Riga Stradins University
HOW TO DISCOVER AND TREAT RENAL DISEASES:
to contribute systemic scientific approach in nephrology
with particular implication on introduction of peritoneal
dialysis (renal replacement therapy) in Latvia and to
expand the role of renal ultrasonoscopy in the
Doctorate work for doctor degree of medical sciences in internal
/specialty - nephrology/
The Doctorate work has been performed in the Centre of
Nephrology of P. Stradiņš Clinical University hospital from 1996 to
1998 and continued till the year 2005 for works mentioned in the list
Work manager: Prof. Aivars Lejnieks
Reviewers: Prof. Andrejs Kalvelis
Prof. Vytautas Kuzminskis, Kaunas,
Lietuva Prof. Valdis Pīrags
The Doctorate work is based on the book of A. Petersons, E.
Veverbrants, I. Lazovskis "How to discover and treat renal diseases"
(580 pages, published on 1998, Riga, author's edition of A.
Petersons, impression 1800 copies). The book is made as a
monograph of A. Petersons with participation of both inspirers of the
work, teachers and nephrology experts - Prof llmars Lazovskis
(chapter on the history of nephrology; 3% of the total amount)
and Prof Egils Veverbrants (chapter "Acid/alkali balance"; 9% of the
The basis of the Doctorate work, working with a monograph "How to
discover and treat renal diseases" has been performed in P.
Stradins Clinical University hospital, Center of Nephrology from
1996 till 1998 and continued till the year 2005 for works mentioned
in the list of publications.
The monograph has served as a mean both for introduction of
peritoneal dialysis in Latvia and more extended integration of renal
ultrasonoscopy in the nephrological practice. The amount of specific
nephrological knowledge defined in the monograph has influenced
the development of clinical practice based on scientifically justified
evidences, including more extended use of glomerulonephritis
morphological classification. In addition, the monograph has not lost
its importance when evaluated after some time.
Topicality of the work
Nephrology as a specialty is undergoing rapid and radical changes
over last 20 years. Among disciplines of internal medicine due to
development of modern technologies, probably only in cardiology
the same serious development and changes of the specialty content
may be observed. At baseline nephrology science (Hamburger,
1963) was engaged in research and treatment of renal diseases, but
nowadays 80% of the nephrologists's attention and time is devoted
to renal replacement therapy (RRT) (haemodialysis, peritoneal
dialysis, kidney transplantation) and associated problems that both
clinically and scientifically include all organ systems of the human
body. In the practical medicine in Latvia from vital organs at
sufficient amount for public only kidneys may be replaced (at small
amount also heart and stem cell transplantation is being performed).
As known, in other developed countries also liver, lung and
pancreas may be transplanted, but no technological replacement
methods for these organs are available. RRT is a life saving therapy
and its costs are very high.
Therefore scientifically justified choice of the treatment method,
control and development may not be overestimated.
After recovery of independence in the nephrology in Latvia a big
influence of soviet traditions has been observed. The clinical
nephrology has developed separately from hemodialysis and
kidney transplantation. Peritoneal dialysis for first patients was
started only on 1994 with large organizational problems. In the
resident program of nephrology established at Riga Stradins
university on the basis of P. Stradins hospital Nephrology centers it
was impossible to get all the necessary knowledge in Latvian,
particularly detailed description of renal replacement methods,
including peritoneal dialysis, morphological classification of
glomerulopathies etc. Therefore availability of up-to-date
scientifically grounded material was very important and actual for
the development of the field.
Figure 1. Principal sheme of peritoneal dialysis
(Inflow bag on the right side, then intraabdominal dwell, and
outflow (left), attaching system 4 times daily as a standart)
Peritoneal dialysis (PD) is one of 3 (also hemodialysis and kidney
transplantation) renal replacement therapy methods used when the
patient kidneys are loosing their function due to disease.
