Журнал «Здоровье ребенка» 2 (45) 2013

At the present stage the priority direction of revmatology is early diagnosis systemic and socially significant diseases in order to assign pathogenesis therapy from the first months of the illness. One of these diseases that lead to the quick disability in childhood, is juvenile rheumatoid arthritis (JRA). Difficulties in the diagnosis of JRA in the initial stages of the pathological process, especially the form of the primary lesions of joints, caused by nonspecific clinical manifestations, and their similarity with other rheumatic diseases, which are also accompanied by arthritis. Until recent times the classical specific marker of laboratory diagnostic for rheumatoid arthritis (RA) was considered rheumatoid factor (RF), which included in the classification criteria from 80-ies of the last century to present time [2, 7]. It's grounds for allocation of two basic variants of RA - seronegative and seropositive. The diagnostic sensitivity of RF is 50-90%, diagnostic specificity – 80-93%. The RF is essential for the diagnosis of RA in adults, but in children the frequency of its detection is much less - only 8-13% of patients [3, 4]. Nowadays much attention is given to new immunological markers of RA, including antibody to cyclic citrullinated peptide (a-CCP) and to modificated citrullinated vimentin (a-MCV). As the RF, they demonstrate a high sensitivity and specificity and correlate with the progression of the destructive changes in joints [8]. The role of these markers in the diagnosis of JRA data is too inconsistent, both in foreign and domestic literature. The goal of our research was to improve the diagnosis of JRA in the early stages of development by determining the frequency of detection of a-CCP and a-MCV and estimating features of clinical and laboratory parameters in seropositivity for these markers patients.

Materials and methods.

The study involved 77 children with symptoms of arthritis, who were hospitalized in the clinic of SE “Institute for Children and Adolescents Health Care of NAMS of Ukraine”. For diagnosis we guided by the International Classification of Diseases X, the Protocols of diagnosis and treatment kardiorevmatological diseases in children (Order of MoH № 362 of 2005). A-CCP has been determined by the method of ECL, a-MCV - the method of ELISA. Radiological stage JRA has been determined by classification by Shteynbroker. Echosonographical research of the structures of the joints was conducted on the device using the SIEMENS sensor from 5 to 9 MHz. At statistic processing material used programs Stagraphics 3.0, Parametric and not parametric criteria.

Discussion and interpretation of the results

At the examination stage, clinical and sonographic signs of arthritis have been found in all the patients. Detailed analysis had enabled us to diagnose juvenile rheumatoid arthritis (JRA) in 29 of them and reactive arthritis (ReA) in 48. The age of the patients ranged from 2 to 18 years with the prevalence of those under 10 (67,5%). Most patients were girls (n=48; 62,3%); 37,7% (n=29) were boys. The duration of disease was less than 6 months (n=31; 40,3%), from 6 months to 2 years (n=29; 37,6%), and more than 2 years (n=17; 22,1%). A-CCP antibodies were positive in 6 patients only; all of them had JRA; they formed group I. Patients with JRA who were negative for a-CCP and a-MCV formed group II (n=21; 27,3%). Patients with an increased level of a-MCV antibodies (n=9; 11,7%) formed group III: 5 (55,6%) of them had JRA and 4 had ReA. Group IV was formed by patients negative for all markers (n=65; 84,4%); (32,3 ± 5,8) % of them had JRA and (67,7 ± 5,8) % had ReA. Of all the patients with JRA, (20,7 ± 7,5) % were a-CCP positive and (17,2 ± 7,5) % were a-MCV positive; the patients with ReA were a-CCP negative; (8,3 ± 4,0) % of them had an increased a-MCV level.

A more detailed analysis has shown that a-CCP positive patients with JRA (group I) were girls at the age of 12-18; all of them had generalized arthropathy. Their mean age at the onset of the disease was (13,5 ± 1,3) years, being much older than the age of group II (р < 0,05) and group III (р < 0,05) patients.

The duration of the disease in group I patients was less than 1 year in 1/3 of cases, 1 year and several months in ½, and more than 2 years in the rest of patients. Patients' complaints mostly included arthralgia and morning joint stiffness. In most patients (83,3%) arthralgia was persistent and lasted during the day; 16,7% of patients had morning arthralgia. The mean pain intensity was (5,0 ± 1,9). Almost every group I patient (83,3 %) had morning joint stiffness, except those who had been receiving a prolonged basic methotrexate treatment (16,7%). The duration of morning joint stiffness has not been different from that of group II patients. Totally, in 16,7% of patients morning joint stiffness persisted until midday; in 33,3% of them it persisted for 1-2 hours; in the rest of the patients it persisted for 30 minutes.

