.

Renal function improvement in liver transplant recipients after early everolimus conversion: A clinical practice cohort study in Spain.

A national, multicenter, retrospective study was conducted to assess the results obtained for liver transplant recipients with conversion to everolimus in daily practice. The study included 477 recipients (481 transplantations). Indications for conversion to everolimus were renal dysfunction (32.6% of cases), hepatocellular carcinoma (HCC; 30.2%; prophylactic treatment for 68.9%), and de novo malignancy (29.7%). The median time from transplantation to conversion to everolimus was 68.7 months for de novo malignancy, 23.8 months for renal dysfunction, and 7.1 months for HCC and other indications. During the first year of treatment, mean everolimus trough levels were 5.4 (standard deviation [SD], 2.7) ng/mL and doses remained stable (1.5 mg/day) from the first month after conversion. An everolimus monotherapy regimen was followed by 28.5% of patients at 12 months. Patients with renal dysfunction showed a glomerular filtration rate (4-variable Modification of Diet in Renal Disease) increase of 10.9 mL (baseline mean, 45.8 [SD, 25.3] versus 57.6 [SD, 27.6] mL/minute/1.73 m(2) ) at 3 months after everolimus initiation (P < 0.001), and 6.8 mL at 12 months. Improvement in renal function was higher in patients with early conversion (<1 year). Adverse events were the primary reason for discontinuation in 11.2% of cases. The probability of survival at 3 years after conversion to everolimus was 83.0%, 71.1%, and 59.5% for the renal dysfunction, de novo malignancy, and HCC groups, respectively. Everolimus is a viable option for the treatment of renal dysfunction, and earlier conversion is associated with better recovery of renal function. Prospective studies are needed to confirm advantages in patients with malignancy.

Identification of novel peptide biomarkers to predict safety and efficacy of cow's milk oral immunotherapy by peptide microarray.

BACKGROUND: Cow's milk oral immunotherapy (CM-OIT) is still an experimental treatment. The development of novel biomarkers to predict the safety and efficacy of CM-OIT is crucial to translate this treatment to common clinical practice. OBJECTIVE: To analyse long-term changes in IgE and IgG4 epitope binding profile induced by CM-OIT to identify safety and efficacy biomarkers. METHODS: We studied 25 CM-allergic children who underwent CM-OIT and seven non-treated CM-allergic children as controls. CM-OIT patients were classified as low, moderate, and high risk according to the number of allergic reactions (safety), time required to achieve desensitization (efficacy) and need of premedication. IgE and IgG4 peptide microarray immunoassay was performed using a library of overlapping peptides of CM proteins at baseline, after oral desensitization, and 6, 12, and 24 months of follow-up. RESULTS: Cow's milk oral immunotherapy induced a rapid increase of IgG4-binding epitopes and a slow decrease in IgE-binding epitopes. High-risk patients recognized a statistically significant higher number of IgE peptides in caseins at all the times studied. Similar but less pronounced changes were observed for IgG4-positive peptides. Clustering analysis grouped together the high-risk patients, and we identified 13 regions of caseins significantly differed between groups of patients. Bioinformatics analysis selected two sets of 16 IgE-binding peptides at baseline that predicted safety (R(2)  = 0.858) and efficacy (R(2)  = 0.732), respectively, of CM-OIT. CONCLUSION AND CLINICAL RELEVANCE: We found two sets of IgE-binding peptides that can be used as novel biomarkers to predict the safety and efficacy of CM-OIT before starting treatment.

"Very early" intrahepatic cholangiocarcinoma in cirrhotic patients: should liver transplantation be reconsidered in these patients?