Using natural functions of peritoneum as a filter, with peritoneal
dialysis it is possible to qualitatively maintain life for patients up to
20 years. In the middle of 80-ies due to development of PD
technologies and reduction of the risk of major complications
(peritonitis) this method has been used wider and wider all over the
world. Proportion of PD among dialysis patients in different countries
varies widely (see table 1), but on average it constituents
approximately 20 to 40%. At most the frequency of PD is influenced
by the medical funding model and the level of prosperity of the state
(PD is cheaper by up to 30% than HD), religion, traditions, social
Table 1. Proportion of peritoneal dialysis among dialysis patients
(National registers - ANZDATA, UK Renal Registry, ADR, USRDS
The main advantages of PD in comparison to hemodialysis (HD) are
1)low price - in developed countries up to -30%,
2)maintains residual renal function for long time allowing better
control of fluid exchange,
3)gives an opportunity to live for people living far away from
4)provides more active life style in the aspect of work and traveling,
Disadvantages of PD in comparison to HD are the risk of abdominal
cavity infection, reduction of peritoneal function after 4 to 7 years,
lower intensity and dose limitations for bigger individuals. Results of
modern studies suggest that 3 renal replacement therapy methods
do not compete mutually, but collaborate in the interests of the
patient and where scientifically and medically motivated choice of
RRT is implemented; all three of them are used in a dynamic
complex. In addition, lege artis PD should be used as the first
method (Fenton S. et al, 1997). Later when reduction of peritoneal
function and/or residual renal function occurs, planned switch to
hemodialysis may be performed. It is established that advantages of
PD concerning the risk of mortality and morbidity in comparison to
HD becomes equal after 2 to 4 years of dialysis (Vonesh E, 1997;
Blake P, 1998). Possibilities of kidney transplantation may be used
by maximum both in PD and HD patients. After transplantation, if
necessary, patients mostly continue with hemodialysis or in the
absence of vascular access - with peritoneal dialysis.
Till 1994 in Latvia this third renal replacement therapy method was
not available. Peritoneal dialysis has been introduced in the
Nephrology centre of P. Stradins clinical university hospital from
1994, starting with 2 patients and meeting large organizational and
financial difficulties. There was also no complete information on the
scientific background of the method and possibilities of use in our
conditions. They were characterized by poor social guaranties for
inhabitants, questionable hygienic conditions, insufficient network of
the out-patient medical care, lack of nephrologists and complete lack
of information on peritoneal dialysis. When starting introduction of
peritoneal dialysis a necessity of wide study on the scientific
background of the method among other renal replacement therapy
methods, as well as on practice of different centers in adaptation of
the method for local conditions becomes actual.
Ultrasonoscopy (US) is a non-invasive, informative, harmless, rapid
and cheap image diagnostic method. With progression of US
technology it as the one available only for radiologists in 80-ies now
has been used also in other fields - particularly
in gynecology and cardiology. The informativeness of the US
method depends largely not only on the equipment quality, but
especiallyon its user-specialist competence in particular specialty.
Therefore large advantages has the nephrologists himself when
examining a nephrological problem with US. From 1986
nephrologists have started to use US in their everyday practice in
Kidney transplantation and Nephrology centers of P. Stradins
hospital. This practice is introduced, gives invaluable information and
operativeness, economic benefit and findings of additional
symptoms. It was very essential to collect this experience, analyze it,
offer for critical review of other colleagues as a methodological
mean, include US as an integral part in the amount of specific
nephrological knowledge. We considered that not less actual task is
to advance particular hypotheses for further studies (diagnostic
importance of renal pyramides in interstitial nephritis, the role of
parenchymal oedema in evaluation of diabetes, the role of cortical
hyperechogenicity in graduation of chronic renal disease etc.).
