The standardization of scientific nomenclature, including widely employed acronyms (often excessively used even orally), has classically been a goal in many languages but it has been achieved only partially. This standardization attempt tries to establish a well-defined lexicon, allowing any information to be recognized, compared, reused in calculations, used for research or statistics and be stored in documents, without losing information and maintain meaning.3 Several initiatives of different scope have served to this purpose, such as the basic International Classification of Diseases Ninth or tenth Revision (ICD-9 or ICD-10) or the International Classification of Diseases 9/10 (ICD-9/ICD-10), even though its initial purpose was not necessarily clinically oriented. It is well known that these systems do not adequately identify patients with chronic kidney disease (CKD) and although ICD-10-CM includes CKD (code N18) with its stages (eg: N18.1–N18.5), it is not used frequently and contains frequent errors. Attempts have also been made to standardize the guides of style in the various scientific journals devoted to specific areas of health sciences.4

In this declaration of intention, more specifically concerning clinical laboratory sciences, where an extremely large number of results are produced every day, it is necessary the standardization of nomenclature (and units) and they have been pioneers in this field.5 Regarding initiatives in Spanish, it is of note the document published in 2018 on nomenclature and units3 as well as the collaboration between the “Working Group on Nomenclature and Spanish Translations of the International Federation of Clinical Chemistry and Clinical Laboratory Sciences”, together with the “Scientific Committee of the Latin American Confederation of Clinical Biochemistry”, and the Terminology Commission and Publications Committee of the Spanish Society of Clinical Chemistry (SEQC). All agreed upon the application of international recommendations, publishing an extensive list of examples6 (sample in Table 1). These recommendations were poorly accepted perhaps due the practical complexity or lack of involvement of clinicians. It was no longer just that the word “bicarbonate” should not be used but “hidrogenocarbonato”; it was that, for example, considering the words “creatinine” or angiotensin- converting enzyme (ACE) as “incorrect” and should be changed to “creatininio” or “peptidyl-dipeptidase-A”.6 The idea is not to transform our daily reality (Table 1).66b It is true that some of the suggested terms did have unquestionable interest in terms of their scientific and linguistic precision.6

In the area purely concerning Nephrology, it is a remarkable milestone the publication of a Kidney Disease: Improving Global Outcomes (KDIGO) guideline whose main objective was the standardization of the nephrology nomenclature for scientific articles written in English, following as a fundamental principle the best possible understanding by patients (English speaking patients).7 This publication was preceded almost two decades earlier by another even more important guideline, devoted to the evaluation and management of CKD, (containing CKD classification and stratification), initially developed by the National Kidney Foundation (NKF) Kidney disease outcomes Quality Initiative (KDOQI) which was later adopted, with minor modifications, by the KDIGO.8,9

These guidelines on CKD had the positive impact of changing the concept of CKD as a severe condition, which required the assistance by nephrologists, to a very frequent situation, often asymptomatic, and with a wide range of secondary manifestations that also required the attention of general practitioners, and the implementation of strategies for prevention, detection and early management.10 There is no doubt that these guidelines had a very important effect not only in clinical practice, by unifying the definition, classification and risks associated with CKD, but also in the field of nephrology research and health policies, although they also generated notable and persistent controversies (eg, in relation to the importance of the age factor or methodological inaccuracies).11

Following the aforementioned KDIGO9 guidelines, several national and local initiatives, such as those led by the Spanish Society of Nephrology (SEN) and the Spanish Society of Laboratory Medicine (SEQC), in which several authors of this editorial were involved, resulted in the publication of the recommendations on the use of equations for estimating the glomerular filtration rate (GFR) in adults (2006),12 tables using the formula derived from the Modification of Diet in Renal Disease (MDRD) study,13 as well as the first consensus document on CKD of the Spanish Society of Family and Community Medicine (SEN- SemFYC) in 2008.14 Subsequently, the recommendations on the assessment of proteinuria regarding the diagnosis and follow-up of CKD were published,15 as well as the assessment of the new Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) for GFR estimation,16 and tables using the new formula.17 Finally, KDIGO published in 2012 the guide of clinical practice for the evaluation and management of CKD.18 In 2014, it was published an important consensus document in Spain, under the direction of the SEN together with other nine medical societies, on the detection and management of CKD addressed to professionals of different specialties, directly or indirectly related to renal patient care, including primary care.1,19 Similarly, the Latin American Society of Nephrology and Hypertension (SLANH) published in the same year 2014 a clinical practice guideline on the prevention, diagnosis and treatment of CKD stages 1–5, with the participation of 30 external reviewers.20 Finally, in 2016 the Spanish Ministry of Health published its guide on CKD21 and a new update of the consensus with ten different specialties will soon be published in this journal.2

Following the same mode of action of the KDIGO on nomenclature and supporting its own recommendations,7 in November 2020 we claimed in a letter to the Editor in Kidney International,22 and more recently in Nefrologia,23 the need for homogenization of the nephrological nomenclature in each language, Spanish in our case, with special emphasis on the acronyms used. Likewise, we revealed the existence of a certain discrimination against classical medical terminology of Latin origin,22,23 shared by other groups and forums.24,25 In fact, it came to our attention that one of the main recommendations made by the KDIGO was to use the term kidney instead of the term “renal” for general descriptions of kidney function and kidney disease since it was stated, in the context of English speaking patients, that the word (noun) kidney was more familiar than the adjective “renal”.7,23,24 It is also definitely of great interest that the Latin American Registry of Kidney Dialysis and Transplantation and the SLANH Acute Kidney Injury Committee (IRA) have just published in December 2020 an Ibero -American consensus proposal to standardize such nomenclature (initiative now also described in Nefrologia).26,27 Members of the Brazilian, Portuguese and Spanish Society of Nephrology were included in this proposal and certainly, it represents a great first step to achieve the desired objective for each of the Latin languages that stick us together.

