On the Pathogenesis of Anaemia and Leukopenia in Filarial (Litomosoides carinii) Infection of Mastomys natalensis

Abstract

Mastomys natalensis infected with the filarial parasite Litomosoides carinii show anaemia and leukopenia. Alterations start with the onset of microfilaraemia. Anaemia is temporally macrocytic (up to 80 days after infection), subsequently normocytic and hypochromic, accompanied by reticulocytosis. Increased intravascular haemolysis (i) and functional disorders of the haemopoetic system (ii) are involved in the pathogenesis. i: Circulating erythrocytes showed increased osmofragility. Hypoglycaeniia demonstrated in parasitaemic animals may be one reason. ii: Histological and electron microscopical investigations of the bone marrow revealed markedly enhanced haemopoiesis in infected animals. However, a high proportion of cells was found pathologically altered already beginning in the late prepatency and increasing in the further course of infection. Thus, dyshaemopoiesis may result in the production of morphologically and functionally aberrant cells which are rapidly eliminated by the MPS which is highly activated in L. carinii infected M . natalensis. Animals and infectionMastomys natalensis (strain GRA Giessen) were conventionally bred and kept in groups in polycarbonate cages on sawdust in climatized rooms. They were fed a diet developed for Syrian hamsters. Drinking water was available ad libitum.Animals were infected with Litomosoides carinii on the natural route by sucking mites (Bdellonyssus bacoti) which were fed previously on microfilaraemic cotton rats (LAMMLER et al., 1968). Haematological studies and osmotic resistance of red blood cellsIn a time course study 14 L. carinii infected Mastomys (group 1) and 14 uninfected controls (group C1) were bled at 2-3 weeks intervals from day 75 to day 190 post infection (p. i.) by puncture of the retroorbital venous plexus to determine parasitaemia levels, the number of erythrocytes, haemoglobin content and packed cell volume (PCV). Microfilariae and erythrocytes were counted by counting chamber methods. The haemoglobin content was determined photometrically (haemoglobincyanide method). Packed cell volume determination used a microhaematocrit method. The mean haemoglobin concentration/lOO ml erythrocytes (MCHC: g%), the mean haemoglobin content/ erythrocyte (MCH: pg) and the mean cell volume of erythrocytes (MCV: pm') were calculated as usual. Animals were necropsied at the end of the experiment. 13 groups (groups 2.1-2.13) of infected animals were used to determine in addition to parameters mentioned above the numbers of reticulocytes and the osmotic resistance of red blood cells. Each group consisted of 9-13 animals. Groups were bled and necropsied for worm counting during a period of between 28 and 300 days p.i. Three groups of uninfected controls (groups C2.1 --C2.3) were investigated at ages which corresponded to that of group 2.2 (51 days p.i.), 2.7 (155 days p. i.) and 2.10 (212 days p. i.). Reticulocytes were determined after vital staining with brillant cresylblue solution. Osmotic resistance was determined by diluting 0.05 ml blood in 0.05 ml of saline with ...

Hematology and Clinical Chemistry Reference Ranges for Laboratory-Bred Natal Multimammate Mice (Mastomys natalensis)

“…Our determined hematological reference ranges are comparable to a smaller and more limited previously published study that used inbred M. natalensis [ 18 ] despite differing blood sampling techniques employed in the studies, which generally can affect the cell composition of the blood [ 19 , 20 ]. Similarly, hematological data of inbred M. coucha is consistent with our data [ 21 ], even though the published data on M. coucha shows lower standard deviations than the data of M. natalensis in this report. Publications prior to the year 1980, or other publications on the “GRA Giessen-strain” or “ Praomys (Mastomys) natalensis ” [ 22 ], have to be considered carefully.…”

Haematology and blood chemistry in free-ranging quokkas (Setonix brachyurus): Reference intervals and assessing the effects of site, sampling time, and infectious agents

“…Infection with the microfilariae Breinlia macropi has been previously reported in quokkas [66,67]. The presence of microfilariae has been considered to be a contributing factor in anaemic processes due to intravascular haemolysis as a result of destructive motility [68][69][70][71]. However, we did not observe significant differences in the PCV or RBC of microfilariae-positive or -negative animals Of all the infections we detected in quokkas, the most common association with blood analytes was with mixed infections with Salmonella and microfilariae (seen only in Rottnest Island animals) or MaHV-6 and Theileria spp.…”

A Comprehensive, Model-Based Review of Vaccine and Repeat Infection Trials for Filariasis

“…Infection results in leukopenia and anemia due to intravascular hemolysis and dyshemopoiesis, with reduced stability and increased osmofragility of red blood cells (189). The exact mechanisms underlying these hematological phenomena are unknown.…”