Till the middle of 90-ies in the nephrology practice clinical
classification of glomerulonephrites (GN) by Tareyev (Tapeeb EM,
1975) has been used. However in the USA and Western Europe
glomerulonephrites are classified mostly by their morphologic
picture or at the syndrome level - by the leading syndrome, also in
everyday practice. Although the morphologic picture of GN has been
outlined also in Latvian sources (Bruveris, Cernevskis, Lazovskis,
1990), however at the level of general classification with
corresponding treatment methods and clinical syndrome it has not
been used. Thus very actual is a scientifically grounded choice,
introduction and use in the nephrology practice of CN classification
by morphologic forms. In parallel to this process it was necessary to
activate and optimize morphologic examination methods (PAS,
immuno hystochemistry, electron microscopy), from which to a large
extent depends nephrological quality in the light of morphological
Particularly actual in the aspect of clinical nephrology is correct
detection of renal function, as well as detection of early renal
dysfunction signs - minimally reduced glomerular filtration rate
(GFR) and microalbuminuria. More and more studies indicate
that these both symptoms are serious, independent factors of high
cardiovascular risk (Ritz E. et al, 2004). If the prevalence of terminal
renal failure requiring huge and increasing funding is relatively small,
than cardiovascular diseases, the background of which probably is a
minimal undiagnosed renal dysfunction, is a much more larger
burden for society both in the aspect of survival, quality of life and
medical expenses. Therefore research of issues associated with
renal function and prescribing of treatment is invaluably actual
problem of modern internal diseases.
Targets of the job
1.To create a scientifically sound, contemporary, scientifically
referenced minimum knowledge supply necessary for any
2.To analyze literature about optimal possibilities of PD usage
in Latvia and to record the first experience about problems of
implementation of this kidney replacement therapy method.
3.To implement and develop scientifically proven, common
principles of PD usage in Latvia.
4.To trace the role of kidney US in nephrology practise and to
highlight hypothesesis about US symptoms based on
5.To create a scientifically sound classification based on GN
clinical syndrome and morphological picture and to implement it
in Latvia through motivations and descriptions.
6.To provide detailed analyses and information about early
functional renal examinations (GFR, MAU), considering their
significant effect on cardiovascular risk in population.
Tasks of the job
1.To perform detailed analyses of literature about each target
2.To select, complement with experience of our centre and
record conclusions in an easy to publish and understand way.
3.To create basis for further researches with references to
originals, as well as to promote a discussion about problems of
clinical nephrology basing on research studies.
4.To assess influence of the monograph on nephrological clinical
studies and development of clinical practise.
5.To turn attention to language and terminology questions in the
field considering the size of edition which includes all aspects of
Novelty of the job
1.For the first time in Latvia - selected, referenced in the text,
essential and sufficient data intended for contemporary
nephrologist have been included in one book.
2.For the first time in Latvia - a detailed review of scientific basis
and practical usage of peritoneal dialysis method (kidney
replacement therapy) has been created.
3.On the ground of basis worked out in monograph following has
happened in Latvia:
a. scientifically sound methodology has been created
for PD usage,
b. a stabile managerial structure of PD has been
created on national level,
c. a data base of dynamic observations of PD patients
has been created in the Nephrology centre of P.
Stradins Clinical Hospital.
4.Analyses, detailed descriptions and illustrations about usage
and implementation of ultrasonography method in nephrology
has for the first time been given in special literature of
5.The job conveys hypothesis about relation between separate
US symptoms and certain nephropathy, the meaning of which
have been proved in clinical practise.
6.Close correlation of clinical syndrome and morphological
picture has been used and implemented in classification of
glomerulonephritis for the first time in Latvia.
7. Basis for referenced data base in nephrology field in Latvian
has been created for the very first time.
Job structure and size
Monograph „How to discover and treat renal impairments" is written
in Latvian language. It includes 20 chapters, 530 pages, 60 tables,
200 pictures, 660 references to the literature in the text
Most of ultrasonography images have been fixed in the result of
clinical observations of the author.
Pictures illustrating essential data about morphology of
glomerulopathia have been obtained due to cooperation with
internationally well-known nephropathologists - Prof. Helmut Rennke
and Prof. Jan Weening, as well as from personal archive of Prof.
