Diagnosis of juvenile chronic arthritis

Laboratory Diagnostics of Juvenile Rheumatoid Arthritis

In the systemic version of juvenile rheumatoid arthritis, leukocytosis (up to 30-50 thousand leukocytes) with a neutrophilic shift to the left (up to 25-30% of stabic leukocytes, sometimes to myelocytes) is often detected, an increase in ESR to 50-80 mm / h, hypochromic anemia, thrombocytosis , an increase in the concentration of C-reactive protein, IgM and IgG in serum.

In the case of a polyarticular variant, hypochromic anemia, minor neutrophilic leukocytosis (up to 15x10 ⁹ / l), ESR above 40 mm / h are revealed . Sometimes a positive ANF in the serum is detected in a low titer. Rheumatoid factor is positive for seropositive variant of juvenile rheumatoid arthritis, negative for seronegative variant. Elevated serum concentrations of IgM, IgG, C-reactive protein. When a seropositive variant of juvenile rheumatoid arthritis occurs HLA DR4 antigen.

In the oligoarticular variant with an early onset, sometimes inflammatory changes in blood indices typical for juvenile rheumatoid arthritis are revealed. In some patients laboratory parameters are within the normal range. In 80% of patients, positive serum ANF is detected, rheumatoid factor is negative, high detection frequency is HLA A2.

In the oligoarticular variant with a late onset in clinical blood analysis, hypochromic anemia, neutrophilic leukocytosis, an increase in ESR greater than 40 mm / h is revealed. Sometimes a positive ANF in a low titer is found, the rheumatoid factor is negative. Increased serum concentrations of IgM, IgG, C-reactive protein. High detection frequency HLA B27.

Determination of the degree of disease activity by laboratory indicators:

• 0 degree - ESR up to 12 mm / h, C-reactive protein is not detected;
• I degree - ESR 13-20 mm / h, C-reactive protein weakly positive ("+");
• II degree - ESR 21-39 mm / h, C-reactive protein positive ("++");
• III degree - ESR 40 mm / h or more, C-reactive protein is sharply positive ("+++", "++++").

Instrumental methods

If there is myopericarditis on the ECG, there will be signs of an overload of the left and / or right parts of the heart, a violation of the coronary circulation, an increase in pressure in the pulmonary artery system.

Echocardiography allows to identify dilatation of the left ventricle, reduction of the left ventricular ejection fraction, hypokinesia of the posterior wall of the left ventricle and / or interventricular septum; signs of relative insufficiency of mitral and / or tricuspid valves, increased pressure in the pulmonary artery; with pericarditis - separation of pericardial sheets, presence of free fluid in the cavity.

Radiographic examination of chest organs reveals an increase in the size of the heart at the expense of the left divisions (less often total), an increase in the cardiothoracic index, an increase in the vascular interstitial pattern of light spotted-cellular character, focal shadows. With fibrosing alveolitis in early stages, the strengthening and deformation of the lung pattern are revealed, with progression - tight sealings, cellular enlightenment, a picture of the "cellular" lung is formed.

An important stage of the examination of the patient is the radiographic examination of the joints.

Determination of the stage of anatomical changes (according to Steinbroke):

• Stage I - epiphyseal osteoporosis;
• II stage - epiphyseal osteoporosis, cartilage unfolding, narrowing of the joint gap, single erosion;
• III stage - destruction of cartilage and bone, formation of bone-cartilage erosions, subluxations in the joints;
• IV stage - criteria of the III stage + fibrous or bone ankylosis.

In addition, define the functional class (according to Steinbroke).

• I class: the functional capacity of joints and the possibility of self-service are preserved.
• II class: the functional capacity of the joints is partially lost, the ability to self-service is preserved.
• III class: the functional capacity of the joints and the ability to self-service are partially lost.
• IV class: the functional capacity of the joints and the ability to self-service are completely lost.

