Tropical infections in the ICU.

Certain arthropod-borne infections are common in tropical regions because of favorable climatic conditions. Water-borne infections like leptospirosis are common due to contamination of water especially during the monsoon floods. Infections like malaria, leptospirosis, dengue fever and typhus sometimes cause life threatening organ dysfunction and have several overlapping features. Most patients present with classicial clinical syndromes: fever and thrombocytopenia are common in dengue, malaria and leptospirosis; coagulopathy is frequent in leptospirosis and viral hepatitis. Hepatorenal syndrome is seen in leptospirosis, falciparum malaria and scrub typhus. The pulmonary renal syndrome is caused by falciparium malaria, leptospirosis, Hantavirus infection and scrub typhus. Fever with altered mental status is produced by bacterial meningitis, Japanese B encephalitis, cerebral malarial, typhoid encephalopathy and fulminant hepatic failure due to viral hepatitis. Subtle differences in features of the organ failure exist among these infections. The diagnosis in some of these diseases is made by demonstration of antibodies in serum, and these may be negative in the first week of the illness. Hence empiric therapy for more than one disorder may be justified in a small proportion of cases. In addition to specific anti-infective therapy, management of organ dysfunction includes use of mechanical ventilation, vasopressor drugs, continuous renal replacement therapy and blood products. Timely transfer of these patients to well-equipped ICUs with experience in managing these cases can considerably decrease mortality and morbidity.

Anti-neutrophil cytoplasmic antibodies (ANCA) in systemic lupus erythematosus: prevalence, clinical associations and correlation with other autoantibodies.

AIM: This study was undertaken to clarify the nature of anti-neutrophil cytoplasmic antibodies (ANCA) along with other autoantibodies in lupus nephritis (LN) patients and in systemic lupus erythematosus (SLE) patients without nephritis and to know their correlation with clinical manifestations and presence of other autoantibodies. MATERIAL AND METHODS: Fourty one LN patients and 18 SLE patients without nephritis were studied. LN patients were subdivided into diffuse proliferative glomerulonephritis (DPGN), focal proliferative glomerulonephritis (FPGN), rapidly progressive glomerulonephritis (RPGN) and membranoproliferative glomerulonephritis (MPGN). Anti-neutrophil cytoplasmic antibodies (ANCA) were detected by indirect immunofluorescence and confocal laser scanning microscope using PMN and HL60 cells. ANCA specificities like anti-myeloperoxidase (anti-MPO), anti-proteinase 3 (anti-PR3), anti-lactoferrin (anti-LF) and anti-cathepsin G (anti-CG) were detected by ELISA. Other autoantibodies like anti-nuclear antibodies (ANA), anti-double stranded DNA (anti-dsDNA), anti-single stranded DNA(anti-ssDNA), anti-ribonucleoproteins (anti-nRNP), anti-Smith antibodies (anti-Sm) and rheumatoid factor (RF) were also tested. RESULTS: ANCA was detected in 37.3% patients. The predominant ANCA pattern was perinuclear (p-ANCA). ANCA positivity was higher in LN patients and when confirmed by ELISA, 54.5% ANCA positives had anti-myeloperoxidase (anti-MPO). The cytoplasmic ANCA (c-ANCA) pattern was not seen in any patient. Two patients having FPGN with crescents showed atypical 'X-ANCA' pattern with dual specificity to anti-MPO and anti-PR3 by ELISA. The titers of ANCA were more in LN as compared to SLE without nephritis. LN cases having DPGN, FPGN, RPGN with crescents had higher titer p-ANCA positivity with corresponding anti-MPO antibodies, along with ANA, anti-dsDNA, anti-ssDNA and anti-Sm + anti-nRNP and also high SLEDAI scores. CONCLUSION: ANCA in SLE may be used as a serological marker along with clinical and histopathological assessment to differentiate vasculitides in LN cases from SLE without nephritis.

Antibodies to Ro/SS-A and La/SS-B in systemic lupus erythematosus and other autoimmune disorders.

AIM: 1. To study the presence of anti-Ro/SS-A, anti-La/SS-B, anti-Sm and anti-nRNP in diagnosed antinuclear factor (ANF) positive systemic lupus erythematosus (SLE) cases and their association with various organ involvement. 2. To study autoantibodies in other autoimmune disorders. MATERIAL AND METHODS: A total of 4050 suspected cases of autoimmune disorders referred for serological work up were evaluated for ANF by indirect immunofluorescence technique, anti-dsDNA by PHA, autoantibodies to Ro-SS-A and La/SS-B by ELISA and rheumatoid factor was tested by latex agglutination using commercial kits. RESULTS: Out of 4050 patients 19.5% were ANF positive and 5% were anti-dsDNA positive. Out of these 50 diagnosed ANF positive cases of SLE, an incidence of anti-dsDNA 54%, anti-Sm 25.9%, anti-nRNP 29.6%, anti-Ro/SS-A 10% and anti-La/SS-B was 22% was observed. In rheumatoid arthritis, 17.4% positivity of anti-Ro/SS-A and 39.1% positivity for anti-La/SS-B was observed. In SLE with renal involvement, joint complaints and skin or malar rash were seen in 66%, 56% and 46%, respectively. CONCLUSION: Determining anti-Ro/SS-A and anti-La/SS-B antibody could be important in evaluating patients with suspected connective tissue disorders, who usually show diverse clinical presentations like skin, kidney and joint manifestations. The most prominent feature in anti-Ro/SS-A and anti-La/SS-B positive patients was skin involvement and sicca complex in 60% of SLE patients.