Results and discussion
In the monograph „How to discover and treat kidney impairments" all
aspects of modern nephrology have been considered, including
clinical nephrology with arterial hypertension and renal
pathomorphology, problems of water-salt balance, problems of
alkaline-acid balance, kidney replacement therapy - either
hemodialysis and peritoneal dyalisis, and principles of renal
transplantation. All the themes are described in an analytical way
basing on most important cognitive sources in nephrology, original
research studies. Selection has been made basing on practical
experience of authors in the field. Attempts are made to give most of
the references straight in the text (referenced). It facilitates the
reader to use source materials, promotes scientific discussion,
creates basis for further elaboration of the data base. Similar
contemporary monograph is not yet available in Estonia, Lithuania
or Finland. It has been widely used not only in the references of
other trials, in scientific and public articles, but has served as
cognitive source of minimum necessary knowledge
in Latvian for residents of internal diseases and nephrology,
nephrologists, professionals who are trained in peritoneal dialysis
Table 2. Dynamics of development of PD program in Latvia
(data of LNSR)
Successful development of state program of peritoneal dialysis
may be considered as one of benefits from publication of the
monograph. Program of peritoneal dialysis in Latvia was started
with 2 patients in the Nephrology Centre of P.Stradins Clinical
Hospital in 1994. Henceforward despite of all difficulties the number
of patients treated with PD is growing (see table 2). By the help of
our Nephrology Centre, PD method was initiated in Nephrology
centres of Children's Hospital, Gailezers Hospital, which currently
are acting as completely independent centres and also in
Nephrology Centres of Valmiera and Liepaja Hospitals. PD problem
investigation in the monography „How to discover and treat renal
impairments?" serves as study aid for safe and precise usage and
implementationofthe method in big Nephrologycentres. It has
helped many people for whom dialysis and consequential survival
was not possible before PD implementation. This mainly refers to
patients who live far from Nephrology centres, elderly people and
children, diabetics and persons with different special needs with
moving difficulties, et c.
Table 3. Penetrance of PD method in dialysis (data of LNSR)
Either in the monograph and after it's publishing it was practically
proved that PD method does not compete with other RRT methods,
but mutually reinforce each other. Good renal transplantation results
were observed in patients who had received PD. It has proved to be
beneficial as also first RRT in patients with maintained residual
function of kidneys. Patients, who have protractedly received
hemodyalisis (which is the main and most intensive method of
dialysis) may experience vascular problems and if transplantation is
impossible, only PD may be helpful. The above mentioned and
several other criteria, including financial aspects, form rational
proportion of peritoneal dialysis and hemodialysis in countries where
choice of a certain RRT method is not influenced by private financial
interests. PD is at optimum used in 20 - 30% of dialysis patients.
Due to scientific approach and education, which has been promoted
by this monograph, proportion of PD among the other dialysis
methods in Latvia comes close to optimum (see Table 3)
Detailed studies, selection and pictorial description of US symptoms
characteristic to renal diseases has been performed. Algorithms of
interpretation of similar US examination results depending on a
patient's clinical condition have been offered. It is suggested to
implement a 4 stage classification for cortical
echogenity US description (Hricak H, 1982). It's advantages have
been tested in long-term practical observations as well as through
analyses of cortical echogenity related available literature.
Looking retrospectively classification of Hricak has turned out to
be useful and has widely spread among nephrologists and
radiologists in Latvia.
Figure 2. - 5. Grading of renal cortical echogenicity
(Grade 0-3, Hricak)
A conception about usage of US in nephrology practise has been
risen and motivated. Such approach in 1998 was observed only in
some centres of Germany (Koeppen-Hagemann, 1992) and
France, but in other countries, especially in USA ultrasonoscopy
was under responsibility of radiologists, moreover radiologists
were only analyzing standard images obtained by technicians.
Recently (Neil, 2002) USA also starts developing gradually the
nephrological way of US examination which is particularly described
in our monograph.
