A quick method of demonstrating bacillaemia in patients with lepromatous leprosy and ultrastructural studies of the circulating acid-fast bacilli.

While studying circulating immune complexes (CIC) in the sera of lepromatous patients by the polyethylene glycol (PEG) precipitation technique, we found (by light microscopy) abundant acid-fast bacilli (AFB), morphologically similar to those seen in slit skin smear preparations from these patients, precipitated with the PEG precipitated materials. Both solid and non-solid AFB could be readily identified. Ultrastructures of these AFB in the PEG aggregates showed some similarity with those detected in the PEG precipitates prepared from armadillo-derived lepromin under identical conditions. The most striking difference between the AFB in the test sera and that in the armadillo-derived lepromin was the absence of any transverse band in the former. This suggested that the AFB in the patients' circulation were not in division stage. Furthermore, electron-dense material were deposited on the AFB co-precipitated from the patients' sera, which were not found on the AFB co-precipitated from the armadillo-derived lepromin.

Ocular immunoglobulins in lepromatous leprosy.

Immunoglobulin levels in the ocular fluids have been estimated in normal subjects and lepromatous leprosy patients. In the normal tear, IgA is the major immunoglobulin while IgG is the only immunoglobulin detected in the aqueous humor. The immunoglobulin profiles in the tear and the aqueous humor in normal subjects are different. The mean IgA level in the tears of the lepromatous leprosy group is significantly lower than in the control patients. IgA and IgG levels are raised in the aqueous humor of some leprosy cases who had suffered from uveitis in the past and also in all cases with active endogenous uveitis. Therefore, in lepromatous leprosy the pattern of immunoglobulin alteration in the tear and the aqueous humor is not parallel.

Serum complement profile in human leprosy and its comparison with immune complex diseases.

In the present study we have estimated the serum levels of early, middle, and distal complement components, e.g., Clq, C3, C4, C5, C8, and C9 along with C1-inactivator and CH50 in patients with tuberculoid and lepromatous leprosy and have compared these results with the levels in healthy subjects as well as with levels in patients with other immune complex diseases. We have also analyzed the cryoglobulins present in the sera of these patients; they consisted of either a single or mixed IgG, IgA, IgM or fibrinogen in most instances. The component C3 was found in only one sample. It appears that unlike lupus nephritis, in which complement is activated by direct path in which complement is activated by direct path in about 30% to 50% of leprosy patients, significant C3 complement consumption takes place primarily via the alternate pathway and is probably initiated by the aggregated immunoglobulins represented in cryoprecipitates. This is further supported by the study of serum factor B and its breakdown product (Ba) in these patients. The question of the role of the middle and distal complement components, such as C5, C8 and C9, during total hemolytic complement and C3 consumption in leprosy remains unanswered.

Immunologic aspects of lepromatous leprosy as related to the immunoglobulins of external secretions: salivary immunoglobulins.

A significant reduction in salivary immunoglobulins in lepromatous leprosy is recorded as compared to normal subjects. Saliva of undernourished subjects and patients with oral malignant tumors, which were studied as controls, showed an appreciable rise in IgA levels in both. It is suggested that impairment of T cell function, which is associated with lepromatous leprosy, is not responsible for the observed low level of salivary immunoglobulins in lepromatous leprosy.

Immunologic aspects of leprosy with reference to extravascular immunoglobulins: their excretion profile in urine.

An aliquot of 24-hour urine collected from leprosy patients was concentrated and examined for the presence of albumin, transferrin, IgG, IgA, IgM, IgD, D3, kappa and lambda light chains by the gel diffusion technic using respective monospecific antisera. Urinary protein excretion profile in lepromatous leprosy patients showed that while excretion of transferrin in the urine was negligible; that of IgG molecules, a substance of higher molecular weight, was significant. It is suggested that the immunoglobulins excreted in the urine may not be plasma-derived, but extravascular in origin. They are probably synthesized in the urinary tract. In the present study, out of 25 leprosy patients, 2 female patients having severe lepra reactions developed urinary tract infections. E. coli and Klebsiella were isolated from their urine. The urinary IgG levels in those two cases were found to be the highest in the series.