“When a great man dies, for years the light he leaves behind him, lies on the paths of men”. Henry Wadsworth Longfellow (1807–1882) U.S. poet.

The world-wide nephrology community has recently lost Prof. Juan Rodríguez Soriano, an internationally recognized scholar, teacher, and researcher of renal tubular physiology and the clinical expression of its disorders. Juan was born in Barcelona, Spain, in 1933, where he received his medical degree in 1956 from the Medical School of Barcelona University. He was recognized in medical school for his scholarship with both the Medical Graduate Extraordinary Award in 1956, and a bit later, with the Medical Doctorate Extraordinary Award. He trained in Pediatrics at the Clinic Hospital in Barcelona, and then moved to Paris in 1959 to work at Hôpital des Enfants Malades, with Professor Pierre Royer, where the first school (course) of pediatric nephrology was established. In his own words, Prof. Soriano explained that the publication of the article entitled "Troubles Héréditaires du tubule rénal chez l’enfant" by Pierre Royer and Henri Lestradet had impressed him deeply. He commented on his experience in Paris: “I vividly remember the arrival in Paris and my first patient there with hemolytic uremic syndrome. In those grey winter afternoons, nephrology was becoming a new discipline apart from internal medicine. Percutaneous renal biopsy in children became available, and renal pathology classification in pediatrics was still an open field. Pathology sessions lead by Dr. Renée Habib and Professor Royer, who discussed hundreds of pediatric and adult renal patients and described new syndromes such as thrombotic microangiopathy, focal and segmental glomerulosclerosis, diffuse mensangial sclerosis, membrano-proliferative glomerulonephritis, or oligomeganephronia, remain unforgettable in my memory. Further, working in Dr. Lestradet's laboratory I also learned how basic biochemistry and renal functional exploratory techniques were for the new discipline of pediatric nephrology. What a privilege having shared such experience with those Masters during 3 years!”.

As new advances in renal pathophysiology arose, in 1963, Juan moved for additional training as a postdoctoral research fellow, to Albert Einstein Hospital and College of Medicine in New York, to work in the newly created Pediatric Nephrology Group under Prof. Henry Barnett and Dr. Chester Edelmann. There, Prof. Soriano and other trainees participated in the standardization of several functional renal tests, the study of urinary acidification physiology in children, renal concentration mechanisms in newborns, and renal biopsy with simultaneous fluoroscopic control, among other techniques. In 1967, he published in Pediatric Research the description of a new syndrome named proximal tubular acidosis, a seminal finding that constituted the first milestone in his storied career.

Prof. Juan Rodríguez Soriano returned to Barcelona in 1967, and was a founder of Pediatric Nephrology there, as clinician chief in Pediatrics at Vall d´ Hebron Children’s Hospital. He was in charge of the busy "dehydration unit" as many infants suffered the consequences of having been fed with a baby formula with both a high salt and protein load. His expertise in acid-base balance and electrolytes contributed not only to improve practice but also to teach generations of pediatricians about the new discipline of developmental renal physiology. At the same time, and equally as important, Juan met his future wife, Maria Jesús Vita, a pediatric radiologist, who remained his lifelong spouse.

In 1970 Prof. Juan Rodríguez Soriano moved to Cruces Hospital in Baracaldo-Bilbao, Spain, as Chairman of Pediatrics and as Professor of Pediatrics first, and Chair of Pediatrics later, at the newly created School of Medicine of the Basque Country University. His broad, open-minded views constituted the foundation of the new Pediatrics Department based on the development of pediatric specialities lead by young, enthusiastic doctors trained abroad in most cases, a remarkably innovative approach in Spain at that time. His profound scientific knowledge, outstanding teaching skills and analytic capabilities, interest in research, and a deep personal and professional integrity resulted in the training of over 300 pediatricians and pediatric specialists and generations of physicians as well as a large number of doctorate degree recipients. With his inseparable professional partner and friend Dr. Alfredo Vallo, he developed the Pediatric Nephrology Division, and the Pediatric Nephrology Physiology laboratory. In addition, he created the Pediatric Kidney Disease Service, which provided modern clinical care to children with renal illnesses throughout Spain, incorporating procedures such as acute and chronic renal replacement therapy by peritoneal dialysis (1970), hemodialysis (1972), and kidney transplantation (1979).

