British Journal of Urology (1975), 41, 585-587 0
Constituents of Urinary Calculi containing Struvite D. JUNE SUTOR Department of Chemistry, University College, London
Struvite (magnesium ammonium phosphate hexahydrate) usually with carbonate-apatite, are the constituents of urinary calculi associated with infection of the urine by urea-splitting organisms. It has been stated that once they are deposited in a stone, further layers will be composed of them and any change in composition is rare. As long ago as 1825, Prout said that mixed phosphates were not followed by other depositions and there were few exceptions to the rule, and in 1963, Prien reported that statistically the exception was only 1 in about 2,300 calculi in which struvite appeared. In our study of the composition of urinary calculi, a number of stones have been found in which either struvite was not deposited to the surface or other compounds were present with struvite, after a marked deposition of this material in the preceding layer or layers. Material and Methods The crystalline composition of 2,533 urinary stones has been determined by the X-ray powder method (Lonsdale, Sutor and Wooley, 1968). By cutting the calculi carefully in half and analysing samples from the different layers when possible, the sequential deposition of the crystalline constituents from the nucleus to the surface was determined in 1,889. The collection analysed is comprised of upper and lower urinary tract stones from children and adults in industrialised and technically-developingcountries, and of bladder stones from museum collections. It is therefore representative of the different types of urolithiasis known (Sutor, Wooley and Illingworth, 1974).
Results Out of the 715 stones in which struvite was present, the sequential deposition of the crystalline constituents could be determined in 615. In 139 of these, other constituents followed a marked deposition of struvite. In 122, the compound was accompanied by struvite; in 16, it replaced struvite; and in 1, both types of deposition had occurred (Tables I and 11). Excluding the apatites, one or both of which usually occur with struvite, all constituents of urinary calculi found in our work (Sutor, Wooley and Illingworth, 1974) could accompany struvite. More often than not, the substance had also been deposited in the inner layers (Table I). Ammonium acid urate and the monoand di-hydrates of calcium oxalate were the most commonly found compounds in this category. All the constituents of urinary calculi, except uric acid dihydrate, sodium acid urate monohydrate, cystine and brushite have been found to completely replace struvite in a stone (Table 11). Calcium oxalate monohydrate was the most frequently occurring compound in this group.
Discussion The study shows that in urinary calculi, compounds are frequently deposited after struvite, and these compounds can either accompany struvite or completely replace it in subsequent layers. This has occurred in all types of stones included in this survey, namely upper and lower urinary tract calculi from adults and children in technically-developing and industrialised countries and bladder stones in museum collections. The compounds usually involved are the most common constituents of stones apart from ammonium acid urate. The frequent occurrence of this material probably results from its formation in urine both infected by urea-splitting organisms and supersaturated with uric acid (Teotia and Sutor, 1971). The formation of struvite in human urinary calculi has not been thoroughly investigated. It is taken as being indicative of infection by urea-splitting organisms but whether it can occur in 47/6A
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BRITISH JOURNAL OF UROLOGY
Table I Number of Times a Compound followed Struvite, and was accompanied by Struvite in that Layer, for a Group of 615 Stones containing Struvite. Usual Type indicates the Compound had been Present in a Previous Layer, Italics indicates no Occurrence in Previous Layer. Constituent Anhydrous uric acid Uric acid dihydrate Ammonium acid urate Sodium acid urate monohydrate Calcium oxalate monohydrate Calcium oxalate dihydrate Cystine Brushite Whitlockite Octacalcium phosphate Unidentified material Number of stones in each group
Group 1
Group 2
Group 3
Group 4
... ......
... ... ... ...... 2 ... ... 2 ...... ......
......
...... ......
1
20
1
...... 10 5
3 4
...... ... 1 1 ... ...... ...... 32
1
1 9
...... 1
I
...... 5 4 1
6 4
...... ......
... ...... 1 1 ......
11
1 I 21
......
2
10 1 2
... 1
... 1 ...... ...
1
1
...
1
2
Unclassified
...... ...... 24
3
...
1
18 3
1
6 4 7 1
I
37 I 4
I
...
3
4
1
1 1
2 1
...
1
... ...
2
4 3
...... ...
Total
......
...... ......
19
40
12 I 4 1 ...
123
Group 1 = Children’s bladder and kidney stones from technically-developing countries and children’s bladder stones from museum collections. Group 2 = Adult bladder stones from technically-developingcountries and museum collections. Group 3 = Adult and children’s upper urinary tract stones from industrialised countries. Group 4 = Adult and children’s lower urinary tract stones from industrialised countries.
Table I1 Number of Times a Compound followed Struvite, but was not accompanied by Struvite in that Layer, for a Group of 61 5 Stones containing Struvite. Usual Type indicates the Compound had been Present in a Previous Layer, Italics indicates no Occurrence in Previous Layer. Constituent Anhydrous uric acid Ammonium acid urate Calcium oxalate monohydrate Calcium oxalate dihydrate Whitlockite Octacalcium phosphate Number of stones in each group
Group 1
......