Differential diagnosis of juvenile rheumatoid arthritis

Disease	Features of articular syndrome	Notes
Acute rheumatic fever	Polyartralgia without visible changes in the joints; with rheumatoid arthritis symmetrical lesion of large joints of lower extremities without deformations, is of a migratory nature, quickly stops on the background of anti-inflammatory therapy of NSAIDs and corticosteroids; develops after 1.5-2 weeks after acute streptococcal infection
Reactive arthritis	They develop 1.5-2 weeks after the infectious diseases of the urogenital organs caused by chlamydia, or diarrhea caused by Yersinia, Salmonella, Shigella; asymmetric defeat of the joints, often lower limbs: knee, ankle, small joints of the feet; the development of unilateral sakroileitis, tendovaginitis of the calcaneal tendon and plantar fasciitis, periostitis of calcaneal tubercles	Yersiniosis can occur with fever, rash, arthralgia, arthritis, high laboratory activity indicators and may be a "mask" of the systemic version of juvenile rheumatoid arthritis; for yersiniosis is characterized by peeling of the skin of the palms and feet; a symptom complex including urethritis, conjunctivitis, arthritis, skin and mucous membrane damage (nail dystrophy with keratosis, keratoderma on the soles and palms), the presence of HLA-B27, was called Reiter's disease
Psoriatic arthritis	Asymmetric oligo- or polyarthritis with involvement of distal interphalangeal joints of the hands and feet or large joints (knee, ankle); develops severe destructive (mutilating) arthritis with bone resorption, ankyloses; sakroileitis and spondylitis in combination with peripheral joint damage	There are typical psoriatic changes in skin and nails
Juvenile ankylosing spondylitis	The defeat of the joints of the lower extremities (hip and knee)	Characteristic of the presence of HLA B27, enthesopathies; Symptoms of a lesion of the spine and sacroiliac joints usually appear after a few years; Progressive destruction of cartilage with ankylosing of ileosacral articulation is characteristic
Systemic lupus erythematosus	In the initial period of the disease there are polyarthralgia of a volatile nature and asymmetric joint damage; in the midst of the disease - symmetrical damage to the joints, not accompanied by erosion and persistent deformities, morning stiffness	It is confirmed by the presence of a typical face erythema, polyserositis (more often pleurisy), nephritis, CNS damage, leukopenia and thrombocytopenia, lupus anticoagulant, ANF, antibodies to DNA, antiphospholipid antibodies
Systemic scleroderma	Arthralgia, passing into subacute or chronic arthritis, the joints are affected symmetrically; in the process involve small joints of the hands and wrist joints with minimal exudative manifestations, but a pronounced softening of the soft tissues, the development of flexion contractures, subluxations	Combined with characteristic skin and radiologic changes
Hemorrhagic vasculitis (Schönlein-Henoch disease)	Arthralgia or arthritis, articular syndrome unstable	Polymorphic, mainly hemorrhagic rash on the lower extremities, large joints, buttocks; combined with abdominal and renal syndrome
Chronic ulcerative colitis and Crohn's disease	Peripheral asymmetric arthritis with predominant involvement of lower limb joints; spondylitis, sacroiliitis; is associated with the activity of the underlying disease	High detection frequency HLAB27
Tuberculosis	Pronounced arthralgia, spinal injury, unilateral rushes, cocksite; develop diffuse osteoporosis, marginal bone defects, rarely limited bone cavity with the presence of sequestration; destruction of the articular ends of bones, their displacement and subluxation; also distinguish reactive polyarthritis, which develops against the background of visceral tuberculosis; characteristic lesion of small joints	It is combined with positive tuberculin tests
Lyme disease (systemic tick-borne borreliosis)	Mono-, oligo-, symmetric polyarthritis; possible development of cartilage and bone erosion	It is combined with tick-borne erythema, defeat of the nervous system, heart
Viral arthritis	Articular syndrome is short-term, completely reversible	They occur in acute viral hepatitis, rubella, epidemic parotitis, smallpox, arbovirus infection, infectious mononucleosis, and others.
Hypertrophic osteoarthropathy (Marie-Bamberger syndrome)	Deflection of fingers in the form of "tympanic sticks", hypertrophic periostitis of long tubular bones, arthralgia or arthritis with effusion to the joint cavity; symmetrical lesion of the distal joints of the upper and lower extremities (wrists, tarsus, knee joints)	Occurs with tuberculosis, fibrosing alveolitis, lung cancer, sarcoidosis
Hemophilia	It is accompanied by hemorrhages in joints with subsequent inflammatory reaction and effusion; affected knee joints, rarely ulnar and ankle, wrist, shoulder and hip; comparatively rare - joints of hands, feet and intervertebral joints	Begins in early childhood
Leukemia	Ossalgia, flying arthralgia, asymmetric arthritis with sharp permanent joint pains, exudative component and pain contractures	It is necessary to exclude in systemic versions of juvenile rheumatoid arthritis
Neoplastic processes (neuroblastoma, sarcoma, osteoid osteoma, metastasis in leukemia)	May be accompanied by myalgia, ossalgia, arthralgia, monoarthritis; characterized by a pronounced pain syndrome in the periarticular regions, a severe general condition that does not correlate with the activity of arthritis	Combines with typical hematological and radiologic changes
Hypothyroidism	Arthralgia with a small edema of soft tissues and non-inflammatory effusion into the joint cavity; affect the knee, ankle joints and joints of the hands, can develop a symptom of the carpal tunnel	Characteristic violations of the formation of the skeleton, slowing the growth of long tubular bones and ossification, osteoporosis, muscle weakness, myalgia
Septic arthritis	It begins acutely; often occurs as a monoarthritis, with severe intoxication, an increase in temperature, acute phase parameters of inflammation, which is not typical for oligoarthritis with early onset

[1], [2], [3], [4]