As said, it is not a matter of not recognizing with humbleness that English is currently the richest and most universal language; it is currently the most widespread in politics, commerce, finance, technology, public demonstrations and science.23 In fact, we must accept and applaud the KDIGO initiative, but claiming at the same time for the use of a non-english terminology that is absolutely correct, precise and even very frequently used in various languages (including English itself!). Not only is Spanish the second most widely spoken language in the world, but some of the proposed changes (eg, the one mentioned on the adjective “renal”) affect many other languages. Furthermore, ‘renal’ stands in relation to anatomical structures (eg ‘renal artery’), historical names such as the United Kingdom Renal Association,22 or nephrological journals (Journal of Renal Nutrition). Moreover, we advise in our letters22,23 not to abandon the use of this term «renal» so that the bibliographic searches are as broad and inclusive as possible (eg, meta-analyses), and we underline the real need to launch an initiative similar to the KDIGO in our language (such as the one already initiated by SLANH and which also includes Portuguese), homogenizing keywords for scientific articles, records, as well as meta - tags in search systems.22,23 The anglophile fixation of the KDIGO has also had a notable impact on social networks and specialized websites.2727b

Independently of frequent misconceptions (eg, the very own definition of chronic kidney disease, kidney failure or insufficiency),28 the arrival of new renal terminology of English origin (eg, Acute Kidney Injury [AKI]), has caused an evident dispersion (from “fallo o falla, fracaso, insuficiencia, daño, lesión o injuria”, with its different acronyms). Likewise, there is a lack of unification of other terms (eg, glomerular filtrate or glomerular filtration (GF) or “tasa” of GF and, more specifically, in frequently used laboratory parameters such as CAC-IAC-RAC (for “cociente, índice, razón, relación” -quotient-index-ratio- of albumin/creatinine in urine). All this dispersion of terminology led us, a broad confluence of nephrologists from very diverse Spanish-speaking countries, to expand our previous claims22–24 and applaud the great initiative of the first proposal by SLANH.26,27 However, this editorial is claiming to create a broad and open basis for discussion among nephrologists in our language (Table 2). Likewise, we praise its approach to the original KDIGO proposals, already universalized and implanted (for example, in the staging G1–G5, A1–A3), whose translation would only generate discrepancies, and avoids harsh terms such as «terminal» or «final», or avoid anglicisms and literal translations that have other connotations in Spanish (such as «injuria»-for damage or lesion - or «severo» -for grave-) (Table 2). Unfortunately, there are still some contradictions (eg renal “failure” with two different definitions) and, on the other hand, some terms that we have used historically should perhaps disappear when the final consensus is achieved and published.

For all these reasons, with great consideration for all these initiatives that have already been launched, we underline the need to share with all Spanish-speaking nephrologists the remaining points of discussion, some of them reflected in this article. In fact, for the elaboration of a final, broad and shared consensus document, we will have to make concessions (linguistically speaking) since, being the same language (Spanish), there are terms that are more familiar to us depending on where we received our training without considering that the “not chosen” terms are incorrect. The uniformity and homogenization of terms acquires greater relevance every day when we think about efficiency, not only in our bibliographic searches but, even more importantly, anticipating and thinking about Artificial Intelligence/Machine - Learning tools and the exploitation of Big-Data.29 In this way, the implementation of computerized medical records is generating a large volume of data that offers a great opportunity to promote knowledge of diseases, improve daily clinical practice, research and education.29 Obviously, a key point for structuring medical information is to encode each variable so that it is unique and correctly defined to allow technical and semantic interoperability between different databases allowing exchange of information. In this sense, beyond the ICD mentioned, there are general initiatives such as the Simple Knowledge Organization System (SKOS), (http://skos.um.es/unesco6/00),2929b the project of international standardidazation of nomenclature for science and technology, Logical Observation Identifiers Names and Codes (LOINC),2929c (http://loinc.org), or the creation of a dictionary of clinical terminologies using international standards such as the Systematized Nomenclature of Medicine –Clinical Terms (SNOMED-CT),2929d which is the broadest, most accurate and comprehensive codified clinical multilingual terminology, developed in the world.

Finally, we believe that it is important to highlight that it is no longer a question of defending our common language and that “renal” is our natural adjective for the kidney in the scientific field, but rather and above all, we clinicians cannot forget that, in the current scenario the individual patient plays a central role in making decisions that must be shared.23,30 This fact is particularly relevant in our specialty, where the degree of evidence of our decisions and clinical actions are generally more in the degree of “suggestions” (evidence grade 2) than that of “recommendations” (grade 1).30 Therefore, we cannot forget that, for our patients, what is really fundamental is not that we scientists or nephrologists use to understand each other by using a common scientific language, but rather that our “kidney” (“renal”) patient understands from us by using plain words of any origin, adapted individually, and even resorting to colloquial or more popular language, whether we are for him “nefró-logos” or “riñón-logos”.23

The production of this editorial has not received any financial support.

The authors have no conflicts of interest related to this article.