Markedly elevated levels of β2-microglobulin in urine with measles viruria in patients with measles

FeMV is a cathepsin-dependent unique morbillivirus infecting the kidneys of domestic cats

Feline morbillivirus (FeMV) is a recently discovered pathogen of domestic cats and has been classified as a morbillivirus in the Paramyxovirus family. We determined the complete sequence of FeMV^US5 directly from an FeMV-positive urine sample without virus isolation or cell passage. Sequence analysis of the viral genome revealed potential divergence from characteristics of archetypal morbilliviruses. First, the virus lacks the canonical polybasic furin cleavage signal in the fusion (F) glycoprotein. Second, conserved amino acids in the hemagglutinin (H) glycoprotein used by all other morbilliviruses for binding and/or fusion activation with the cellular receptor CD150 (signaling lymphocyte activation molecule [SLAM]/F1) are absent. We show that, despite this sequence divergence, FeMV H glycoprotein uses feline CD150 as a receptor and cannot use human CD150. We demonstrate that the protease responsible for cleaving the FeMV F glycoprotein is a cathepsin, making FeMV a unique morbillivirus and more similar to the closely related zoonotic Nipah and Hendra viruses. We developed a reverse genetics system for FeMV^US5 and generated recombinant viruses expressing Venus fluorescent protein from an additional transcription unit located either between the phospho-protein (P) and matrix (M) genes or the H and large (L) genes of the genome. We used these recombinant FeMVs to establish a natural infection and demonstrate that FeMV causes an acute morbillivirus-like disease in the cat. Virus was shed in the urine and detectable in the kidneys at later time points. This opens the door for long-term studies to address the postulated role of this morbillivirus in the development of chronic kidney disease.

Urinary β-2-microglobulin as an alternative marker for fetal inflammatory response and development of bronchopulmonary dysplasia in premature infants

OBJECTIVE

To evaluate the clinical utility of urinary β-2-microglobulin (B2M) at birth, an alternative to proinflammatory cytokines, as an indicative marker of fetal inflammatory response and subsequent higher risk of bronchopulmonary dysplasia (BPD) in premature infants.

STUDY DESIGN

The relationship between urinary B2M at birth and the occurrence of BPD was examined in 96 premature infants with a description of perinatal backgrounds. Constructing a receiver-operating characteristic curve to determine the cutoff value of urinary B2M at birth for the development of BPD, a multivariate logistic regression analysis was performed to evaluate whether elevated urinary B2M at birth can be used as a predictor of BPD.

RESULTS

BPD was diagnosed in 34% (33/96) of the infants. Neonates with BPD had a significantly higher occurrence rate of chorioamnionitis and greater levels of median urinary B2M at birth than did those without BPD. The selected cutoff value of urinary B2M at birth correlated with the development of BPD, even after adjusting for gestational age and other confounding factors.

CONCLUSIONS

Elevated urinary B2M levels at birth can be used as an alternative marker of fetal inflammatory response and subsequent higher risk of BPD in premature infants.

The challenges and strategies for laboratory diagnosis of measles in an international setting

Serum-based measles-specific IgM EIAs are the recommended laboratory assays for diagnosis of acute measles infections and appear to be sufficient for measles control programs. However, serum samples are not ideal for molecular characterization of measles virus. Although neither laboratory nor field-based diagnostic tests that rival the EIAs have been developed, laboratory surveillance could be improved if specimen collection were simplified. Ideally the collection method should be noninvasive, have no requirement for a cold chain, and/or have no requirement for technically sophisticated equipment. Two alternative specimen collection technologies appear promising and can be used for both diagnostics and for collecting pertinent genotyping information: oral fluid and filter paper collection methods. These methods are compared along with their respective utilities in supporting measles diagnosis and strain surveillance.