A retrospective cohort multicenter study was conducted to analyze the risk factors for tumor recurrence after liver transplantation (LT) in cirrhotic patients found to have an intrahepatic cholangiocarcinoma (iCCA) on pathology examination. We also aimed to ascertain whether there existed a subgroup of patients with single tumors ≤2 cm ("very early") in which results after LT can be acceptable. Twenty-nine patients comprised the study group, eight of whom had a "very early" iCCA (four of them incidentals). The risk of tumor recurrence was significantly associated with larger tumor size as well as larger tumor volume, microscopic vascular invasion and poor degree of differentiation. None of the patients in the "very early" iCCA subgroup presented tumor recurrence compared to 36.4% of those with single tumors >2 cm or multinodular tumors, p = 0.02. The 1-, 3- and 5-year actuarial survival of those in the "very early" iCCA subgroup was 100%, 73% and 73%, respectively. The present is the first multicenter attempt to ascertain the risk factors for tumor recurrence in cirrhotic patients found to have an iCCA on pathology examination. Cirrhotic patients with iCCA ≤2 cm achieved excellent 5-year survival, and validation of these findings by other groups may change the current exclusion of such patients from transplant programs.

Intrahepatic cholangiocarcinoma or mixed hepatocellular-cholangiocarcinoma in patients undergoing liver transplantation: a Spanish matched cohort multicenter study.

OBJECTIVE: To evaluate the outcome of patients with hepatocellular-cholangiocarcinoma (HCC-CC) or intrahepatic cholangiocarcinoma (I-CC) on pathological examination after liver transplantation for HCC. BACKGROUND: Information on the outcome of cirrhotic patients undergoing a transplant for HCC and with a diagnosis of HCC-CC or I-CC by pathological study is limited. METHODS: Multicenter, retrospective, matched cohort 1:2 study. STUDY GROUP: 42 patients undergoing a transplant for HCC and with a diagnosis of HCC-CC or I-CC by pathological study; and control group: 84 patients with a diagnosis of HCC. I-CC subgroup: 27 patients compared with 54 controls; HCC-CC subgroup: 15 patients compared with 30 controls. Patients were also divided according to the preoperative tumor size and number: uninodular tumors 2 cm or smaller and multinodular or uninodular tumors 2 cm or larger. Median follow-up: 51 (range, 3-142) months. RESULTS: The 1-, 3-, and 5-year actuarial survival rate differed between the study and control groups (83%, 70%, and 60% vs 99%, 94%, and 89%, respectively; P < 0.001). Differences were found in 1-, 3-, and 5-year actuarial survival rates between the I-CC subgroup and their controls (78%, 66%, and 51% vs 100%, 98%, and 93%; P < 0.001), but no differences were observed between the HCC-CC subgroup and their controls (93%, 78%, and 78% vs 97%, 86%, and 86%; P = 0.9). Patients with uninodular tumors 2 cm or smaller in the study and control groups had similar 1-, 3-, and 5-year survival rate (92%, 83%, 62% vs 100%, 80%, 80%; P = 0.4). In contrast, patients in the study group with multinodular or uninodular tumors larger than 2 cm had worse 1-, 3-, and 5-year survival rates than their controls (80%, 66%, and 61% vs 99%, 96%, and 90%; P < 0.001). CONCLUSIONS: Patients with HCC-CC have similar survival to patients undergoing a transplant for HCC. Preoperative diagnosis of HCC-CC should not prompt the exclusion of these patients from transplant option.

Fine mapping of LrSV2, a race-specific adult plant leaf rust resistance gene on wheat chromosome 3BS.

KEY MESSAGE: Fine mapping permits the precise positioning of genes within chromosomes, prerequisite for positional cloning that will allow its rational use and the study of the underlying molecular action mechanism. Three leaf rust resistance genes were identified in the durable leaf rust resistant Argentinean wheat variety Sinvalocho MA: the seedling resistance gene Lr3 on distal 6BL and two adult plant resistance genes, LrSV1 and LrSV2, on chromosomes 2DS and 3BS, respectively. To develop a high-resolution genetic map for LrSV2, 10 markers were genotyped on 343 F2 individuals from a cross between Sinvalocho MA and Gama6. The closest co-dominant markers on both sides of the gene (3 microsatellites and 2 STMs) were analyzed on 965 additional F2s from the same cross. Microsatellite marker cfb5010 cosegregated with LrSV2 whereas flanking markers were found at 1 cM distal and at 0.3 cM proximal to the gene. SSR markers designed from the sequences of cv Chinese Spring BAC clones spanning the LrSV2 genetic interval were tested on the recombinants, allowing the identification of microsatellite swm13 at 0.15 cM distal to LrSV2. This delimited an interval of 0.45 cM around the gene flanked by the SSR markers swm13 and gwm533 at the subtelomeric end of chromosome 3BS.