General condition of group I patients was satisfactory in 50,0%; moderate in 33,3% and severe in 16,7%. Severe condition was encountered with approximately the same frequency in group I and group III; group II and group IV had no patients in severe condition. As mentioned before, the main feature of articular syndrome in group I patients was the presence of polyarticular arthropathy. Their median number of active joints by Ritchie index was (8,8 ± 7,1)  being greatly increased in comparison with a-CCP negative patients (р < 0,01). Articular syndrome in group I patients had a high percentage of ankle joint lesions and those of the small articulations of the hand (83,3%); wrist joint lesions and those of the small articulations of the foot (66,7%). Group I patients had an increased occurrence of arthritis of the small articulations of the hand compared with group II and III ((42,9 ± 10,8) %, р<0,01 and (44,4 ± 16,6) %, р<0,05 respectively). The same tendency has been noticed in the occurrence of the small articulations of the foot lesions compared with that of group II ((23,8 ± 9,3) %, р < 0,05). Knee joint lesions took place in 50% of patients of group I; elbow joint lesions - in 33,3%; hip joint lesions – in 16,7 %: approximately the same rates of lesion occurrence have been encountered in other groups of patients. Temporomandibular joint lesions have been encountered in (50,0 ± 20,4) % and cervical spine lesions in (66,7 ± 19,2) %, mostly occurring in a-CCP positive patients with JRA than in a-CCP negative ones (respectively, (9,5 ± 6,4) % and (28,6 ± 9,9) %, р < 0,05)). Joint effusion was moderate in most cases ((66,7 ± 19,2) %). The rate of bursitis ((66,7 ± 19,2) %) and regional amyotrophy (50,0 ± 20,4) %) in group I were approximately equal to those in all groups of patients.

 Graded with the Steinbrocker system, the patients’ radiographs had shown no changes in 16,7%; 33,3% of patients were assigned stage I and stage II; 16,7% were assigned stage III. It shoud be observed that group I patients had more frequent radiographic changes corresponding to Stage III than those of group II and III (р < 0,05); while the percentage of more than 2 year history in these groups was the same.

The analysis of the laboratory parameters indicated a high erythrocyte sedimentation rate (ESR) in 1/3 of group I patients; a high C-reactive protein concentration - in 1/2 of them. The levels of seromucoid, sialic acids and glycoproteins in the serum were not significantly different from normal. 33,2% of group I patients had an increased rheumatoid factor;  50,0% of them had high anti-MCV levels. The analysis of cellular immunity indicated that group I patients had a decreased percentage of mature T lymphocytes (CD3) ((48,7 ± 2,4) %, р < 0,05) as compared to normal and to the same parameter in group II patients. Phagocytic activity of neutrophils was not changed; phagocytic number was low in all groups (with no significant difference among them) as compared to healthy peers (р < 0,05). The analysis of humoral immunity indicated that circulating immune complexes, hemolytic complement activity, immunoglobulin A, G and M levels were normal. Anti-inflammatory cytokine IL-1-beta, and TNF-beta levels were normal; IL-6 level was high in group I, II and III patients as compared to normal, with no significant difference among them (р < 0,05).

Group II, formed by both a-CCP and a-MCV negative patients with JRA, included both boys and girls with respective sex ratio 1:2; their age ranged from 2 to 17 years. At the time of examination, the duration of the disease was less than 6 months in (28,6 ± 9,9) % of patients; from 6 months to 1 year in (14,3 ± 7,6) %; 1-2 years in (19,0 ± 8,6) %; more than 2 years in (38,1 ± 10,6) %. The mean age at the onset of the disease was (6,2 ± 2,0) years which was significantly less than the age of group I patients (р<0,001). Patients' complaints, as those of group I, mostly included arthralgia and morning joint stiffness. The small percentage of patients ((4,8 ± 4,7)%) with no arthralgia had oligoarthritis and received a prolonged methotrexate treatment. Most patients (52,4 %) had arthralgia during the day; 33,3% had morning arthralgia, and 9,5% had evening arthralgia. The mean pain intensity was (4,2 ± 0,7) being not significantly different from that in group I. A significant group II feature was the absence of morning joint stiffness in (42,9 ± 10,8) % of patients; when present, it was short and irregular. General condition of group II patients was satisfactory (42,9 %) or moderate (57,1%). As opposed to group I, there were no patients in severe conditions. Generalized form of arthritis prevailed in group II patients ((71,4 ± 9,9) %). They mostly had knee joint lesions (85,7 ± 7,6) %), ankle joint lesions ((71,4 ± 9,9) %), wrist joint lesions ((61,9 ± 10,6) %). Arthritis of the small articulations of the hand occurred half less than in group I patients (р < 0,01); the same can be said about arthritis of the small articulations of the foot ((23,8 ± 9,3) %; р < 0,05). Cervical spine lesions were less frequent than those in group I ((28,6 ± 9,9) %; р < 0,05). Arthritis of elbow joints occurred in (23,8 ± 9,3) % of group II patients. Temporomandibular joint lesions were quite rare (9,5 %). As opposed to group I, some patients had arthritis of shoulder joints (4,8%). Joint effusion was moderate in most cases (95,2 %). Nevertheless, their Ritchie index was much lower than in group I patients (р < 0,01). Most group II patients had regional amyotrophy (66,7 %) and bursitis (47,6 %). At early JRA stages, some patients (14,3 ± 7,6) % had a specific eye  lesion (uveitis). Steinbrocker stage scores were not significantly different from those of group I. There were no changes in radigoraphs of (19,0 ± 8,6) % of patients; (42,9 ± 10,8) % of patients were assigned stage I; (28,6 ± 9,9) % were assigned stage II, and (9,5 ± 6,4) % were assigned stage III. Laboratory parameters were not significantly different from those of group I (including such data as ESR; C-reactive protein concentration; the levels of seromucoid, sialic acids, glycoproteins; cellular immunity and humoral immunity parameters; and the level of cytokines).