Morphological classification of glomerulopathias has been used for
detailed analyses of pathogenesis and therapy possibilities of
separate diseases. It has for the first time been completely reviewed
and used as basic classification for glomerulonephritis. Associations
with clinical glomerulal syndomes - nephrotic and nephritic - have
been highlighted and motivated.
Figure 6. FSGS in light microscopy (PAS)
Figure 7. IgA nephropathy (immunperoxidase)
Pathologies with variable study results or contradictory opinions of
different authors have been handled through scientific discussion
and open polemics. It has been reflected in the job. For example,
1) status of minimal change glomerulonephritis (MCG) as
an independent disease or as part of focal segmental
2) debated hypothesis about similarity or direct pathogenetic
relation of IgA nephropathy to Henoch-Scheonlein purpura
3) Hemolytic uremic syndrome (HUS) and thrombotic
thrombocytopenic purpura are included in a wider
pathogenically sound group - thrombotic microangiopathy
4) Not so widely used, but very practical 3-type division of
rapidly progressive glomerulonephritis (RPGN) has been
The significant role of AKI for almost all patients with increased
blood-pressure or chronic renal disease has been highlighted in the
job. After 1998 when the monograph was published the meaning of
this therapy has been proven in new controlled studies
Additional hypothesis raised in the job
1.US oedema symptoms of renal parenchyme (thickness > 15
mm; kidney length > 12 cm; and cortical hypoechogenity) in
patients with short medical history of Type 1 diabetes mellitus
can indicate to diabetic metabolic decompensation and
2.Increased echogenity of medullar pyramids may indicate to an
acute intersticial nephritis and may help in differential diagnosis
between mostly intersticial or glomerular impairment.
3.US of kidneys should be preferably performed by the
nephrologist him-/herself on everyday basis.
1.The extent of specific knowledge and scientific conclusions in
nephrology should include the minimum which is reviewed in the
monograph and basically complies with UEMS
2.Also in Latvia PD is an effective kidney replacement therapy
method which does not compete with other methods, but
successfully incorporates in the common therapy complex.
3.The inclusion of US in the range of routine examinations of
nephrologists, especially if it is performed by a specialist
him-/herself significantly improves quality of diagnostics and rate
4.Cortical echogenity of kidneys, signs of oedema and the type
of medullar pyramids in US are relatively specific symptoms for
certain renal diseases and for clinical condition of a renal patient.
1.In everyday diagnostics of glomerulopathies morphological
classification approved by renal biopsy should be used.
2.Peritoneal dialysis in patients without contraindications should
be used as first or initial renal replacement therapy method,
incorporating the two other methods later on during.
3.Nephrological or „blind" implantation of peritoneal dialysis
catheter is effective, quick, safe in all cases, when surgical
implantation is not indicated.
4.In all cases when US equipment is available, it is
recommended that a nephrologist him-/herself should perform
5.Indirect US renal biopsy method combined with automatic
single-use biopsy needles (e.g. COOK) is good to be used in
everyday conditions of a nephrology unit to minimize the risks of
obtaining a qualitative bioptate.
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zinātniskas pieejas veicinātāja nefroloģijā ar īpašu ietekmi peritoneālās
dialīzes (nieru aizstājterapija) metodes ieviešanā Latvijā un nieru
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slimību katedras sēde 2005.g. rudenī
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ārstu kongress, Rīga, 2005.
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- 7th Baltic Conference of Nephrology, 2004., Riga
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Peritoneal Dialysis Meeting, 2003, Pernava, Igaunija
6."Specificity of Development of Nephrology in Latvia" - 6th Conference
of Baltic Societies of Nephrology, 2002, Kaunas, Lietuva
7."Importance of Dialysate Quality in Peritoneal Dialysis"- Gambro
Baltijas valstu konference, 2002., Rīga"
8.Hypertension in Kidney Disease" - 2nd Baltic - Nordic
Meeting on Hypertension, 2001. g., Rīga.
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