SLIT: indications, follow-up, and management.

Specific sublingual immunotherapy (SLIT) has been proved to be a safe and effective approach in respiratory allergy. However, further research is required on aspects such as patient selection, use of optimal dosing, effects on asthma, long-term effects, and management of adverse reactions. In addition, the widely heterogeneous nature of studies on SLIT performed to date and the application of the criteria for subcutaneous immunotherapy make it difficult for the prescribing clinician to draw accurate and useful conclusions. Therefore, the QUASAR Group (QUality in the Administration of SLIT in Allergic Rhinitis), which comprises allergologists with broad clinical experience in SLIT, investigated the latest research findings and available data on this approach. Working parties were formed in 3 different categories: selection of candidates for SLIT, treatment efficacy, and adverse reactions. We performed a PubMed search for articles that were representative of each category and found 850. From these, we finally selected 266 articles, which were reviewed to retrieve data on SLIT. Evidence for each clinical question was graded according to the Oxford classification. The resulting text was evaluated on 3 occasions by all the members of the group until the final version was agreed upon. In this version, we review available evidence on SLIT, particularly with pollens, which is the subject of most articles. In areas where evidence is insufficient, an alternative agreed upon by the members of the QUASAR group is presented. Finally, we propose algorithms for selecting candidates for SLIT and for management of adverse events.

Impact of Periodontitis on the Leakage of Oral Bacteria to the Gut.

Colorectal cancer (CRC) and periodontitis have recently been related due to the higher incidence of CRC in periodontal patients and the involvement of periodontal pathogens in carcinogenesis, suggesting that leakage from the oral cavity to the gut occurs. However, the magnitude of this pass-through in healthy individuals is controversial, and the effect that periodontitis could play in it is understudied. To evaluate the rate of bacterial leakage from the oral cavity to the gut, we analyzed the microbial composition of saliva, subgingival plaque, and fecal samples in healthy individuals without gastrointestinal disorders, including 20 periodontitis patients and 20 oral healthy controls, using PacBio full-length 16S rRNA gene sequencing. As expected, we observed a higher abundance of periodontal pathogens in the subgingival plaque and saliva of periodontal patients. In contrast, no significant differences were found between the fecal samples of both groups, implying that gut samples from periodontal patients were not enriched in periodontal pathogens. Fusobacterium nucleatum, a biomarker of CRC, was not found in the fecal samples of any participant. Our study does show a small leakage of some oral bacteria (mainly streptococci) to the gut, regardless of periodontal health status. Future studies should test whether other host factors and/or the preexistence of a gut disorder must be present in addition to periodontitis to promote the colonization of the gut by oral pathogens. The absence of periodontal pathogens in feces supports the idea that these bacteria could be used as biomarkers of intestinal disorders, including CRC.

Annual incidence of hepatocellular carcinoma among patients with alcoholic cirrhosis and identification of risk groups.