...... ...... ...... ...... ...... 0
Group 2
...
2
...
Group 3
...... 1 ...
Group 4
...
I
......
...... ......
... 2 1 1 ......
... ... ...... 1 ... 1 ...
4
7
3
2 3
...
2
1
1 2
Unclassified
...... ...... 2 1
1
... ...... ...... 3
Total
... 4 9 1 2 1
3
... 2 2 1
...
17
Key to groups in Table I.
sterile urine is not known. As in other studies where the composition of stones containing struvite has been determined, data were not available to assess if the latter situation is possible. However, struvite is the usual constituent of calculi from cats and is formed in non-infected urine (Jackson, 1971). This suggests that, under certain circumstances, struvite might precipitate from noninfected human urine. Although the conditions under which compounds accompany or replace struvite in stones are not known, this work has shown that the presence of such compounds is not as uncommon as hitherto thought.
CONSTITUENTS OF URINARY CALCULI CONTAINING STRUVITE
587
Summary In a collection of 615 stones containing struvite and in which the sequential deposition of the constituents from the nucleus to the surface had been determined, other substances were found to follow a marked deposition of struvite in 139 cases. In 122, the compound was accompanied by struvite, in 16, struvite was replaced by it and in 1, both types of deposition had occurred indifferent layers. All urinary stone constituents could accompany struvite and many could replace this compound. This work was financed by the Medical Research Council.
References JACKSON, 0. (1971). The treatment and subsequent prevention of struvite urolithiasis in cats. Journal of Small Animal Practice, 12, 555-568. LONSDALE, K., SUTOR, D. J. and WOOLEY, S. E. (1968). Composition of urinary calculi by X-ray diffraction. Collected data from various localities. I. Norwich (England) and District, 1773-1961. British Journal of Urology, 40,33-36. PRIEN,E. L. (1963). Crystallographic analysis of urinary calculi: a 23-year survey study. Journal of Urology, 89, 917-924. PROUT,W. (1825). An inquiry into the nature and treatment of diabetes, calculus and other affections of the urinary organs. 2nd ed. London. Baldwin, Cradock and Joy. SUTOR, D. J., WOOLEY,S. E. and ILLINGWORTH, J. J. (1974). A geographical and historical survey of the composition of urinary stones. British Journal of Urology, 46, 393-407. TEOTIA, M. and SUTOR, D. J. (1971). Crystallisation of ammonium acid urate and other uric acid derivatives from urine. British Journal of Urology, 43, 381-386.
The Author D. June Sutor, PhD, Associate Senior Research Fellow.
Constituents of Urinary Calculi containing Struvite D. JUNE SUTOR Department of Chemistry, University College, London
Struvite (magnesium ammonium phosphate hexahydrate) usually with carbonate-apatite, are the constituents of urinary calculi associated with infection of the urine by urea-splitting organisms. It has been stated that once they are deposited in a stone, further layers will be composed of them and any change in composition is rare. As long ago as 1825, Prout said that mixed phosphates were not followed by other depositions and there were few exceptions to the rule, and in 1963, Prien reported that statistically the exception was only 1 in about 2,300 calculi in which struvite appeared. In our study of the composition of urinary calculi, a number of stones have been found in which either struvite was not deposited to the surface or other compounds were present with struvite, after a marked deposition of this material in the preceding layer or layers. Material and Methods The crystalline composition of 2,533 urinary stones has been determined by the X-ray powder method (Lonsdale, Sutor and Wooley, 1968). By cutting the calculi carefully in half and analysing samples from the different layers when possible, the sequential deposition of the crystalline constituents from the nucleus to the surface was determined in 1,889. The collection analysed is comprised of upper and lower urinary tract stones from children and adults in industrialised and technically-developingcountries, and of bladder stones from museum collections. It is therefore representative of the different types of urolithiasis known (Sutor, Wooley and Illingworth, 1974).
Results Out of the 715 stones in which struvite was present, the sequential deposition of the crystalline constituents could be determined in 615. In 139 of these, other constituents followed a marked deposition of struvite. In 122, the compound was accompanied by struvite; in 16, it replaced struvite; and in 1, both types of deposition had occurred (Tables I and 11). Excluding the apatites, one or both of which usually occur with struvite, all constituents of urinary calculi found in our work (Sutor, Wooley and Illingworth, 1974) could accompany struvite. More often than not, the substance had also been deposited in the inner layers (Table I). Ammonium acid urate and the monoand di-hydrates of calcium oxalate were the most commonly found compounds in this category. All the constituents of urinary calculi, except uric acid dihydrate, sodium acid urate monohydrate, cystine and brushite have been found to completely replace struvite in a stone (Table 11). Calcium oxalate monohydrate was the most frequently occurring compound in this group.