Group III was formed by a-MCV positive patients (n=9; girls: 6; boys: 3; age: 2-16). 5 of them had JRA. The rest had ReA with polyarticular lesions and were mostly girls ((80,0 ± 17,9) %). It should be observed that three patients (60,0 %) had an increased anti-CCP level. At the time of examination, the disease duration was less than 6 months in most patients (66,7%); 1-2 years in 11,1%; more than 2 years in 11,1%. The most of the patients (88,9%) had arthralgia. The mean pain intensity was (4,2 ± 1,8). 1/3 of patients had an accentuated and persisting (until midday) morning joint stiffness; it lasted for 1,5-2 hours in 22,2% of patients, occurring briefly or not occurring at all in the rest. General condition of group III patients was mostly satisfactory (44,4 %) or moderate (44,4%); it must be observed that some patients (11,2%) were in severe condition which was not encountered in the patients of group I and group IV.

Articular syndrome had no significant differences as compared to group IV; most patients (55,6%) had polyarticular lesions (mostly those with JRA). 22,2% of patients had oligoarthritis and 22,2% had monoarthritis. Their median number of active joints by Ritchie index was (6,2 ± 5,1) and was not significantly different from that in other groups. Group III patients mostly had knee joint lesions (88,9 ± 10,5) % occurring significantly higher than in group I patients (р < 0,05). 55,6% of patients had ankle joint lesions. Temporomandibular joint lesions, lesions of the small articulations of the hand occurred at the same rate (44,4%); wrist joint lesions; lesions of the small articulations of the foot; cervical spine lesions occurred at the same rate (33,3%), with a lesser occurrence of lesions of the small articulations of the hand as compared to group I (83,3 %, р<0,05); and a higher occurrence of temporomandibular joint lesions as compared to group IV (4,6 %, р < 0,001). Hip joint lesions (22,2%) and elbow joint lesions (11,1%) had the same rate as in other groups. It must be observed that elbow joint lesions in groups III and IV were only encountered in patients with more than 2-year JRA duration. Group III patients had no shoulder joint lesions, occurred in (6,2 ± 3,0) % group IV patients. Joint effusion was moderate in 55,6% of patients and minimal in 22,2%; 22,2% of group III patients had an evident joint effusion which did not occur in group I and group II. Regional amyotrophy occurred in (44,4 ± 16,6) % of patients; 33,3% of patients had bursitis (mostly those with JRA). The patients’ radiographs had no specific changes in 55,6% of cases. 22,2% of patients had focal or diffuse osteoporosis; 22,2% of patients had osteoporosis accompanied by radiographically visible joint space narrowing which was scored as Steinbrocker stage II. As opposed to other groups, group III had no patients at Steinbrocker stage III.

 The analysis of the laboratory parameters indicated a high ESR in 66,7% of patients which was more frequent than in group I (33,2%) and group IV (15,4%); (р < 0,05). An increased C-reactive protein concentration was encountered in 33,3% of patients. On the opposite of group I, all group III patients were RF negative. The analysis of cellular immunity indicated that group III patients had a decreased percentage of mature T lymphocytes (CD3) ((49,0 ± 2,5) %, р < 0,05) as compared to normal. Relative percentage of CD4 was normal and that of CD8 was decreased as compared to group IV (р < 0,05). Both spontaneous and stimulated NBT test results were normal. Phagocytic activity of neutrophils had a downward trend (with no significant difference found) accompanied by a significant decrease in phagocytic number as compared to healthy peers (р < 0,05). Circulating immune complexes, hemolytic complement activity, general immunoglobulin A, G and M levels, IL-1-beta, TNF-beta  levels were normal. IL-6 level was high as compared to group IV and healthy peers (р < 0,05).

Conclusions

1. The rate of a-CCP positivity in patients with JRA was 20,7%; that of a-MCV positivity was 17,2%. A-CCP antibodies can be considered a specific JRA-marker while a-MCV antibodies can indicate arthritides of other geneses.

2. A-CCP positive patients with JRA were older than the others (12-18 years old); they had poliarticular lesions; a large amount of active joints; an accentuated and persisting morning joint stiffness; a high rate of lesions of the small articulations of the hand, cervical spine lesions; temporomandibular joint lesions; they tended to an accelerated development of Steinbrocker stage III. More than 30% of them were RF positive; more than 50% of them were a-MCV positive.

3. A-MCV positive patients with JRA and ReA in most cases were younger than a-CCP positive ones. Their main features were RF negativity; high occurrence of knee joint lesions accompanied by an accentuated effusion. Their Steinbrocker score was rarely higher than stage II.