BACKGROUND & AIMS: The incidence of hepatocellular carcinoma (HCC) and associated risk factors in patients with alcoholic cirrhosis are not well defined. Surveillance for HCC among patients with cirrhosis who do not have hepatitis B is cost effective only if the expected risk of HCC exceeds 1.5% per year. We performed a prospective study to determine the incidence of HCC among patients with alcoholic cirrhosis and to identify risk factors. METHODS: We analyzed data from a surveillance program of 450 patients, aged 40 to 75 years, with alcoholic cirrhosis of Child-Pugh class A or B; patients were enrolled at the liver unit of a tertiary center from September 1992 through March 2010. Data were collected on 20 demographic, clinical, and laboratory variables at the start of the study. Patients were examined every 3 to 6 months for 5 years to identify risk factors for HCC; incidence was determined from a median follow-up time of 42 months. RESULTS: Over the follow-up period, 62 patients developed HCC (43 in the first 5 y of follow-up evaluation), with an annual incidence of 2.6%. By using multivariate analysis, age 55 years and older (hazard ratio, 2.39; 95% confidence interval, 1.27-4.51) and platelet counts less than 125 × 10(3)/mm(3) (hazard ratio, 3.29; 95% confidence interval, 1.39-7.85) were associated independently with the development of HCC. These variables were used to define 3 risk groups. The annual incidence of HCC in the group without either of these factors was 0.3% (n = 93), the annual incidence with 1 factor was 2.6% (n = 228), and the annual incidence with both factors was 4.8% (n = 129) (P < .0001). CONCLUSIONS: The annual incidence of HCC among patients with alcoholic cirrhosis of Child-Pugh class A or B is around 2.5%. Age and platelet count can be used to classify the patients in 3 different risk groups for HCC development within the next 5 years.

The Murine Oral Metatranscriptome Reveals Microbial and Host Signatures of Periodontal Disease.

Periodontal disease is accompanied by alterations to cellular profiles and biological activities of both the subgingival microbiome and host tissues. Although significant progress has been made in describing the molecular basis of the homeostatic balance of host-commensal microbe interactions in health compared to the destructive imbalance in disease, particularly with respect to immune and inflammatory systems, few studies have attempted a comprehensive analysis in diverse host models. Here, we describe the development and application of a metatranscriptomic approach to analysis of host-microbe gene transcription in a murine periodontal disease model, based on oral gavage infection using Porphyromonas gingivalis in C57BL6/J mice. We generated 24 metatranscriptomic libraries from individual mouse oral swabs, representing health and disease. On average, 76% ± 11.7% reads in each sample belonged to the murine host genome and the remainder to the microbes. We found 3,468 (2.4% of the total) murine host transcripts differentially expressed between health and disease, of which 76% were overexpressed in periodontitis. Predictably, there were prominent alterations to genes and pathways linked with the host immune compartment in disease-the CD40 signaling pathway being the top enriched biological process in this data set. However, in addition, we observed significant alterations to other biological processes in disease, particularly cellular/metabolic processes and biological regulation. The number of differentially expressed microbial genes particularly indicated shifts in carbon metabolism pathways in disease with potential consequences for metabolic end-product formation. Together, these metatranscriptome data reveal marked changes between the gene expression patterns in both the murine host and microbiota, which may represent signatures of health and disease, providing the basis for future functional studies of prokaryotic and eukaryotic cellular responses in periodontal disease. In addition, the noninvasive protocol developed in this study will enable further longitudinal and interventionist studies of host-microbe gene expression networks.

Genetic analysis of leaf rust resistance genes and associated markers in the durable resistant wheat cultivar Sinvalocho MA.

In the cross of the durable leaf rust resistant wheat Sinvalocho MA and the susceptible line Gama6, four specific genes were identified: the seedling resistance gene Lr3, the adult plant resistance (APR) genes LrSV1 and LrSV2 coming from Sinvalocho MA, and the seedling resistance gene LrG6 coming from Gama6. Lr3 was previously mapped on 6BL in the same cross. LrSV1 was mapped on chromosome 2DS where resistance genes Lr22a and Lr22b have been reported. Results from rust reaction have shown that LrSV1 from Sinvalocho is not the same allele as Lr22b and an allelism test with Lr22a showed that they could be alleles or closely linked genes. LrSV1 was mapped in an 8.5-cM interval delimited by markers gwm296 distal and gwm261 proximal. Adult gene LrSV2 was mapped on chromosome 3BS, cosegregating with gwm533 in a 7.2-cM interval encompassed by markers gwm389 and gwm493, where other disease resistance genes are located, such as seedling gene Lr27 for leaf rust, Sr2 for stem rust, QTL Qfhs.ndsu-3BS for resistance to Fusarium gramineum and wheat powdery mildew resistance. The gene LrG6 was mapped on chromosome 2BL, with the closest marker gwm382 at 0.6 cM. Lines carrying LrSV1, LrSV2 and LrG6 tested under field natural infection conditions, showed low disease infection type and severity, suggesting that this kind of resistance can be explained by additive effects of APR and seedling resistance genes. The identification of new sources of resistance from South American land races and old varieties, supported by modern DNA technology, contributes to sustainability of agriculture through plant breeding.

