Glomerular mannose-binding lectin deposition is a useful prognostic predictor in immunoglobulin A nephropathy.

There is accumulating evidence to support a hypothesis of the activation of the lectin complement pathway in immunoglobulin A nephropathy (IgAN). The glomerular deposition of mannose-binding lectin (MBL), an initiator of the lectin pathway, has been identified, but its clinical significance has not been defined consistently. The aim of the present study was to investigate the value of glomerular MBL deposition as a useful histological biomarker in evaluating the severity and predicting the prognosis of IgAN. We included all consecutive patients with biopsy-proven primary IgAN from December 2008 to July 2010. Renal deposition of MBL was detected by immunofluorescence. The biopsy material from 131 patients (72 men) was thus used for MBL staining. The deposition of MBL was observed in a predominantly mesangial pattern in 45 patients (34·35%), which presented as global or segmental deposition. Compared with the patients without glomerular MBL deposition, those with glomerular MBL deposition had more severe proteinuria, decreased renal function, lower levels of serum albumin and a greater possibility of hypertension at the time of renal biopsy; they had more severe histological changes according to the Oxford classification (i.e. mesangial hypercellularity, segmental glomerulosclerosis, endocapillary hypercellularity and tubular atrophy/interstitial fibrosis), and their ratio presented an increase as the histopathological phenotypes segregated according to Lee's classification; furthermore, the follow-up data demonstrated that they had a lower renal remission rate. In conclusion, glomerular MBL deposition may predict a poor prognosis, and thus can be a new prognostic factor in IgA nephropathy.

Rapid diagnosis in early stage renal tuberculosis by real-time polymerase chain reaction on renal biopsy specimens.

OBJECTIVE: To determine the early rapid diagnosis of renal tuberculosis (RTB) by real-time polymerase chain reaction (PCR) on renal biopsy specimens. METHODS: Ninety patients were selected for this study. The patients were divided into the following three groups: RTB, non-RTB (N-RTB) and clinically suspected RTB (CS-RTB). The renal biopsy specimens of these patients were used for Mycobacterium tuberculosis DNA detection by real-time PCR, using 35 and 40 as cycle threshold (C(T)) cut-off values. Morning urine samples were collected for M. tuberculosis culture. RESULTS: In the RTB group, 25 C(T)35 and 28 C(T)40 patients were PCR-positive, seven of whom were urine M. tuberculosis culture-positive. In the N-RTB group, four C(T)35 and 13 C(T)40 patients were PCR-positive, none of whom were urine M. tuberculosis culture-positive. In the CS-RTB group, nine C(T)35 and 14 C(T)40 patients were PCR-positive, two of whom were urine M. tuberculosis culture-positive during 12 months of follow-up. The sensitivity and specificity of real-time PCR (C(T)40) were respectively 93.3% and 56.7%. The sensitivity and specificity of real-time PCR (C(T)35) were respectively 83.3% and 86.7%. The sensitivity and specificity of the urine M. tuberculosis culture were respectively 23.3% and 100%. CONCLUSIONS: The detection of M. tuberculosis DNA in renal biopsy tissue by real-time PCR is highly sensitive. Real-time PCR can increase diagnostic accuracy and provide valuable information regarding the early diagnosis of RTB.

Genetic diversity and multiple infections of Plasmodium vivax malaria in Western Thailand.

Using two polymorphic genetic markers, the merozoite surface protein-3alpha (MSP-3alpha) and the circumsporozoite protein (CSP), we investigated the population diversity of Plasmodium vivax in Mae Sod, Thailand from April 2000 through June 2001. Genotyping the parasites isolated from 90 malaria patients attending two local clinics for the dimorphic CSP gene revealed that the majority of the parasites (77%) were the VK210 type. Genotyping the MSP3-alpha gene indicated that P. vivax populations exhibited an equally high level of polymorphism as those from Papua New Guinea, a hyperendemic region. Based on the length of polymerase chain reaction products, three major types of the MSP-3alpha locus were distinguished, with frequencies of 74.8%, 18.7%, and 6.5%, respectively. The 13 alleles distinguished by restriction fragment length polymorphism analysis did not show a significant seasonal variation in frequency. Genotyping the MSP-3alpha and CSP genes showed that 19.3% and 25.6% of the patients had multiple infections, respectively, and the combined rate was 35.6%. Comparisons of MSP-3alpha sequences from nine clones further confirmed the high level of genetic diversity of the parasite and also suggested that geographic isolation may exist. These results strongly indicate that P. vivax populations are highly diverse and multiple clonal infections are common in this malaria-hypoendemic region of Thailand.