Discussion The study shows that in urinary calculi, compounds are frequently deposited after struvite, and these compounds can either accompany struvite or completely replace it in subsequent layers. This has occurred in all types of stones included in this survey, namely upper and lower urinary tract calculi from adults and children in technically-developing and industrialised countries and bladder stones in museum collections. The compounds usually involved are the most common constituents of stones apart from ammonium acid urate. The frequent occurrence of this material probably results from its formation in urine both infected by urea-splitting organisms and supersaturated with uric acid (Teotia and Sutor, 1971). The formation of struvite in human urinary calculi has not been thoroughly investigated. It is taken as being indicative of infection by urea-splitting organisms but whether it can occur in 47/6A
585
5 86
BRITISH JOURNAL OF UROLOGY
Table I Number of Times a Compound followed Struvite, and was accompanied by Struvite in that Layer, for a Group of 615 Stones containing Struvite. Usual Type indicates the Compound had been Present in a Previous Layer, Italics indicates no Occurrence in Previous Layer. Constituent Anhydrous uric acid Uric acid dihydrate Ammonium acid urate Sodium acid urate monohydrate Calcium oxalate monohydrate Calcium oxalate dihydrate Cystine Brushite Whitlockite Octacalcium phosphate Unidentified material Number of stones in each group
Group 1
Group 2
Group 3
Group 4
... ......
... ... ... ...... 2 ... ... 2 ...... ......
......
...... ......
1
20
1
...... 10 5
3 4
...... ... 1 1 ... ...... ...... 32
1
1 9
...... 1
I
...... 5 4 1
6 4
...... ......
... ...... 1 1 ......
11
1 I 21
......
2
10 1 2
... 1
... 1 ...... ...
1
1
...
1
2
Unclassified
...... ...... 24
3
...
1
18 3
1
6 4 7 1
I
37 I 4
I
...
3
4
1
1 1
2 1
...
1
... ...
2
4 3
...... ...
Total
......
...... ......
19
40
12 I 4 1 ...
123
Group 1 = Children’s bladder and kidney stones from technically-developing countries and children’s bladder stones from museum collections. Group 2 = Adult bladder stones from technically-developingcountries and museum collections. Group 3 = Adult and children’s upper urinary tract stones from industrialised countries. Group 4 = Adult and children’s lower urinary tract stones from industrialised countries.
Table I1 Number of Times a Compound followed Struvite, but was not accompanied by Struvite in that Layer, for a Group of 61 5 Stones containing Struvite. Usual Type indicates the Compound had been Present in a Previous Layer, Italics indicates no Occurrence in Previous Layer. Constituent Anhydrous uric acid Ammonium acid urate Calcium oxalate monohydrate Calcium oxalate dihydrate Whitlockite Octacalcium phosphate Number of stones in each group
Group 1
......
...... ...... ...... ...... ...... 0
Group 2
...
2
...
Group 3
...... 1 ...
Group 4
...
I
......
...... ......
... 2 1 1 ......
... ... ...... 1 ... 1 ...
4
7
3
2 3
...
2
1
1 2
Unclassified
...... ...... 2 1
1
... ...... ...... 3
Total
... 4 9 1 2 1
3
... 2 2 1
...
17
Key to groups in Table I.
sterile urine is not known. As in other studies where the composition of stones containing struvite has been determined, data were not available to assess if the latter situation is possible. However, struvite is the usual constituent of calculi from cats and is formed in non-infected urine (Jackson, 1971). This suggests that, under certain circumstances, struvite might precipitate from noninfected human urine. Although the conditions under which compounds accompany or replace struvite in stones are not known, this work has shown that the presence of such compounds is not as uncommon as hitherto thought.
CONSTITUENTS OF URINARY CALCULI CONTAINING STRUVITE
587
Summary In a collection of 615 stones containing struvite and in which the sequential deposition of the constituents from the nucleus to the surface had been determined, other substances were found to follow a marked deposition of struvite in 139 cases. In 122, the compound was accompanied by struvite, in 16, struvite was replaced by it and in 1, both types of deposition had occurred indifferent layers. All urinary stone constituents could accompany struvite and many could replace this compound. This work was financed by the Medical Research Council.
References JACKSON, 0. (1971). The treatment and subsequent prevention of struvite urolithiasis in cats. Journal of Small Animal Practice, 12, 555-568. LONSDALE, K., SUTOR, D. J. and WOOLEY, S. E. (1968). Composition of urinary calculi by X-ray diffraction. Collected data from various localities. I. Norwich (England) and District, 1773-1961. British Journal of Urology, 40,33-36. PRIEN,E. L. (1963). Crystallographic analysis of urinary calculi: a 23-year survey study. Journal of Urology, 89, 917-924. PROUT,W. (1825). An inquiry into the nature and treatment of diabetes, calculus and other affections of the urinary organs. 2nd ed. London. Baldwin, Cradock and Joy. SUTOR, D. J., WOOLEY,S. E. and ILLINGWORTH, J. J. (1974). A geographical and historical survey of the composition of urinary stones. British Journal of Urology, 46, 393-407. TEOTIA, M. and SUTOR, D. J. (1971). Crystallisation of ammonium acid urate and other uric acid derivatives from urine. British Journal of Urology, 43, 381-386.
The Author D. June Sutor, PhD, Associate Senior Research Fellow.