Latex allergy: Position Paper.

Correct management of latex allergy is essential to ensure adequate care of patients who are allergic to latex, which is ubiquitous in the health care setting. In this Position Paper, the Latex Committee of the Spanish Society of Allergology and Clinical Immunology provides guidelines for the management of latex allergy.

The tongue biofilm metatranscriptome identifies metabolic pathways associated with the presence or absence of halitosis.

Intra-oral halitosis usually results from the production of volatile sulfur compounds, such as methyl mercaptan and hydrogen sulfide, by the tongue microbiota. There are currently no reports on the microbial gene-expression profiles of the tongue microbiota in halitosis. In this study, we performed RNAseq of tongue coating samples from individuals with and without halitosis. The activity of Streptococcus (including S. parasanguinis), Veillonella (including V. dispar) and Rothia (including R. mucilaginosa) was associated with halitosis-free individuals while Prevotella (including P. shahi), Fusobacterium (including F. nucleatum) and Leptotrichia were associated with halitosis. Interestingly, the metatranscriptome of patients that only had halitosis levels of methyl mercaptan was similar to that of halitosis-free individuals. Finally, gene expression profiles showed a significant over-expression of genes involved in L-cysteine and L-homocysteine synthesis, as well as nitrate reduction genes, in halitosis-free individuals and an over-expression of genes responsible for cysteine degradation into hydrogen sulfide in halitosis patients.

Using CDOM spectral shape information to improve the estimation of DOC concentration in inland waters: A case study of Andean Patagonian Lakes.

For the last two decades different scientific disciplines have focused on lacustrine dissolved organic matter (DOM) given its importance in the biogeochemistry of carbon and in ecosystem functioning. New satellites supply the appropriate resolutions to evaluate chromophoric dissolved organic matter (CDOM) in inland waters, opening the possibility to estimate DOM at appropriate spatiotemporal scales. This requires, however, a robust relationship between CDOM and dissolved organic carbon (DOC). In this work, we evaluated the use of CDOM as a proxy of DOC in 7 Andean Patagonian lakes. Considering the entire data set, CDOM absorption coefficients (a355 and a440) were linearly related with DOC. Shallow lakes, however, drove this relationship showing a moderate relationship, whereas, deep lakes with lower colour presented a weaker relationship. Therefore, we assessed the use of CDOM spectral shape information to improve DOC estimates regardless of observed DOM differences due to climatic seasonality and lakes' morphometry. The use of well-known CDOM spectral shape metrics (i.e., S275-295 and a250:a365 ratio) significantly improved DOC estimation. Particularly, using a Gaussian decomposition approach we found that much of the variation in the spectral shape, associated with the variability of CDOM:DOC ratio, was explained by differences in two dynamic regions centred at 270 and 320 nm. A strong nonlinear relationship was found between the a270:a320 ratio and the DOC-specific absorption coefficients a*355 and a*440. This was translated into a further improvement in DOC estimation yielding the higher R2 and lower mean absolute differences (MAPD < 16%), either considering the entire data set or shallow and deep lakes separately. Our results highlight that incorporating the CDOM spectral shape information improves the characterization of the DOC pool of inland waters, which is particularly relevant for remote and/or inaccessible sites and has significant implications for the environmental management, biogeochemical studies and future remote sensing applications.