RENAL INVOLVEMENT IN PATIENTS WITH RHEUMATOID ARTHRITIS- A HOSPITAL-BASED OBSERVATIONAL STUDY.

Abstract

Background: Rheumatoid arthritis is a chronic multisystem, immuno-inammatory disease characterized by articular and extra-articular manifestations. The disease's hallmark is synovial inammation and potential to cause cartilage damage, bone erosion, and subsequent damage to joint integrity. Rheumatoid arthritis is a systemic disease with a variety of extra-articular manifestations. The predominant well-recognized systemic manifestations include Sjogren's syndrome, pulmonary, cardiac, neurological, renal, gastrointestinal, dermal involvement, vasculitis, and Felty's syndrome. Regarding renal involvement in connective tissue disease, the focus is on systemic lupus erythematosus (SLE). The affection of kidneys in RA is more or less overlooked and mainly attributed to drugs (NSAIDs, DMARDs like gold and d-penicillamine, which are less commonly used in today's scenario. The other primary etiology of kidney involvement in RA is secondary amyloidosis, commonly associated with the long-term disease process. Vasculitis with RA is a relatively less common etiology of renal involvement in RA. Renal involvement in Rheumatoid arthritis has been well documented with a prevalence of 1-5%. Although impairment of renal function is often mild to moderate, renalrelated mortality signicantly contributes to the increased mortality of RA. The kidney is involved in RA with both glomerular and tubular damage. Renal damage in RA, however, is usually asymptomatic and is detected on laboratory investigation. It is often difcult to differentiate between damage due to disease activity and drugs used to treat RA. It is a hospita Methods: l based observational study conducted at Gauhati Medical college, Assam, for one year. All Adult (> 18 years) patients fullled the 2010 American College of Rheumatology Criteria for Rheumatoid arthritis were included. Patients with diabetes mellitus congestive heart failure, urinary tract infection, long standing and uncontrolled hypertension, preexisting renal disease , overlap syndrome and pregnant patients were excluded. Detailed clinical history was taken from all included patients regarding onset and duration of disease. Disease activity was measured using disease activity score -28 -(DAS-28). Routine investigation, ESR, CRP, renal function test, ultrasonography and urine for microalbuminuria were measured in all included patients. The maximum age was Results: 68 years, the minimum was 20 years, and the mean age was 40.22 ± 11.58. The study group included 38 females and 12 males accounting for 76% and 24%, respectively. The mean disease duration was 18.6 months with a range of 3-60 months. All patients presented with polyarthritis(100%). History of morning stiffness was present in 54% of patients, while 46% had generalized weakness and constitutional symptoms. In our study, microalbuminuria was found in 15 patients (30%). Mmicroalbuminuria was seen more commonly in the age group between 41-50 years. Microalbuminuria was signicantly associated with higher ESR values. Out of 15 patients positive for microalbuminuria, 13 patients had ESR >50, and 7 had ESR >100 with a p-value <0.001. Mean CRP was 42.45 mg/l in microalbuminuria-positive patients as compared to 16.19mg/l in microalbuminuria-negative patient. Out of 15 patients with microalbuminuria positive had evidence of erosion on x-ray, with a p-value of 0.017. Conclusion: From the present study, it can be concluded that the peak age of the disease is 31-50 years, with female preponderance. Polyarthritis is the most common presenting symptom, and most patients have an insidious onset. Constitutional symptoms like fever, malaise, and anorexia are more common among the extra-articular features. Asymptomatic renal involvement is common, and microalbuminuria is frequently seen in patients with Rheumatoid Arthritis. The presence of microalbuminuria is a sensitive indicator of increased renal vascular permeability in rheumatoid arthritis patients. Immunological methods for detecting microalbuminuria should be routinely used in all Rheumatoid Arthritis patients to detect renal involvement in its initial phase to devise the most appropriate treatment.