However, what made the Pediatric Nephrology Division at Cruces Hospital known worldwide was Prof. Juan Rodríguez Soriano’s expertise in tubulopathies. He trained many pediatric nephrologists during his professional life, including Drs. Gonzalo Castillo†, Joaquin Pedrero, Roberto Oliveros, M. Jesús Quintela, Doroteo Arruabarrena, Víctor García-Nieto, M. José Sebastian, Mercedes Ubetagoyena, Gema Ariceta, and Mireia Aguirre, all of whom continue his legacy in the field. During his career, Juan remained actively involved in research, focusing on acid-base balance and pathophysiology, water and electrolyte handling by the kidney, tubular disorders, and the clinical expression of those dysfunctions in infants and children, until his retirement in 2003. His interest extended to other disorders too, such as hypoaldosteronism and pseudohypoaldosteronism, Bartter and Gitelman syndromes, hypomagnesemia of renal origin, postnatal renal function maturation, and long-term quality of life in young adults with kidney disease since childhood. He was inspired by the molecular biology revolution and contributed to the discovery of ATP6V1B1 and ATP6V0A4 encoding-gene mutations in Renal Tubular Acidosis, ROMK and CLCKB mutations in Bartter syndrome types II and III, mineralocorticoid receptor gene mutations in autosomal dominant pseudo-hypoaldosteronism type I, CLDN16 and CLDN19 encoding-genes mutations in familial hypomagnesemia-hypercalciuria-nephrocalcinosis, and MYH9 gene encoding for the NMMHC-IIA mutations in MYH9-related disease.

He worked tirelessly for the international community of Pediatric Nephrology. He was a founding member of the European Society for Paediatric Nephrology (ESPN) that celebrated its first meeting in September 1967 in Glasgow, with Garvin Arneil as meeting president. The following year, in September 1968, Prof. Juan Rodríguez Soriano was also a founding member of the International Society of Pediatric Nephrology (IPNA) that celebrated its first meeting organized by Gustavo Gordillo, in Guadalajara, Mexico. He continued to participate in most ESPN and IPNA meetings, presenting original papers, giving invited lectures, and playing an active part in the life of those societies. He organized and was president of the 36th Annual Meeting of the ESPN held in Bilbao, Spain, in 2002. Additionally, he maintained a collaborated relationship with the Latino-American Society of Pediatric Nephrology (ALANEPE) in Spain. Prof. Juan Rodríguez Soriano was a founding member of the Spanish Society of Pediatric Nephrology in 1973. He was member of the European Society for Pediatric Research, International Pediatric Association, International Society of Nephrology, The American Federation for Clinical Research, and Latin Group of Pediatrics; and locally, a member of The Spanish Society of Pediatrics (AEP), Spanish Society of Nephrology (SEN) Spanish Society of Pediatric Nephrology (AENP), North Society of Nephrology, Basque-Navarre Society of Pediatrics (AVNP), and Catalonian Society of Pediatrics.

Prof. Juan Rodríguez Soriano's research and international contributions led to more than 300 articles, book chapters, and monographs, some of them written after his retirement as he continued to be active in the intellectual pursues of our discipline. He gave lectures all over the world. He was coordinator of the advisory scientific committee of the ALANEPE, assistant director and journal editor of Pediatric Research, member of the editorial committee of International Journal of Pediatric Nephrology, Pediatric Nephrology, Acta Paediatrica Scandinavica, and Jornal Brasileiro de Nefrologia. In Spain, he directed the journal Revista Española de Pediatría, and Anales Españoles de Pediatría, and was a member of the editorial committee of Acta Pediátrica, Nefrología, and JANO journals. He participated as an advisor in several official committees focused on Children’s Health, Nutrition, Training in Pediatrics, and Medical Research as well.

His important contributions were rewarded with several distinctions and honors. He was recognized with the Gran Cruz de la Orden Civil de Sanidad, the highest award in the medical field, by the government of Spain in 1990, and he received the Orden Académica “Alejo Zuloaga”, the highest medal by the Venezuelan Carabobo University in Valencia, Venezuela. Several scientific societies (Argentine La Plata Society of Pediatrics, French Society of Pediatrics, ALANEPE, AEP, SEN, AENP, AVNP, Catalonian Society of Pediatrics, Valencian Society of Pediatrics, and Galician Society of Pediatrics) named him as an honorary member. He was also an honorary distinguished guest at the V Meeting of ALANEPE in Valencia, Venezuela in 1999, and named honorary director of the journal Anales Españoles de Pediatría.

The nephrology community is saddened by Prof. Juan Rodríguez Soriano's death. He is survived by his spouse Maria Jesús, their three children Maria Luisa, Emilio, and Juan, and two grandchildren, Eduardo and Santiago. His disciples share their loss and extend to them our friendship, our admiration and acknowledgement that the man they loved was our Master in pediatric nephrology.